X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/de355530ae67247cbd0da700edb3a2a1dae884c2..ca66cea69e6e866fd781ae2260d9474bdd48f2ca:/bsd/hfs/hfs_chash.c diff --git a/bsd/hfs/hfs_chash.c b/bsd/hfs/hfs_chash.c index 5cc8d871d..4c6401fcd 100644 --- a/bsd/hfs/hfs_chash.c +++ b/bsd/hfs/hfs_chash.c @@ -1,23 +1,29 @@ /* - * Copyright (c) 2002 Apple Computer, Inc. All rights reserved. + * Copyright (c) 2002-2006 Apple Computer, 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@ */ /* @@ -59,12 +65,22 @@ #include #include #include +#include #include #include #include + +#include "hfs.h" /* XXX bringup */ #include "hfs_cnode.h" +extern lck_attr_t * hfs_lock_attr; +extern lck_grp_t * hfs_mutex_group; +extern lck_grp_t * hfs_rwlock_group; + +lck_grp_t * chash_lck_grp; +lck_grp_attr_t * chash_lck_grp_attr; +lck_attr_t * chash_lck_attr; /* * Structures associated with cnode caching. @@ -72,7 +88,8 @@ LIST_HEAD(cnodehashhead, cnode) *cnodehashtbl; u_long cnodehash; /* size of hash table - 1 */ #define CNODEHASH(device, inum) (&cnodehashtbl[((device) + (inum)) & cnodehash]) -struct slock hfs_chash_slock; + +lck_mtx_t hfs_chash_mutex; /* * Initialize cnode hash table. @@ -81,8 +98,31 @@ __private_extern__ void hfs_chashinit() { - cnodehashtbl = hashinit(desiredvnodes, M_HFSMNT, &cnodehash); - simple_lock_init(&hfs_chash_slock); + chash_lck_grp_attr= lck_grp_attr_alloc_init(); + chash_lck_grp = lck_grp_alloc_init("cnode_hash", chash_lck_grp_attr); + chash_lck_attr = lck_attr_alloc_init(); + + lck_mtx_init(&hfs_chash_mutex, chash_lck_grp, chash_lck_attr); +} + +static void hfs_chash_lock(void) +{ + lck_mtx_lock(&hfs_chash_mutex); +} + +static void hfs_chash_unlock(void) +{ + lck_mtx_unlock(&hfs_chash_mutex); +} + +__private_extern__ +void +hfs_chashinit_finish() +{ + hfs_chash_lock(); + if (!cnodehashtbl) + cnodehashtbl = hashinit(desiredvnodes, M_HFSMNT, &cnodehash); + hfs_chash_unlock(); } @@ -90,123 +130,277 @@ hfs_chashinit() * Use the device, inum pair to find the incore cnode. * * If it is in core, but locked, wait for it. - * - * If the requested vnode (fork) is not available, then - * take a reference on the other vnode (fork) so that - * the upcoming getnewvnode can not aquire it. */ __private_extern__ -struct cnode * -hfs_chashget(dev_t dev, ino_t inum, int wantrsrc, - struct vnode **vpp, struct vnode **rvpp) +struct vnode * +hfs_chash_getvnode(dev_t dev, ino_t inum, int wantrsrc, int skiplock) { - struct proc *p = current_proc(); struct cnode *cp; struct vnode *vp; int error; + u_int32_t vid; - *vpp = NULLVP; - *rvpp = NULLVP; /* * Go through the hash list * If a cnode is in the process of being cleaned out or being * allocated, wait for it to be finished and then try again. */ loop: - simple_lock(&hfs_chash_slock); + hfs_chash_lock(); for (cp = CNODEHASH(dev, inum)->lh_first; cp; cp = cp->c_hash.le_next) { if ((cp->c_fileid != inum) || (cp->c_dev != dev)) continue; - if (ISSET(cp->c_flag, C_ALLOC)) { - /* - * cnode is being created. Wait for it to finish. - */ - SET(cp->c_flag, C_WALLOC); - simple_unlock(&hfs_chash_slock); - (void) tsleep((caddr_t)cp, PINOD, "hfs_chashget-1", 0); + /* Wait if cnode is being created or reclaimed. */ + if (ISSET(cp->c_hflag, H_ALLOC | H_TRANSIT | H_ATTACH)) { + SET(cp->c_hflag, H_WAITING); + + (void) msleep(cp, &hfs_chash_mutex, PDROP | PINOD, + "hfs_chash_getvnode", 0); goto loop; - } - if (ISSET(cp->c_flag, C_TRANSIT)) { - /* - * cnode is getting reclaimed wait for - * the operation to complete and return - * error + } + /* Obtain the desired vnode. */ + vp = wantrsrc ? cp->c_rsrc_vp : cp->c_vp; + if (vp == NULLVP) + goto exit; + + vid = vnode_vid(vp); + hfs_chash_unlock(); + + if ((error = vnode_getwithvid(vp, vid))) { + /* + * If vnode is being reclaimed, or has + * already changed identity, no need to wait */ - SET(cp->c_flag, C_WTRANSIT); - simple_unlock(&hfs_chash_slock); - (void)tsleep((caddr_t)cp, PINOD, "hfs_chashget-2", 0); - goto loop; + return (NULL); } - if (cp->c_flag & C_NOEXISTS) + if (!skiplock && hfs_lock(cp, HFS_EXCLUSIVE_LOCK) != 0) { + vnode_put(vp); + return (NULL); + } + + /* + * Skip cnodes that are not in the name space anymore + * we need to check with the cnode lock held because + * we may have blocked acquiring the vnode ref or the + * lock on the cnode which would allow the node to be + * unlinked + */ + if (cp->c_flag & (C_NOEXISTS | C_DELETED)) { + if (!skiplock) + hfs_unlock(cp); + vnode_put(vp); + + return (NULL); + } + return (vp); + } +exit: + hfs_chash_unlock(); + return (NULL); +} + + +/* + * Use the device, fileid pair to snoop an incore cnode. + */ +__private_extern__ +int +hfs_chash_snoop(dev_t dev, ino_t inum, int (*callout)(const struct cat_desc *, + const struct cat_attr *, void *), void * arg) +{ + struct cnode *cp; + int result = ENOENT; + + /* + * Go through the hash list + * If a cnode is in the process of being cleaned out or being + * allocated, wait for it to be finished and then try again. + */ + hfs_chash_lock(); + for (cp = CNODEHASH(dev, inum)->lh_first; cp; cp = cp->c_hash.le_next) { + if ((cp->c_fileid != inum) || (cp->c_dev != dev)) continue; + /* Skip cnodes being created or reclaimed. */ + if (!ISSET(cp->c_hflag, H_ALLOC | H_TRANSIT | H_ATTACH)) { + result = callout(&cp->c_desc, &cp->c_attr, arg); + } + break; + } + hfs_chash_unlock(); + return (result); +} + +/* + * Use the device, fileid pair to find the incore cnode. + * If no cnode if found one is created + * + * If it is in core, but locked, wait for it. + * + * If the cnode is C_DELETED, then return NULL since that + * inum is no longer valid for lookups (open-unlinked file). + */ +__private_extern__ +struct cnode * +hfs_chash_getcnode(dev_t dev, ino_t inum, struct vnode **vpp, int wantrsrc, int skiplock) +{ + struct cnode *cp; + struct cnode *ncp = NULL; + vnode_t vp; + u_int32_t vid; + + /* + * Go through the hash list + * If a cnode is in the process of being cleaned out or being + * allocated, wait for it to be finished and then try again. + */ +loop: + hfs_chash_lock(); + +loop_with_lock: + for (cp = CNODEHASH(dev, inum)->lh_first; cp; cp = cp->c_hash.le_next) { + if ((cp->c_fileid != inum) || (cp->c_dev != dev)) + continue; /* - * Try getting the desired vnode first. If - * it isn't available then take a reference - * on the other vnode. + * Wait if cnode is being created, attached to or reclaimed. */ - vp = wantrsrc ? cp->c_rsrc_vp : cp->c_vp; - if (vp == NULLVP) - vp = wantrsrc ? cp->c_vp : cp->c_rsrc_vp; - if (vp == NULLVP) - panic("hfs_chashget: orphaned cnode in hash"); + if (ISSET(cp->c_hflag, H_ALLOC | H_ATTACH | H_TRANSIT)) { + SET(cp->c_hflag, H_WAITING); - simple_lock(&vp->v_interlock); - simple_unlock(&hfs_chash_slock); - if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK, p)) - goto loop; - else if (cp->c_flag & C_NOEXISTS) { + (void) msleep(cp, &hfs_chash_mutex, PINOD, + "hfs_chash_getcnode", 0); + goto loop_with_lock; + } + vp = wantrsrc ? cp->c_rsrc_vp : cp->c_vp; + if (vp == NULL) { /* - * While we were blocked the cnode got deleted. + * The desired vnode isn't there so tag the cnode. */ - vput(vp); - goto loop; + SET(cp->c_hflag, H_ATTACH); + + hfs_chash_unlock(); + } else { + vid = vnode_vid(vp); + + hfs_chash_unlock(); + + if (vnode_getwithvid(vp, vid)) + goto loop; + } + if (ncp) { + /* + * someone else won the race to create + * this cnode and add it to the hash + * just dump our allocation + */ + FREE_ZONE(ncp, sizeof(struct cnode), M_HFSNODE); + ncp = NULL; + } + + if (!skiplock) { + hfs_lock(cp, HFS_FORCE_LOCK); } - if (VNODE_IS_RSRC(vp)) - *rvpp = vp; - else - *vpp = vp; /* - * Note that vget can block before aquiring the - * cnode lock. So we need to check if the vnode - * we wanted was created while we blocked. + * Skip cnodes that are not in the name space anymore + * we need to check with the cnode lock held because + * we may have blocked acquiring the vnode ref or the + * lock on the cnode which would allow the node to be + * unlinked. + * + * Don't return a cnode in this case since the inum + * is no longer valid for lookups. */ - if (wantrsrc && *rvpp == NULL && cp->c_rsrc_vp) { - error = vget(cp->c_rsrc_vp, 0, p); - vput(*vpp); /* ref no longer needed */ - *vpp = NULL; - if (error) - goto loop; - *rvpp = cp->c_rsrc_vp; - - } else if (!wantrsrc && *vpp == NULL && cp->c_vp) { - error = vget(cp->c_vp, 0, p); - vput(*rvpp); /* ref no longer needed */ - *rvpp = NULL; - if (error) - goto loop; - *vpp = cp->c_vp; + if ((cp->c_flag & (C_NOEXISTS | C_DELETED)) && !wantrsrc) { + if (!skiplock) + hfs_unlock(cp); + if (vp != NULLVP) { + vnode_put(vp); + } else { + hfs_chash_lock(); + CLR(cp->c_hflag, H_ATTACH); + if (ISSET(cp->c_hflag, H_WAITING)) { + CLR(cp->c_hflag, H_WAITING); + wakeup((caddr_t)cp); + } + hfs_chash_unlock(); + } + vp = NULL; + cp = NULL; } + *vpp = vp; return (cp); } - simple_unlock(&hfs_chash_slock); - return (NULL); + + /* + * Allocate a new cnode + */ + if (skiplock && !wantrsrc) + panic("%s - should never get here when skiplock is set \n", __FUNCTION__); + + if (ncp == NULL) { + hfs_chash_unlock(); + + MALLOC_ZONE(ncp, struct cnode *, sizeof(struct cnode), M_HFSNODE, M_WAITOK); + /* + * since we dropped the chash lock, + * we need to go back and re-verify + * that this node hasn't come into + * existence... + */ + goto loop; + } + bzero(ncp, sizeof(struct cnode)); + SET(ncp->c_hflag, H_ALLOC); + ncp->c_fileid = inum; + ncp->c_dev = dev; + TAILQ_INIT(&ncp->c_hintlist); /* make the list empty */ + TAILQ_INIT(&ncp->c_originlist); + + lck_rw_init(&ncp->c_rwlock, hfs_rwlock_group, hfs_lock_attr); + if (!skiplock) + (void) hfs_lock(ncp, HFS_EXCLUSIVE_LOCK); + + /* Insert the new cnode with it's H_ALLOC flag set */ + LIST_INSERT_HEAD(CNODEHASH(dev, inum), ncp, c_hash); + hfs_chash_unlock(); + + *vpp = NULL; + return (ncp); +} + + +__private_extern__ +void +hfs_chashwakeup(struct cnode *cp, int hflags) +{ + hfs_chash_lock(); + + CLR(cp->c_hflag, hflags); + + if (ISSET(cp->c_hflag, H_WAITING)) { + CLR(cp->c_hflag, H_WAITING); + wakeup((caddr_t)cp); + } + hfs_chash_unlock(); } /* - * Insert a cnode into the hash table. + * Re-hash two cnodes in the hash table. */ __private_extern__ void -hfs_chashinsert(struct cnode *cp) +hfs_chash_rehash(struct cnode *cp1, struct cnode *cp2) { - if (cp->c_fileid == 0) - panic("hfs_chashinsert: trying to insert file id 0"); - simple_lock(&hfs_chash_slock); - LIST_INSERT_HEAD(CNODEHASH(cp->c_dev, cp->c_fileid), cp, c_hash); - simple_unlock(&hfs_chash_slock); + hfs_chash_lock(); + + LIST_REMOVE(cp1, c_hash); + LIST_REMOVE(cp2, c_hash); + LIST_INSERT_HEAD(CNODEHASH(cp1->c_dev, cp1->c_fileid), cp1, c_hash); + LIST_INSERT_HEAD(CNODEHASH(cp2->c_dev, cp2->c_fileid), cp2, c_hash); + + hfs_chash_unlock(); } @@ -214,13 +408,114 @@ hfs_chashinsert(struct cnode *cp) * Remove a cnode from the hash table. */ __private_extern__ -void +int hfs_chashremove(struct cnode *cp) { - simple_lock(&hfs_chash_slock); + hfs_chash_lock(); + + /* Check if a vnode is getting attached */ + if (ISSET(cp->c_hflag, H_ATTACH)) { + hfs_chash_unlock(); + return (EBUSY); + } + if (cp->c_hash.le_next || cp->c_hash.le_prev) { + LIST_REMOVE(cp, c_hash); + cp->c_hash.le_next = NULL; + cp->c_hash.le_prev = NULL; + } + hfs_chash_unlock(); + return (0); +} + +/* + * Remove a cnode from the hash table and wakeup any waiters. + */ +__private_extern__ +void +hfs_chash_abort(struct cnode *cp) +{ + hfs_chash_lock(); + LIST_REMOVE(cp, c_hash); cp->c_hash.le_next = NULL; cp->c_hash.le_prev = NULL; - simple_unlock(&hfs_chash_slock); + + CLR(cp->c_hflag, H_ATTACH | H_ALLOC); + if (ISSET(cp->c_hflag, H_WAITING)) { + CLR(cp->c_hflag, H_WAITING); + wakeup((caddr_t)cp); + } + hfs_chash_unlock(); +} + + +/* + * mark a cnode as in transition + */ +__private_extern__ +void +hfs_chash_mark_in_transit(struct cnode *cp) +{ + hfs_chash_lock(); + + SET(cp->c_hflag, H_TRANSIT); + + hfs_chash_unlock(); } +/* Search a cnode in the hash. This function does not return cnode which + * are getting created, destroyed or in transition. Note that this function + * does not acquire the cnode hash mutex, and expects the caller to acquire it. + * On success, returns pointer to the cnode found. On failure, returns NULL. + */ +static +struct cnode * +hfs_chash_search_cnid(dev_t dev, cnid_t cnid) +{ + struct cnode *cp; + + for (cp = CNODEHASH(dev, cnid)->lh_first; cp; cp = cp->c_hash.le_next) { + if ((cp->c_fileid == cnid) && (cp->c_dev == dev)) { + break; + } + } + + /* If cnode is being created or reclaimed, return error. */ + if (cp && ISSET(cp->c_hflag, H_ALLOC | H_TRANSIT | H_ATTACH)) { + cp = NULL; + } + + return cp; +} + +/* Search a cnode corresponding to given device and ID in the hash. If the + * found cnode has kHFSHasChildLinkBit cleared, set it. If the cnode is not + * found, no new cnode is created and error is returned. + * + * Return values - + * -1 : The cnode was not found. + * 0 : The cnode was found, and the kHFSHasChildLinkBit was already set. + * 1 : The cnode was found, the kHFSHasChildLinkBit was not set, and the + * function had to set that bit. + */ +__private_extern__ +int +hfs_chash_set_childlinkbit(dev_t dev, cnid_t cnid) +{ + int retval = -1; + struct cnode *cp; + + hfs_chash_lock(); + cp = hfs_chash_search_cnid(dev, cnid); + if (cp) { + if (cp->c_attr.ca_recflags & kHFSHasChildLinkMask) { + retval = 0; + } else { + cp->c_attr.ca_recflags |= kHFSHasChildLinkMask; + retval = 1; + } + } + hfs_chash_unlock(); + + return retval; +}