/*
- * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2010 Apple Inc. All rights reserved.
*
- * @APPLE_LICENSE_HEADER_START@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
- * The contents of this file constitute Original Code as defined in and
- * are subject to the Apple Public Source License Version 1.1 (the
- * "License"). You may not use this file except in compliance with the
- * License. Please obtain a copy of the License at
- * http://www.apple.com/publicsource and read it before using this file.
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
*
- * This Original Code and all software distributed under the License are
- * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
+ *
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
- * License for the specific language governing rights and limitations
- * under the License.
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
*
- * @APPLE_LICENSE_HEADER_END@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
/* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
/*-
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
- * The NEXTSTEP Software License Agreement specifies the terms
- * and conditions for redistribution.
- *
* @(#)vfs_bio.c 8.6 (Berkeley) 1/11/94
*/
* Leffler, et al.: The Design and Implementation of the 4.3BSD
* UNIX Operating System (Addison Welley, 1989)
*/
-#define ZALLOC_METADATA 1
#include <sys/param.h>
#include <sys/systm.h>
-#include <sys/proc.h>
-#include <sys/buf.h>
-#include <sys/vnode.h>
-#include <sys/mount.h>
+#include <sys/proc_internal.h>
+#include <sys/buf_internal.h>
+#include <sys/vnode_internal.h>
+#include <sys/mount_internal.h>
#include <sys/trace.h>
#include <sys/malloc.h>
#include <sys/resourcevar.h>
#include <miscfs/specfs/specdev.h>
#include <sys/ubc.h>
-#include <vm/vm_pageout.h>
+#include <sys/kauth.h>
#if DIAGNOSTIC
#include <kern/assert.h>
#endif /* DIAGNOSTIC */
#include <kern/task.h>
#include <kern/zalloc.h>
+#include <kern/lock.h>
+
+#include <sys/fslog.h> /* fslog_io_error() */
+
+#include <mach/mach_types.h>
+#include <mach/memory_object_types.h>
+#include <kern/sched_prim.h> /* thread_block() */
+
+#include <vm/vm_kern.h>
+#include <vm/vm_pageout.h>
#include <sys/kdebug.h>
-extern void bufqinc(int q);
-extern void bufqdec(int q);
-extern void bufq_balance_thread_init();
+#include <libkern/OSAtomic.h>
+#include <libkern/OSDebug.h>
+#include <sys/ubc_internal.h>
+
+#include <sys/sdt.h>
+
+
+#if BALANCE_QUEUES
+static __inline__ void bufqinc(int q);
+static __inline__ void bufqdec(int q);
+#endif
+
+int bcleanbuf(buf_t bp, boolean_t discard);
+static int brecover_data(buf_t bp);
+static boolean_t incore(vnode_t vp, daddr64_t blkno);
+/* timeout is in msecs */
+static buf_t getnewbuf(int slpflag, int slptimeo, int *queue);
+static void bremfree_locked(buf_t bp);
+static void buf_reassign(buf_t bp, vnode_t newvp);
+static errno_t buf_acquire_locked(buf_t bp, int flags, int slpflag, int slptimeo);
+static int buf_iterprepare(vnode_t vp, struct buflists *, int flags);
+static void buf_itercomplete(vnode_t vp, struct buflists *, int flags);
+static boolean_t buffer_cache_gc(int);
+static buf_t buf_brelse_shadow(buf_t bp);
+static void buf_free_meta_store(buf_t bp);
+
+static buf_t buf_create_shadow_internal(buf_t bp, boolean_t force_copy,
+ uintptr_t external_storage, void (*iodone)(buf_t, void *), void *arg, int priv);
+
-extern void reassignbuf(struct buf *, struct vnode *);
-static struct buf *getnewbuf(int slpflag, int slptimeo, int *queue);
+__private_extern__ int bdwrite_internal(buf_t, int);
-extern int niobuf; /* The number of IO buffer headers for cluster IO */
-int blaundrycnt;
+/* zone allocated buffer headers */
+static void bufzoneinit(void) __attribute__((section("__TEXT, initcode")));
+static void bcleanbuf_thread_init(void) __attribute__((section("__TEXT, initcode")));
+static void bcleanbuf_thread(void);
+
+static zone_t buf_hdr_zone;
+static int buf_hdr_count;
-#if TRACE
-struct proc *traceproc;
-int tracewhich, tracebuf[TRCSIZ];
-u_int tracex;
-char traceflags[TR_NFLAGS];
-#endif /* TRACE */
/*
* Definitions for the buffer hash lists.
LIST_HEAD(bufhashhdr, buf) *bufhashtbl, invalhash;
u_long bufhash;
+static buf_t incore_locked(vnode_t vp, daddr64_t blkno, struct bufhashhdr *dp);
+
/* Definitions for the buffer stats. */
struct bufstats bufstats;
-/*
- * Insq/Remq for the buffer hash lists.
- */
-#if 0
-#define binshash(bp, dp) LIST_INSERT_HEAD(dp, bp, b_hash)
-#define bremhash(bp) LIST_REMOVE(bp, b_hash)
-#endif /* 0 */
+/* Number of delayed write buffers */
+long nbdwrite = 0;
+int blaundrycnt = 0;
+static int boot_nbuf_headers = 0;
+static TAILQ_HEAD(delayqueue, buf) delaybufqueue;
-TAILQ_HEAD(ioqueue, buf) iobufqueue;
-TAILQ_HEAD(bqueues, buf) bufqueues[BQUEUES];
-int needbuffer;
-int need_iobuffer;
+static TAILQ_HEAD(ioqueue, buf) iobufqueue;
+static TAILQ_HEAD(bqueues, buf) bufqueues[BQUEUES];
+static int needbuffer;
+static int need_iobuffer;
+
+static lck_grp_t *buf_mtx_grp;
+static lck_attr_t *buf_mtx_attr;
+static lck_grp_attr_t *buf_mtx_grp_attr;
+static lck_mtx_t *iobuffer_mtxp;
+static lck_mtx_t *buf_mtxp;
+
+static int buf_busycount;
+
+static __inline__ int
+buf_timestamp(void)
+{
+ struct timeval t;
+ microuptime(&t);
+ return (t.tv_sec);
+}
/*
* Insq/Remq for the buffer free lists.
*/
+#if BALANCE_QUEUES
#define binsheadfree(bp, dp, whichq) do { \
TAILQ_INSERT_HEAD(dp, bp, b_freelist); \
bufqinc((whichq)); \
- (bp)->b_whichq = whichq; \
- (bp)->b_timestamp = time.tv_sec; \
} while (0)
#define binstailfree(bp, dp, whichq) do { \
TAILQ_INSERT_TAIL(dp, bp, b_freelist); \
bufqinc((whichq)); \
- (bp)->b_whichq = whichq; \
- (bp)->b_timestamp = time.tv_sec; \
} while (0)
+#else
+#define binsheadfree(bp, dp, whichq) do { \
+ TAILQ_INSERT_HEAD(dp, bp, b_freelist); \
+ } while (0)
+
+#define binstailfree(bp, dp, whichq) do { \
+ TAILQ_INSERT_TAIL(dp, bp, b_freelist); \
+ } while (0)
+#endif
+
#define BHASHENTCHECK(bp) \
if ((bp)->b_hash.le_prev != (struct buf **)0xdeadbeef) \
- panic("%x: b_hash.le_prev is not deadbeef", (bp));
+ panic("%p: b_hash.le_prev is not deadbeef", (bp));
#define BLISTNONE(bp) \
(bp)->b_hash.le_next = (struct buf *)0; \
(bp)->b_hash.le_prev = (struct buf **)0xdeadbeef;
-simple_lock_data_t bufhashlist_slock; /* lock on buffer hash list */
+/*
+ * Insq/Remq for the vnode usage lists.
+ */
+#define bufinsvn(bp, dp) LIST_INSERT_HEAD(dp, bp, b_vnbufs)
+#define bufremvn(bp) { \
+ LIST_REMOVE(bp, b_vnbufs); \
+ (bp)->b_vnbufs.le_next = NOLIST; \
+}
/*
* Time in seconds before a buffer on a list is
int age_is_stale = AGE_IS_STALE;
int meta_is_stale = META_IS_STALE;
-#if 1
-void
-blistenterhead(struct bufhashhdr * head, struct buf * bp)
+#define MAXLAUNDRY 10
+
+/* LIST_INSERT_HEAD() with assertions */
+static __inline__ void
+blistenterhead(struct bufhashhdr * head, buf_t bp)
{
if ((bp->b_hash.le_next = (head)->lh_first) != NULL)
(head)->lh_first->b_hash.le_prev = &(bp)->b_hash.le_next;
bp->b_hash.le_prev = &(head)->lh_first;
if (bp->b_hash.le_prev == (struct buf **)0xdeadbeef)
panic("blistenterhead: le_prev is deadbeef");
-
}
-#endif
-#if 1
-void
-binshash(struct buf *bp, struct bufhashhdr *dp)
+static __inline__ void
+binshash(buf_t bp, struct bufhashhdr *dp)
{
-int s;
-
-struct buf *nbp;
+#if DIAGNOSTIC
+ buf_t nbp;
+#endif /* DIAGNOSTIC */
- simple_lock(&bufhashlist_slock);
-#if 0
- if(incore(bp->b_vp, bp->b_lblkno)) {
- panic("adding to queue already existing element");
- }
-#endif /* 0 */
BHASHENTCHECK(bp);
-
+
+#if DIAGNOSTIC
nbp = dp->lh_first;
for(; nbp != NULL; nbp = nbp->b_hash.le_next) {
if(nbp == bp)
panic("buf already in hashlist");
}
+#endif /* DIAGNOSTIC */
-#if 0
- LIST_INSERT_HEAD(dp, bp, b_hash);
-#else
blistenterhead(dp, bp);
-#endif
- simple_unlock(&bufhashlist_slock);
}
-void
-bremhash(struct buf *bp)
+static __inline__ void
+bremhash(buf_t bp)
{
- int s;
-
- simple_lock(&bufhashlist_slock);
if (bp->b_hash.le_prev == (struct buf **)0xdeadbeef)
panic("bremhash le_prev is deadbeef");
if (bp->b_hash.le_next == bp)
if (bp->b_hash.le_next != NULL)
bp->b_hash.le_next->b_hash.le_prev = bp->b_hash.le_prev;
*bp->b_hash.le_prev = (bp)->b_hash.le_next;
- simple_unlock(&bufhashlist_slock);
}
-#endif /* 1 */
-
-
/*
- * Remove a buffer from the free list it's on
+ * buf_mtxp held.
*/
-void
-bremfree(bp)
- struct buf *bp;
+static __inline__ void
+bmovelaundry(buf_t bp)
{
- struct bqueues *dp = NULL;
- int whichq = -1;
-
- /*
- * We only calculate the head of the freelist when removing
- * the last element of the list as that is the only time that
- * it is needed (e.g. to reset the tail pointer).
- *
- * NB: This makes an assumption about how tailq's are implemented.
- */
- if (bp->b_freelist.tqe_next == NULL) {
- for (dp = bufqueues; dp < &bufqueues[BQUEUES]; dp++)
- if (dp->tqh_last == &bp->b_freelist.tqe_next)
- break;
- if (dp == &bufqueues[BQUEUES])
- panic("bremfree: lost tail");
- }
- TAILQ_REMOVE(dp, bp, b_freelist);
- whichq = bp->b_whichq;
- bufqdec(whichq);
- bp->b_whichq = -1;
- bp->b_timestamp = 0;
+ bp->b_whichq = BQ_LAUNDRY;
+ bp->b_timestamp = buf_timestamp();
+ binstailfree(bp, &bufqueues[BQ_LAUNDRY], BQ_LAUNDRY);
+ blaundrycnt++;
}
static __inline__ void
-bufhdrinit(struct buf *bp)
+buf_release_credentials(buf_t bp)
{
- bzero((char *)bp, sizeof *bp);
- bp->b_dev = NODEV;
- bp->b_rcred = NOCRED;
- bp->b_wcred = NOCRED;
- bp->b_vnbufs.le_next = NOLIST;
- bp->b_flags = B_INVAL;
-
- return;
+ if (IS_VALID_CRED(bp->b_rcred)) {
+ kauth_cred_unref(&bp->b_rcred);
+ }
+ if (IS_VALID_CRED(bp->b_wcred)) {
+ kauth_cred_unref(&bp->b_wcred);
+ }
}
-/*
- * Initialize buffers and hash links for buffers.
- */
-void
-bufinit()
-{
- register struct buf *bp;
- register struct bqueues *dp;
- register int i;
- int metabuf;
- long whichq;
- static void bufzoneinit();
- static void bcleanbuf_thread_init();
- /* Initialize the buffer queues ('freelists') and the hash table */
- for (dp = bufqueues; dp < &bufqueues[BQUEUES]; dp++)
- TAILQ_INIT(dp);
- bufhashtbl = hashinit(nbuf, M_CACHE, &bufhash);
+int
+buf_valid(buf_t bp) {
- simple_lock_init(&bufhashlist_slock );
+ if ( (bp->b_flags & (B_DONE | B_DELWRI)) )
+ return 1;
+ return 0;
+}
- metabuf = nbuf/8; /* reserved for meta buf */
+int
+buf_fromcache(buf_t bp) {
- /* Initialize the buffer headers */
- for (i = 0; i < nbuf; i++) {
- bp = &buf[i];
- bufhdrinit(bp);
+ if ( (bp->b_flags & B_CACHE) )
+ return 1;
+ return 0;
+}
- /*
- * metabuf buffer headers on the meta-data list and
- * rest of the buffer headers on the empty list
- */
- if (--metabuf)
- whichq = BQ_META;
- else
- whichq = BQ_EMPTY;
+void
+buf_markinvalid(buf_t bp) {
+
+ SET(bp->b_flags, B_INVAL);
+}
- BLISTNONE(bp);
- dp = &bufqueues[whichq];
- binsheadfree(bp, dp, whichq);
- binshash(bp, &invalhash);
- }
+void
+buf_markdelayed(buf_t bp) {
+
+ if (!ISSET(bp->b_flags, B_DELWRI)) {
+ SET(bp->b_flags, B_DELWRI);
- for (; i < nbuf + niobuf; i++) {
- bp = &buf[i];
- bufhdrinit(bp);
- binsheadfree(bp, &iobufqueue, -1);
+ OSAddAtomicLong(1, &nbdwrite);
+ buf_reassign(bp, bp->b_vp);
}
+ SET(bp->b_flags, B_DONE);
+}
- printf("using %d buffer headers and %d cluster IO buffer headers\n",
- nbuf, niobuf);
+void
+buf_markclean(buf_t bp) {
- /* Set up zones used by the buffer cache */
- bufzoneinit();
+ if (ISSET(bp->b_flags, B_DELWRI)) {
+ CLR(bp->b_flags, B_DELWRI);
- /* start the bcleanbuf() thread */
- bcleanbuf_thread_init();
+ OSAddAtomicLong(-1, &nbdwrite);
+ buf_reassign(bp, bp->b_vp);
+ }
+}
-#if 0 /* notyet */
- /* create a thread to do dynamic buffer queue balancing */
- bufq_balance_thread_init();
-#endif /* XXX */
+void
+buf_markeintr(buf_t bp) {
+
+ SET(bp->b_flags, B_EINTR);
}
-/* __inline */
-struct buf *
-bio_doread(vp, blkno, size, cred, async, queuetype)
- struct vnode *vp;
- daddr_t blkno;
- int size;
- struct ucred *cred;
- int async;
- int queuetype;
-{
- register struct buf *bp;
- struct proc *p = current_proc();
- bp = getblk(vp, blkno, size, 0, 0, queuetype);
+void
+buf_markaged(buf_t bp) {
+
+ SET(bp->b_flags, B_AGE);
+}
- /*
- * If buffer does not have data valid, start a read.
- * Note that if buffer is B_INVAL, getblk() won't return it.
- * Therefore, it's valid if it's I/O has completed or been delayed.
- */
- if (!ISSET(bp->b_flags, (B_DONE | B_DELWRI))) {
- /* Start I/O for the buffer (keeping credentials). */
- SET(bp->b_flags, B_READ | async);
- if (cred != NOCRED && bp->b_rcred == NOCRED) {
- /*
- * NFS has embedded ucred.
- * Can not crhold() here as that causes zone corruption
- */
- bp->b_rcred = crdup(cred);
- }
- VOP_STRATEGY(bp);
+int
+buf_fua(buf_t bp) {
- trace(TR_BREADMISS, pack(vp, size), blkno);
+ if ((bp->b_flags & B_FUA) == B_FUA)
+ return 1;
+ return 0;
+}
- /* Pay for the read. */
- if (p && p->p_stats)
- p->p_stats->p_ru.ru_inblock++; /* XXX */
- } else if (async) {
- brelse(bp);
- }
+void
+buf_markfua(buf_t bp) {
- trace(TR_BREADHIT, pack(vp, size), blkno);
+ SET(bp->b_flags, B_FUA);
+}
- return (bp);
+#ifdef CONFIG_PROTECT
+void *
+buf_getcpaddr(buf_t bp) {
+ return bp->b_cpentry;
}
-/*
- * Read a disk block.
- * This algorithm described in Bach (p.54).
- */
-int
-bread(vp, blkno, size, cred, bpp)
- struct vnode *vp;
- daddr_t blkno;
- int size;
- struct ucred *cred;
- struct buf **bpp;
-{
- register struct buf *bp;
- /* Get buffer for block. */
- bp = *bpp = bio_doread(vp, blkno, size, cred, 0, BLK_READ);
+void
+buf_setcpaddr(buf_t bp, void *cp_entry_addr) {
+ bp->b_cpentry = (struct cprotect *) cp_entry_addr;
+}
- /* Wait for the read to complete, and return result. */
- return (biowait(bp));
+#else
+void *
+buf_getcpaddr(buf_t bp __unused) {
+ return NULL;
}
-/*
- * Read a disk block. [bread() for meta-data]
- * This algorithm described in Bach (p.54).
- */
-int
-meta_bread(vp, blkno, size, cred, bpp)
- struct vnode *vp;
- daddr_t blkno;
- int size;
- struct ucred *cred;
- struct buf **bpp;
-{
- register struct buf *bp;
+void
+buf_setcpaddr(buf_t bp __unused, void *cp_entry_addr __unused) {
+ return;
+}
+#endif /* CONFIG_PROTECT */
- /* Get buffer for block. */
- bp = *bpp = bio_doread(vp, blkno, size, cred, 0, BLK_META);
+errno_t
+buf_error(buf_t bp) {
+
+ return (bp->b_error);
+}
- /* Wait for the read to complete, and return result. */
- return (biowait(bp));
+void
+buf_seterror(buf_t bp, errno_t error) {
+
+ if ((bp->b_error = error))
+ SET(bp->b_flags, B_ERROR);
+ else
+ CLR(bp->b_flags, B_ERROR);
}
-/*
- * Read-ahead multiple disk blocks. The first is sync, the rest async.
- * Trivial modification to the breada algorithm presented in Bach (p.55).
- */
-int
-breadn(vp, blkno, size, rablks, rasizes, nrablks, cred, bpp)
- struct vnode *vp;
- daddr_t blkno; int size;
- daddr_t rablks[]; int rasizes[];
- int nrablks;
- struct ucred *cred;
- struct buf **bpp;
-{
- register struct buf *bp;
- int i;
+void
+buf_setflags(buf_t bp, int32_t flags) {
- bp = *bpp = bio_doread(vp, blkno, size, cred, 0, BLK_READ);
+ SET(bp->b_flags, (flags & BUF_X_WRFLAGS));
+}
- /*
- * For each of the read-ahead blocks, start a read, if necessary.
- */
- for (i = 0; i < nrablks; i++) {
- /* If it's in the cache, just go on to next one. */
- if (incore(vp, rablks[i]))
- continue;
+void
+buf_clearflags(buf_t bp, int32_t flags) {
- /* Get a buffer for the read-ahead block */
- (void) bio_doread(vp, rablks[i], rasizes[i], cred, B_ASYNC, BLK_READ);
- }
+ CLR(bp->b_flags, (flags & BUF_X_WRFLAGS));
+}
- /* Otherwise, we had to start a read for it; wait until it's valid. */
- return (biowait(bp));
+int32_t
+buf_flags(buf_t bp) {
+
+ return ((bp->b_flags & BUF_X_RDFLAGS));
}
-/*
- * Read with single-block read-ahead. Defined in Bach (p.55), but
- * implemented as a call to breadn().
- * XXX for compatibility with old file systems.
- */
-int
-breada(vp, blkno, size, rablkno, rabsize, cred, bpp)
- struct vnode *vp;
- daddr_t blkno; int size;
- daddr_t rablkno; int rabsize;
- struct ucred *cred;
- struct buf **bpp;
-{
+void
+buf_reset(buf_t bp, int32_t io_flags) {
+
+ CLR(bp->b_flags, (B_READ | B_WRITE | B_ERROR | B_DONE | B_INVAL | B_ASYNC | B_NOCACHE | B_FUA));
+ SET(bp->b_flags, (io_flags & (B_ASYNC | B_READ | B_WRITE | B_NOCACHE)));
- return (breadn(vp, blkno, size, &rablkno, &rabsize, 1, cred, bpp));
+ bp->b_error = 0;
}
-/*
- * Block write. Described in Bach (p.56)
- */
-int
-bwrite(bp)
- struct buf *bp;
-{
- int rv, sync, wasdelayed;
- struct proc *p = current_proc();
- upl_t upl;
- upl_page_info_t *pl;
- void * object;
- kern_return_t kret;
- struct vnode *vp = bp->b_vp;
+uint32_t
+buf_count(buf_t bp) {
+
+ return (bp->b_bcount);
+}
- /* Remember buffer type, to switch on it later. */
- sync = !ISSET(bp->b_flags, B_ASYNC);
- wasdelayed = ISSET(bp->b_flags, B_DELWRI);
- CLR(bp->b_flags, (B_READ | B_DONE | B_ERROR | B_DELWRI));
+void
+buf_setcount(buf_t bp, uint32_t bcount) {
+
+ bp->b_bcount = bcount;
+}
- if (!sync) {
- /*
- * If not synchronous, pay for the I/O operation and make
- * sure the buf is on the correct vnode queue. We have
- * to do this now, because if we don't, the vnode may not
- * be properly notified that its I/O has completed.
- */
- if (wasdelayed)
- reassignbuf(bp, vp);
- else
- if (p && p->p_stats)
- p->p_stats->p_ru.ru_oublock++; /* XXX */
- }
+uint32_t
+buf_size(buf_t bp) {
+
+ return (bp->b_bufsize);
+}
- trace(TR_BWRITE, pack(vp, bp->b_bcount), bp->b_lblkno);
+void
+buf_setsize(buf_t bp, uint32_t bufsize) {
+
+ bp->b_bufsize = bufsize;
+}
- /* Initiate disk write. Make sure the appropriate party is charged. */
- SET(bp->b_flags, B_WRITEINPROG);
- vp->v_numoutput++;
-
- VOP_STRATEGY(bp);
+uint32_t
+buf_resid(buf_t bp) {
+
+ return (bp->b_resid);
+}
- if (sync) {
- /*
- * If I/O was synchronous, wait for it to complete.
- */
- rv = biowait(bp);
+void
+buf_setresid(buf_t bp, uint32_t resid) {
+
+ bp->b_resid = resid;
+}
- /*
- * Pay for the I/O operation, if it's not been paid for, and
- * make sure it's on the correct vnode queue. (async operatings
- * were payed for above.)
- */
- if (wasdelayed)
- reassignbuf(bp, vp);
- else
- if (p && p->p_stats)
- p->p_stats->p_ru.ru_oublock++; /* XXX */
+uint32_t
+buf_dirtyoff(buf_t bp) {
- /* Release the buffer. */
- brelse(bp);
+ return (bp->b_dirtyoff);
+}
- return (rv);
- } else {
- return (0);
- }
-}
+uint32_t
+buf_dirtyend(buf_t bp) {
-int
-vn_bwrite(ap)
- struct vop_bwrite_args *ap;
-{
- return (bwrite(ap->a_bp));
+ return (bp->b_dirtyend);
}
-/*
- * Delayed write.
- *
- * The buffer is marked dirty, but is not queued for I/O.
- * This routine should be used when the buffer is expected
- * to be modified again soon, typically a small write that
- * partially fills a buffer.
- *
- * NB: magnetic tapes cannot be delayed; they must be
- * written in the order that the writes are requested.
- *
- * Described in Leffler, et al. (pp. 208-213).
- */
void
-bdwrite(bp)
- struct buf *bp;
-{
- struct proc *p = current_proc();
- kern_return_t kret;
- upl_t upl;
- upl_page_info_t *pl;
-
- /*
- * If the block hasn't been seen before:
- * (1) Mark it as having been seen,
- * (2) Charge for the write.
- * (3) Make sure it's on its vnode's correct block list,
- */
- if (!ISSET(bp->b_flags, B_DELWRI)) {
- SET(bp->b_flags, B_DELWRI);
- if (p && p->p_stats)
- p->p_stats->p_ru.ru_oublock++; /* XXX */
-
- reassignbuf(bp, bp->b_vp);
- }
-
+buf_setdirtyoff(buf_t bp, uint32_t dirtyoff) {
+
+ bp->b_dirtyoff = dirtyoff;
+}
- /* If this is a tape block, write it the block now. */
- if (ISSET(bp->b_flags, B_TAPE)) {
- /* bwrite(bp); */
- VOP_BWRITE(bp);
- return;
- }
+void
+buf_setdirtyend(buf_t bp, uint32_t dirtyend) {
+
+ bp->b_dirtyend = dirtyend;
+}
- /* Otherwise, the "write" is done, so mark and release the buffer. */
- SET(bp->b_flags, B_DONE);
- brelse(bp);
+uintptr_t
+buf_dataptr(buf_t bp) {
+
+ return (bp->b_datap);
}
-/*
- * Asynchronous block write; just an asynchronous bwrite().
- */
void
-bawrite(bp)
- struct buf *bp;
-{
+buf_setdataptr(buf_t bp, uintptr_t data) {
+
+ bp->b_datap = data;
+}
- SET(bp->b_flags, B_ASYNC);
- VOP_BWRITE(bp);
+vnode_t
+buf_vnode(buf_t bp) {
+
+ return (bp->b_vp);
}
-/*
- * Release a buffer on to the free lists.
- * Described in Bach (p. 46).
- */
void
-brelse(bp)
- struct buf *bp;
-{
- struct bqueues *bufq;
- int s;
- long whichq;
+buf_setvnode(buf_t bp, vnode_t vp) {
+
+ bp->b_vp = vp;
+}
- KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 388)) | DBG_FUNC_START,
- bp->b_lblkno * PAGE_SIZE, bp, bp->b_data, bp->b_flags, 0);
- trace(TR_BRELSE, pack(bp->b_vp, bp->b_bufsize), bp->b_lblkno);
+void *
+buf_callback(buf_t bp)
+{
+ if ( !(bp->b_flags & B_CALL) )
+ return ((void *) NULL);
- /* IO is done. Cleanup the UPL state */
- if (!ISSET(bp->b_flags, B_META)
- && UBCINFOEXISTS(bp->b_vp) && bp->b_bufsize) {
- kern_return_t kret;
- upl_t upl;
- int upl_flags;
+ return ((void *)bp->b_iodone);
+}
- if ( !ISSET(bp->b_flags, B_PAGELIST)) {
- if ( !ISSET(bp->b_flags, B_INVAL)) {
- kret = ubc_create_upl(bp->b_vp,
- ubc_blktooff(bp->b_vp, bp->b_lblkno),
- bp->b_bufsize,
- &upl,
- NULL,
- UPL_PRECIOUS);
- if (kret != KERN_SUCCESS)
- panic("brelse: Failed to get pagelists");
-#ifdef UBC_DEBUG
- upl_ubc_alias_set(upl, bp, 5);
-#endif /* UBC_DEBUG */
- } else
- upl = (upl_t) 0;
- } else {
- upl = bp->b_pagelist;
- kret = ubc_upl_unmap(upl);
- if (kret != KERN_SUCCESS)
- panic("kernel_upl_unmap failed");
- bp->b_data = 0;
- }
- if (upl) {
- if (bp->b_flags & (B_ERROR | B_INVAL)) {
- if (bp->b_flags & (B_READ | B_INVAL))
- upl_flags = UPL_ABORT_DUMP_PAGES;
- else
- upl_flags = 0;
- ubc_upl_abort(upl, upl_flags);
- } else {
- if (ISSET(bp->b_flags, (B_DELWRI | B_WASDIRTY)))
- upl_flags = UPL_COMMIT_SET_DIRTY ;
- else
- upl_flags = UPL_COMMIT_CLEAR_DIRTY ;
- ubc_upl_commit_range(upl, 0, bp->b_bufsize, upl_flags |
- UPL_COMMIT_INACTIVATE | UPL_COMMIT_FREE_ON_EMPTY);
- }
- s = splbio();
- CLR(bp->b_flags, B_PAGELIST);
- bp->b_pagelist = 0;
- splx(s);
- }
- } else {
- if(ISSET(bp->b_flags, B_PAGELIST))
- panic("brelse: pagelist set for non VREG; vp=%x", bp->b_vp);
- }
+errno_t
+buf_setcallback(buf_t bp, void (*callback)(buf_t, void *), void *transaction)
+{
+ if (callback)
+ bp->b_flags |= (B_CALL | B_ASYNC);
+ else
+ bp->b_flags &= ~B_CALL;
+ bp->b_transaction = transaction;
+ bp->b_iodone = callback;
- /* Wake up any processes waiting for any buffer to become free. */
- if (needbuffer) {
- needbuffer = 0;
- wakeup(&needbuffer);
- }
+ return (0);
+}
- /* Wake up any proceeses waiting for _this_ buffer to become free. */
- if (ISSET(bp->b_flags, B_WANTED)) {
- CLR(bp->b_flags, B_WANTED);
- wakeup(bp);
- }
+errno_t
+buf_setupl(buf_t bp, upl_t upl, uint32_t offset)
+{
- /* Block disk interrupts. */
- s = splbio();
+ if ( !(bp->b_lflags & BL_IOBUF) )
+ return (EINVAL);
- /*
- * Determine which queue the buffer should be on, then put it there.
- */
+ if (upl)
+ bp->b_flags |= B_CLUSTER;
+ else
+ bp->b_flags &= ~B_CLUSTER;
+ bp->b_upl = upl;
+ bp->b_uploffset = offset;
- /* If it's locked, don't report an error; try again later. */
- if (ISSET(bp->b_flags, (B_LOCKED|B_ERROR)) == (B_LOCKED|B_ERROR))
- CLR(bp->b_flags, B_ERROR);
+ return (0);
+}
- /* If it's not cacheable, or an error, mark it invalid. */
- if (ISSET(bp->b_flags, (B_NOCACHE|B_ERROR)))
- SET(bp->b_flags, B_INVAL);
+buf_t
+buf_clone(buf_t bp, int io_offset, int io_size, void (*iodone)(buf_t, void *), void *arg)
+{
+ buf_t io_bp;
- if ((bp->b_bufsize <= 0) || ISSET(bp->b_flags, B_INVAL)) {
- /*
- * If it's invalid or empty, dissociate it from its vnode
- * and put on the head of the appropriate queue.
- */
- if (bp->b_vp)
- brelvp(bp);
- CLR(bp->b_flags, B_DELWRI);
- if (bp->b_bufsize <= 0)
- whichq = BQ_EMPTY; /* no data */
- else
- whichq = BQ_AGE; /* invalid data */
+ if (io_offset < 0 || io_size < 0)
+ return (NULL);
- bufq = &bufqueues[whichq];
- binsheadfree(bp, bufq, whichq);
- } else {
- /*
- * It has valid data. Put it on the end of the appropriate
- * queue, so that it'll stick around for as long as possible.
- */
- if (ISSET(bp->b_flags, B_LOCKED))
- whichq = BQ_LOCKED; /* locked in core */
- else if (ISSET(bp->b_flags, B_META))
- whichq = BQ_META; /* meta-data */
- else if (ISSET(bp->b_flags, B_AGE))
- whichq = BQ_AGE; /* stale but valid data */
- else
- whichq = BQ_LRU; /* valid data */
+ if ((unsigned)(io_offset + io_size) > (unsigned)bp->b_bcount)
+ return (NULL);
- bufq = &bufqueues[whichq];
- binstailfree(bp, bufq, whichq);
+ if (bp->b_flags & B_CLUSTER) {
+ if (io_offset && ((bp->b_uploffset + io_offset) & PAGE_MASK))
+ return (NULL);
+
+ if (((bp->b_uploffset + io_offset + io_size) & PAGE_MASK) && ((io_offset + io_size) < bp->b_bcount))
+ return (NULL);
}
+ io_bp = alloc_io_buf(bp->b_vp, 0);
- /* Unlock the buffer. */
- CLR(bp->b_flags, (B_AGE | B_ASYNC | B_BUSY | B_NOCACHE));
+ io_bp->b_flags = bp->b_flags & (B_COMMIT_UPL | B_META | B_PAGEIO | B_CLUSTER | B_PHYS | B_RAW | B_ASYNC | B_READ | B_FUA);
- /* Allow disk interrupts. */
- splx(s);
+ if (iodone) {
+ io_bp->b_transaction = arg;
+ io_bp->b_iodone = iodone;
+ io_bp->b_flags |= B_CALL;
+ }
+ if (bp->b_flags & B_CLUSTER) {
+ io_bp->b_upl = bp->b_upl;
+ io_bp->b_uploffset = bp->b_uploffset + io_offset;
+ } else {
+ io_bp->b_datap = (uintptr_t)(((char *)bp->b_datap) + io_offset);
+ }
+ io_bp->b_bcount = io_size;
- KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 388)) | DBG_FUNC_END,
- bp, bp->b_data, bp->b_flags, 0, 0);
+ return (io_bp);
}
-/*
- * Determine if a block is in the cache.
- * Just look on what would be its hash chain. If it's there, return
- * a pointer to it, unless it's marked invalid. If it's marked invalid,
- * we normally don't return the buffer, unless the caller explicitly
- * wants us to.
- */
-struct buf *
-incore(vp, blkno)
- struct vnode *vp;
- daddr_t blkno;
+
+int
+buf_shadow(buf_t bp)
{
- struct buf *bp;
- int bufseen = 0;
+ if (bp->b_lflags & BL_SHADOW)
+ return 1;
+ return 0;
+}
- bp = BUFHASH(vp, blkno)->lh_first;
- /* Search hash chain */
- for (; bp != NULL; bp = bp->b_hash.le_next, bufseen++) {
- if (bp->b_lblkno == blkno && bp->b_vp == vp &&
- !ISSET(bp->b_flags, B_INVAL))
- return (bp);
- if(bufseen >= nbuf)
- panic("walked more than nbuf in incore");
-
- }
+buf_t
+buf_create_shadow_priv(buf_t bp, boolean_t force_copy, uintptr_t external_storage, void (*iodone)(buf_t, void *), void *arg)
+{
+ return (buf_create_shadow_internal(bp, force_copy, external_storage, iodone, arg, 1));
+}
- return (0);
+buf_t
+buf_create_shadow(buf_t bp, boolean_t force_copy, uintptr_t external_storage, void (*iodone)(buf_t, void *), void *arg)
+{
+ return (buf_create_shadow_internal(bp, force_copy, external_storage, iodone, arg, 0));
}
-/* XXX FIXME -- Update the comment to reflect the UBC changes -- */
-/*
- * Get a block of requested size that is associated with
- * a given vnode and block offset. If it is found in the
- * block cache, mark it as having been found, make it busy
- * and return it. Otherwise, return an empty block of the
- * correct size. It is up to the caller to insure that the
- * cached blocks be of the correct size.
- */
-struct buf *
-getblk(vp, blkno, size, slpflag, slptimeo, operation)
- register struct vnode *vp;
- daddr_t blkno;
- int size, slpflag, slptimeo, operation;
+
+static buf_t
+buf_create_shadow_internal(buf_t bp, boolean_t force_copy, uintptr_t external_storage, void (*iodone)(buf_t, void *), void *arg, int priv)
{
- struct buf *bp;
- int s, err;
- upl_t upl;
- upl_page_info_t *pl;
- kern_return_t kret;
- int error=0;
- int pagedirty = 0;
+ buf_t io_bp;
- KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 386)) | DBG_FUNC_START,
- blkno * PAGE_SIZE, size, operation, 0, 0);
-start:
+ KERNEL_DEBUG(0xbbbbc000 | DBG_FUNC_START, bp, 0, 0, 0, 0);
- s = splbio();
- if (bp = incore(vp, blkno)) {
- /* Found in the Buffer Cache */
- if (ISSET(bp->b_flags, B_BUSY)) {
- /* but is busy */
- switch (operation) {
- case BLK_READ:
- case BLK_WRITE:
- case BLK_META:
- SET(bp->b_flags, B_WANTED);
- bufstats.bufs_busyincore++;
- err = tsleep(bp, slpflag | (PRIBIO + 1), "getblk",
- slptimeo);
- splx(s);
- /*
- * Callers who call with PCATCH or timeout are
- * willing to deal with the NULL pointer
- */
- if (err && ((slpflag & PCATCH) ||
- ((err == EWOULDBLOCK) && slptimeo)))
- return (NULL);
- goto start;
- /*NOTREACHED*/
- break;
+ if ( !(bp->b_flags & B_META) || (bp->b_lflags & BL_IOBUF)) {
- case BLK_PAGEIN:
- /* pagein operation must not use getblk */
- panic("getblk: pagein for incore busy buffer");
- splx(s);
- /*NOTREACHED*/
- break;
+ KERNEL_DEBUG(0xbbbbc000 | DBG_FUNC_END, bp, 0, 0, 0, 0);
+ return (NULL);
+ }
+#ifdef BUF_MAKE_PRIVATE
+ if (bp->b_shadow_ref && bp->b_data_ref == 0 && external_storage == 0)
+ panic("buf_create_shadow: %p is in the private state (%d, %d)", bp, bp->b_shadow_ref, bp->b_data_ref);
+#endif
+ io_bp = alloc_io_buf(bp->b_vp, priv);
- case BLK_PAGEOUT:
- /* pageout operation must not use getblk */
- panic("getblk: pageout for incore busy buffer");
- splx(s);
- /*NOTREACHED*/
- break;
+ io_bp->b_flags = bp->b_flags & (B_META | B_ZALLOC | B_ASYNC | B_READ | B_FUA);
+ io_bp->b_blkno = bp->b_blkno;
+ io_bp->b_lblkno = bp->b_lblkno;
- default:
- panic("getblk: %d unknown operation 1", operation);
- /*NOTREACHED*/
- break;
- }
+ if (iodone) {
+ io_bp->b_transaction = arg;
+ io_bp->b_iodone = iodone;
+ io_bp->b_flags |= B_CALL;
+ }
+ if (force_copy == FALSE) {
+ io_bp->b_bcount = bp->b_bcount;
+ io_bp->b_bufsize = bp->b_bufsize;
+
+ if (external_storage) {
+ io_bp->b_datap = external_storage;
+#ifdef BUF_MAKE_PRIVATE
+ io_bp->b_data_store = NULL;
+#endif
} else {
- /* not busy */
- SET(bp->b_flags, (B_BUSY | B_CACHE));
- bremfree(bp);
- bufstats.bufs_incore++;
- splx(s);
+ io_bp->b_datap = bp->b_datap;
+#ifdef BUF_MAKE_PRIVATE
+ io_bp->b_data_store = bp;
+#endif
+ }
+ *(buf_t *)(&io_bp->b_orig) = bp;
- allocbuf(bp, size);
- if (ISSET(bp->b_flags, B_PAGELIST))
- panic("pagelist buffer is not busy");
+ lck_mtx_lock_spin(buf_mtxp);
- switch (operation) {
- case BLK_READ:
- case BLK_WRITE:
- if (UBCISVALID(bp->b_vp) && bp->b_bufsize) {
- kret = ubc_create_upl(vp,
- ubc_blktooff(vp, bp->b_lblkno),
- bp->b_bufsize,
- &upl,
- &pl,
- UPL_PRECIOUS);
- if (kret != KERN_SUCCESS)
- panic("Failed to get pagelists");
+ io_bp->b_lflags |= BL_SHADOW;
+ io_bp->b_shadow = bp->b_shadow;
+ bp->b_shadow = io_bp;
+ bp->b_shadow_ref++;
- SET(bp->b_flags, B_PAGELIST);
- bp->b_pagelist = upl;
+#ifdef BUF_MAKE_PRIVATE
+ if (external_storage)
+ io_bp->b_lflags |= BL_EXTERNAL;
+ else
+ bp->b_data_ref++;
+#endif
+ lck_mtx_unlock(buf_mtxp);
+ } else {
+ if (external_storage) {
+#ifdef BUF_MAKE_PRIVATE
+ io_bp->b_lflags |= BL_EXTERNAL;
+#endif
+ io_bp->b_bcount = bp->b_bcount;
+ io_bp->b_bufsize = bp->b_bufsize;
+ io_bp->b_datap = external_storage;
+ } else {
+ allocbuf(io_bp, bp->b_bcount);
- if ( !upl_valid_page(pl, 0))
- panic("getblk: incore buffer without valid page");
+ io_bp->b_lflags |= BL_IOBUF_ALLOC;
+ }
+ bcopy((caddr_t)bp->b_datap, (caddr_t)io_bp->b_datap, bp->b_bcount);
- if (upl_dirty_page(pl, 0))
- SET(bp->b_flags, B_WASDIRTY);
- else
- CLR(bp->b_flags, B_WASDIRTY);
+#ifdef BUF_MAKE_PRIVATE
+ io_bp->b_data_store = NULL;
+#endif
+ }
+ KERNEL_DEBUG(0xbbbbc000 | DBG_FUNC_END, bp, bp->b_shadow_ref, 0, io_bp, 0);
- kret = ubc_upl_map(upl, (vm_address_t *)&(bp->b_data));
- if (kret != KERN_SUCCESS) {
- panic("getblk: ubc_upl_map() failed with (%d)",
- kret);
- }
- if (bp->b_data == 0) panic("ubc_upl_map mapped 0");
- }
- break;
+ return (io_bp);
+}
- case BLK_META:
- /*
- * VM is not involved in IO for the meta data
- * buffer already has valid data
- */
- if(bp->b_data == 0)
- panic("bp->b_data null incore buf=%x", bp);
- break;
- case BLK_PAGEIN:
- case BLK_PAGEOUT:
- panic("getblk: paging operation 1");
- break;
+#ifdef BUF_MAKE_PRIVATE
+errno_t
+buf_make_private(buf_t bp)
+{
+ buf_t ds_bp;
+ buf_t t_bp;
+ struct buf my_buf;
- default:
- panic("getblk: %d unknown operation 2", operation);
- /*NOTREACHED*/
- break;
- }
- }
- } else { /* not incore() */
- int queue = BQ_EMPTY; /* Start with no preference */
- splx(s);
-
- if ((operation == BLK_META) || (UBCINVALID(vp)) ||
- !(UBCINFOEXISTS(vp))) {
- operation = BLK_META;
- }
- if ((bp = getnewbuf(slpflag, slptimeo, &queue)) == NULL)
- goto start;
- if (incore(vp, blkno)) {
- SET(bp->b_flags, B_INVAL);
- binshash(bp, &invalhash);
- brelse(bp);
- goto start;
- }
+ KERNEL_DEBUG(0xbbbbc004 | DBG_FUNC_START, bp, bp->b_shadow_ref, 0, 0, 0);
- /*
- * if it is meta, the queue may be set to other
- * type so reset as well as mark it to be B_META
- * so that when buffer is released it will goto META queue
- * Also, if the vnode is not VREG, then it is META
- */
- if (operation == BLK_META) {
- SET(bp->b_flags, B_META);
- queue = BQ_META;
- }
- /*
- * Insert in the hash so that incore() can find it
- */
- binshash(bp, BUFHASH(vp, blkno));
+ if (bp->b_shadow_ref == 0 || bp->b_data_ref == 0 || ISSET(bp->b_lflags, BL_SHADOW)) {
- allocbuf(bp, size);
+ KERNEL_DEBUG(0xbbbbc004 | DBG_FUNC_END, bp, bp->b_shadow_ref, 0, EINVAL, 0);
+ return (EINVAL);
+ }
+ my_buf.b_flags = B_META;
+ my_buf.b_datap = (uintptr_t)NULL;
+ allocbuf(&my_buf, bp->b_bcount);
- switch (operation) {
- case BLK_META:
- /* buffer data is invalid */
+ bcopy((caddr_t)bp->b_datap, (caddr_t)my_buf.b_datap, bp->b_bcount);
-#if !ZALLOC_METADATA
- if (bp->b_data)
- panic("bp->b_data is not nul; %x",bp);
- kret = kmem_alloc(kernel_map,
- &bp->b_data, bp->b_bufsize);
- if (kret != KERN_SUCCESS)
- panic("getblk: kmem_alloc() returned %d", kret);
-#endif /* ZALLOC_METADATA */
-
- if(bp->b_data == 0)
- panic("bp->b_data is null %x",bp);
-
- bp->b_blkno = bp->b_lblkno = blkno;
- s = splbio();
- bgetvp(vp, bp);
- bufstats.bufs_miss++;
- splx(s);
- if (bp->b_data == 0)
- panic("b_data is 0: 2");
-
- /* wakeup the buffer */
- CLR(bp->b_flags, B_WANTED);
- wakeup(bp);
+ lck_mtx_lock_spin(buf_mtxp);
+
+ for (t_bp = bp->b_shadow; t_bp; t_bp = t_bp->b_shadow) {
+ if ( !ISSET(bp->b_lflags, BL_EXTERNAL))
break;
+ }
+ ds_bp = t_bp;
- case BLK_READ:
- case BLK_WRITE:
+ if (ds_bp == NULL && bp->b_data_ref)
+ panic("buf_make_private: b_data_ref != 0 && ds_bp == NULL");
- if (ISSET(bp->b_flags, B_PAGELIST))
- panic("B_PAGELIST in bp=%x",bp);
+ if (ds_bp && (bp->b_data_ref == 0 || bp->b_shadow_ref == 0))
+ panic("buf_make_private: ref_count == 0 && ds_bp != NULL");
- kret = ubc_create_upl(vp,
- ubc_blktooff(vp, blkno),
- bp->b_bufsize,
- &upl,
- &pl,
- UPL_PRECIOUS);
- if (kret != KERN_SUCCESS)
- panic("Failed to get pagelists");
+ if (ds_bp == NULL) {
+ lck_mtx_unlock(buf_mtxp);
-#ifdef UBC_DEBUG
- upl_ubc_alias_set(upl, bp, 4);
-#endif /* UBC_DEBUG */
- bp->b_blkno = bp->b_lblkno = blkno;
- bp->b_pagelist = upl;
+ buf_free_meta_store(&my_buf);
- SET(bp->b_flags, B_PAGELIST);
+ KERNEL_DEBUG(0xbbbbc004 | DBG_FUNC_END, bp, bp->b_shadow_ref, 0, EINVAL, 0);
+ return (EINVAL);
+ }
+ for (t_bp = bp->b_shadow; t_bp; t_bp = t_bp->b_shadow) {
+ if ( !ISSET(t_bp->b_lflags, BL_EXTERNAL))
+ t_bp->b_data_store = ds_bp;
+ }
+ ds_bp->b_data_ref = bp->b_data_ref;
- if (upl_valid_page(pl, 0)) {
- SET(bp->b_flags, B_CACHE | B_DONE);
- bufstats.bufs_vmhits++;
+ bp->b_data_ref = 0;
+ bp->b_datap = my_buf.b_datap;
- pagedirty = upl_dirty_page(pl, 0);
+ lck_mtx_unlock(buf_mtxp);
- if (pagedirty)
- SET(bp->b_flags, B_WASDIRTY);
+ KERNEL_DEBUG(0xbbbbc004 | DBG_FUNC_END, bp, bp->b_shadow_ref, 0, 0, 0);
+ return (0);
+}
+#endif
- if (vp->v_tag == VT_NFS) {
- off_t f_offset;
- int valid_size;
- bp->b_validoff = 0;
- bp->b_dirtyoff = 0;
+void
+buf_setfilter(buf_t bp, void (*filter)(buf_t, void *), void *transaction,
+ void (**old_iodone)(buf_t, void *), void **old_transaction)
+{
+ if (old_iodone)
+ *old_iodone = bp->b_iodone;
+ if (old_transaction)
+ *old_transaction = bp->b_transaction;
+
+ bp->b_transaction = transaction;
+ bp->b_iodone = filter;
+ if (filter)
+ bp->b_flags |= B_FILTER;
+ else
+ bp->b_flags &= ~B_FILTER;
+}
- f_offset = ubc_blktooff(vp, blkno);
- if (f_offset > vp->v_ubcinfo->ui_size) {
- CLR(bp->b_flags, (B_CACHE|B_DONE|B_WASDIRTY));
- bp->b_validend = 0;
- bp->b_dirtyend = 0;
- } else {
- valid_size = min(((unsigned int)(vp->v_ubcinfo->ui_size - f_offset)), PAGE_SIZE);
- bp->b_validend = valid_size;
+daddr64_t
+buf_blkno(buf_t bp) {
- if (pagedirty)
- bp->b_dirtyend = valid_size;
- else
- bp->b_dirtyend = 0;
+ return (bp->b_blkno);
+}
- KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 386)) | DBG_FUNC_NONE,
- bp->b_validend, bp->b_dirtyend,
- (int)vp->v_ubcinfo->ui_size, 0, 0);
- }
- } else {
- bp->b_validoff = 0;
- bp->b_dirtyoff = 0;
+daddr64_t
+buf_lblkno(buf_t bp) {
- if (pagedirty) {
- /* page is dirty */
- bp->b_validend = bp->b_bcount;
- bp->b_dirtyend = bp->b_bcount;
- } else {
- /* page is clean */
- bp->b_validend = bp->b_bcount;
- bp->b_dirtyend = 0;
- }
- }
- if (error = VOP_BMAP(vp, bp->b_lblkno, NULL, &bp->b_blkno, NULL)) {
- panic("VOP_BMAP failed in getblk");
- /*NOTREACHED*/
- /*
- * XXX: We probably should invalidate the VM Page
- */
- bp->b_error = error;
- SET(bp->b_flags, (B_ERROR | B_INVAL));
- /* undo B_DONE that was set before upl_commit() */
- CLR(bp->b_flags, B_DONE);
- brelse(bp);
- return (0);
- }
- } else {
- bufstats.bufs_miss++;
- }
- kret = ubc_upl_map(upl, (vm_address_t *)&(bp->b_data));
- if (kret != KERN_SUCCESS) {
- panic("getblk: ubc_upl_map() "
- "failed with (%d)", kret);
- }
- if (bp->b_data == 0) panic("kernel_upl_map mapped 0");
+ return (bp->b_lblkno);
+}
- s = splbio();
- bgetvp(vp, bp);
- splx(s);
+void
+buf_setblkno(buf_t bp, daddr64_t blkno) {
- break;
+ bp->b_blkno = blkno;
+}
- case BLK_PAGEIN:
- case BLK_PAGEOUT:
- panic("getblk: paging operation 2");
- break;
- default:
- panic("getblk: %d unknown operation 3", operation);
- /*NOTREACHED*/
- break;
- }
- }
+void
+buf_setlblkno(buf_t bp, daddr64_t lblkno) {
- if (bp->b_data == NULL)
- panic("getblk: bp->b_addr is null");
+ bp->b_lblkno = lblkno;
+}
- if (bp->b_bufsize & 0xfff) {
-#if ZALLOC_METADATA
- if (ISSET(bp->b_flags, B_META) && (bp->b_bufsize & 0x1ff))
-#endif /* ZALLOC_METADATA */
- panic("getblk: bp->b_bufsize = %d", bp->b_bufsize);
- }
+dev_t
+buf_device(buf_t bp) {
+
+ return (bp->b_dev);
+}
- KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 386)) | DBG_FUNC_END,
- bp, bp->b_data, bp->b_flags, 3, 0);
+errno_t
+buf_setdevice(buf_t bp, vnode_t vp) {
- return (bp);
+ if ((vp->v_type != VBLK) && (vp->v_type != VCHR))
+ return EINVAL;
+ bp->b_dev = vp->v_rdev;
+
+ return 0;
}
-/*
- * Get an empty, disassociated buffer of given size.
- */
-struct buf *
-geteblk(size)
- int size;
-{
- struct buf *bp;
- int queue = BQ_EMPTY;
-#if !ZALLOC_METADATA
- kern_return_t kret;
- vm_size_t desired_size = roundup(size, CLBYTES);
- if (desired_size > MAXBSIZE)
- panic("geteblk: buffer larger than MAXBSIZE requested");
-#endif /* ZALLOC_METADATA */
+void *
+buf_drvdata(buf_t bp) {
- while ((bp = getnewbuf(0, 0, &queue)) == 0)
- ;
-#if ZALLOC_METADATA
- SET(bp->b_flags, (B_META|B_INVAL));
-#else
- SET(bp->b_flags, B_INVAL);
-#endif /* ZALLOC_METADATA */
+ return (bp->b_drvdata);
+}
-#if DIAGNOSTIC
- assert(queue == BQ_EMPTY);
-#endif /* DIAGNOSTIC */
- /* XXX need to implement logic to deal with other queues */
+void
+buf_setdrvdata(buf_t bp, void *drvdata) {
-#if !ZALLOC_METADATA
- /* Empty buffer - allocate pages */
- kret = kmem_alloc_aligned(kernel_map, &bp->b_data, desired_size);
- if (kret != KERN_SUCCESS)
- panic("geteblk: kmem_alloc_aligned returned %d", kret);
-#endif /* ZALLOC_METADATA */
+ bp->b_drvdata = drvdata;
+}
- binshash(bp, &invalhash);
- allocbuf(bp, size);
- bufstats.bufs_eblk++;
+void *
+buf_fsprivate(buf_t bp) {
- return (bp);
+ return (bp->b_fsprivate);
}
-#if ZALLOC_METADATA
-/*
- * Zones for the meta data buffers
- */
+void
+buf_setfsprivate(buf_t bp, void *fsprivate) {
-#define MINMETA 512
-#define MAXMETA 4096
+ bp->b_fsprivate = fsprivate;
+}
-struct meta_zone_entry {
- zone_t mz_zone;
- vm_size_t mz_size;
- vm_size_t mz_max;
- char *mz_name;
-};
+kauth_cred_t
+buf_rcred(buf_t bp) {
-struct meta_zone_entry meta_zones[] = {
- {NULL, (MINMETA * 1), 128 * (MINMETA * 1), "buf.512" },
- {NULL, (MINMETA * 2), 64 * (MINMETA * 2), "buf.1024" },
- {NULL, (MINMETA * 3), 16 * (MINMETA * 3), "buf.1536" },
- {NULL, (MINMETA * 4), 16 * (MINMETA * 4), "buf.2048" },
- {NULL, (MINMETA * 5), 16 * (MINMETA * 5), "buf.2560" },
- {NULL, (MINMETA * 6), 16 * (MINMETA * 6), "buf.3072" },
- {NULL, (MINMETA * 7), 16 * (MINMETA * 7), "buf.3584" },
- {NULL, (MINMETA * 8), 512 * (MINMETA * 8), "buf.4096" },
- {NULL, 0, 0, "" } /* End */
-};
-#endif /* ZALLOC_METADATA */
+ return (bp->b_rcred);
+}
-zone_t buf_hdr_zone;
-int buf_hdr_count;
+kauth_cred_t
+buf_wcred(buf_t bp) {
-/*
- * Initialize the meta data zones
- */
-static void
-bufzoneinit(void)
+ return (bp->b_wcred);
+}
+
+void *
+buf_upl(buf_t bp) {
+
+ return (bp->b_upl);
+}
+
+uint32_t
+buf_uploffset(buf_t bp) {
+
+ return ((uint32_t)(bp->b_uploffset));
+}
+
+proc_t
+buf_proc(buf_t bp) {
+
+ return (bp->b_proc);
+}
+
+
+errno_t
+buf_map(buf_t bp, caddr_t *io_addr)
{
-#if ZALLOC_METADATA
- int i;
+ buf_t real_bp;
+ vm_offset_t vaddr;
+ kern_return_t kret;
- for (i = 0; meta_zones[i].mz_size != 0; i++) {
- meta_zones[i].mz_zone =
- zinit(meta_zones[i].mz_size,
- meta_zones[i].mz_max,
- PAGE_SIZE,
- meta_zones[i].mz_name);
+ if ( !(bp->b_flags & B_CLUSTER)) {
+ *io_addr = (caddr_t)bp->b_datap;
+ return (0);
}
-#endif /* ZALLOC_METADATA */
- buf_hdr_zone = zinit(sizeof(struct buf), 32, PAGE_SIZE, "buf headers");
+ real_bp = (buf_t)(bp->b_real_bp);
+
+ if (real_bp && real_bp->b_datap) {
+ /*
+ * b_real_bp is only valid if B_CLUSTER is SET
+ * if it's non-zero, than someone did a cluster_bp call
+ * if the backing physical pages were already mapped
+ * in before the call to cluster_bp (non-zero b_datap),
+ * than we just use that mapping
+ */
+ *io_addr = (caddr_t)real_bp->b_datap;
+ return (0);
+ }
+ kret = ubc_upl_map(bp->b_upl, &vaddr); /* Map it in */
+
+ if (kret != KERN_SUCCESS) {
+ *io_addr = NULL;
+
+ return(ENOMEM);
+ }
+ vaddr += bp->b_uploffset;
+
+ *io_addr = (caddr_t)vaddr;
+
+ return (0);
}
-#if ZALLOC_METADATA
-static zone_t
-getbufzone(size_t size)
+errno_t
+buf_unmap(buf_t bp)
{
- int i;
+ buf_t real_bp;
+ kern_return_t kret;
+
+ if ( !(bp->b_flags & B_CLUSTER))
+ return (0);
+ /*
+ * see buf_map for the explanation
+ */
+ real_bp = (buf_t)(bp->b_real_bp);
+
+ if (real_bp && real_bp->b_datap)
+ return (0);
+
+ if ((bp->b_lflags & BL_IOBUF) &&
+ ((bp->b_flags & (B_PAGEIO | B_READ)) != (B_PAGEIO | B_READ))) {
+ /*
+ * ignore pageins... the 'right' thing will
+ * happen due to the way we handle speculative
+ * clusters...
+ *
+ * when we commit these pages, we'll hit
+ * it with UPL_COMMIT_INACTIVE which
+ * will clear the reference bit that got
+ * turned on when we touched the mapping
+ */
+ bp->b_flags |= B_AGE;
+ }
+ kret = ubc_upl_unmap(bp->b_upl);
+
+ if (kret != KERN_SUCCESS)
+ return (EINVAL);
+ return (0);
+}
- if (size % 512)
- panic("getbufzone: incorect size = %d", size);
- i = (size / 512) - 1;
- return (meta_zones[i].mz_zone);
+void
+buf_clear(buf_t bp) {
+ caddr_t baddr;
+
+ if (buf_map(bp, &baddr) == 0) {
+ bzero(baddr, bp->b_bcount);
+ buf_unmap(bp);
+ }
+ bp->b_resid = 0;
}
-#endif /* ZALLOC_METADATA */
/*
- * With UBC, there is no need to expand / shrink the file data
- * buffer. The VM uses the same pages, hence no waste.
- * All the file data buffers can have one size.
- * In fact expand / shrink would be an expensive operation.
- *
- * Only exception to this is meta-data buffers. Most of the
- * meta data operations are smaller than PAGE_SIZE. Having the
- * meta-data buffers grow and shrink as needed, optimizes use
- * of the kernel wired memory.
+ * Read or write a buffer that is not contiguous on disk.
+ * buffer is marked done/error at the conclusion
*/
-
-int
-allocbuf(bp, size)
- struct buf *bp;
- int size;
+static int
+buf_strategy_fragmented(vnode_t devvp, buf_t bp, off_t f_offset, size_t contig_bytes)
{
- vm_size_t desired_size;
+ vnode_t vp = buf_vnode(bp);
+ buf_t io_bp; /* For reading or writing a single block */
+ int io_direction;
+ int io_resid;
+ size_t io_contig_bytes;
+ daddr64_t io_blkno;
+ int error = 0;
+ int bmap_flags;
- desired_size = roundup(size, CLBYTES);
+ /*
+ * save our starting point... the bp was already mapped
+ * in buf_strategy before we got called
+ * no sense doing it again.
+ */
+ io_blkno = bp->b_blkno;
+ /*
+ * Make sure we redo this mapping for the next I/O
+ * i.e. this can never be a 'permanent' mapping
+ */
+ bp->b_blkno = bp->b_lblkno;
+
+ /*
+ * Get an io buffer to do the deblocking
+ */
+ io_bp = alloc_io_buf(devvp, 0);
- if(desired_size < PAGE_SIZE)
- desired_size = PAGE_SIZE;
- if (desired_size > MAXBSIZE)
- panic("allocbuf: buffer larger than MAXBSIZE requested");
+ io_bp->b_lblkno = bp->b_lblkno;
+ io_bp->b_datap = bp->b_datap;
+ io_resid = bp->b_bcount;
+ io_direction = bp->b_flags & B_READ;
+ io_contig_bytes = contig_bytes;
+
+ if (bp->b_flags & B_READ)
+ bmap_flags = VNODE_READ;
+ else
+ bmap_flags = VNODE_WRITE;
-#if ZALLOC_METADATA
- if (ISSET(bp->b_flags, B_META)) {
- kern_return_t kret;
- zone_t zprev, z;
- size_t nsize = roundup(size, MINMETA);
+ for (;;) {
+ if (io_blkno == -1)
+ /*
+ * this is unexepected, but we'll allow for it
+ */
+ bzero((caddr_t)io_bp->b_datap, (int)io_contig_bytes);
+ else {
+ io_bp->b_bcount = io_contig_bytes;
+ io_bp->b_bufsize = io_contig_bytes;
+ io_bp->b_resid = io_contig_bytes;
+ io_bp->b_blkno = io_blkno;
+
+ buf_reset(io_bp, io_direction);
- if (bp->b_data) {
- vm_offset_t elem = (vm_offset_t)bp->b_data;
+ /*
+ * Call the device to do the I/O and wait for it. Make sure the appropriate party is charged for write
+ */
- if (ISSET(bp->b_flags, B_ZALLOC))
- if (bp->b_bufsize <= MAXMETA) {
- if (bp->b_bufsize < nsize) {
- /* reallocate to a bigger size */
- desired_size = nsize;
+ if (!ISSET(bp->b_flags, B_READ))
+ OSAddAtomic(1, &devvp->v_numoutput);
- zprev = getbufzone(bp->b_bufsize);
- z = getbufzone(nsize);
- bp->b_data = (caddr_t)zalloc(z);
- if(bp->b_data == 0)
- panic("allocbuf: zalloc() returned NULL");
- bcopy(elem, bp->b_data, bp->b_bufsize);
- zfree(zprev, elem);
- } else {
- desired_size = bp->b_bufsize;
- }
- } else
- panic("allocbuf: B_ZALLOC set incorrectly");
- else
- if (bp->b_bufsize < desired_size) {
- /* reallocate to a bigger size */
- kret = kmem_alloc(kernel_map, &bp->b_data, desired_size);
- if (kret != KERN_SUCCESS)
- panic("allocbuf: kmem_alloc() returned %d", kret);
- if(bp->b_data == 0)
- panic("allocbuf: null b_data");
- bcopy(elem, bp->b_data, bp->b_bufsize);
- kmem_free(kernel_map, elem, bp->b_bufsize);
- } else {
- desired_size = bp->b_bufsize;
- }
- } else {
- /* new allocation */
- if (nsize <= MAXMETA) {
- desired_size = nsize;
- z = getbufzone(nsize);
- bp->b_data = (caddr_t)zalloc(z);
- if(bp->b_data == 0)
- panic("allocbuf: zalloc() returned NULL 2");
- SET(bp->b_flags, B_ZALLOC);
- } else {
- kret = kmem_alloc(kernel_map, &bp->b_data, desired_size);
- if (kret != KERN_SUCCESS)
- panic("allocbuf: kmem_alloc() 2 returned %d", kret);
- if(bp->b_data == 0)
- panic("allocbuf: null b_data 2");
+ if ((error = VNOP_STRATEGY(io_bp)))
+ break;
+ if ((error = (int)buf_biowait(io_bp)))
+ break;
+ if (io_bp->b_resid) {
+ io_resid -= (io_contig_bytes - io_bp->b_resid);
+ break;
}
}
- }
+ if ((io_resid -= io_contig_bytes) == 0)
+ break;
+ f_offset += io_contig_bytes;
+ io_bp->b_datap += io_contig_bytes;
- if (ISSET(bp->b_flags, B_META) && (bp->b_data == 0))
- panic("allocbuf: bp->b_data is NULL");
-#endif /* ZALLOC_METADATA */
+ /*
+ * Map the current position to a physical block number
+ */
+ if ((error = VNOP_BLOCKMAP(vp, f_offset, io_resid, &io_blkno, &io_contig_bytes, NULL, bmap_flags, NULL)))
+ break;
+ }
+ buf_free(io_bp);
+
+ if (error)
+ buf_seterror(bp, error);
+ bp->b_resid = io_resid;
+ /*
+ * This I/O is now complete
+ */
+ buf_biodone(bp);
- bp->b_bufsize = desired_size;
- bp->b_bcount = size;
+ return error;
}
+
/*
- * Get a new buffer from one of the free lists.
- *
- * Request for a queue is passes in. The queue from which the buffer was taken
- * from is returned. Out of range queue requests get BQ_EMPTY. Request for
- * BQUEUE means no preference. Use heuristics in that case.
- * Heuristics is as follows:
- * Try BQ_AGE, BQ_LRU, BQ_EMPTY, BQ_META in that order.
- * If none available block till one is made available.
- * If buffers available on both BQ_AGE and BQ_LRU, check the timestamps.
- * Pick the most stale buffer.
- * If found buffer was marked delayed write, start the async. write
- * and restart the search.
- * Initialize the fields and disassociate the buffer from the vnode.
- * Remove the buffer from the hash. Return the buffer and the queue
- * on which it was found.
+ * struct vnop_strategy_args {
+ * struct buf *a_bp;
+ * } *ap;
*/
+errno_t
+buf_strategy(vnode_t devvp, void *ap)
+{
+ buf_t bp = ((struct vnop_strategy_args *)ap)->a_bp;
+ vnode_t vp = bp->b_vp;
+ int bmap_flags;
+ errno_t error;
+#if CONFIG_DTRACE
+ int dtrace_io_start_flag = 0; /* We only want to trip the io:::start
+ * probe once, with the true phisical
+ * block in place (b_blkno)
+ */
+
+#endif
+
+ if (vp == NULL || vp->v_type == VCHR || vp->v_type == VBLK)
+ panic("buf_strategy: b_vp == NULL || vtype == VCHR | VBLK\n");
+ /*
+ * associate the physical device with
+ * with this buf_t even if we don't
+ * end up issuing the I/O...
+ */
+ bp->b_dev = devvp->v_rdev;
-static struct buf *
-getnewbuf(slpflag, slptimeo, queue)
- int slpflag, slptimeo;
- int *queue;
-{
- register struct buf *bp;
- register struct buf *lru_bp;
- register struct buf *age_bp;
- register struct buf *meta_bp;
- register int age_time, lru_time, bp_time, meta_time;
- int s;
- struct ucred *cred;
- int req = *queue; /* save it for restarts */
-
-start:
- s = splbio();
-
- /* invalid request gets empty queue */
- if ((*queue > BQUEUES) || (*queue < 0)
- || (*queue == BQ_LAUNDRY) || (*queue == BQ_LOCKED))
- *queue = BQ_EMPTY;
+ if (bp->b_flags & B_READ)
+ bmap_flags = VNODE_READ;
+ else
+ bmap_flags = VNODE_WRITE;
- /* (*queue == BQUEUES) means no preference */
- if (*queue != BQUEUES) {
- /* Try for the requested queue first */
- bp = bufqueues[*queue].tqh_first;
- if (bp)
- goto found;
- }
+ if ( !(bp->b_flags & B_CLUSTER)) {
- /* Unable to use requested queue */
- age_bp = bufqueues[BQ_AGE].tqh_first;
- lru_bp = bufqueues[BQ_LRU].tqh_first;
- meta_bp = bufqueues[BQ_META].tqh_first;
+ if ( (bp->b_upl) ) {
+ /*
+ * we have a UPL associated with this bp
+ * go through cluster_bp which knows how
+ * to deal with filesystem block sizes
+ * that aren't equal to the page size
+ */
+ DTRACE_IO1(start, buf_t, bp);
+ return (cluster_bp(bp));
+ }
+ if (bp->b_blkno == bp->b_lblkno) {
+ off_t f_offset;
+ size_t contig_bytes;
+
+ if ((error = VNOP_BLKTOOFF(vp, bp->b_lblkno, &f_offset))) {
+ DTRACE_IO1(start, buf_t, bp);
+ buf_seterror(bp, error);
+ buf_biodone(bp);
+
+ return (error);
+ }
+ if ((error = VNOP_BLOCKMAP(vp, f_offset, bp->b_bcount, &bp->b_blkno, &contig_bytes, NULL, bmap_flags, NULL))) {
+ DTRACE_IO1(start, buf_t, bp);
+ buf_seterror(bp, error);
+ buf_biodone(bp);
- if (!age_bp && !lru_bp && !meta_bp) { /* Unavailble on AGE or LRU */
- /* Try the empty list first */
- bp = bufqueues[BQ_EMPTY].tqh_first;
- if (bp) {
- *queue = BQ_EMPTY;
- goto found;
+ return (error);
+ }
+
+ DTRACE_IO1(start, buf_t, bp);
+#if CONFIG_DTRACE
+ dtrace_io_start_flag = 1;
+#endif /* CONFIG_DTRACE */
+
+ if ((bp->b_blkno == -1) || (contig_bytes == 0)) {
+ /* Set block number to force biodone later */
+ bp->b_blkno = -1;
+ buf_clear(bp);
+ }
+ else if ((long)contig_bytes < bp->b_bcount) {
+ return (buf_strategy_fragmented(devvp, bp, f_offset, contig_bytes));
+ }
+ }
+
+#if CONFIG_DTRACE
+ if (dtrace_io_start_flag == 0) {
+ DTRACE_IO1(start, buf_t, bp);
+ dtrace_io_start_flag = 1;
}
+#endif /* CONFIG_DTRACE */
+
+ if (bp->b_blkno == -1) {
+ buf_biodone(bp);
+ return (0);
+ }
+ }
- /* Create a new temparory buffer header */
- bp = (struct buf *)zalloc(buf_hdr_zone);
+#if CONFIG_DTRACE
+ if (dtrace_io_start_flag == 0)
+ DTRACE_IO1(start, buf_t, bp);
+#endif /* CONFIG_DTRACE */
- if (bp) {
- bufhdrinit(bp);
- BLISTNONE(bp);
- binshash(bp, &invalhash);
- SET(bp->b_flags, B_HDRALLOC);
- *queue = BQ_EMPTY;
- binsheadfree(bp, &bufqueues[BQ_EMPTY], BQ_EMPTY);
- buf_hdr_count++;
- goto found;
- }
+ /*
+ * we can issue the I/O because...
+ * either B_CLUSTER is set which
+ * means that the I/O is properly set
+ * up to be a multiple of the page size, or
+ * we were able to successfully set up the
+ * phsyical block mapping
+ */
+ return (VOCALL(devvp->v_op, VOFFSET(vnop_strategy), ap));
+}
- /* Log this error condition */
- printf("getnewbuf: No useful buffers");
- /* wait for a free buffer of any kind */
- needbuffer = 1;
- bufstats.bufs_sleeps++;
- tsleep(&needbuffer, slpflag|(PRIBIO+1), "getnewbuf", slptimeo);
- splx(s);
- return (0);
- }
- /* Buffer available either on AGE or LRU or META */
- bp = NULL;
- *queue = -1;
+buf_t
+buf_alloc(vnode_t vp)
+{
+ return(alloc_io_buf(vp, 0));
+}
+
+void
+buf_free(buf_t bp) {
+
+ free_io_buf(bp);
+}
+
+
+/*
+ * iterate buffers for the specified vp.
+ * if BUF_SCAN_DIRTY is set, do the dirty list
+ * if BUF_SCAN_CLEAN is set, do the clean list
+ * if neither flag is set, default to BUF_SCAN_DIRTY
+ * if BUF_NOTIFY_BUSY is set, call the callout function using a NULL bp for busy pages
+ */
+
+struct buf_iterate_info_t {
+ int flag;
+ struct buflists *listhead;
+};
+
+void
+buf_iterate(vnode_t vp, int (*callout)(buf_t, void *), int flags, void *arg)
+{
+ buf_t bp;
+ int retval;
+ struct buflists local_iterblkhd;
+ int lock_flags = BAC_NOWAIT | BAC_REMOVE;
+ int notify_busy = flags & BUF_NOTIFY_BUSY;
+ struct buf_iterate_info_t list[2];
+ int num_lists, i;
+
+ if (flags & BUF_SKIP_LOCKED)
+ lock_flags |= BAC_SKIP_LOCKED;
+ if (flags & BUF_SKIP_NONLOCKED)
+ lock_flags |= BAC_SKIP_NONLOCKED;
+
+ if ( !(flags & (BUF_SCAN_DIRTY | BUF_SCAN_CLEAN)))
+ flags |= BUF_SCAN_DIRTY;
+
+ num_lists = 0;
+
+ if (flags & BUF_SCAN_DIRTY) {
+ list[num_lists].flag = VBI_DIRTY;
+ list[num_lists].listhead = &vp->v_dirtyblkhd;
+ num_lists++;
+ }
+ if (flags & BUF_SCAN_CLEAN) {
+ list[num_lists].flag = VBI_CLEAN;
+ list[num_lists].listhead = &vp->v_cleanblkhd;
+ num_lists++;
+ }
+
+ for (i = 0; i < num_lists; i++) {
+ lck_mtx_lock(buf_mtxp);
+
+ if (buf_iterprepare(vp, &local_iterblkhd, list[i].flag)) {
+ lck_mtx_unlock(buf_mtxp);
+ continue;
+ }
+ while (!LIST_EMPTY(&local_iterblkhd)) {
+ bp = LIST_FIRST(&local_iterblkhd);
+ LIST_REMOVE(bp, b_vnbufs);
+ LIST_INSERT_HEAD(list[i].listhead, bp, b_vnbufs);
+
+ if (buf_acquire_locked(bp, lock_flags, 0, 0)) {
+ if (notify_busy) {
+ bp = NULL;
+ } else {
+ continue;
+ }
+ }
+
+ lck_mtx_unlock(buf_mtxp);
+
+ retval = callout(bp, arg);
+
+ switch (retval) {
+ case BUF_RETURNED:
+ if (bp)
+ buf_brelse(bp);
+ break;
+ case BUF_CLAIMED:
+ break;
+ case BUF_RETURNED_DONE:
+ if (bp)
+ buf_brelse(bp);
+ lck_mtx_lock(buf_mtxp);
+ goto out;
+ case BUF_CLAIMED_DONE:
+ lck_mtx_lock(buf_mtxp);
+ goto out;
+ }
+ lck_mtx_lock(buf_mtxp);
+ } /* while list has more nodes */
+ out:
+ buf_itercomplete(vp, &local_iterblkhd, list[i].flag);
+ lck_mtx_unlock(buf_mtxp);
+ } /* for each list */
+} /* buf_iterate */
+
+
+/*
+ * Flush out and invalidate all buffers associated with a vnode.
+ */
+int
+buf_invalidateblks(vnode_t vp, int flags, int slpflag, int slptimeo)
+{
+ buf_t bp;
+ int aflags;
+ int error = 0;
+ int must_rescan = 1;
+ struct buflists local_iterblkhd;
+
+
+ if (LIST_EMPTY(&vp->v_cleanblkhd) && LIST_EMPTY(&vp->v_dirtyblkhd))
+ return (0);
+
+ lck_mtx_lock(buf_mtxp);
+
+ for (;;) {
+ if (must_rescan == 0)
+ /*
+ * the lists may not be empty, but all that's left at this
+ * point are metadata or B_LOCKED buffers which are being
+ * skipped... we know this because we made it through both
+ * the clean and dirty lists without dropping buf_mtxp...
+ * each time we drop buf_mtxp we bump "must_rescan"
+ */
+ break;
+ if (LIST_EMPTY(&vp->v_cleanblkhd) && LIST_EMPTY(&vp->v_dirtyblkhd))
+ break;
+ must_rescan = 0;
+ /*
+ * iterate the clean list
+ */
+ if (buf_iterprepare(vp, &local_iterblkhd, VBI_CLEAN)) {
+ goto try_dirty_list;
+ }
+ while (!LIST_EMPTY(&local_iterblkhd)) {
+
+ bp = LIST_FIRST(&local_iterblkhd);
+
+ LIST_REMOVE(bp, b_vnbufs);
+ LIST_INSERT_HEAD(&vp->v_cleanblkhd, bp, b_vnbufs);
- /* Buffer available either on AGE or LRU */
- if (!age_bp) {
- bp = lru_bp;
- *queue = BQ_LRU;
- } else if (!lru_bp) {
- bp = age_bp;
- *queue = BQ_AGE;
- } else { /* buffer available on both AGE and LRU */
- age_time = time.tv_sec - age_bp->b_timestamp;
- lru_time = time.tv_sec - lru_bp->b_timestamp;
- if ((age_time < 0) || (lru_time < 0)) { /* time set backwards */
- bp = age_bp;
- *queue = BQ_AGE;
/*
- * we should probably re-timestamp eveything in the
- * queues at this point with the current time
+ * some filesystems distinguish meta data blocks with a negative logical block #
*/
- } else {
- if ((lru_time >= lru_is_stale) && (age_time < age_is_stale)) {
- bp = lru_bp;
- *queue = BQ_LRU;
- } else {
- bp = age_bp;
- *queue = BQ_AGE;
+ if ((flags & BUF_SKIP_META) && (bp->b_lblkno < 0 || ISSET(bp->b_flags, B_META)))
+ continue;
+
+ aflags = BAC_REMOVE;
+
+ if ( !(flags & BUF_INVALIDATE_LOCKED) )
+ aflags |= BAC_SKIP_LOCKED;
+
+ if ( (error = (int)buf_acquire_locked(bp, aflags, slpflag, slptimeo)) ) {
+ if (error == EDEADLK)
+ /*
+ * this buffer was marked B_LOCKED...
+ * we didn't drop buf_mtxp, so we
+ * we don't need to rescan
+ */
+ continue;
+ if (error == EAGAIN) {
+ /*
+ * found a busy buffer... we blocked and
+ * dropped buf_mtxp, so we're going to
+ * need to rescan after this pass is completed
+ */
+ must_rescan++;
+ continue;
+ }
+ /*
+ * got some kind of 'real' error out of the msleep
+ * in buf_acquire_locked, terminate the scan and return the error
+ */
+ buf_itercomplete(vp, &local_iterblkhd, VBI_CLEAN);
+
+ lck_mtx_unlock(buf_mtxp);
+ return (error);
+ }
+ lck_mtx_unlock(buf_mtxp);
+
+ if (bp->b_flags & B_LOCKED)
+ KERNEL_DEBUG(0xbbbbc038, bp, 0, 0, 0, 0);
+
+ CLR(bp->b_flags, B_LOCKED);
+ SET(bp->b_flags, B_INVAL);
+ buf_brelse(bp);
+
+ lck_mtx_lock(buf_mtxp);
+
+ /*
+ * by dropping buf_mtxp, we allow new
+ * buffers to be added to the vnode list(s)
+ * we'll have to rescan at least once more
+ * if the queues aren't empty
+ */
+ must_rescan++;
+ }
+ buf_itercomplete(vp, &local_iterblkhd, VBI_CLEAN);
+
+try_dirty_list:
+ /*
+ * Now iterate on dirty blks
+ */
+ if (buf_iterprepare(vp, &local_iterblkhd, VBI_DIRTY)) {
+ continue;
+ }
+ while (!LIST_EMPTY(&local_iterblkhd)) {
+ bp = LIST_FIRST(&local_iterblkhd);
+
+ LIST_REMOVE(bp, b_vnbufs);
+ LIST_INSERT_HEAD(&vp->v_dirtyblkhd, bp, b_vnbufs);
+
+ /*
+ * some filesystems distinguish meta data blocks with a negative logical block #
+ */
+ if ((flags & BUF_SKIP_META) && (bp->b_lblkno < 0 || ISSET(bp->b_flags, B_META)))
+ continue;
+
+ aflags = BAC_REMOVE;
+
+ if ( !(flags & BUF_INVALIDATE_LOCKED) )
+ aflags |= BAC_SKIP_LOCKED;
+
+ if ( (error = (int)buf_acquire_locked(bp, aflags, slpflag, slptimeo)) ) {
+ if (error == EDEADLK)
+ /*
+ * this buffer was marked B_LOCKED...
+ * we didn't drop buf_mtxp, so we
+ * we don't need to rescan
+ */
+ continue;
+ if (error == EAGAIN) {
+ /*
+ * found a busy buffer... we blocked and
+ * dropped buf_mtxp, so we're going to
+ * need to rescan after this pass is completed
+ */
+ must_rescan++;
+ continue;
+ }
+ /*
+ * got some kind of 'real' error out of the msleep
+ * in buf_acquire_locked, terminate the scan and return the error
+ */
+ buf_itercomplete(vp, &local_iterblkhd, VBI_DIRTY);
+
+ lck_mtx_unlock(buf_mtxp);
+ return (error);
}
+ lck_mtx_unlock(buf_mtxp);
+
+ if (bp->b_flags & B_LOCKED)
+ KERNEL_DEBUG(0xbbbbc038, bp, 0, 0, 1, 0);
+
+ CLR(bp->b_flags, B_LOCKED);
+ SET(bp->b_flags, B_INVAL);
+
+ if (ISSET(bp->b_flags, B_DELWRI) && (flags & BUF_WRITE_DATA))
+ (void) VNOP_BWRITE(bp);
+ else
+ buf_brelse(bp);
+
+ lck_mtx_lock(buf_mtxp);
+ /*
+ * by dropping buf_mtxp, we allow new
+ * buffers to be added to the vnode list(s)
+ * we'll have to rescan at least once more
+ * if the queues aren't empty
+ */
+ must_rescan++;
}
+ buf_itercomplete(vp, &local_iterblkhd, VBI_DIRTY);
}
+ lck_mtx_unlock(buf_mtxp);
- if (!bp) { /* Neither on AGE nor on LRU */
- bp = meta_bp;
- *queue = BQ_META;
- } else if (meta_bp) {
- bp_time = time.tv_sec - bp->b_timestamp;
- meta_time = time.tv_sec - meta_bp->b_timestamp;
+ return (0);
+}
- if (!(bp_time < 0) && !(meta_time < 0)) {
- /* time not set backwards */
- int bp_is_stale;
- bp_is_stale = (*queue == BQ_LRU) ?
- lru_is_stale : age_is_stale;
+void
+buf_flushdirtyblks(vnode_t vp, int wait, int flags, const char *msg) {
+ buf_t bp;
+ int writes_issued = 0;
+ errno_t error;
+ int busy = 0;
+ struct buflists local_iterblkhd;
+ int lock_flags = BAC_NOWAIT | BAC_REMOVE;
+
+ if (flags & BUF_SKIP_LOCKED)
+ lock_flags |= BAC_SKIP_LOCKED;
+ if (flags & BUF_SKIP_NONLOCKED)
+ lock_flags |= BAC_SKIP_NONLOCKED;
+loop:
+ lck_mtx_lock(buf_mtxp);
+
+ if (buf_iterprepare(vp, &local_iterblkhd, VBI_DIRTY) == 0) {
+ while (!LIST_EMPTY(&local_iterblkhd)) {
+ bp = LIST_FIRST(&local_iterblkhd);
+ LIST_REMOVE(bp, b_vnbufs);
+ LIST_INSERT_HEAD(&vp->v_dirtyblkhd, bp, b_vnbufs);
+
+ if ((error = buf_acquire_locked(bp, lock_flags, 0, 0)) == EBUSY)
+ busy++;
+ if (error)
+ continue;
+ lck_mtx_unlock(buf_mtxp);
+
+ bp->b_flags &= ~B_LOCKED;
- if ((meta_time >= meta_is_stale) &&
- (bp_time < bp_is_stale)) {
- bp = meta_bp;
- *queue = BQ_META;
+ /*
+ * Wait for I/O associated with indirect blocks to complete,
+ * since there is no way to quickly wait for them below.
+ */
+ if ((bp->b_vp == vp) || (wait == 0))
+ (void) buf_bawrite(bp);
+ else
+ (void) VNOP_BWRITE(bp);
+ writes_issued++;
+
+ lck_mtx_lock(buf_mtxp);
+ }
+ buf_itercomplete(vp, &local_iterblkhd, VBI_DIRTY);
+ }
+ lck_mtx_unlock(buf_mtxp);
+
+ if (wait) {
+ (void)vnode_waitforwrites(vp, 0, 0, 0, msg);
+
+ if (vp->v_dirtyblkhd.lh_first && busy) {
+ /*
+ * we had one or more BUSY buffers on
+ * the dirtyblock list... most likely
+ * these are due to delayed writes that
+ * were moved to the bclean queue but
+ * have not yet been 'written'.
+ * if we issued some writes on the
+ * previous pass, we try again immediately
+ * if we didn't, we'll sleep for some time
+ * to allow the state to change...
+ */
+ if (writes_issued == 0) {
+ (void)tsleep((caddr_t)&vp->v_numoutput,
+ PRIBIO + 1, "vnode_flushdirtyblks", hz/20);
}
+ writes_issued = 0;
+ busy = 0;
+
+ goto loop;
}
}
+}
- if (bp == NULL)
- panic("getnewbuf: null bp");
-found:
- if (bp->b_hash.le_prev == (struct buf **)0xdeadbeef)
- panic("getnewbuf: le_prev is deadbeef");
+/*
+ * called with buf_mtxp held...
+ * this lock protects the queue manipulation
+ */
+static int
+buf_iterprepare(vnode_t vp, struct buflists *iterheadp, int flags)
+{
+ struct buflists * listheadp;
+
+ if (flags & VBI_DIRTY)
+ listheadp = &vp->v_dirtyblkhd;
+ else
+ listheadp = &vp->v_cleanblkhd;
+
+ while (vp->v_iterblkflags & VBI_ITER) {
+ vp->v_iterblkflags |= VBI_ITERWANT;
+ msleep(&vp->v_iterblkflags, buf_mtxp, 0, "buf_iterprepare", NULL);
+ }
+ if (LIST_EMPTY(listheadp)) {
+ LIST_INIT(iterheadp);
+ return(EINVAL);
+ }
+ vp->v_iterblkflags |= VBI_ITER;
- if(ISSET(bp->b_flags, B_BUSY))
- panic("getnewbuf reusing BUSY buf");
+ iterheadp->lh_first = listheadp->lh_first;
+ listheadp->lh_first->b_vnbufs.le_prev = &iterheadp->lh_first;
+ LIST_INIT(listheadp);
- /* Clean it */
- if (bcleanbuf(bp)) {
- /* bawrite() issued, buffer not ready */
- splx(s);
- *queue = req;
- goto start;
+ return(0);
+}
+
+/*
+ * called with buf_mtxp held...
+ * this lock protects the queue manipulation
+ */
+static void
+buf_itercomplete(vnode_t vp, struct buflists *iterheadp, int flags)
+{
+ struct buflists * listheadp;
+ buf_t bp;
+
+ if (flags & VBI_DIRTY)
+ listheadp = &vp->v_dirtyblkhd;
+ else
+ listheadp = &vp->v_cleanblkhd;
+
+ while (!LIST_EMPTY(iterheadp)) {
+ bp = LIST_FIRST(iterheadp);
+ LIST_REMOVE(bp, b_vnbufs);
+ LIST_INSERT_HEAD(listheadp, bp, b_vnbufs);
+ }
+ vp->v_iterblkflags &= ~VBI_ITER;
+
+ if (vp->v_iterblkflags & VBI_ITERWANT) {
+ vp->v_iterblkflags &= ~VBI_ITERWANT;
+ wakeup(&vp->v_iterblkflags);
}
- splx(s);
- return (bp);
}
-#include <mach/mach_types.h>
-#include <mach/memory_object_types.h>
-/*
- * Clean a buffer.
- * Returns 0 is buffer is ready to use,
- * Returns 1 if issued a bawrite() to indicate
- * that the buffer is not ready.
+
+static void
+bremfree_locked(buf_t bp)
+{
+ struct bqueues *dp = NULL;
+ int whichq;
+
+ whichq = bp->b_whichq;
+
+ if (whichq == -1) {
+ if (bp->b_shadow_ref == 0)
+ panic("bremfree_locked: %p not on freelist", bp);
+ /*
+ * there are clones pointing to 'bp'...
+ * therefore, it was not put on a freelist
+ * when buf_brelse was last called on 'bp'
+ */
+ return;
+ }
+ /*
+ * We only calculate the head of the freelist when removing
+ * the last element of the list as that is the only time that
+ * it is needed (e.g. to reset the tail pointer).
+ *
+ * NB: This makes an assumption about how tailq's are implemented.
+ */
+ if (bp->b_freelist.tqe_next == NULL) {
+ dp = &bufqueues[whichq];
+
+ if (dp->tqh_last != &bp->b_freelist.tqe_next)
+ panic("bremfree: lost tail");
+ }
+ TAILQ_REMOVE(dp, bp, b_freelist);
+
+#if BALANCE_QUEUES
+ bufqdec(whichq);
+#endif
+ if (whichq == BQ_LAUNDRY)
+ blaundrycnt--;
+
+ bp->b_whichq = -1;
+ bp->b_timestamp = 0;
+ bp->b_shadow = 0;
+}
+
+/*
+ * Associate a buffer with a vnode.
+ * buf_mtxp must be locked on entry
*/
-int
-bcleanbuf(struct buf *bp)
+static void
+bgetvp_locked(vnode_t vp, buf_t bp)
+{
+
+ if (bp->b_vp != vp)
+ panic("bgetvp_locked: not free");
+
+ if (vp->v_type == VBLK || vp->v_type == VCHR)
+ bp->b_dev = vp->v_rdev;
+ else
+ bp->b_dev = NODEV;
+ /*
+ * Insert onto list for new vnode.
+ */
+ bufinsvn(bp, &vp->v_cleanblkhd);
+}
+
+/*
+ * Disassociate a buffer from a vnode.
+ * buf_mtxp must be locked on entry
+ */
+static void
+brelvp_locked(buf_t bp)
+{
+ /*
+ * Delete from old vnode list, if on one.
+ */
+ if (bp->b_vnbufs.le_next != NOLIST)
+ bufremvn(bp);
+
+ bp->b_vp = (vnode_t)NULL;
+}
+
+/*
+ * Reassign a buffer from one vnode to another.
+ * Used to assign file specific control information
+ * (indirect blocks) to the vnode to which they belong.
+ */
+static void
+buf_reassign(buf_t bp, vnode_t newvp)
{
- int s;
- struct ucred *cred;
+ struct buflists *listheadp;
+
+ if (newvp == NULL) {
+ printf("buf_reassign: NULL");
+ return;
+ }
+ lck_mtx_lock_spin(buf_mtxp);
+
+ /*
+ * Delete from old vnode list, if on one.
+ */
+ if (bp->b_vnbufs.le_next != NOLIST)
+ bufremvn(bp);
+ /*
+ * If dirty, put on list of dirty buffers;
+ * otherwise insert onto list of clean buffers.
+ */
+ if (ISSET(bp->b_flags, B_DELWRI))
+ listheadp = &newvp->v_dirtyblkhd;
+ else
+ listheadp = &newvp->v_cleanblkhd;
+ bufinsvn(bp, listheadp);
+
+ lck_mtx_unlock(buf_mtxp);
+}
+
+static __inline__ void
+bufhdrinit(buf_t bp)
+{
+ bzero((char *)bp, sizeof *bp);
+ bp->b_dev = NODEV;
+ bp->b_rcred = NOCRED;
+ bp->b_wcred = NOCRED;
+ bp->b_vnbufs.le_next = NOLIST;
+ bp->b_flags = B_INVAL;
+
+ return;
+}
+
+/*
+ * Initialize buffers and hash links for buffers.
+ */
+__private_extern__ void
+bufinit(void)
+{
+ buf_t bp;
+ struct bqueues *dp;
+ int i;
+
+ nbuf_headers = 0;
+ /* Initialize the buffer queues ('freelists') and the hash table */
+ for (dp = bufqueues; dp < &bufqueues[BQUEUES]; dp++)
+ TAILQ_INIT(dp);
+ bufhashtbl = hashinit(nbuf_hashelements, M_CACHE, &bufhash);
+
+ buf_busycount = 0;
+
+ /* Initialize the buffer headers */
+ for (i = 0; i < max_nbuf_headers; i++) {
+ nbuf_headers++;
+ bp = &buf_headers[i];
+ bufhdrinit(bp);
+
+ BLISTNONE(bp);
+ dp = &bufqueues[BQ_EMPTY];
+ bp->b_whichq = BQ_EMPTY;
+ bp->b_timestamp = buf_timestamp();
+ binsheadfree(bp, dp, BQ_EMPTY);
+ binshash(bp, &invalhash);
+ }
+ boot_nbuf_headers = nbuf_headers;
+
+ TAILQ_INIT(&iobufqueue);
+ TAILQ_INIT(&delaybufqueue);
+
+ for (; i < nbuf_headers + niobuf_headers; i++) {
+ bp = &buf_headers[i];
+ bufhdrinit(bp);
+ bp->b_whichq = -1;
+ binsheadfree(bp, &iobufqueue, -1);
+ }
+
+ /*
+ * allocate lock group attribute and group
+ */
+ buf_mtx_grp_attr = lck_grp_attr_alloc_init();
+ buf_mtx_grp = lck_grp_alloc_init("buffer cache", buf_mtx_grp_attr);
+
+ /*
+ * allocate the lock attribute
+ */
+ buf_mtx_attr = lck_attr_alloc_init();
+
+ /*
+ * allocate and initialize mutex's for the buffer and iobuffer pools
+ */
+ buf_mtxp = lck_mtx_alloc_init(buf_mtx_grp, buf_mtx_attr);
+ iobuffer_mtxp = lck_mtx_alloc_init(buf_mtx_grp, buf_mtx_attr);
+
+ if (iobuffer_mtxp == NULL)
+ panic("couldn't create iobuffer mutex");
+
+ if (buf_mtxp == NULL)
+ panic("couldn't create buf mutex");
+
+ /*
+ * allocate and initialize cluster specific global locks...
+ */
+ cluster_init();
+
+ printf("using %d buffer headers and %d cluster IO buffer headers\n",
+ nbuf_headers, niobuf_headers);
+
+ /* Set up zones used by the buffer cache */
+ bufzoneinit();
+
+ /* start the bcleanbuf() thread */
+ bcleanbuf_thread_init();
+
+ /* Register a callout for relieving vm pressure */
+ if (vm_set_buffer_cleanup_callout(buffer_cache_gc) != KERN_SUCCESS) {
+ panic("Couldn't register buffer cache callout for vm pressure!\n");
+ }
+
+#if BALANCE_QUEUES
+ {
+ static void bufq_balance_thread_init(void) __attribute__((section("__TEXT, initcode")));
+ /* create a thread to do dynamic buffer queue balancing */
+ bufq_balance_thread_init();
+ }
+#endif /* notyet */
+}
+
+
+
+/*
+ * Zones for the meta data buffers
+ */
+
+#define MINMETA 512
+#define MAXMETA 8192
+
+struct meta_zone_entry {
+ zone_t mz_zone;
+ vm_size_t mz_size;
+ vm_size_t mz_max;
+ const char *mz_name;
+};
+
+struct meta_zone_entry meta_zones[] = {
+ {NULL, (MINMETA * 1), 128 * (MINMETA * 1), "buf.512" },
+ {NULL, (MINMETA * 2), 64 * (MINMETA * 2), "buf.1024" },
+ {NULL, (MINMETA * 4), 16 * (MINMETA * 4), "buf.2048" },
+ {NULL, (MINMETA * 8), 512 * (MINMETA * 8), "buf.4096" },
+ {NULL, (MINMETA * 16), 512 * (MINMETA * 16), "buf.8192" },
+ {NULL, 0, 0, "" } /* End */
+};
+
+/*
+ * Initialize the meta data zones
+ */
+static void
+bufzoneinit(void)
+{
+ int i;
+
+ for (i = 0; meta_zones[i].mz_size != 0; i++) {
+ meta_zones[i].mz_zone =
+ zinit(meta_zones[i].mz_size,
+ meta_zones[i].mz_max,
+ PAGE_SIZE,
+ meta_zones[i].mz_name);
+ zone_change(meta_zones[i].mz_zone, Z_CALLERACCT, FALSE);
+ }
+ buf_hdr_zone = zinit(sizeof(struct buf), 32, PAGE_SIZE, "buf headers");
+ zone_change(buf_hdr_zone, Z_CALLERACCT, FALSE);
+}
+
+static __inline__ zone_t
+getbufzone(size_t size)
+{
+ int i;
+
+ if ((size % 512) || (size < MINMETA) || (size > MAXMETA))
+ panic("getbufzone: incorect size = %lu", size);
+
+ for (i = 0; meta_zones[i].mz_size != 0; i++) {
+ if (meta_zones[i].mz_size >= size)
+ break;
+ }
+
+ return (meta_zones[i].mz_zone);
+}
+
+
+
+static struct buf *
+bio_doread(vnode_t vp, daddr64_t blkno, int size, kauth_cred_t cred, int async, int queuetype)
+{
+ buf_t bp;
+
+ bp = buf_getblk(vp, blkno, size, 0, 0, queuetype);
+
+ /*
+ * If buffer does not have data valid, start a read.
+ * Note that if buffer is B_INVAL, buf_getblk() won't return it.
+ * Therefore, it's valid if it's I/O has completed or been delayed.
+ */
+ if (!ISSET(bp->b_flags, (B_DONE | B_DELWRI))) {
+ struct proc *p;
+
+ p = current_proc();
+
+ /* Start I/O for the buffer (keeping credentials). */
+ SET(bp->b_flags, B_READ | async);
+ if (IS_VALID_CRED(cred) && !IS_VALID_CRED(bp->b_rcred)) {
+ kauth_cred_ref(cred);
+ bp->b_rcred = cred;
+ }
+
+ VNOP_STRATEGY(bp);
+
+ trace(TR_BREADMISS, pack(vp, size), blkno);
+
+ /* Pay for the read. */
+ if (p && p->p_stats)
+ OSIncrementAtomicLong(&p->p_stats->p_ru.ru_inblock); /* XXX */
+
+ if (async) {
+ /*
+ * since we asked for an ASYNC I/O
+ * the biodone will do the brelse
+ * we don't want to pass back a bp
+ * that we don't 'own'
+ */
+ bp = NULL;
+ }
+ } else if (async) {
+ buf_brelse(bp);
+ bp = NULL;
+ }
+
+ trace(TR_BREADHIT, pack(vp, size), blkno);
+
+ return (bp);
+}
+
+/*
+ * Perform the reads for buf_breadn() and buf_meta_breadn().
+ * Trivial modification to the breada algorithm presented in Bach (p.55).
+ */
+static errno_t
+do_breadn_for_type(vnode_t vp, daddr64_t blkno, int size, daddr64_t *rablks, int *rasizes,
+ int nrablks, kauth_cred_t cred, buf_t *bpp, int queuetype)
+{
+ buf_t bp;
+ int i;
+
+ bp = *bpp = bio_doread(vp, blkno, size, cred, 0, queuetype);
+
+ /*
+ * For each of the read-ahead blocks, start a read, if necessary.
+ */
+ for (i = 0; i < nrablks; i++) {
+ /* If it's in the cache, just go on to next one. */
+ if (incore(vp, rablks[i]))
+ continue;
+
+ /* Get a buffer for the read-ahead block */
+ (void) bio_doread(vp, rablks[i], rasizes[i], cred, B_ASYNC, queuetype);
+ }
+
+ /* Otherwise, we had to start a read for it; wait until it's valid. */
+ return (buf_biowait(bp));
+}
+
+
+/*
+ * Read a disk block.
+ * This algorithm described in Bach (p.54).
+ */
+errno_t
+buf_bread(vnode_t vp, daddr64_t blkno, int size, kauth_cred_t cred, buf_t *bpp)
+{
+ buf_t bp;
+
+ /* Get buffer for block. */
+ bp = *bpp = bio_doread(vp, blkno, size, cred, 0, BLK_READ);
+
+ /* Wait for the read to complete, and return result. */
+ return (buf_biowait(bp));
+}
+
+/*
+ * Read a disk block. [bread() for meta-data]
+ * This algorithm described in Bach (p.54).
+ */
+errno_t
+buf_meta_bread(vnode_t vp, daddr64_t blkno, int size, kauth_cred_t cred, buf_t *bpp)
+{
+ buf_t bp;
+
+ /* Get buffer for block. */
+ bp = *bpp = bio_doread(vp, blkno, size, cred, 0, BLK_META);
+
+ /* Wait for the read to complete, and return result. */
+ return (buf_biowait(bp));
+}
+
+/*
+ * Read-ahead multiple disk blocks. The first is sync, the rest async.
+ */
+errno_t
+buf_breadn(vnode_t vp, daddr64_t blkno, int size, daddr64_t *rablks, int *rasizes, int nrablks, kauth_cred_t cred, buf_t *bpp)
+{
+ return (do_breadn_for_type(vp, blkno, size, rablks, rasizes, nrablks, cred, bpp, BLK_READ));
+}
+
+/*
+ * Read-ahead multiple disk blocks. The first is sync, the rest async.
+ * [buf_breadn() for meta-data]
+ */
+errno_t
+buf_meta_breadn(vnode_t vp, daddr64_t blkno, int size, daddr64_t *rablks, int *rasizes, int nrablks, kauth_cred_t cred, buf_t *bpp)
+{
+ return (do_breadn_for_type(vp, blkno, size, rablks, rasizes, nrablks, cred, bpp, BLK_META));
+}
+
+/*
+ * Block write. Described in Bach (p.56)
+ */
+errno_t
+buf_bwrite(buf_t bp)
+{
+ int sync, wasdelayed;
+ errno_t rv;
+ proc_t p = current_proc();
+ vnode_t vp = bp->b_vp;
+
+ if (bp->b_datap == 0) {
+ if (brecover_data(bp) == 0)
+ return (0);
+ }
+ /* Remember buffer type, to switch on it later. */
+ sync = !ISSET(bp->b_flags, B_ASYNC);
+ wasdelayed = ISSET(bp->b_flags, B_DELWRI);
+ CLR(bp->b_flags, (B_READ | B_DONE | B_ERROR | B_DELWRI));
+
+ if (wasdelayed)
+ OSAddAtomicLong(-1, &nbdwrite);
+
+ if (!sync) {
+ /*
+ * If not synchronous, pay for the I/O operation and make
+ * sure the buf is on the correct vnode queue. We have
+ * to do this now, because if we don't, the vnode may not
+ * be properly notified that its I/O has completed.
+ */
+ if (wasdelayed)
+ buf_reassign(bp, vp);
+ else
+ if (p && p->p_stats)
+ OSIncrementAtomicLong(&p->p_stats->p_ru.ru_oublock); /* XXX */
+ }
+ trace(TR_BUFWRITE, pack(vp, bp->b_bcount), bp->b_lblkno);
+
+ /* Initiate disk write. Make sure the appropriate party is charged. */
+
+ OSAddAtomic(1, &vp->v_numoutput);
+
+ VNOP_STRATEGY(bp);
+
+ if (sync) {
+ /*
+ * If I/O was synchronous, wait for it to complete.
+ */
+ rv = buf_biowait(bp);
+
+ /*
+ * Pay for the I/O operation, if it's not been paid for, and
+ * make sure it's on the correct vnode queue. (async operatings
+ * were payed for above.)
+ */
+ if (wasdelayed)
+ buf_reassign(bp, vp);
+ else
+ if (p && p->p_stats)
+ OSIncrementAtomicLong(&p->p_stats->p_ru.ru_oublock); /* XXX */
+
+ /* Release the buffer. */
+ // XXXdbg - only if the unused bit is set
+ if (!ISSET(bp->b_flags, B_NORELSE)) {
+ buf_brelse(bp);
+ } else {
+ CLR(bp->b_flags, B_NORELSE);
+ }
+
+ return (rv);
+ } else {
+ return (0);
+ }
+}
+
+int
+vn_bwrite(struct vnop_bwrite_args *ap)
+{
+ return (buf_bwrite(ap->a_bp));
+}
+
+/*
+ * Delayed write.
+ *
+ * The buffer is marked dirty, but is not queued for I/O.
+ * This routine should be used when the buffer is expected
+ * to be modified again soon, typically a small write that
+ * partially fills a buffer.
+ *
+ * NB: magnetic tapes cannot be delayed; they must be
+ * written in the order that the writes are requested.
+ *
+ * Described in Leffler, et al. (pp. 208-213).
+ *
+ * Note: With the ability to allocate additional buffer
+ * headers, we can get in to the situation where "too" many
+ * buf_bdwrite()s can create situation where the kernel can create
+ * buffers faster than the disks can service. Doing a buf_bawrite() in
+ * cases where we have "too many" outstanding buf_bdwrite()s avoids that.
+ */
+__private_extern__ int
+bdwrite_internal(buf_t bp, int return_error)
+{
+ proc_t p = current_proc();
+ vnode_t vp = bp->b_vp;
+
+ /*
+ * If the block hasn't been seen before:
+ * (1) Mark it as having been seen,
+ * (2) Charge for the write.
+ * (3) Make sure it's on its vnode's correct block list,
+ */
+ if (!ISSET(bp->b_flags, B_DELWRI)) {
+ SET(bp->b_flags, B_DELWRI);
+ if (p && p->p_stats)
+ OSIncrementAtomicLong(&p->p_stats->p_ru.ru_oublock); /* XXX */
+ OSAddAtomicLong(1, &nbdwrite);
+ buf_reassign(bp, vp);
+ }
+
+ /*
+ * if we're not LOCKED, but the total number of delayed writes
+ * has climbed above 75% of the total buffers in the system
+ * return an error if the caller has indicated that it can
+ * handle one in this case, otherwise schedule the I/O now
+ * this is done to prevent us from allocating tons of extra
+ * buffers when dealing with virtual disks (i.e. DiskImages),
+ * because additional buffers are dynamically allocated to prevent
+ * deadlocks from occurring
+ *
+ * however, can't do a buf_bawrite() if the LOCKED bit is set because the
+ * buffer is part of a transaction and can't go to disk until
+ * the LOCKED bit is cleared.
+ */
+ if (!ISSET(bp->b_flags, B_LOCKED) && nbdwrite > ((nbuf_headers/4)*3)) {
+ if (return_error)
+ return (EAGAIN);
+ /*
+ * If the vnode has "too many" write operations in progress
+ * wait for them to finish the IO
+ */
+ (void)vnode_waitforwrites(vp, VNODE_ASYNC_THROTTLE, 0, 0, "buf_bdwrite");
+
+ return (buf_bawrite(bp));
+ }
+
+ /* Otherwise, the "write" is done, so mark and release the buffer. */
+ SET(bp->b_flags, B_DONE);
+ buf_brelse(bp);
+ return (0);
+}
+
+errno_t
+buf_bdwrite(buf_t bp)
+{
+ return (bdwrite_internal(bp, 0));
+}
+
+
+/*
+ * Asynchronous block write; just an asynchronous buf_bwrite().
+ *
+ * Note: With the abilitty to allocate additional buffer
+ * headers, we can get in to the situation where "too" many
+ * buf_bawrite()s can create situation where the kernel can create
+ * buffers faster than the disks can service.
+ * We limit the number of "in flight" writes a vnode can have to
+ * avoid this.
+ */
+static int
+bawrite_internal(buf_t bp, int throttle)
+{
+ vnode_t vp = bp->b_vp;
+
+ if (vp) {
+ if (throttle)
+ /*
+ * If the vnode has "too many" write operations in progress
+ * wait for them to finish the IO
+ */
+ (void)vnode_waitforwrites(vp, VNODE_ASYNC_THROTTLE, 0, 0, (const char *)"buf_bawrite");
+ else if (vp->v_numoutput >= VNODE_ASYNC_THROTTLE)
+ /*
+ * return to the caller and
+ * let him decide what to do
+ */
+ return (EWOULDBLOCK);
+ }
+ SET(bp->b_flags, B_ASYNC);
+
+ return (VNOP_BWRITE(bp));
+}
+
+errno_t
+buf_bawrite(buf_t bp)
+{
+ return (bawrite_internal(bp, 1));
+}
+
+
+
+static void
+buf_free_meta_store(buf_t bp)
+{
+ if (bp->b_bufsize) {
+ if (ISSET(bp->b_flags, B_ZALLOC)) {
+ zone_t z;
+
+ z = getbufzone(bp->b_bufsize);
+ zfree(z, (void *)bp->b_datap);
+ } else
+ kmem_free(kernel_map, bp->b_datap, bp->b_bufsize);
+
+ bp->b_datap = (uintptr_t)NULL;
+ bp->b_bufsize = 0;
+ }
+}
+
+
+static buf_t
+buf_brelse_shadow(buf_t bp)
+{
+ buf_t bp_head;
+ buf_t bp_temp;
+ buf_t bp_return = NULL;
+#ifdef BUF_MAKE_PRIVATE
+ buf_t bp_data;
+ int data_ref = 0;
+#endif
+ lck_mtx_lock_spin(buf_mtxp);
+
+ bp_head = (buf_t)bp->b_orig;
+
+ if (bp_head->b_whichq != -1)
+ panic("buf_brelse_shadow: bp_head on freelist %d\n", bp_head->b_whichq);
+
+#ifdef BUF_MAKE_PRIVATE
+ if (bp_data = bp->b_data_store) {
+ bp_data->b_data_ref--;
+ /*
+ * snapshot the ref count so that we can check it
+ * outside of the lock... we only want the guy going
+ * from 1 -> 0 to try and release the storage
+ */
+ data_ref = bp_data->b_data_ref;
+ }
+#endif
+ KERNEL_DEBUG(0xbbbbc008 | DBG_FUNC_START, bp, bp_head, bp_head->b_shadow_ref, 0, 0);
+
+ bp_head->b_shadow_ref--;
+
+ for (bp_temp = bp_head; bp_temp && bp != bp_temp->b_shadow; bp_temp = bp_temp->b_shadow);
+
+ if (bp_temp == NULL)
+ panic("buf_brelse_shadow: bp not on list %p", bp_head);
+
+ bp_temp->b_shadow = bp_temp->b_shadow->b_shadow;
+
+#ifdef BUF_MAKE_PRIVATE
+ /*
+ * we're about to free the current 'owner' of the data buffer and
+ * there is at least one other shadow buf_t still pointing at it
+ * so transfer it to the first shadow buf left in the chain
+ */
+ if (bp == bp_data && data_ref) {
+ if ((bp_data = bp_head->b_shadow) == NULL)
+ panic("buf_brelse_shadow: data_ref mismatch bp(%p)", bp);
+
+ for (bp_temp = bp_data; bp_temp; bp_temp = bp_temp->b_shadow)
+ bp_temp->b_data_store = bp_data;
+ bp_data->b_data_ref = data_ref;
+ }
+#endif
+ if (bp_head->b_shadow_ref == 0 && bp_head->b_shadow)
+ panic("buf_relse_shadow: b_shadow != NULL && b_shadow_ref == 0 bp(%p)", bp);
+ if (bp_head->b_shadow_ref && bp_head->b_shadow == 0)
+ panic("buf_relse_shadow: b_shadow == NULL && b_shadow_ref != 0 bp(%p)", bp);
+
+ if (bp_head->b_shadow_ref == 0) {
+ if (!ISSET(bp_head->b_lflags, BL_BUSY)) {
+
+ CLR(bp_head->b_flags, B_AGE);
+ bp_head->b_timestamp = buf_timestamp();
+
+ if (ISSET(bp_head->b_flags, B_LOCKED)) {
+ bp_head->b_whichq = BQ_LOCKED;
+ binstailfree(bp_head, &bufqueues[BQ_LOCKED], BQ_LOCKED);
+ } else {
+ bp_head->b_whichq = BQ_META;
+ binstailfree(bp_head, &bufqueues[BQ_META], BQ_META);
+ }
+ } else if (ISSET(bp_head->b_lflags, BL_WAITSHADOW)) {
+ CLR(bp_head->b_lflags, BL_WAITSHADOW);
+
+ bp_return = bp_head;
+ }
+ }
+ lck_mtx_unlock(buf_mtxp);
+#ifdef BUF_MAKE_PRIVATE
+ if (bp == bp_data && data_ref == 0)
+ buf_free_meta_store(bp);
+
+ bp->b_data_store = NULL;
+#endif
+ KERNEL_DEBUG(0xbbbbc008 | DBG_FUNC_END, bp, 0, 0, 0, 0);
+
+ return (bp_return);
+}
+
+
+/*
+ * Release a buffer on to the free lists.
+ * Described in Bach (p. 46).
+ */
+void
+buf_brelse(buf_t bp)
+{
+ struct bqueues *bufq;
+ long whichq;
+ upl_t upl;
+ int need_wakeup = 0;
+ int need_bp_wakeup = 0;
+
+
+ if (bp->b_whichq != -1 || !(bp->b_lflags & BL_BUSY))
+ panic("buf_brelse: bad buffer = %p\n", bp);
+
+#ifdef JOE_DEBUG
+ (void) OSBacktrace(&bp->b_stackbrelse[0], 6);
+
+ bp->b_lastbrelse = current_thread();
+ bp->b_tag = 0;
+#endif
+ if (bp->b_lflags & BL_IOBUF) {
+ buf_t shadow_master_bp = NULL;
+
+ if (ISSET(bp->b_lflags, BL_SHADOW))
+ shadow_master_bp = buf_brelse_shadow(bp);
+ else if (ISSET(bp->b_lflags, BL_IOBUF_ALLOC))
+ buf_free_meta_store(bp);
+ free_io_buf(bp);
+
+ if (shadow_master_bp) {
+ bp = shadow_master_bp;
+ goto finish_shadow_master;
+ }
+ return;
+ }
+
+ KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 388)) | DBG_FUNC_START,
+ bp->b_lblkno * PAGE_SIZE, bp, bp->b_datap,
+ bp->b_flags, 0);
+
+ trace(TR_BRELSE, pack(bp->b_vp, bp->b_bufsize), bp->b_lblkno);
+
+ /*
+ * if we're invalidating a buffer that has the B_FILTER bit
+ * set then call the b_iodone function so it gets cleaned
+ * up properly.
+ *
+ * the HFS journal code depends on this
+ */
+ if (ISSET(bp->b_flags, B_META) && ISSET(bp->b_flags, B_INVAL)) {
+ if (ISSET(bp->b_flags, B_FILTER)) { /* if necessary, call out */
+ void (*iodone_func)(struct buf *, void *) = bp->b_iodone;
+ void *arg = bp->b_transaction;
+
+ CLR(bp->b_flags, B_FILTER); /* but note callout done */
+ bp->b_iodone = NULL;
+ bp->b_transaction = NULL;
+
+ if (iodone_func == NULL) {
+ panic("brelse: bp @ %p has NULL b_iodone!\n", bp);
+ }
+ (*iodone_func)(bp, arg);
+ }
+ }
+ /*
+ * I/O is done. Cleanup the UPL state
+ */
+ upl = bp->b_upl;
+
+ if ( !ISSET(bp->b_flags, B_META) && UBCINFOEXISTS(bp->b_vp) && bp->b_bufsize) {
+ kern_return_t kret;
+ int upl_flags;
+
+ if (upl == NULL) {
+ if ( !ISSET(bp->b_flags, B_INVAL)) {
+ kret = ubc_create_upl(bp->b_vp,
+ ubc_blktooff(bp->b_vp, bp->b_lblkno),
+ bp->b_bufsize,
+ &upl,
+ NULL,
+ UPL_PRECIOUS);
+
+ if (kret != KERN_SUCCESS)
+ panic("brelse: Failed to create UPL");
+#if UPL_DEBUG
+ upl_ubc_alias_set(upl, (uintptr_t) bp, (uintptr_t) 5);
+#endif /* UPL_DEBUG */
+ }
+ } else {
+ if (bp->b_datap) {
+ kret = ubc_upl_unmap(upl);
+
+ if (kret != KERN_SUCCESS)
+ panic("ubc_upl_unmap failed");
+ bp->b_datap = (uintptr_t)NULL;
+ }
+ }
+ if (upl) {
+ if (bp->b_flags & (B_ERROR | B_INVAL)) {
+ if (bp->b_flags & (B_READ | B_INVAL))
+ upl_flags = UPL_ABORT_DUMP_PAGES;
+ else
+ upl_flags = 0;
+
+ ubc_upl_abort(upl, upl_flags);
+ } else {
+ if (ISSET(bp->b_flags, B_DELWRI | B_WASDIRTY))
+ upl_flags = UPL_COMMIT_SET_DIRTY ;
+ else
+ upl_flags = UPL_COMMIT_CLEAR_DIRTY ;
+
+ ubc_upl_commit_range(upl, 0, bp->b_bufsize, upl_flags |
+ UPL_COMMIT_INACTIVATE | UPL_COMMIT_FREE_ON_EMPTY);
+ }
+ bp->b_upl = NULL;
+ }
+ } else {
+ if ( (upl) )
+ panic("brelse: UPL set for non VREG; vp=%p", bp->b_vp);
+ }
+
+ /*
+ * If it's locked, don't report an error; try again later.
+ */
+ if (ISSET(bp->b_flags, (B_LOCKED|B_ERROR)) == (B_LOCKED|B_ERROR))
+ CLR(bp->b_flags, B_ERROR);
+ /*
+ * If it's not cacheable, or an error, mark it invalid.
+ */
+ if (ISSET(bp->b_flags, (B_NOCACHE|B_ERROR)))
+ SET(bp->b_flags, B_INVAL);
+
+ if ((bp->b_bufsize <= 0) ||
+ ISSET(bp->b_flags, B_INVAL) ||
+ (ISSET(bp->b_lflags, BL_WANTDEALLOC) && !ISSET(bp->b_flags, B_DELWRI))) {
+
+ boolean_t delayed_buf_free_meta_store = FALSE;
+
+ /*
+ * If it's invalid or empty, dissociate it from its vnode,
+ * release its storage if B_META, and
+ * clean it up a bit and put it on the EMPTY queue
+ */
+ if (ISSET(bp->b_flags, B_DELWRI))
+ OSAddAtomicLong(-1, &nbdwrite);
+
+ if (ISSET(bp->b_flags, B_META)) {
+ if (bp->b_shadow_ref)
+ delayed_buf_free_meta_store = TRUE;
+ else
+ buf_free_meta_store(bp);
+ }
+ /*
+ * nuke any credentials we were holding
+ */
+ buf_release_credentials(bp);
+
+ lck_mtx_lock_spin(buf_mtxp);
+
+ if (bp->b_shadow_ref) {
+ SET(bp->b_lflags, BL_WAITSHADOW);
+
+ lck_mtx_unlock(buf_mtxp);
+
+ return;
+ }
+ if (delayed_buf_free_meta_store == TRUE) {
+
+ lck_mtx_unlock(buf_mtxp);
+finish_shadow_master:
+ buf_free_meta_store(bp);
+
+ lck_mtx_lock_spin(buf_mtxp);
+ }
+ CLR(bp->b_flags, (B_META | B_ZALLOC | B_DELWRI | B_LOCKED | B_AGE | B_ASYNC | B_NOCACHE | B_FUA));
+
+ if (bp->b_vp)
+ brelvp_locked(bp);
+
+ bremhash(bp);
+ BLISTNONE(bp);
+ binshash(bp, &invalhash);
+
+ bp->b_whichq = BQ_EMPTY;
+ binsheadfree(bp, &bufqueues[BQ_EMPTY], BQ_EMPTY);
+ } else {
+
+ /*
+ * It has valid data. Put it on the end of the appropriate
+ * queue, so that it'll stick around for as long as possible.
+ */
+ if (ISSET(bp->b_flags, B_LOCKED))
+ whichq = BQ_LOCKED; /* locked in core */
+ else if (ISSET(bp->b_flags, B_META))
+ whichq = BQ_META; /* meta-data */
+ else if (ISSET(bp->b_flags, B_AGE))
+ whichq = BQ_AGE; /* stale but valid data */
+ else
+ whichq = BQ_LRU; /* valid data */
+ bufq = &bufqueues[whichq];
+
+ bp->b_timestamp = buf_timestamp();
+
+ lck_mtx_lock_spin(buf_mtxp);
+
+ /*
+ * the buf_brelse_shadow routine doesn't take 'ownership'
+ * of the parent buf_t... it updates state that is protected by
+ * the buf_mtxp, and checks for BL_BUSY to determine whether to
+ * put the buf_t back on a free list. b_shadow_ref is protected
+ * by the lock, and since we have not yet cleared B_BUSY, we need
+ * to check it while holding the lock to insure that one of us
+ * puts this buf_t back on a free list when it is safe to do so
+ */
+ if (bp->b_shadow_ref == 0) {
+ CLR(bp->b_flags, (B_AGE | B_ASYNC | B_NOCACHE));
+ bp->b_whichq = whichq;
+ binstailfree(bp, bufq, whichq);
+ } else {
+ /*
+ * there are still cloned buf_t's pointing
+ * at this guy... need to keep it off the
+ * freelists until a buf_brelse is done on
+ * the last clone
+ */
+ CLR(bp->b_flags, (B_ASYNC | B_NOCACHE));
+ }
+ }
+ if (needbuffer) {
+ /*
+ * needbuffer is a global
+ * we're currently using buf_mtxp to protect it
+ * delay doing the actual wakeup until after
+ * we drop buf_mtxp
+ */
+ needbuffer = 0;
+ need_wakeup = 1;
+ }
+ if (ISSET(bp->b_lflags, BL_WANTED)) {
+ /*
+ * delay the actual wakeup until after we
+ * clear BL_BUSY and we've dropped buf_mtxp
+ */
+ need_bp_wakeup = 1;
+ }
+ /*
+ * Unlock the buffer.
+ */
+ CLR(bp->b_lflags, (BL_BUSY | BL_WANTED));
+ buf_busycount--;
+
+ lck_mtx_unlock(buf_mtxp);
+
+ if (need_wakeup) {
+ /*
+ * Wake up any processes waiting for any buffer to become free.
+ */
+ wakeup(&needbuffer);
+ }
+ if (need_bp_wakeup) {
+ /*
+ * Wake up any proceeses waiting for _this_ buffer to become free.
+ */
+ wakeup(bp);
+ }
+ KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 388)) | DBG_FUNC_END,
+ bp, bp->b_datap, bp->b_flags, 0, 0);
+}
+
+/*
+ * Determine if a block is in the cache.
+ * Just look on what would be its hash chain. If it's there, return
+ * a pointer to it, unless it's marked invalid. If it's marked invalid,
+ * we normally don't return the buffer, unless the caller explicitly
+ * wants us to.
+ */
+static boolean_t
+incore(vnode_t vp, daddr64_t blkno)
+{
+ boolean_t retval;
+ struct bufhashhdr *dp;
+
+ dp = BUFHASH(vp, blkno);
+
+ lck_mtx_lock_spin(buf_mtxp);
+
+ if (incore_locked(vp, blkno, dp))
+ retval = TRUE;
+ else
+ retval = FALSE;
+ lck_mtx_unlock(buf_mtxp);
+
+ return (retval);
+}
+
+
+static buf_t
+incore_locked(vnode_t vp, daddr64_t blkno, struct bufhashhdr *dp)
+{
+ struct buf *bp;
+
+ /* Search hash chain */
+ for (bp = dp->lh_first; bp != NULL; bp = bp->b_hash.le_next) {
+ if (bp->b_lblkno == blkno && bp->b_vp == vp &&
+ !ISSET(bp->b_flags, B_INVAL)) {
+ return (bp);
+ }
+ }
+ return (NULL);
+}
+
+
+/* XXX FIXME -- Update the comment to reflect the UBC changes (please) -- */
+/*
+ * Get a block of requested size that is associated with
+ * a given vnode and block offset. If it is found in the
+ * block cache, mark it as having been found, make it busy
+ * and return it. Otherwise, return an empty block of the
+ * correct size. It is up to the caller to insure that the
+ * cached blocks be of the correct size.
+ */
+buf_t
+buf_getblk(vnode_t vp, daddr64_t blkno, int size, int slpflag, int slptimeo, int operation)
+{
+ buf_t bp;
+ int err;
+ upl_t upl;
+ upl_page_info_t *pl;
+ kern_return_t kret;
+ int ret_only_valid;
+ struct timespec ts;
+ int upl_flags;
+ struct bufhashhdr *dp;
+
+ KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 386)) | DBG_FUNC_START,
+ (uintptr_t)(blkno * PAGE_SIZE), size, operation, 0, 0);
+
+ ret_only_valid = operation & BLK_ONLYVALID;
+ operation &= ~BLK_ONLYVALID;
+ dp = BUFHASH(vp, blkno);
+start:
+ lck_mtx_lock_spin(buf_mtxp);
+
+ if ((bp = incore_locked(vp, blkno, dp))) {
+ /*
+ * Found in the Buffer Cache
+ */
+ if (ISSET(bp->b_lflags, BL_BUSY)) {
+ /*
+ * but is busy
+ */
+ switch (operation) {
+ case BLK_READ:
+ case BLK_WRITE:
+ case BLK_META:
+ SET(bp->b_lflags, BL_WANTED);
+ bufstats.bufs_busyincore++;
+
+ /*
+ * don't retake the mutex after being awakened...
+ * the time out is in msecs
+ */
+ ts.tv_sec = (slptimeo/1000);
+ ts.tv_nsec = (slptimeo % 1000) * 10 * NSEC_PER_USEC * 1000;
+
+ KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 396)) | DBG_FUNC_NONE,
+ (uintptr_t)blkno, size, operation, 0, 0);
+
+ err = msleep(bp, buf_mtxp, slpflag | PDROP | (PRIBIO + 1), "buf_getblk", &ts);
+
+ /*
+ * Callers who call with PCATCH or timeout are
+ * willing to deal with the NULL pointer
+ */
+ if (err && ((slpflag & PCATCH) || ((err == EWOULDBLOCK) && slptimeo)))
+ return (NULL);
+ goto start;
+ /*NOTREACHED*/
+ break;
+
+ default:
+ /*
+ * unknown operation requested
+ */
+ panic("getblk: paging or unknown operation for incore busy buffer - %x\n", operation);
+ /*NOTREACHED*/
+ break;
+ }
+ } else {
+ /*
+ * buffer in core and not busy
+ */
+ SET(bp->b_lflags, BL_BUSY);
+ SET(bp->b_flags, B_CACHE);
+ buf_busycount++;
+
+ bremfree_locked(bp);
+ bufstats.bufs_incore++;
+
+ lck_mtx_unlock(buf_mtxp);
+#ifdef JOE_DEBUG
+ bp->b_owner = current_thread();
+ bp->b_tag = 1;
+#endif
+ if ( (bp->b_upl) )
+ panic("buffer has UPL, but not marked BUSY: %p", bp);
+
+ if ( !ret_only_valid && bp->b_bufsize != size)
+ allocbuf(bp, size);
+
+ upl_flags = 0;
+ switch (operation) {
+ case BLK_WRITE:
+ /*
+ * "write" operation: let the UPL subsystem
+ * know that we intend to modify the buffer
+ * cache pages we're gathering.
+ */
+ upl_flags |= UPL_WILL_MODIFY;
+ case BLK_READ:
+ upl_flags |= UPL_PRECIOUS;
+ if (UBCINFOEXISTS(bp->b_vp) && bp->b_bufsize) {
+ kret = ubc_create_upl(vp,
+ ubc_blktooff(vp, bp->b_lblkno),
+ bp->b_bufsize,
+ &upl,
+ &pl,
+ upl_flags);
+ if (kret != KERN_SUCCESS)
+ panic("Failed to create UPL");
+
+ bp->b_upl = upl;
+
+ if (upl_valid_page(pl, 0)) {
+ if (upl_dirty_page(pl, 0))
+ SET(bp->b_flags, B_WASDIRTY);
+ else
+ CLR(bp->b_flags, B_WASDIRTY);
+ } else
+ CLR(bp->b_flags, (B_DONE | B_CACHE | B_WASDIRTY | B_DELWRI));
+
+ kret = ubc_upl_map(upl, (vm_offset_t*)&(bp->b_datap));
+
+ if (kret != KERN_SUCCESS)
+ panic("getblk: ubc_upl_map() failed with (%d)", kret);
+ }
+ break;
+
+ case BLK_META:
+ /*
+ * VM is not involved in IO for the meta data
+ * buffer already has valid data
+ */
+ break;
+
+ default:
+ panic("getblk: paging or unknown operation for incore buffer- %d\n", operation);
+ /*NOTREACHED*/
+ break;
+ }
+ }
+ } else { /* not incore() */
+ int queue = BQ_EMPTY; /* Start with no preference */
+
+ if (ret_only_valid) {
+ lck_mtx_unlock(buf_mtxp);
+ return (NULL);
+ }
+ if ((vnode_isreg(vp) == 0) || (UBCINFOEXISTS(vp) == 0) /*|| (vnode_issystem(vp) == 1)*/)
+ operation = BLK_META;
+
+ if ((bp = getnewbuf(slpflag, slptimeo, &queue)) == NULL)
+ goto start;
+
+ /*
+ * getnewbuf may block for a number of different reasons...
+ * if it does, it's then possible for someone else to
+ * create a buffer for the same block and insert it into
+ * the hash... if we see it incore at this point we dump
+ * the buffer we were working on and start over
+ */
+ if (incore_locked(vp, blkno, dp)) {
+ SET(bp->b_flags, B_INVAL);
+ binshash(bp, &invalhash);
+
+ lck_mtx_unlock(buf_mtxp);
+
+ buf_brelse(bp);
+ goto start;
+ }
+ /*
+ * NOTE: YOU CAN NOT BLOCK UNTIL binshash() HAS BEEN
+ * CALLED! BE CAREFUL.
+ */
+
+ /*
+ * mark the buffer as B_META if indicated
+ * so that when buffer is released it will goto META queue
+ */
+ if (operation == BLK_META)
+ SET(bp->b_flags, B_META);
+
+ bp->b_blkno = bp->b_lblkno = blkno;
+ bp->b_vp = vp;
+
+ /*
+ * Insert in the hash so that incore() can find it
+ */
+ binshash(bp, BUFHASH(vp, blkno));
+
+ bgetvp_locked(vp, bp);
+
+ lck_mtx_unlock(buf_mtxp);
+
+ allocbuf(bp, size);
+
+ upl_flags = 0;
+ switch (operation) {
+ case BLK_META:
+ /*
+ * buffer data is invalid...
+ *
+ * I don't want to have to retake buf_mtxp,
+ * so the miss and vmhits counters are done
+ * with Atomic updates... all other counters
+ * in bufstats are protected with either
+ * buf_mtxp or iobuffer_mtxp
+ */
+ OSAddAtomicLong(1, &bufstats.bufs_miss);
+ break;
+
+ case BLK_WRITE:
+ /*
+ * "write" operation: let the UPL subsystem know
+ * that we intend to modify the buffer cache pages
+ * we're gathering.
+ */
+ upl_flags |= UPL_WILL_MODIFY;
+ case BLK_READ:
+ { off_t f_offset;
+ size_t contig_bytes;
+ int bmap_flags;
+
+ if ( (bp->b_upl) )
+ panic("bp already has UPL: %p",bp);
+
+ f_offset = ubc_blktooff(vp, blkno);
+
+ upl_flags |= UPL_PRECIOUS;
+ kret = ubc_create_upl(vp,
+ f_offset,
+ bp->b_bufsize,
+ &upl,
+ &pl,
+ upl_flags);
+
+ if (kret != KERN_SUCCESS)
+ panic("Failed to create UPL");
+#if UPL_DEBUG
+ upl_ubc_alias_set(upl, (uintptr_t) bp, (uintptr_t) 4);
+#endif /* UPL_DEBUG */
+ bp->b_upl = upl;
+
+ if (upl_valid_page(pl, 0)) {
+
+ if (operation == BLK_READ)
+ bmap_flags = VNODE_READ;
+ else
+ bmap_flags = VNODE_WRITE;
+
+ SET(bp->b_flags, B_CACHE | B_DONE);
+
+ OSAddAtomicLong(1, &bufstats.bufs_vmhits);
+
+ bp->b_validoff = 0;
+ bp->b_dirtyoff = 0;
+
+ if (upl_dirty_page(pl, 0)) {
+ /* page is dirty */
+ SET(bp->b_flags, B_WASDIRTY);
+
+ bp->b_validend = bp->b_bcount;
+ bp->b_dirtyend = bp->b_bcount;
+ } else {
+ /* page is clean */
+ bp->b_validend = bp->b_bcount;
+ bp->b_dirtyend = 0;
+ }
+ /*
+ * try to recreate the physical block number associated with
+ * this buffer...
+ */
+ if (VNOP_BLOCKMAP(vp, f_offset, bp->b_bcount, &bp->b_blkno, &contig_bytes, NULL, bmap_flags, NULL))
+ panic("getblk: VNOP_BLOCKMAP failed");
+ /*
+ * if the extent represented by this buffer
+ * is not completely physically contiguous on
+ * disk, than we can't cache the physical mapping
+ * in the buffer header
+ */
+ if ((long)contig_bytes < bp->b_bcount)
+ bp->b_blkno = bp->b_lblkno;
+ } else {
+ OSAddAtomicLong(1, &bufstats.bufs_miss);
+ }
+ kret = ubc_upl_map(upl, (vm_offset_t *)&(bp->b_datap));
+
+ if (kret != KERN_SUCCESS)
+ panic("getblk: ubc_upl_map() failed with (%d)", kret);
+ break;
+ }
+ default:
+ panic("getblk: paging or unknown operation - %x", operation);
+ /*NOTREACHED*/
+ break;
+ }
+ }
+ KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 386)) | DBG_FUNC_END,
+ bp, bp->b_datap, bp->b_flags, 3, 0);
+
+#ifdef JOE_DEBUG
+ (void) OSBacktrace(&bp->b_stackgetblk[0], 6);
+#endif
+ return (bp);
+}
+
+/*
+ * Get an empty, disassociated buffer of given size.
+ */
+buf_t
+buf_geteblk(int size)
+{
+ buf_t bp = NULL;
+ int queue = BQ_EMPTY;
+
+ do {
+ lck_mtx_lock_spin(buf_mtxp);
+
+ bp = getnewbuf(0, 0, &queue);
+ } while (bp == NULL);
+
+ SET(bp->b_flags, (B_META|B_INVAL));
+
+#if DIAGNOSTIC
+ assert(queue == BQ_EMPTY);
+#endif /* DIAGNOSTIC */
+ /* XXX need to implement logic to deal with other queues */
+
+ binshash(bp, &invalhash);
+ bufstats.bufs_eblk++;
+
+ lck_mtx_unlock(buf_mtxp);
+
+ allocbuf(bp, size);
+
+ return (bp);
+}
+
+uint32_t
+buf_redundancy_flags(buf_t bp)
+{
+ return bp->b_redundancy_flags;
+}
+
+void
+buf_set_redundancy_flags(buf_t bp, uint32_t flags)
+{
+ SET(bp->b_redundancy_flags, flags);
+}
+
+void
+buf_clear_redundancy_flags(buf_t bp, uint32_t flags)
+{
+ CLR(bp->b_redundancy_flags, flags);
+}
+
+/*
+ * With UBC, there is no need to expand / shrink the file data
+ * buffer. The VM uses the same pages, hence no waste.
+ * All the file data buffers can have one size.
+ * In fact expand / shrink would be an expensive operation.
+ *
+ * Only exception to this is meta-data buffers. Most of the
+ * meta data operations are smaller than PAGE_SIZE. Having the
+ * meta-data buffers grow and shrink as needed, optimizes use
+ * of the kernel wired memory.
+ */
+
+int
+allocbuf(buf_t bp, int size)
+{
+ vm_size_t desired_size;
+
+ desired_size = roundup(size, CLBYTES);
+
+ if (desired_size < PAGE_SIZE)
+ desired_size = PAGE_SIZE;
+ if (desired_size > MAXBSIZE)
+ panic("allocbuf: buffer larger than MAXBSIZE requested");
+
+ if (ISSET(bp->b_flags, B_META)) {
+ zone_t zprev, z;
+ int nsize = roundup(size, MINMETA);
+
+ if (bp->b_datap) {
+ vm_offset_t elem = (vm_offset_t)bp->b_datap;
+
+ if (ISSET(bp->b_flags, B_ZALLOC)) {
+ if (bp->b_bufsize < nsize) {
+ /* reallocate to a bigger size */
+
+ zprev = getbufzone(bp->b_bufsize);
+ if (nsize <= MAXMETA) {
+ desired_size = nsize;
+ z = getbufzone(nsize);
+ /* b_datap not really a ptr */
+ *(void **)(&bp->b_datap) = zalloc(z);
+ } else {
+ bp->b_datap = (uintptr_t)NULL;
+ kmem_alloc_kobject(kernel_map, (vm_offset_t *)&bp->b_datap, desired_size);
+ CLR(bp->b_flags, B_ZALLOC);
+ }
+ bcopy((void *)elem, (caddr_t)bp->b_datap, bp->b_bufsize);
+ zfree(zprev, (void *)elem);
+ } else {
+ desired_size = bp->b_bufsize;
+ }
+
+ } else {
+ if ((vm_size_t)bp->b_bufsize < desired_size) {
+ /* reallocate to a bigger size */
+ bp->b_datap = (uintptr_t)NULL;
+ kmem_alloc_kobject(kernel_map, (vm_offset_t *)&bp->b_datap, desired_size);
+ bcopy((const void *)elem, (caddr_t)bp->b_datap, bp->b_bufsize);
+ kmem_free(kernel_map, elem, bp->b_bufsize);
+ } else {
+ desired_size = bp->b_bufsize;
+ }
+ }
+ } else {
+ /* new allocation */
+ if (nsize <= MAXMETA) {
+ desired_size = nsize;
+ z = getbufzone(nsize);
+ /* b_datap not really a ptr */
+ *(void **)(&bp->b_datap) = zalloc(z);
+ SET(bp->b_flags, B_ZALLOC);
+ } else
+ kmem_alloc_kobject(kernel_map, (vm_offset_t *)&bp->b_datap, desired_size);
+ }
+
+ if (bp->b_datap == 0)
+ panic("allocbuf: NULL b_datap");
+ }
+ bp->b_bufsize = desired_size;
+ bp->b_bcount = size;
+
+ return (0);
+}
+
+/*
+ * Get a new buffer from one of the free lists.
+ *
+ * Request for a queue is passes in. The queue from which the buffer was taken
+ * from is returned. Out of range queue requests get BQ_EMPTY. Request for
+ * BQUEUE means no preference. Use heuristics in that case.
+ * Heuristics is as follows:
+ * Try BQ_AGE, BQ_LRU, BQ_EMPTY, BQ_META in that order.
+ * If none available block till one is made available.
+ * If buffers available on both BQ_AGE and BQ_LRU, check the timestamps.
+ * Pick the most stale buffer.
+ * If found buffer was marked delayed write, start the async. write
+ * and restart the search.
+ * Initialize the fields and disassociate the buffer from the vnode.
+ * Remove the buffer from the hash. Return the buffer and the queue
+ * on which it was found.
+ *
+ * buf_mtxp is held upon entry
+ * returns with buf_mtxp locked if new buf available
+ * returns with buf_mtxp UNlocked if new buf NOT available
+ */
+
+static buf_t
+getnewbuf(int slpflag, int slptimeo, int * queue)
+{
+ buf_t bp;
+ buf_t lru_bp;
+ buf_t age_bp;
+ buf_t meta_bp;
+ int age_time, lru_time, bp_time, meta_time;
+ int req = *queue; /* save it for restarts */
+ struct timespec ts;
+
+start:
+ /*
+ * invalid request gets empty queue
+ */
+ if ((*queue >= BQUEUES) || (*queue < 0)
+ || (*queue == BQ_LAUNDRY) || (*queue == BQ_LOCKED))
+ *queue = BQ_EMPTY;
+
+
+ if (*queue == BQ_EMPTY && (bp = bufqueues[*queue].tqh_first))
+ goto found;
+
+ /*
+ * need to grow number of bufs, add another one rather than recycling
+ */
+ if (nbuf_headers < max_nbuf_headers) {
+ /*
+ * Increment count now as lock
+ * is dropped for allocation.
+ * That avoids over commits
+ */
+ nbuf_headers++;
+ goto add_newbufs;
+ }
+ /* Try for the requested queue first */
+ bp = bufqueues[*queue].tqh_first;
+ if (bp)
+ goto found;
+
+ /* Unable to use requested queue */
+ age_bp = bufqueues[BQ_AGE].tqh_first;
+ lru_bp = bufqueues[BQ_LRU].tqh_first;
+ meta_bp = bufqueues[BQ_META].tqh_first;
+
+ if (!age_bp && !lru_bp && !meta_bp) {
+ /*
+ * Unavailble on AGE or LRU or META queues
+ * Try the empty list first
+ */
+ bp = bufqueues[BQ_EMPTY].tqh_first;
+ if (bp) {
+ *queue = BQ_EMPTY;
+ goto found;
+ }
+ /*
+ * We have seen is this is hard to trigger.
+ * This is an overcommit of nbufs but needed
+ * in some scenarios with diskiamges
+ */
+
+add_newbufs:
+ lck_mtx_unlock(buf_mtxp);
+
+ /* Create a new temporary buffer header */
+ bp = (struct buf *)zalloc(buf_hdr_zone);
+
+ if (bp) {
+ bufhdrinit(bp);
+ bp->b_whichq = BQ_EMPTY;
+ bp->b_timestamp = buf_timestamp();
+ BLISTNONE(bp);
+ SET(bp->b_flags, B_HDRALLOC);
+ *queue = BQ_EMPTY;
+ }
+ lck_mtx_lock_spin(buf_mtxp);
+
+ if (bp) {
+ binshash(bp, &invalhash);
+ binsheadfree(bp, &bufqueues[BQ_EMPTY], BQ_EMPTY);
+ buf_hdr_count++;
+ goto found;
+ }
+ /* subtract already accounted bufcount */
+ nbuf_headers--;
+
+ bufstats.bufs_sleeps++;
+
+ /* wait for a free buffer of any kind */
+ needbuffer = 1;
+ /* hz value is 100 */
+ ts.tv_sec = (slptimeo/1000);
+ /* the hz value is 100; which leads to 10ms */
+ ts.tv_nsec = (slptimeo % 1000) * NSEC_PER_USEC * 1000 * 10;
+
+ msleep(&needbuffer, buf_mtxp, slpflag | PDROP | (PRIBIO+1), "getnewbuf", &ts);
+ return (NULL);
+ }
+
+ /* Buffer available either on AGE or LRU or META */
+ bp = NULL;
+ *queue = -1;
+
+ /* Buffer available either on AGE or LRU */
+ if (!age_bp) {
+ bp = lru_bp;
+ *queue = BQ_LRU;
+ } else if (!lru_bp) {
+ bp = age_bp;
+ *queue = BQ_AGE;
+ } else { /* buffer available on both AGE and LRU */
+ int t = buf_timestamp();
+
+ age_time = t - age_bp->b_timestamp;
+ lru_time = t - lru_bp->b_timestamp;
+ if ((age_time < 0) || (lru_time < 0)) { /* time set backwards */
+ bp = age_bp;
+ *queue = BQ_AGE;
+ /*
+ * we should probably re-timestamp eveything in the
+ * queues at this point with the current time
+ */
+ } else {
+ if ((lru_time >= lru_is_stale) && (age_time < age_is_stale)) {
+ bp = lru_bp;
+ *queue = BQ_LRU;
+ } else {
+ bp = age_bp;
+ *queue = BQ_AGE;
+ }
+ }
+ }
+
+ if (!bp) { /* Neither on AGE nor on LRU */
+ bp = meta_bp;
+ *queue = BQ_META;
+ } else if (meta_bp) {
+ int t = buf_timestamp();
+
+ bp_time = t - bp->b_timestamp;
+ meta_time = t - meta_bp->b_timestamp;
+
+ if (!(bp_time < 0) && !(meta_time < 0)) {
+ /* time not set backwards */
+ int bp_is_stale;
+ bp_is_stale = (*queue == BQ_LRU) ?
+ lru_is_stale : age_is_stale;
+
+ if ((meta_time >= meta_is_stale) &&
+ (bp_time < bp_is_stale)) {
+ bp = meta_bp;
+ *queue = BQ_META;
+ }
+ }
+ }
+found:
+ if (ISSET(bp->b_flags, B_LOCKED) || ISSET(bp->b_lflags, BL_BUSY))
+ panic("getnewbuf: bp @ %p is LOCKED or BUSY! (flags 0x%x)\n", bp, bp->b_flags);
+
+ /* Clean it */
+ if (bcleanbuf(bp, FALSE)) {
+ /*
+ * moved to the laundry thread, buffer not ready
+ */
+ *queue = req;
+ goto start;
+ }
+ return (bp);
+}
+
+
+/*
+ * Clean a buffer.
+ * Returns 0 if buffer is ready to use,
+ * Returns 1 if issued a buf_bawrite() to indicate
+ * that the buffer is not ready.
+ *
+ * buf_mtxp is held upon entry
+ * returns with buf_mtxp locked
+ */
+int
+bcleanbuf(buf_t bp, boolean_t discard)
+{
+ /* Remove from the queue */
+ bremfree_locked(bp);
+
+#ifdef JOE_DEBUG
+ bp->b_owner = current_thread();
+ bp->b_tag = 2;
+#endif
+ /*
+ * If buffer was a delayed write, start the IO by queuing
+ * it on the LAUNDRY queue, and return 1
+ */
+ if (ISSET(bp->b_flags, B_DELWRI)) {
+ if (discard) {
+ SET(bp->b_lflags, BL_WANTDEALLOC);
+ }
+
+ bmovelaundry(bp);
+
+ lck_mtx_unlock(buf_mtxp);
+
+ wakeup(&bufqueues[BQ_LAUNDRY]);
+ /*
+ * and give it a chance to run
+ */
+ (void)thread_block(THREAD_CONTINUE_NULL);
+
+ lck_mtx_lock_spin(buf_mtxp);
+
+ return (1);
+ }
+#ifdef JOE_DEBUG
+ bp->b_owner = current_thread();
+ bp->b_tag = 8;
+#endif
+ /*
+ * Buffer is no longer on any free list... we own it
+ */
+ SET(bp->b_lflags, BL_BUSY);
+ buf_busycount++;
+
+ bremhash(bp);
+
+ /*
+ * disassociate us from our vnode, if we had one...
+ */
+ if (bp->b_vp)
+ brelvp_locked(bp);
+
+ lck_mtx_unlock(buf_mtxp);
+
+ BLISTNONE(bp);
+
+ if (ISSET(bp->b_flags, B_META))
+ buf_free_meta_store(bp);
+
+ trace(TR_BRELSE, pack(bp->b_vp, bp->b_bufsize), bp->b_lblkno);
+
+ buf_release_credentials(bp);
+
+ /* If discarding, just move to the empty queue */
+ if (discard) {
+ lck_mtx_lock_spin(buf_mtxp);
+ CLR(bp->b_flags, (B_META | B_ZALLOC | B_DELWRI | B_LOCKED | B_AGE | B_ASYNC | B_NOCACHE | B_FUA));
+ bp->b_whichq = BQ_EMPTY;
+ binshash(bp, &invalhash);
+ binsheadfree(bp, &bufqueues[BQ_EMPTY], BQ_EMPTY);
+ CLR(bp->b_lflags, BL_BUSY);
+ buf_busycount--;
+ } else {
+ /* Not discarding: clean up and prepare for reuse */
+ bp->b_bufsize = 0;
+ bp->b_datap = (uintptr_t)NULL;
+ bp->b_upl = (void *)NULL;
+ /*
+ * preserve the state of whether this buffer
+ * was allocated on the fly or not...
+ * the only other flag that should be set at
+ * this point is BL_BUSY...
+ */
+#ifdef JOE_DEBUG
+ bp->b_owner = current_thread();
+ bp->b_tag = 3;
+#endif
+ bp->b_lflags = BL_BUSY;
+ bp->b_flags = (bp->b_flags & B_HDRALLOC);
+ bp->b_dev = NODEV;
+ bp->b_blkno = bp->b_lblkno = 0;
+ bp->b_iodone = NULL;
+ bp->b_error = 0;
+ bp->b_resid = 0;
+ bp->b_bcount = 0;
+ bp->b_dirtyoff = bp->b_dirtyend = 0;
+ bp->b_validoff = bp->b_validend = 0;
+#ifdef CONFIG_PROTECT
+ bp->b_cpentry = 0;
+#endif
+
+ lck_mtx_lock_spin(buf_mtxp);
+ }
+ return (0);
+}
+
+
+
+errno_t
+buf_invalblkno(vnode_t vp, daddr64_t lblkno, int flags)
+{
+ buf_t bp;
+ errno_t error;
+ struct bufhashhdr *dp;
+
+ dp = BUFHASH(vp, lblkno);
+
+relook:
+ lck_mtx_lock_spin(buf_mtxp);
+
+ if ((bp = incore_locked(vp, lblkno, dp)) == (struct buf *)0) {
+ lck_mtx_unlock(buf_mtxp);
+ return (0);
+ }
+ if (ISSET(bp->b_lflags, BL_BUSY)) {
+ if ( !ISSET(flags, BUF_WAIT)) {
+ lck_mtx_unlock(buf_mtxp);
+ return (EBUSY);
+ }
+ SET(bp->b_lflags, BL_WANTED);
+
+ error = msleep((caddr_t)bp, buf_mtxp, PDROP | (PRIBIO + 1), "buf_invalblkno", NULL);
+
+ if (error) {
+ return (error);
+ }
+ goto relook;
+ }
+ bremfree_locked(bp);
+ SET(bp->b_lflags, BL_BUSY);
+ SET(bp->b_flags, B_INVAL);
+ buf_busycount++;
+#ifdef JOE_DEBUG
+ bp->b_owner = current_thread();
+ bp->b_tag = 4;
+#endif
+ lck_mtx_unlock(buf_mtxp);
+ buf_brelse(bp);
+
+ return (0);
+}
+
+
+void
+buf_drop(buf_t bp)
+{
+ int need_wakeup = 0;
+
+ lck_mtx_lock_spin(buf_mtxp);
+
+ if (ISSET(bp->b_lflags, BL_WANTED)) {
+ /*
+ * delay the actual wakeup until after we
+ * clear BL_BUSY and we've dropped buf_mtxp
+ */
+ need_wakeup = 1;
+ }
+#ifdef JOE_DEBUG
+ bp->b_owner = current_thread();
+ bp->b_tag = 9;
+#endif
+ /*
+ * Unlock the buffer.
+ */
+ CLR(bp->b_lflags, (BL_BUSY | BL_WANTED));
+ buf_busycount--;
+
+ lck_mtx_unlock(buf_mtxp);
+
+ if (need_wakeup) {
+ /*
+ * Wake up any proceeses waiting for _this_ buffer to become free.
+ */
+ wakeup(bp);
+ }
+}
+
+
+errno_t
+buf_acquire(buf_t bp, int flags, int slpflag, int slptimeo) {
+ errno_t error;
+
+ lck_mtx_lock_spin(buf_mtxp);
+
+ error = buf_acquire_locked(bp, flags, slpflag, slptimeo);
+
+ lck_mtx_unlock(buf_mtxp);
+
+ return (error);
+}
+
+
+static errno_t
+buf_acquire_locked(buf_t bp, int flags, int slpflag, int slptimeo)
+{
+ errno_t error;
+ struct timespec ts;
+
+ if (ISSET(bp->b_flags, B_LOCKED)) {
+ if ((flags & BAC_SKIP_LOCKED))
+ return (EDEADLK);
+ } else {
+ if ((flags & BAC_SKIP_NONLOCKED))
+ return (EDEADLK);
+ }
+ if (ISSET(bp->b_lflags, BL_BUSY)) {
+ /*
+ * since the lck_mtx_lock may block, the buffer
+ * may become BUSY, so we need to
+ * recheck for a NOWAIT request
+ */
+ if (flags & BAC_NOWAIT)
+ return (EBUSY);
+ SET(bp->b_lflags, BL_WANTED);
+
+ /* the hz value is 100; which leads to 10ms */
+ ts.tv_sec = (slptimeo/100);
+ ts.tv_nsec = (slptimeo % 100) * 10 * NSEC_PER_USEC * 1000;
+ error = msleep((caddr_t)bp, buf_mtxp, slpflag | (PRIBIO + 1), "buf_acquire", &ts);
+
+ if (error)
+ return (error);
+ return (EAGAIN);
+ }
+ if (flags & BAC_REMOVE)
+ bremfree_locked(bp);
+ SET(bp->b_lflags, BL_BUSY);
+ buf_busycount++;
+
+#ifdef JOE_DEBUG
+ bp->b_owner = current_thread();
+ bp->b_tag = 5;
+#endif
+ return (0);
+}
+
+
+/*
+ * Wait for operations on the buffer to complete.
+ * When they do, extract and return the I/O's error value.
+ */
+errno_t
+buf_biowait(buf_t bp)
+{
+ while (!ISSET(bp->b_flags, B_DONE)) {
+
+ lck_mtx_lock_spin(buf_mtxp);
+
+ if (!ISSET(bp->b_flags, B_DONE)) {
+ DTRACE_IO1(wait__start, buf_t, bp);
+ (void) msleep(bp, buf_mtxp, PDROP | (PRIBIO+1), "buf_biowait", NULL);
+ DTRACE_IO1(wait__done, buf_t, bp);
+ } else
+ lck_mtx_unlock(buf_mtxp);
+ }
+ /* check for interruption of I/O (e.g. via NFS), then errors. */
+ if (ISSET(bp->b_flags, B_EINTR)) {
+ CLR(bp->b_flags, B_EINTR);
+ return (EINTR);
+ } else if (ISSET(bp->b_flags, B_ERROR))
+ return (bp->b_error ? bp->b_error : EIO);
+ else
+ return (0);
+}
+
+
+/*
+ * Mark I/O complete on a buffer.
+ *
+ * If a callback has been requested, e.g. the pageout
+ * daemon, do so. Otherwise, awaken waiting processes.
+ *
+ * [ Leffler, et al., says on p.247:
+ * "This routine wakes up the blocked process, frees the buffer
+ * for an asynchronous write, or, for a request by the pagedaemon
+ * process, invokes a procedure specified in the buffer structure" ]
+ *
+ * In real life, the pagedaemon (or other system processes) wants
+ * to do async stuff to, and doesn't want the buffer buf_brelse()'d.
+ * (for swap pager, that puts swap buffers on the free lists (!!!),
+ * for the vn device, that puts malloc'd buffers on the free lists!)
+ */
+extern struct timeval priority_IO_timestamp_for_root;
+extern int hard_throttle_on_root;
+
+void
+buf_biodone(buf_t bp)
+{
+ mount_t mp;
+
+ KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 387)) | DBG_FUNC_START,
+ bp, bp->b_datap, bp->b_flags, 0, 0);
+
+ if (ISSET(bp->b_flags, B_DONE))
+ panic("biodone already");
+
+ if (ISSET(bp->b_flags, B_ERROR)) {
+ fslog_io_error(bp);
+ }
+
+ if (bp->b_vp && bp->b_vp->v_mount) {
+ mp = bp->b_vp->v_mount;
+ } else {
+ mp = NULL;
+ }
+
+ if (mp && (bp->b_flags & B_READ) == 0) {
+ update_last_io_time(mp);
+ INCR_PENDING_IO(-(pending_io_t)buf_count(bp), mp->mnt_pending_write_size);
+ } else if (mp) {
+ INCR_PENDING_IO(-(pending_io_t)buf_count(bp), mp->mnt_pending_read_size);
+ }
+
+ if (kdebug_enable) {
+ int code = DKIO_DONE;
+
+ if (bp->b_flags & B_READ)
+ code |= DKIO_READ;
+ if (bp->b_flags & B_ASYNC)
+ code |= DKIO_ASYNC;
+
+ if (bp->b_flags & B_META)
+ code |= DKIO_META;
+ else if (bp->b_flags & B_PAGEIO)
+ code |= DKIO_PAGING;
+
+ if (bp->b_flags & B_THROTTLED_IO)
+ code |= DKIO_THROTTLE;
+ else if (bp->b_flags & B_PASSIVE)
+ code |= DKIO_PASSIVE;
+
+ KERNEL_DEBUG_CONSTANT(FSDBG_CODE(DBG_DKRW, code) | DBG_FUNC_NONE,
+ bp, (uintptr_t)bp->b_vp,
+ bp->b_resid, bp->b_error, 0);
+ }
+ if ((bp->b_vp != NULLVP) &&
+ ((bp->b_flags & (B_IOSTREAMING | B_PAGEIO | B_READ)) == (B_PAGEIO | B_READ)) &&
+ (bp->b_vp->v_mount->mnt_kern_flag & MNTK_ROOTDEV)) {
+ microuptime(&priority_IO_timestamp_for_root);
+ hard_throttle_on_root = 0;
+ }
+
+ /*
+ * I/O was done, so don't believe
+ * the DIRTY state from VM anymore...
+ * and we need to reset the THROTTLED/PASSIVE
+ * indicators
+ */
+ CLR(bp->b_flags, (B_WASDIRTY | B_THROTTLED_IO | B_PASSIVE));
+ DTRACE_IO1(done, buf_t, bp);
+
+ if (!ISSET(bp->b_flags, B_READ) && !ISSET(bp->b_flags, B_RAW))
+ /*
+ * wake up any writer's blocked
+ * on throttle or waiting for I/O
+ * to drain
+ */
+ vnode_writedone(bp->b_vp);
+
+ if (ISSET(bp->b_flags, (B_CALL | B_FILTER))) { /* if necessary, call out */
+ void (*iodone_func)(struct buf *, void *) = bp->b_iodone;
+ void *arg = bp->b_transaction;
+ int callout = ISSET(bp->b_flags, B_CALL);
+
+ if (iodone_func == NULL)
+ panic("biodone: bp @ %p has NULL b_iodone!\n", bp);
+
+ CLR(bp->b_flags, (B_CALL | B_FILTER)); /* filters and callouts are one-shot */
+ bp->b_iodone = NULL;
+ bp->b_transaction = NULL;
+
+ if (callout)
+ SET(bp->b_flags, B_DONE); /* note that it's done */
+
+ (*iodone_func)(bp, arg);
+
+ if (callout) {
+ /*
+ * assumes that the callback function takes
+ * ownership of the bp and deals with releasing it if necessary
+ */
+ goto biodone_done;
+ }
+ /*
+ * in this case the call back function is acting
+ * strictly as a filter... it does not take
+ * ownership of the bp and is expecting us
+ * to finish cleaning up... this is currently used
+ * by the HFS journaling code
+ */
+ }
+ if (ISSET(bp->b_flags, B_ASYNC)) { /* if async, release it */
+ SET(bp->b_flags, B_DONE); /* note that it's done */
+
+ buf_brelse(bp);
+ } else { /* or just wakeup the buffer */
+ /*
+ * by taking the mutex, we serialize
+ * the buf owner calling buf_biowait so that we'll
+ * only see him in one of 2 states...
+ * state 1: B_DONE wasn't set and he's
+ * blocked in msleep
+ * state 2: he's blocked trying to take the
+ * mutex before looking at B_DONE
+ * BL_WANTED is cleared in case anyone else
+ * is blocked waiting for the buffer... note
+ * that we haven't cleared B_BUSY yet, so if
+ * they do get to run, their going to re-set
+ * BL_WANTED and go back to sleep
+ */
+ lck_mtx_lock_spin(buf_mtxp);
+
+ CLR(bp->b_lflags, BL_WANTED);
+ SET(bp->b_flags, B_DONE); /* note that it's done */
+
+ lck_mtx_unlock(buf_mtxp);
+
+ wakeup(bp);
+ }
+biodone_done:
+ KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 387)) | DBG_FUNC_END,
+ (uintptr_t)bp, (uintptr_t)bp->b_datap, bp->b_flags, 0, 0);
+}
+
+/*
+ * Return a count of buffers on the "locked" queue.
+ */
+int
+count_lock_queue(void)
+{
+ buf_t bp;
+ int n = 0;
+
+ lck_mtx_lock_spin(buf_mtxp);
+
+ for (bp = bufqueues[BQ_LOCKED].tqh_first; bp;
+ bp = bp->b_freelist.tqe_next)
+ n++;
+ lck_mtx_unlock(buf_mtxp);
+
+ return (n);
+}
+
+/*
+ * Return a count of 'busy' buffers. Used at the time of shutdown.
+ */
+int
+count_busy_buffers(void)
+{
+ return buf_busycount + bufstats.bufs_iobufinuse;
+}
+
+#if DIAGNOSTIC
+/*
+ * Print out statistics on the current allocation of the buffer pool.
+ * Can be enabled to print out on every ``sync'' by setting "syncprt"
+ * in vfs_syscalls.c using sysctl.
+ */
+void
+vfs_bufstats()
+{
+ int i, j, count;
+ struct buf *bp;
+ struct bqueues *dp;
+ int counts[MAXBSIZE/CLBYTES+1];
+ static char *bname[BQUEUES] =
+ { "LOCKED", "LRU", "AGE", "EMPTY", "META", "LAUNDRY" };
+
+ for (dp = bufqueues, i = 0; dp < &bufqueues[BQUEUES]; dp++, i++) {
+ count = 0;
+ for (j = 0; j <= MAXBSIZE/CLBYTES; j++)
+ counts[j] = 0;
+
+ lck_mtx_lock(buf_mtxp);
+
+ for (bp = dp->tqh_first; bp; bp = bp->b_freelist.tqe_next) {
+ counts[bp->b_bufsize/CLBYTES]++;
+ count++;
+ }
+ lck_mtx_unlock(buf_mtxp);
+
+ printf("%s: total-%d", bname[i], count);
+ for (j = 0; j <= MAXBSIZE/CLBYTES; j++)
+ if (counts[j] != 0)
+ printf(", %d-%d", j * CLBYTES, counts[j]);
+ printf("\n");
+ }
+}
+#endif /* DIAGNOSTIC */
+
+#define NRESERVEDIOBUFS 128
+
+
+buf_t
+alloc_io_buf(vnode_t vp, int priv)
+{
+ buf_t bp;
+
+ lck_mtx_lock_spin(iobuffer_mtxp);
+
+ while (((niobuf_headers - NRESERVEDIOBUFS < bufstats.bufs_iobufinuse) && !priv) ||
+ (bp = iobufqueue.tqh_first) == NULL) {
+ bufstats.bufs_iobufsleeps++;
+
+ need_iobuffer = 1;
+ (void) msleep(&need_iobuffer, iobuffer_mtxp, PSPIN | (PRIBIO+1), (const char *)"alloc_io_buf", NULL);
+ }
+ TAILQ_REMOVE(&iobufqueue, bp, b_freelist);
+
+ bufstats.bufs_iobufinuse++;
+ if (bufstats.bufs_iobufinuse > bufstats.bufs_iobufmax)
+ bufstats.bufs_iobufmax = bufstats.bufs_iobufinuse;
+
+ lck_mtx_unlock(iobuffer_mtxp);
+
+ /*
+ * initialize various fields
+ * we don't need to hold the mutex since the buffer
+ * is now private... the vp should have a reference
+ * on it and is not protected by this mutex in any event
+ */
+ bp->b_timestamp = 0;
+ bp->b_proc = NULL;
+
+ bp->b_datap = 0;
+ bp->b_flags = 0;
+ bp->b_lflags = BL_BUSY | BL_IOBUF;
+ bp->b_redundancy_flags = 0;
+ bp->b_blkno = bp->b_lblkno = 0;
+#ifdef JOE_DEBUG
+ bp->b_owner = current_thread();
+ bp->b_tag = 6;
+#endif
+ bp->b_iodone = NULL;
+ bp->b_error = 0;
+ bp->b_resid = 0;
+ bp->b_bcount = 0;
+ bp->b_bufsize = 0;
+ bp->b_upl = NULL;
+ bp->b_vp = vp;
+#ifdef CONFIG_PROTECT
+ bp->b_cpentry = 0;
+#endif
+
+ if (vp && (vp->v_type == VBLK || vp->v_type == VCHR))
+ bp->b_dev = vp->v_rdev;
+ else
+ bp->b_dev = NODEV;
+
+ return (bp);
+}
+
+
+void
+free_io_buf(buf_t bp)
+{
+ int need_wakeup = 0;
+
+ /*
+ * put buffer back on the head of the iobufqueue
+ */
+ bp->b_vp = NULL;
+ bp->b_flags = B_INVAL;
+
+ lck_mtx_lock_spin(iobuffer_mtxp);
+
+ binsheadfree(bp, &iobufqueue, -1);
+
+ if (need_iobuffer) {
+ /*
+ * Wake up any processes waiting because they need an io buffer
+ *
+ * do the wakeup after we drop the mutex... it's possible that the
+ * wakeup will be superfluous if need_iobuffer gets set again and
+ * another thread runs this path, but it's highly unlikely, doesn't
+ * hurt, and it means we don't hold up I/O progress if the wakeup blocks
+ * trying to grab a task related lock...
+ */
+ need_iobuffer = 0;
+ need_wakeup = 1;
+ }
+ if (bufstats.bufs_iobufinuse <= 0)
+ panic("free_io_buf: bp(%p) - bufstats.bufs_iobufinuse < 0", bp);
+
+ bufstats.bufs_iobufinuse--;
+
+ lck_mtx_unlock(iobuffer_mtxp);
+
+ if (need_wakeup)
+ wakeup(&need_iobuffer);
+}
+
+
+void
+buf_list_lock(void)
+{
+ lck_mtx_lock_spin(buf_mtxp);
+}
+
+void
+buf_list_unlock(void)
+{
+ lck_mtx_unlock(buf_mtxp);
+}
+
+/*
+ * If getnewbuf() calls bcleanbuf() on the same thread
+ * there is a potential for stack overrun and deadlocks.
+ * So we always handoff the work to a worker thread for completion
+ */
+
+
+static void
+bcleanbuf_thread_init(void)
+{
+ thread_t thread = THREAD_NULL;
+
+ /* create worker thread */
+ kernel_thread_start((thread_continue_t)bcleanbuf_thread, NULL, &thread);
+ thread_deallocate(thread);
+}
+
+typedef int (*bcleanbufcontinuation)(int);
+
+static void
+bcleanbuf_thread(void)
+{
+ struct buf *bp;
+ int error = 0;
+ int loopcnt = 0;
+
+ for (;;) {
+ lck_mtx_lock_spin(buf_mtxp);
+
+ while ( (bp = TAILQ_FIRST(&bufqueues[BQ_LAUNDRY])) == NULL) {
+ (void)msleep0(&bufqueues[BQ_LAUNDRY], buf_mtxp, PRIBIO|PDROP, "blaundry", 0, (bcleanbufcontinuation)bcleanbuf_thread);
+ }
+
+ /*
+ * Remove from the queue
+ */
+ bremfree_locked(bp);
+
+ /*
+ * Buffer is no longer on any free list
+ */
+ SET(bp->b_lflags, BL_BUSY);
+ buf_busycount++;
+
+#ifdef JOE_DEBUG
+ bp->b_owner = current_thread();
+ bp->b_tag = 10;
+#endif
+
+ lck_mtx_unlock(buf_mtxp);
+ /*
+ * do the IO
+ */
+ error = bawrite_internal(bp, 0);
+
+ if (error) {
+ bp->b_whichq = BQ_LAUNDRY;
+ bp->b_timestamp = buf_timestamp();
+
+ lck_mtx_lock_spin(buf_mtxp);
+
+ binstailfree(bp, &bufqueues[BQ_LAUNDRY], BQ_LAUNDRY);
+ blaundrycnt++;
+
+ /* we never leave a busy page on the laundry queue */
+ CLR(bp->b_lflags, BL_BUSY);
+ buf_busycount--;
+#ifdef JOE_DEBUG
+ bp->b_owner = current_thread();
+ bp->b_tag = 11;
+#endif
+
+ lck_mtx_unlock(buf_mtxp);
+
+ if (loopcnt > MAXLAUNDRY) {
+ /*
+ * bawrite_internal() can return errors if we're throttled. If we've
+ * done several I/Os and failed, give the system some time to unthrottle
+ * the vnode
+ */
+ (void)tsleep((void *)&bufqueues[BQ_LAUNDRY], PRIBIO, "blaundry", 1);
+ loopcnt = 0;
+ } else {
+ /* give other threads a chance to run */
+ (void)thread_block(THREAD_CONTINUE_NULL);
+ loopcnt++;
+ }
+ }
+ }
+}
+
+
+static int
+brecover_data(buf_t bp)
+{
+ int upl_offset;
+ upl_t upl;
+ upl_page_info_t *pl;
+ kern_return_t kret;
+ vnode_t vp = bp->b_vp;
+ int upl_flags;
+
+
+ if ( !UBCINFOEXISTS(vp) || bp->b_bufsize == 0)
+ goto dump_buffer;
+
+ upl_flags = UPL_PRECIOUS;
+ if (! (buf_flags(bp) & B_READ)) {
+ /*
+ * "write" operation: let the UPL subsystem know
+ * that we intend to modify the buffer cache pages we're
+ * gathering.
+ */
+ upl_flags |= UPL_WILL_MODIFY;
+ }
+
+ kret = ubc_create_upl(vp,
+ ubc_blktooff(vp, bp->b_lblkno),
+ bp->b_bufsize,
+ &upl,
+ &pl,
+ upl_flags);
+ if (kret != KERN_SUCCESS)
+ panic("Failed to create UPL");
+
+ for (upl_offset = 0; upl_offset < bp->b_bufsize; upl_offset += PAGE_SIZE) {
+
+ if (!upl_valid_page(pl, upl_offset / PAGE_SIZE) || !upl_dirty_page(pl, upl_offset / PAGE_SIZE)) {
+ ubc_upl_abort(upl, 0);
+ goto dump_buffer;
+ }
+ }
+ bp->b_upl = upl;
+
+ kret = ubc_upl_map(upl, (vm_offset_t *)&(bp->b_datap));
- s = splbio();
+ if (kret != KERN_SUCCESS)
+ panic("getblk: ubc_upl_map() failed with (%d)", kret);
+ return (1);
- /* Remove from the queue */
- bremfree(bp);
+dump_buffer:
+ bp->b_bufsize = 0;
+ SET(bp->b_flags, B_INVAL);
+ buf_brelse(bp);
- /* Buffer is no longer on free lists. */
- SET(bp->b_flags, B_BUSY);
+ return(0);
+}
- if (bp->b_hash.le_prev == (struct buf **)0xdeadbeef)
- panic("bcleanbuf: le_prev is deadbeef");
+boolean_t
+buffer_cache_gc(int all)
+{
+ buf_t bp;
+ boolean_t did_large_zfree = FALSE;
+ boolean_t need_wakeup = FALSE;
+ int now = buf_timestamp();
+ uint32_t found = 0, total_found = 0;
+ struct bqueues privq;
+ int thresh_hold = BUF_STALE_THRESHHOLD;
- /*
- * If buffer was a delayed write, start the IO by queuing
- * it on the LAUNDRY queue, and return 1
+ if (all)
+ thresh_hold = 0;
+ /*
+ * We only care about metadata (incore storage comes from zalloc()).
+ * No more than 1024 buffers total, and only those not accessed within the
+ * last 30s. We will also only examine 128 buffers during a single grab
+ * of the lock in order to limit lock hold time.
*/
- if (ISSET(bp->b_flags, B_DELWRI)) {
- splx(s);
- binstailfree(bp, &bufqueues[BQ_LAUNDRY], BQ_LAUNDRY);
- blaundrycnt++;
- wakeup(&blaundrycnt);
- return (1);
- }
+ lck_mtx_lock(buf_mtxp);
+ do {
+ found = 0;
+ TAILQ_INIT(&privq);
+ need_wakeup = FALSE;
+
+ while (((bp = TAILQ_FIRST(&bufqueues[BQ_META]))) &&
+ (now > bp->b_timestamp) &&
+ (now - bp->b_timestamp > thresh_hold) &&
+ (found < BUF_MAX_GC_BATCH_SIZE)) {
+
+ /* Remove from free list */
+ bremfree_locked(bp);
+ found++;
+
+#ifdef JOE_DEBUG
+ bp->b_owner = current_thread();
+ bp->b_tag = 12;
+#endif
- if (bp->b_vp)
- brelvp(bp);
- bremhash(bp);
- BLISTNONE(bp);
+ /* If dirty, move to laundry queue and remember to do wakeup */
+ if (ISSET(bp->b_flags, B_DELWRI)) {
+ SET(bp->b_lflags, BL_WANTDEALLOC);
- splx(s);
+ bmovelaundry(bp);
+ need_wakeup = TRUE;
- if (ISSET(bp->b_flags, B_META)) {
-#if ZALLOC_METADATA
- vm_offset_t elem = (vm_offset_t)bp->b_data;
- if (elem == 0)
- panic("bcleanbuf: NULL bp->b_data B_META buffer");
+ continue;
+ }
- if (ISSET(bp->b_flags, B_ZALLOC)) {
- if (bp->b_bufsize <= MAXMETA) {
- zone_t z;
+ /*
+ * Mark busy and put on private list. We could technically get
+ * away without setting BL_BUSY here.
+ */
+ SET(bp->b_lflags, BL_BUSY);
+ buf_busycount++;
- z = getbufzone(bp->b_bufsize);
- bp->b_data = (caddr_t)0xdeadbeef;
- zfree(z, elem);
- CLR(bp->b_flags, B_ZALLOC);
- } else
- panic("bcleanbuf: B_ZALLOC set incorrectly");
- } else {
- bp->b_data = (caddr_t)0xdeadbeef;
- kmem_free(kernel_map, elem, bp->b_bufsize);
+ /*
+ * Remove from hash and dissociate from vp.
+ */
+ bremhash(bp);
+ if (bp->b_vp) {
+ brelvp_locked(bp);
+ }
+
+ TAILQ_INSERT_TAIL(&privq, bp, b_freelist);
}
-#else
- if (bp->b_data == 0)
- panic("bcleanbuf: bp->b_data == NULL for B_META buffer");
- kmem_free(kernel_map, bp->b_data, bp->b_bufsize);
-#endif /* ZALLOC_METADATA */
- }
+ if (found == 0) {
+ break;
+ }
- trace(TR_BRELSE, pack(bp->b_vp, bp->b_bufsize), bp->b_lblkno);
+ /* Drop lock for batch processing */
+ lck_mtx_unlock(buf_mtxp);
- /* disassociate us from our vnode, if we had one... */
- s = splbio();
+ /* Wakeup and yield for laundry if need be */
+ if (need_wakeup) {
+ wakeup(&bufqueues[BQ_LAUNDRY]);
+ (void)thread_block(THREAD_CONTINUE_NULL);
+ }
- /* clear out various other fields */
- bp->b_bufsize = 0;
- bp->b_data = 0;
- bp->b_flags = B_BUSY;
- bp->b_dev = NODEV;
- bp->b_blkno = bp->b_lblkno = 0;
- bp->b_iodone = 0;
- bp->b_error = 0;
- bp->b_resid = 0;
- bp->b_bcount = 0;
- bp->b_dirtyoff = bp->b_dirtyend = 0;
- bp->b_validoff = bp->b_validend = 0;
+ /* Clean up every buffer on private list */
+ TAILQ_FOREACH(bp, &privq, b_freelist) {
+ /* Take note if we've definitely freed at least a page to a zone */
+ if ((ISSET(bp->b_flags, B_ZALLOC)) && (buf_size(bp) >= PAGE_SIZE)) {
+ did_large_zfree = TRUE;
+ }
- /* nuke any credentials we were holding */
- cred = bp->b_rcred;
- if (cred != NOCRED) {
- bp->b_rcred = NOCRED;
- crfree(cred);
- }
- cred = bp->b_wcred;
- if (cred != NOCRED) {
- bp->b_wcred = NOCRED;
- crfree(cred);
- }
- splx(s);
- return (0);
-}
+ trace(TR_BRELSE, pack(bp->b_vp, bp->b_bufsize), bp->b_lblkno);
+ /* Free Storage */
+ buf_free_meta_store(bp);
-/*
- * Wait for operations on the buffer to complete.
- * When they do, extract and return the I/O's error value.
- */
-int
-biowait(bp)
- struct buf *bp;
-{
- upl_t upl;
- upl_page_info_t *pl;
- int s;
- kern_return_t kret;
+ /* Release credentials */
+ buf_release_credentials(bp);
- s = splbio();
- while (!ISSET(bp->b_flags, B_DONE))
- tsleep(bp, PRIBIO + 1, "biowait", 0);
- splx(s);
-
- /* check for interruption of I/O (e.g. via NFS), then errors. */
- if (ISSET(bp->b_flags, B_EINTR)) {
- CLR(bp->b_flags, B_EINTR);
- return (EINTR);
- } else if (ISSET(bp->b_flags, B_ERROR))
- return (bp->b_error ? bp->b_error : EIO);
- else
- return (0);
-}
+ /* Prepare for moving to empty queue */
+ CLR(bp->b_flags, (B_META | B_ZALLOC | B_DELWRI | B_LOCKED
+ | B_AGE | B_ASYNC | B_NOCACHE | B_FUA));
+ bp->b_whichq = BQ_EMPTY;
+ BLISTNONE(bp);
+ }
-/*
- * Mark I/O complete on a buffer.
- *
- * If a callback has been requested, e.g. the pageout
- * daemon, do so. Otherwise, awaken waiting processes.
- *
- * [ Leffler, et al., says on p.247:
- * "This routine wakes up the blocked process, frees the buffer
- * for an asynchronous write, or, for a request by the pagedaemon
- * process, invokes a procedure specified in the buffer structure" ]
- *
- * In real life, the pagedaemon (or other system processes) wants
- * to do async stuff to, and doesn't want the buffer brelse()'d.
- * (for swap pager, that puts swap buffers on the free lists (!!!),
- * for the vn device, that puts malloc'd buffers on the free lists!)
- */
-void
-biodone(bp)
- struct buf *bp;
-{
- boolean_t funnel_state;
- int s;
+ lck_mtx_lock(buf_mtxp);
- funnel_state = thread_funnel_set(kernel_flock, TRUE);
+ /* Back under lock, move them all to invalid hash and clear busy */
+ TAILQ_FOREACH(bp, &privq, b_freelist) {
+ binshash(bp, &invalhash);
+ CLR(bp->b_lflags, BL_BUSY);
+ buf_busycount--;
- KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 387)) | DBG_FUNC_START,
- bp, bp->b_data, bp->b_flags, 0, 0);
+#ifdef JOE_DEBUG
+ if (bp->b_owner != current_thread()) {
+ panic("Buffer stolen from buffer_cache_gc()");
+ }
+ bp->b_owner = current_thread();
+ bp->b_tag = 13;
+#endif
+ }
- if (ISSET(bp->b_flags, B_DONE))
- panic("biodone already");
- SET(bp->b_flags, B_DONE); /* note that it's done */
- /*
- * I/O was done, so don't believe
- * the DIRTY state from VM anymore
- */
- CLR(bp->b_flags, B_WASDIRTY);
+ /* And do a big bulk move to the empty queue */
+ TAILQ_CONCAT(&bufqueues[BQ_EMPTY], &privq, b_freelist);
+ total_found += found;
- if (!ISSET(bp->b_flags, B_READ) && !ISSET(bp->b_flags, B_RAW))
- vwakeup(bp); /* wake up reader */
-
- if (ISSET(bp->b_flags, B_CALL)) { /* if necessary, call out */
- CLR(bp->b_flags, B_CALL); /* but note callout done */
- (*bp->b_iodone)(bp);
- } else if (ISSET(bp->b_flags, B_ASYNC)) /* if async, release it */
- brelse(bp);
- else { /* or just wakeup the buffer */
- CLR(bp->b_flags, B_WANTED);
- wakeup(bp);
- }
+ } while ((all || (total_found < BUF_MAX_GC_COUNT)) && (found == BUF_MAX_GC_BATCH_SIZE));
- KERNEL_DEBUG((FSDBG_CODE(DBG_FSRW, 387)) | DBG_FUNC_END,
- bp, bp->b_data, bp->b_flags, 0, 0);
+ lck_mtx_unlock(buf_mtxp);
- thread_funnel_set(kernel_flock, funnel_state);
+ return did_large_zfree;
}
-/*
- * Return a count of buffers on the "locked" queue.
- */
-int
-count_lock_queue()
-{
- register struct buf *bp;
- register int n = 0;
-
- for (bp = bufqueues[BQ_LOCKED].tqh_first; bp;
- bp = bp->b_freelist.tqe_next)
- n++;
- return (n);
-}
/*
- * Return a count of 'busy' buffers. Used at the time of shutdown.
+ * disabled for now
*/
-int
-count_busy_buffers()
-{
- register struct buf *bp;
- register int nbusy = 0;
- for (bp = &buf[nbuf]; --bp >= buf; )
- if ((bp->b_flags & (B_BUSY|B_INVAL)) == B_BUSY)
- nbusy++;
- return (nbusy);
-}
+#if FLUSH_QUEUES
-#if 1 /*DIAGNOSTIC */
-/*
- * Print out statistics on the current allocation of the buffer pool.
- * Can be enabled to print out on every ``sync'' by setting "syncprt"
- * in vfs_syscalls.c using sysctl.
- */
-void
-vfs_bufstats()
+#define NFLUSH 32
+
+static int
+bp_cmp(void *a, void *b)
{
- int s, i, j, count;
- register struct buf *bp;
- register struct bqueues *dp;
- int counts[MAXBSIZE/CLBYTES+1];
- static char *bname[BQUEUES] =
- { "LOCKED", "LRU", "AGE", "EMPTY", "META", "LAUNDRY" };
+ buf_t *bp_a = *(buf_t **)a,
+ *bp_b = *(buf_t **)b;
+ daddr64_t res;
- for (dp = bufqueues, i = 0; dp < &bufqueues[BQUEUES]; dp++, i++) {
- count = 0;
- for (j = 0; j <= MAXBSIZE/CLBYTES; j++)
- counts[j] = 0;
- s = splbio();
- for (bp = dp->tqh_first; bp; bp = bp->b_freelist.tqe_next) {
- counts[bp->b_bufsize/CLBYTES]++;
- count++;
- }
- splx(s);
- printf("%s: total-%d", bname[i], count);
- for (j = 0; j <= MAXBSIZE/CLBYTES; j++)
- if (counts[j] != 0)
- printf(", %d-%d", j * CLBYTES, counts[j]);
- printf("\n");
- }
+ // don't have to worry about negative block
+ // numbers so this is ok to do.
+ //
+ res = (bp_a->b_blkno - bp_b->b_blkno);
+
+ return (int)res;
}
-#endif /* DIAGNOSTIC */
-#define NRESERVEDIOBUFS 16
-struct buf *
-alloc_io_buf(vp, priv)
- struct vnode *vp;
- int priv;
+int
+bflushq(int whichq, mount_t mp)
{
- register struct buf *bp;
- int s;
+ buf_t bp, next;
+ int i, buf_count;
+ int total_writes = 0;
+ static buf_t flush_table[NFLUSH];
- s = splbio();
-
- while (niobuf - NRESERVEDIOBUFS < bufstats.bufs_iobufinuse && !priv) {
- need_iobuffer = 1;
- bufstats.bufs_iobufsleeps++;
- (void) tsleep(&need_iobuffer, (PRIBIO+1), "alloc_io_buf", 0);
+ if (whichq < 0 || whichq >= BQUEUES) {
+ return (0);
}
- while ((bp = iobufqueue.tqh_first) == NULL) {
- need_iobuffer = 1;
- bufstats.bufs_iobufsleeps++;
- (void) tsleep(&need_iobuffer, (PRIBIO+1), "alloc_io_buf1", 0);
- }
+ restart:
+ lck_mtx_lock(buf_mtxp);
- TAILQ_REMOVE(&iobufqueue, bp, b_freelist);
- bp->b_timestamp = 0;
+ bp = TAILQ_FIRST(&bufqueues[whichq]);
- /* clear out various fields */
- bp->b_flags = B_BUSY;
- bp->b_blkno = bp->b_lblkno = 0;
- bp->b_iodone = 0;
- bp->b_error = 0;
- bp->b_resid = 0;
- bp->b_bcount = 0;
- bp->b_bufsize = 0;
- bp->b_vp = vp;
+ for (buf_count = 0; bp; bp = next) {
+ next = bp->b_freelist.tqe_next;
+
+ if (bp->b_vp == NULL || bp->b_vp->v_mount != mp) {
+ continue;
+ }
- if (vp->v_type == VBLK || vp->v_type == VCHR)
- bp->b_dev = vp->v_rdev;
- else
- bp->b_dev = NODEV;
- bufstats.bufs_iobufinuse++;
- if (bufstats.bufs_iobufinuse > bufstats.bufs_iobufmax)
- bufstats.bufs_iobufmax = bufstats.bufs_iobufinuse;
- splx(s);
+ if (ISSET(bp->b_flags, B_DELWRI) && !ISSET(bp->b_lflags, BL_BUSY)) {
- return (bp);
-}
+ bremfree_locked(bp);
+#ifdef JOE_DEBUG
+ bp->b_owner = current_thread();
+ bp->b_tag = 7;
+#endif
+ SET(bp->b_lflags, BL_BUSY);
+ buf_busycount++;
-void
-free_io_buf(bp)
- struct buf *bp;
-{
- int s;
+ flush_table[buf_count] = bp;
+ buf_count++;
+ total_writes++;
- s = splbio();
- /* put buffer back on the head of the iobufqueue */
- bp->b_vp = NULL;
- bp->b_flags = B_INVAL;
+ if (buf_count >= NFLUSH) {
+ lck_mtx_unlock(buf_mtxp);
- binsheadfree(bp, &iobufqueue, -1);
+ qsort(flush_table, buf_count, sizeof(struct buf *), bp_cmp);
- /* Wake up any processes waiting for any buffer to become free. */
- if (need_iobuffer) {
- need_iobuffer = 0;
- wakeup(&need_iobuffer);
+ for (i = 0; i < buf_count; i++) {
+ buf_bawrite(flush_table[i]);
+ }
+ goto restart;
+ }
+ }
}
- bufstats.bufs_iobufinuse--;
- splx(s);
+ lck_mtx_unlock(buf_mtxp);
+
+ if (buf_count > 0) {
+ qsort(flush_table, buf_count, sizeof(struct buf *), bp_cmp);
+
+ for (i = 0; i < buf_count; i++) {
+ buf_bawrite(flush_table[i]);
+ }
+ }
+
+ return (total_writes);
}
+#endif
-/* not hookedup yet */
+#if BALANCE_QUEUES
/* XXX move this to a separate file */
+
+/*
+ * NOTE: THIS CODE HAS NOT BEEN UPDATED
+ * WITH RESPECT TO THE NEW LOCKING MODEL
+ */
+
+
/*
* Dynamic Scaling of the Buffer Queues
*/
typedef long long blsize_t;
-blsize_t MAXNBUF; /* initialize to (mem_size / PAGE_SIZE) */
+blsize_t MAXNBUF; /* initialize to (sane_size / PAGE_SIZE) */
/* Global tunable limits */
blsize_t nbufh; /* number of buffer headers */
blsize_t nbuflow; /* minimum number of buffer headers required */
long bufqscanwait = 0;
-extern void bufqscan_thread();
-extern int balancebufq(int q);
-extern int btrimempty(int n);
-extern int initbufqscan(void);
-extern int nextbufq(int q);
-extern void buqlimprt(int all);
+static void bufqscan_thread();
+static int balancebufq(int q);
+static int btrimempty(int n);
+static __inline__ int initbufqscan(void);
+static __inline__ int nextbufq(int q);
+static void buqlimprt(int all);
-void
-bufq_balance_thread_init()
+
+static __inline__ void
+bufqinc(int q)
+{
+ if ((q < 0) || (q >= BQUEUES))
+ return;
+
+ bufqlim[q].bl_num++;
+ return;
+}
+
+static __inline__ void
+bufqdec(int q)
+{
+ if ((q < 0) || (q >= BQUEUES))
+ return;
+
+ bufqlim[q].bl_num--;
+ return;
+}
+
+static void
+bufq_balance_thread_init(void)
{
+ thread_t thread = THREAD_NULL;
if (bufqscanwait++ == 0) {
- int i;
/* Initalize globals */
- MAXNBUF = (mem_size / PAGE_SIZE);
- nbufh = nbuf;
+ MAXNBUF = (sane_size / PAGE_SIZE);
+ nbufh = nbuf_headers;
nbuflow = min(nbufh, 100);
nbufhigh = min(MAXNBUF, max(nbufh, 2048));
- nbuftarget = (mem_size >> 5) / PAGE_SIZE;
+ nbuftarget = (sane_size >> 5) / PAGE_SIZE;
nbuftarget = max(nbuflow, nbuftarget);
nbuftarget = min(nbufhigh, nbuftarget);
}
/* create worker thread */
- kernel_thread(kernel_task, bufqscan_thread);
+ kernel_thread_start((thread_continue_t)bufqscan_thread, NULL, &thread);
+ thread_deallocate(thread);
}
/* The workloop for the buffer balancing thread */
-void
+static void
bufqscan_thread()
{
- boolean_t funnel_state;
int moretodo = 0;
- funnel_state = thread_funnel_set(kernel_flock, TRUE);
-
for(;;) {
do {
int q; /* buffer queue to process */
- for (q = initbufqscan(); q; ) {
+ q = initbufqscan();
+ for (; q; ) {
moretodo |= balancebufq(q);
q = nextbufq(q);
}
} while (moretodo);
-#if 1 || DIAGNOSTIC
+#if DIAGNOSTIC
vfs_bufstats();
buqlimprt(0);
#endif
(void)tsleep((void *)&bufqscanwait, PRIBIO, "bufqscanwait", 60 * hz);
moretodo = 0;
}
-
- (void) thread_funnel_set(kernel_flock, FALSE);
}
/* Seed for the buffer queue balancing */
-int
+static __inline__ int
initbufqscan()
{
/* Start with AGE queue */
}
/* Pick next buffer queue to balance */
-int
+static __inline__ int
nextbufq(int q)
{
int order[] = { BQ_AGE, BQ_LRU, BQ_META, BQ_EMPTY, 0 };
}
/* function to balance the buffer queues */
-int
+static int
balancebufq(int q)
{
int moretodo = 0;
- int s = splbio();
- int n;
+ int n, t;
/* reject invalid q */
if ((q < 0) || (q >= BQUEUES))
moretodo |= btrimempty(n);
goto out;
}
+
+ t = buf_timestamp():
for (; n > 0; n--) {
struct buf *bp = bufqueues[q].tqh_first;
break;
/* check if it's stale */
- if ((time.tv_sec - bp->b_timestamp) > bufqlim[q].bl_stale) {
- if (bcleanbuf(bp)) {
- /* bawrite() issued, bp not ready */
+ if ((t - bp->b_timestamp) > bufqlim[q].bl_stale) {
+ if (bcleanbuf(bp, FALSE)) {
+ /* buf_bawrite() issued, bp not ready */
moretodo = 1;
} else {
/* release the cleaned buffer to BQ_EMPTY */
SET(bp->b_flags, B_INVAL);
- brelse(bp);
+ buf_brelse(bp);
}
} else
break;
}
out:
- splx(s);
return (moretodo);
}
-int
+static int
btrimempty(int n)
{
/*
return (0);
}
-void
-bufqinc(int q)
-{
- if ((q < 0) || (q >= BQUEUES))
- return;
-
- bufqlim[q].bl_num++;
- return;
-}
-
-void
-bufqdec(int q)
-{
- if ((q < 0) || (q >= BQUEUES))
- return;
-
- bufqlim[q].bl_num--;
- return;
-}
-
-void
+static void
buqlimprt(int all)
{
int i;
if (all)
for (i = 0; i < BQUEUES; i++) {
printf("%s : ", bname[i]);
- printf("min = %d, ", (long)bufqlim[i].bl_nlow);
- printf("cur = %d, ", (long)bufqlim[i].bl_num);
- printf("max = %d, ", (long)bufqlim[i].bl_nlhigh);
- printf("target = %d, ", (long)bufqlim[i].bl_target);
- printf("stale after %d seconds\n", bufqlim[i].bl_stale);
+ printf("min = %ld, ", (long)bufqlim[i].bl_nlow);
+ printf("cur = %ld, ", (long)bufqlim[i].bl_num);
+ printf("max = %ld, ", (long)bufqlim[i].bl_nlhigh);
+ printf("target = %ld, ", (long)bufqlim[i].bl_target);
+ printf("stale after %ld seconds\n", bufqlim[i].bl_stale);
}
else
for (i = 0; i < BQUEUES; i++) {
printf("%s : ", bname[i]);
- printf("cur = %d, ", (long)bufqlim[i].bl_num);
+ printf("cur = %ld, ", (long)bufqlim[i].bl_num);
}
}
-/*
- * If the getnewbuf() calls bcleanbuf() on the same thread
- * there is a potential for stack overrun and deadlocks.
- * So we always handoff the work to worker thread for completion
- */
-
-static void
-bcleanbuf_thread_init()
-{
- static void bcleanbuf_thread();
-
- /* create worker thread */
- kernel_thread(kernel_task, bcleanbuf_thread);
-}
-
-static void
-bcleanbuf_thread()
-{
- boolean_t funnel_state;
- struct buf *bp;
-
- funnel_state = thread_funnel_set(kernel_flock, TRUE);
-
-doit:
- while (blaundrycnt == 0)
- (void)tsleep((void *)&blaundrycnt, PRIBIO, "blaundry", 60 * hz);
- bp = TAILQ_FIRST(&bufqueues[BQ_LAUNDRY]);
- /* Remove from the queue */
- bremfree(bp);
- blaundrycnt--;
- /* do the IO */
- bawrite(bp);
- /* start again */
- goto doit;
+#endif
- (void) thread_funnel_set(kernel_flock, funnel_state);
-}
projects / apple / xnu.git / blobdiff