/*
- * Copyright (c) 2000-2007 Apple Inc. All rights reserved.
+ * Copyright (c) 2000-2015 Apple Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
#include <sys/time.h>
#include <sys/mount_internal.h>
#include <sys/vnode_internal.h>
+#include <miscfs/specfs/specdev.h>
#include <sys/namei.h>
#include <sys/errno.h>
#include <sys/malloc.h>
#include <sys/kauth.h>
#include <sys/user.h>
#include <sys/paths.h>
+#include <os/overflow.h>
#if CONFIG_MACF
#include <security/mac_framework.h>
int desiredNodes;
int desiredNegNodes;
int ncs_negtotal;
+int nc_disabled = 0;
TAILQ_HEAD(, namecache) nchead; /* chain of all name cache entries */
TAILQ_HEAD(, namecache) neghead; /* chain of only negative cache entries */
lck_grp_t * namecache_lck_grp;
lck_grp_attr_t * namecache_lck_grp_attr;
lck_attr_t * namecache_lck_attr;
-lck_rw_t * namecache_rw_lock;
+
+lck_grp_t * strcache_lck_grp;
+lck_grp_attr_t * strcache_lck_grp_attr;
+lck_attr_t * strcache_lck_attr;
+
+lck_rw_t * namecache_rw_lock;
+lck_rw_t * strtable_rw_lock;
+
+#define NUM_STRCACHE_LOCKS 1024
+
+lck_mtx_t strcache_mtx_locks[NUM_STRCACHE_LOCKS];
+
static vnode_t cache_lookup_locked(vnode_t dvp, struct componentname *cnp);
-static int remove_name_locked(const char *);
-static const char *add_name_locked(const char *, size_t, u_int, u_int);
-static void init_string_table(void) __attribute__((section("__TEXT, initcode")));
+static const char *add_name_internal(const char *, uint32_t, u_int, boolean_t, u_int);
+static void init_string_table(void);
static void cache_delete(struct namecache *, int);
-static void cache_enter_locked(vnode_t dvp, vnode_t vp, struct componentname *cnp);
+static void cache_enter_locked(vnode_t dvp, vnode_t vp, struct componentname *cnp, const char *strname);
#ifdef DUMP_STRING_TABLE
/*
void dump_string_table(void);
#endif /* DUMP_STRING_TABLE */
-static void init_crc32(void) __attribute__((section("__TEXT, initcode")));
+static void init_crc32(void);
static unsigned int crc32tab[256];
#define NCHHASH(dvp, hash_val) \
(&nchashtbl[(dvp->v_id ^ (hash_val)) & nchashmask])
+/*
+ * This function tries to check if a directory vp is a subdirectory of dvp
+ * only from valid v_parent pointers. It is called with the name cache lock
+ * held and does not drop the lock anytime inside the function.
+ *
+ * It returns a boolean that indicates whether or not it was able to
+ * successfully infer the parent/descendent relationship via the v_parent
+ * pointers, or if it could not infer such relationship and that the decision
+ * must be delegated to the owning filesystem.
+ *
+ * If it does not defer the decision, i.e. it was successfuly able to determine
+ * the parent/descendent relationship, *is_subdir tells the caller if vp is a
+ * subdirectory of dvp.
+ *
+ * If the decision is deferred, *next_vp is where it stopped i.e. *next_vp
+ * is the vnode whose parent is to be determined from the filesystem.
+ * *is_subdir, in this case, is not indicative of anything and should be
+ * ignored.
+ *
+ * The return value and output args should be used as follows :
+ *
+ * defer = cache_check_vnode_issubdir(vp, dvp, is_subdir, next_vp);
+ * if (!defer) {
+ * if (*is_subdir)
+ * vp is subdirectory;
+ * else
+ * vp is not a subdirectory;
+ * } else {
+ * if (*next_vp)
+ * check this vnode's parent from the filesystem
+ * else
+ * error (likely because of forced unmount).
+ * }
+ *
+ */
+static boolean_t
+cache_check_vnode_issubdir(vnode_t vp, vnode_t dvp, boolean_t *is_subdir,
+ vnode_t *next_vp)
+{
+ vnode_t tvp = vp;
+ int defer = FALSE;
+
+ *is_subdir = FALSE;
+ *next_vp = NULLVP;
+ while (1) {
+ mount_t tmp;
+
+ if (tvp == dvp) {
+ *is_subdir = TRUE;
+ break;
+ } else if (tvp == rootvnode) {
+ /* *is_subdir = FALSE */
+ break;
+ }
+ tmp = tvp->v_mount;
+ while ((tvp->v_flag & VROOT) && tmp && tmp->mnt_vnodecovered &&
+ tvp != dvp && tvp != rootvnode) {
+ tvp = tmp->mnt_vnodecovered;
+ tmp = tvp->v_mount;
+ }
-//
-// This function builds the path to a filename in "buff". The
-// length of the buffer *INCLUDING* the trailing zero byte is
-// returned in outlen. NOTE: the length includes the trailing
-// zero byte and thus the length is one greater than what strlen
-// would return. This is important and lots of code elsewhere
-// in the kernel assumes this behavior.
-//
-// This function can call vnop in file system if the parent vnode
-// does not exist or when called for hardlinks via volfs path.
-// If BUILDPATH_NO_FS_ENTER is set in flags, it only uses values present
-// in the name cache and does not enter the file system.
-//
+ /*
+ * If dvp is not at the top of a mount "stack" then
+ * vp is not a subdirectory of dvp either.
+ */
+ if (tvp == dvp || tvp == rootvnode) {
+ /* *is_subdir = FALSE */
+ break;
+ }
+
+ if (!tmp) {
+ defer = TRUE;
+ *next_vp = NULLVP;
+ break;
+ }
+
+ if ((tvp->v_flag & VISHARDLINK) || !(tvp->v_parent)) {
+ defer = TRUE;
+ *next_vp = tvp;
+ break;
+ }
+
+ tvp = tvp->v_parent;
+ }
+
+ return (defer);
+}
+
+/* maximum times retry from potentially transient errors in vnode_issubdir */
+#define MAX_ERROR_RETRY 3
+
+/*
+ * This function checks if a given directory (vp) is a subdirectory of dvp.
+ * It walks backwards from vp and if it hits dvp in its parent chain,
+ * it is a subdirectory. If it encounters the root directory, it is not
+ * a subdirectory.
+ *
+ * This function returns an error if it is unsuccessful and 0 on success.
+ *
+ * On entry (and exit) vp has an iocount and if this function has to take
+ * any iocounts on other vnodes in the parent chain traversal, it releases them.
+ */
int
-build_path(vnode_t first_vp, char *buff, int buflen, int *outlen, int flags, vfs_context_t ctx)
+vnode_issubdir(vnode_t vp, vnode_t dvp, int *is_subdir, vfs_context_t ctx)
+{
+ vnode_t start_vp, tvp;
+ vnode_t vp_with_iocount;
+ int error = 0;
+ char dotdotbuf[] = "..";
+ int error_retry_count = 0; /* retry count for potentially transient
+ errors */
+
+ *is_subdir = FALSE;
+ tvp = start_vp = vp;
+ /*
+ * Anytime we acquire an iocount in this function, we save the vnode
+ * in this variable and release it before exiting.
+ */
+ vp_with_iocount = NULLVP;
+
+ while (1) {
+ boolean_t defer;
+ vnode_t pvp;
+ uint32_t vid;
+ struct componentname cn;
+ boolean_t is_subdir_locked = FALSE;
+
+ if (tvp == dvp) {
+ *is_subdir = TRUE;
+ break;
+ } else if (tvp == rootvnode) {
+ /* *is_subdir = FALSE */
+ break;
+ }
+
+ NAME_CACHE_LOCK_SHARED();
+
+ defer = cache_check_vnode_issubdir(tvp, dvp, &is_subdir_locked,
+ &tvp);
+
+ if (defer && tvp)
+ vid = vnode_vid(tvp);
+
+ NAME_CACHE_UNLOCK();
+
+ if (!defer) {
+ *is_subdir = is_subdir_locked;
+ break;
+ }
+
+ if (!tvp) {
+ if (error_retry_count++ < MAX_ERROR_RETRY) {
+ tvp = vp;
+ continue;
+ }
+ error = ENOENT;
+ break;
+ }
+
+ if (tvp != start_vp) {
+ if (vp_with_iocount) {
+ vnode_put(vp_with_iocount);
+ vp_with_iocount = NULLVP;
+ }
+
+ error = vnode_getwithvid(tvp, vid);
+ if (error) {
+ if (error_retry_count++ < MAX_ERROR_RETRY) {
+ tvp = vp;
+ error = 0;
+ continue;
+ }
+ break;
+ }
+
+ vp_with_iocount = tvp;
+ }
+
+ bzero(&cn, sizeof(cn));
+ cn.cn_nameiop = LOOKUP;
+ cn.cn_flags = ISLASTCN | ISDOTDOT;
+ cn.cn_context = ctx;
+ cn.cn_pnbuf = &dotdotbuf[0];
+ cn.cn_pnlen = sizeof(dotdotbuf);
+ cn.cn_nameptr = cn.cn_pnbuf;
+ cn.cn_namelen = 2;
+
+ pvp = NULLVP;
+ if ((error = VNOP_LOOKUP(tvp, &pvp, &cn, ctx)))
+ break;
+
+ if (!(tvp->v_flag & VISHARDLINK) && tvp->v_parent != pvp) {
+ (void)vnode_update_identity(tvp, pvp, NULL, 0, 0,
+ VNODE_UPDATE_PARENT);
+ }
+
+ if (vp_with_iocount)
+ vnode_put(vp_with_iocount);
+
+ vp_with_iocount = tvp = pvp;
+ }
+
+ if (vp_with_iocount)
+ vnode_put(vp_with_iocount);
+
+ return (error);
+}
+
+/*
+ * This function builds the path in "buff" from the supplied vnode.
+ * The length of the buffer *INCLUDING* the trailing zero byte is
+ * returned in outlen. NOTE: the length includes the trailing zero
+ * byte and thus the length is one greater than what strlen would
+ * return. This is important and lots of code elsewhere in the kernel
+ * assumes this behavior.
+ *
+ * This function can call vnop in file system if the parent vnode
+ * does not exist or when called for hardlinks via volfs path.
+ * If BUILDPATH_NO_FS_ENTER is set in flags, it only uses values present
+ * in the name cache and does not enter the file system.
+ *
+ * If BUILDPATH_CHECK_MOVED is set in flags, we return EAGAIN when
+ * we encounter ENOENT during path reconstruction. ENOENT means that
+ * one of the parents moved while we were building the path. The
+ * caller can special handle this case by calling build_path again.
+ *
+ * If BUILDPATH_VOLUME_RELATIVE is set in flags, we return path
+ * that is relative to the nearest mount point, i.e. do not
+ * cross over mount points during building the path.
+ *
+ * passed in vp must have a valid io_count reference
+ *
+ * If parent vnode is non-NULL it also must have an io count. This
+ * allows build_path_with_parent to be safely called for operations
+ * unlink, rmdir and rename that already have io counts on the target
+ * and the directory. In this way build_path_with_parent does not have
+ * to try and obtain an additional io count on the parent. Taking an
+ * io count ont the parent can lead to dead lock if a forced unmount
+ * occures at the right moment. For a fuller explaination on how this
+ * can occur see the comment for vn_getpath_with_parent.
+ *
+ */
+int
+build_path_with_parent(vnode_t first_vp, vnode_t parent_vp, char *buff, int buflen, int *outlen, int flags, vfs_context_t ctx)
{
- vnode_t vp;
+ vnode_t vp, tvp;
+ vnode_t vp_with_iocount;
vnode_t proc_root_dir_vp;
char *end;
const char *str;
int ret = 0;
int fixhardlink;
- if (first_vp == NULLVP) {
+ if (first_vp == NULLVP)
return (EINVAL);
- }
- /* Grab the process fd so we can evaluate fd_rdir. */
- if (vfs_context_proc(ctx)->p_fd) {
- proc_root_dir_vp = vfs_context_proc(ctx)->p_fd->fd_rdir;
- } else {
- proc_root_dir_vp = NULL;
- }
+
+ if (buflen <= 1)
+ return (ENOSPC);
+
+ /*
+ * Grab the process fd so we can evaluate fd_rdir.
+ */
+ if (vfs_context_proc(ctx)->p_fd)
+ proc_root_dir_vp = vfs_context_proc(ctx)->p_fd->fd_rdir;
+ else
+ proc_root_dir_vp = NULL;
+
+ vp_with_iocount = NULLVP;
again:
vp = first_vp;
+
end = &buff[buflen-1];
*end = '\0';
- /* Check if this is the root of a file system. */
+ /*
+ * holding the NAME_CACHE_LOCK in shared mode is
+ * sufficient to stabilize both the vp->v_parent chain
+ * and the 'vp->v_mount->mnt_vnodecovered' chain
+ *
+ * if we need to drop this lock, we must first grab the v_id
+ * from the vnode we're currently working with... if that
+ * vnode doesn't already have an io_count reference (the vp
+ * passed in comes with one), we must grab a reference
+ * after we drop the NAME_CACHE_LOCK via vnode_getwithvid...
+ * deadlocks may result if you call vnode_get while holding
+ * the NAME_CACHE_LOCK... we lazily release the reference
+ * we pick up the next time we encounter a need to drop
+ * the NAME_CACHE_LOCK or before we return from this routine
+ */
+ NAME_CACHE_LOCK_SHARED();
+
+ /*
+ * Check if this is the root of a file system.
+ */
while (vp && vp->v_flag & VROOT) {
if (vp->v_mount == NULL) {
- return (EINVAL);
+ ret = EINVAL;
+ goto out_unlock;
}
if ((vp->v_mount->mnt_flag & MNT_ROOTFS) || (vp == proc_root_dir_vp)) {
/*
* just "/".
*/
*--end = '/';
- goto out;
+
+ goto out_unlock;
} else {
- vp = vp->v_mount->mnt_vnodecovered;
+ /*
+ * This the root of the volume and the caller does not
+ * want to cross mount points. Therefore just return
+ * '/' as the relative path.
+ */
+ if (flags & BUILDPATH_VOLUME_RELATIVE) {
+ *--end = '/';
+ goto out_unlock;
+ } else {
+ vp = vp->v_mount->mnt_vnodecovered;
+ }
}
}
- NAME_CACHE_LOCK_SHARED();
while ((vp != NULLVP) && (vp->v_parent != vp)) {
+ int vid;
+
/*
* For hardlinks the v_name may be stale, so if its OK
* to enter a file system, ask the file system for the
fixhardlink = (vp->v_flag & VISHARDLINK) &&
(vp->v_mount->mnt_kern_flag & MNTK_PATH_FROM_ID) &&
!(flags & BUILDPATH_NO_FS_ENTER);
+
if (!fixhardlink) {
str = vp->v_name;
+
if (str == NULL || *str == '\0') {
- if (vp->v_parent != NULL) {
+ if (vp->v_parent != NULL)
ret = EINVAL;
- } else {
+ else
ret = ENOENT;
- }
- break;
+ goto out_unlock;
}
len = strlen(str);
/*
*/
if ((end - buff) < (len + 1)) {
ret = ENOSPC;
- break;
+ goto out_unlock;
}
- /* Copy the name backwards. */
+ /*
+ * Copy the name backwards.
+ */
str += len;
- for (; len > 0; len--) {
+ for (; len > 0; len--)
*--end = *--str;
- }
- /* Add a path separator. */
+ /*
+ * Add a path separator.
+ */
*--end = '/';
}
* Walk up the parent chain.
*/
if (((vp->v_parent != NULLVP) && !fixhardlink) ||
- (flags & BUILDPATH_NO_FS_ENTER)) {
+ (flags & BUILDPATH_NO_FS_ENTER)) {
+
+ /*
+ * In this if () block we are not allowed to enter the filesystem
+ * to conclusively get the most accurate parent identifier.
+ * As a result, if 'vp' does not identify '/' and it
+ * does not have a valid v_parent, then error out
+ * and disallow further path construction
+ */
+ if ((vp->v_parent == NULLVP) && (rootvnode != vp)) {
+ /*
+ * Only '/' is allowed to have a NULL parent
+ * pointer. Upper level callers should ideally
+ * re-drive name lookup on receiving a ENOENT.
+ */
+ ret = ENOENT;
+
+ /* The code below will exit early if 'tvp = vp' == NULL */
+ }
vp = vp->v_parent;
- // if the vnode we have in hand isn't a directory and it
- // has a v_parent, then we started with the resource fork
- // so skip up to avoid getting a duplicate copy of the
- // file name in the path.
+ /*
+ * if the vnode we have in hand isn't a directory and it
+ * has a v_parent, then we started with the resource fork
+ * so skip up to avoid getting a duplicate copy of the
+ * file name in the path.
+ */
if (vp && !vnode_isdir(vp) && vp->v_parent) {
- vp = vp->v_parent;
+ vp = vp->v_parent;
}
- } else /* No parent, go get it if supported. */ {
+ } else {
+ /*
+ * No parent, go get it if supported.
+ */
struct vnode_attr va;
vnode_t dvp;
- int vid;
- /* Make sure file system supports obtaining a path from id. */
+ /*
+ * Make sure file system supports obtaining a path from id.
+ */
if (!(vp->v_mount->mnt_kern_flag & MNTK_PATH_FROM_ID)) {
ret = ENOENT;
- break;
+ goto out_unlock;
}
- vid = vp->v_id;
+ vid = vp->v_id;
+
NAME_CACHE_UNLOCK();
- if (vnode_getwithvid(vp, vid) != 0) {
- /* vnode was recycled, so start over. */
- goto again;
- }
-
+ if (vp != first_vp && vp != parent_vp && vp != vp_with_iocount) {
+ if (vp_with_iocount) {
+ vnode_put(vp_with_iocount);
+ vp_with_iocount = NULLVP;
+ }
+ if (vnode_getwithvid(vp, vid))
+ goto again;
+ vp_with_iocount = vp;
+ }
VATTR_INIT(&va);
VATTR_WANTED(&va, va_parentid);
+
if (fixhardlink) {
VATTR_WANTED(&va, va_name);
MALLOC_ZONE(va.va_name, caddr_t, MAXPATHLEN, M_NAMEI, M_WAITOK);
} else {
va.va_name = NULL;
}
- /* Ask the file system for its parent id and for its name (optional). */
+ /*
+ * Ask the file system for its parent id and for its name (optional).
+ */
ret = vnode_getattr(vp, &va, ctx);
if (fixhardlink) {
if ((ret == 0) && (VATTR_IS_SUPPORTED(&va, va_name))) {
str = va.va_name;
+ vnode_update_identity(vp, NULL, str, strlen(str), 0, VNODE_UPDATE_NAME);
} else if (vp->v_name) {
str = vp->v_name;
ret = 0;
}
len = strlen(str);
- /* Check that there's enough space. */
+ /*
+ * Check that there's enough space.
+ */
if ((end - buff) < (len + 1)) {
ret = ENOSPC;
} else {
/* Copy the name backwards. */
str += len;
-
+
for (; len > 0; len--) {
*--end = *--str;
}
- /* Add a path separator. */
+ /*
+ * Add a path separator.
+ */
*--end = '/';
}
- bad_news:
+bad_news:
FREE_ZONE(va.va_name, MAXPATHLEN, M_NAMEI);
}
if (ret || !VATTR_IS_SUPPORTED(&va, va_parentid)) {
- vnode_put(vp);
ret = ENOENT;
goto out;
}
- /* Ask the file system for the parent vnode. */
- ret = VFS_VGET(vp->v_mount, (ino64_t)va.va_parentid, &dvp, ctx);
- if (ret) {
- vnode_put(vp);
+ /*
+ * Ask the file system for the parent vnode.
+ */
+ if ((ret = VFS_VGET(vp->v_mount, (ino64_t)va.va_parentid, &dvp, ctx)))
goto out;
- }
- if (!fixhardlink && (vp->v_parent != dvp)) {
+
+ if (!fixhardlink && (vp->v_parent != dvp))
vnode_update_identity(vp, dvp, NULL, 0, 0, VNODE_UPDATE_PARENT);
- }
- vnode_put(vp);
+
+ if (vp_with_iocount)
+ vnode_put(vp_with_iocount);
vp = dvp;
+ vp_with_iocount = vp;
+
+ NAME_CACHE_LOCK_SHARED();
+
/*
- * We are no longer under the name cache lock here.
- * So to avoid a race for vnode termination, take a
- * reference on the vnode and drop that reference
- * after reacquiring the name cache lock. We use the
- * vnode_rele_ext call with the dont_reenter flag
- * set to avoid re-entering the file system which
- * could possibly re-enter the name cache.
+ * if the vnode we have in hand isn't a directory and it
+ * has a v_parent, then we started with the resource fork
+ * so skip up to avoid getting a duplicate copy of the
+ * file name in the path.
*/
- if (vnode_ref(dvp) != 0) {
- dvp = NULLVP;
- }
- vnode_put(vp);
- NAME_CACHE_LOCK_SHARED();
+ if (vp && !vnode_isdir(vp) && vp->v_parent)
+ vp = vp->v_parent;
+ }
- if (dvp) {
- vnode_rele_ext(dvp, 0, 1);
- }
+ if (vp && (flags & BUILDPATH_CHECKACCESS)) {
+ vid = vp->v_id;
- // if the vnode we have in hand isn't a directory and it
- // has a v_parent, then we started with the resource fork
- // so skip up to avoid getting a duplicate copy of the
- // file name in the path.
- if (vp && !vnode_isdir(vp) && vp->v_parent) {
- vp = vp->v_parent;
+ NAME_CACHE_UNLOCK();
+
+ if (vp != first_vp && vp != parent_vp && vp != vp_with_iocount) {
+ if (vp_with_iocount) {
+ vnode_put(vp_with_iocount);
+ vp_with_iocount = NULLVP;
+ }
+ if (vnode_getwithvid(vp, vid))
+ goto again;
+ vp_with_iocount = vp;
}
+ if ((ret = vnode_authorize(vp, NULL, KAUTH_VNODE_SEARCH, ctx)))
+ goto out; /* no peeking */
+
+ NAME_CACHE_LOCK_SHARED();
}
+
/*
* When a mount point is crossed switch the vp.
* Continue until we find the root or we find
* a vnode that's not the root of a mounted
* file system.
*/
- while (vp) {
- if (vp == proc_root_dir_vp) {
- NAME_CACHE_UNLOCK();
- goto out; /* encountered the root */
+ tvp = vp;
+
+ while (tvp) {
+ if (tvp == proc_root_dir_vp)
+ goto out_unlock; /* encountered the root */
+
+ if (!(tvp->v_flag & VROOT) || !tvp->v_mount)
+ break; /* not the root of a mounted FS */
+
+ if (flags & BUILDPATH_VOLUME_RELATIVE) {
+ /* Do not cross over mount points */
+ tvp = NULL;
+ } else {
+ tvp = tvp->v_mount->mnt_vnodecovered;
}
- if (!(vp->v_flag & VROOT) || !vp->v_mount)
- break; /* not the root of a mounted FS */
- vp = vp->v_mount->mnt_vnodecovered;
}
+ if (tvp == NULLVP)
+ goto out_unlock;
+ vp = tvp;
}
+out_unlock:
NAME_CACHE_UNLOCK();
out:
- /* Slide the name down to the beginning of the buffer. */
+ if (vp_with_iocount)
+ vnode_put(vp_with_iocount);
+ /*
+ * Slide the name down to the beginning of the buffer.
+ */
memmove(buff, end, &buff[buflen] - end);
-
- *outlen = &buff[buflen] - end; /* length includes the trailing zero byte */
+
+ /*
+ * length includes the trailing zero byte
+ */
+ *outlen = &buff[buflen] - end;
+ /* One of the parents was moved during path reconstruction.
+ * The caller is interested in knowing whether any of the
+ * parents moved via BUILDPATH_CHECK_MOVED, so return EAGAIN.
+ */
+ if ((ret == ENOENT) && (flags & BUILDPATH_CHECK_MOVED)) {
+ ret = EAGAIN;
+ }
+
return (ret);
}
+int
+build_path(vnode_t first_vp, char *buff, int buflen, int *outlen, int flags, vfs_context_t ctx)
+{
+ return (build_path_with_parent(first_vp, NULL, buff, buflen, outlen, flags, ctx));
+}
/*
* return NULLVP if vp's parent doesn't
vnode_getname(vnode_t vp)
{
const char *name = NULL;
-
- NAME_CACHE_LOCK();
+
+ NAME_CACHE_LOCK_SHARED();
if (vp->v_name)
- name = add_name_locked(vp->v_name, strlen(vp->v_name), 0, 0);
+ name = vfs_addname(vp->v_name, strlen(vp->v_name), 0, 0);
NAME_CACHE_UNLOCK();
return (name);
void
vnode_putname(const char *name)
{
- NAME_CACHE_LOCK();
+ vfs_removename(name);
+}
- remove_name_locked(name);
+static const char unknown_vnodename[] = "(unknown vnode name)";
- NAME_CACHE_UNLOCK();
+const char *
+vnode_getname_printable(vnode_t vp)
+{
+ const char *name = vnode_getname(vp);
+ if (name != NULL)
+ return name;
+
+ switch (vp->v_type) {
+ case VCHR:
+ case VBLK:
+ {
+ /*
+ * Create an artificial dev name from
+ * major and minor device number
+ */
+ char dev_name[64];
+ (void) snprintf(dev_name, sizeof(dev_name),
+ "%c(%u, %u)", VCHR == vp->v_type ? 'c':'b',
+ major(vp->v_rdev), minor(vp->v_rdev));
+ /*
+ * Add the newly created dev name to the name
+ * cache to allow easier cleanup. Also,
+ * vfs_addname allocates memory for the new name
+ * and returns it.
+ */
+ NAME_CACHE_LOCK_SHARED();
+ name = vfs_addname(dev_name, strlen(dev_name), 0, 0);
+ NAME_CACHE_UNLOCK();
+ return name;
+ }
+ default:
+ return unknown_vnodename;
+ }
}
+void
+vnode_putname_printable(const char *name)
+{
+ if (name == unknown_vnodename)
+ return;
+ vnode_putname(name);
+}
+
/*
* if VNODE_UPDATE_PARENT, and we can take
* if VNODE_UPDATE_CACHE, flush the name cache entries associated with vp
*/
void
-vnode_update_identity(vnode_t vp, vnode_t dvp, const char *name, int name_len, int name_hashval, int flags)
+vnode_update_identity(vnode_t vp, vnode_t dvp, const char *name, int name_len, uint32_t name_hashval, int flags)
{
struct namecache *ncp;
vnode_t old_parentvp = NULLVP;
-#if NAMEDSTREAMS
int isstream = (vp->v_flag & VISNAMEDSTREAM);
int kusecountbumped = 0;
-#endif
+ kauth_cred_t tcred = NULL;
+ const char *vname = NULL;
+ const char *tname = NULL;
if (flags & VNODE_UPDATE_PARENT) {
if (dvp && vnode_ref(dvp) != 0) {
dvp = NULLVP;
}
-#if NAMEDSTREAMS
/* Don't count a stream's parent ref during unmounts */
if (isstream && dvp && (dvp != vp) && (dvp != vp->v_parent) && (dvp->v_type == VREG)) {
vnode_lock_spin(dvp);
kusecountbumped = 1;
vnode_unlock(dvp);
}
-#endif
} else {
dvp = NULLVP;
}
- NAME_CACHE_LOCK();
+ if ( (flags & VNODE_UPDATE_NAME) ) {
+ if (name != vp->v_name) {
+ if (name && *name) {
+ if (name_len == 0)
+ name_len = strlen(name);
+ tname = vfs_addname(name, name_len, name_hashval, 0);
+ }
+ } else
+ flags &= ~VNODE_UPDATE_NAME;
+ }
+ if ( (flags & (VNODE_UPDATE_PURGE | VNODE_UPDATE_PARENT | VNODE_UPDATE_CACHE | VNODE_UPDATE_NAME)) ) {
- if ( (flags & VNODE_UPDATE_NAME) && (name != vp->v_name) ) {
- if (vp->v_name != NULL) {
- remove_name_locked(vp->v_name);
- vp->v_name = NULL;
+ NAME_CACHE_LOCK();
+
+ if ( (flags & VNODE_UPDATE_PURGE) ) {
+
+ if (vp->v_parent)
+ vp->v_parent->v_nc_generation++;
+
+ while ( (ncp = LIST_FIRST(&vp->v_nclinks)) )
+ cache_delete(ncp, 1);
+
+ while ( (ncp = TAILQ_FIRST(&vp->v_ncchildren)) )
+ cache_delete(ncp, 1);
+
+ /*
+ * Use a temp variable to avoid kauth_cred_unref() while NAME_CACHE_LOCK is held
+ */
+ tcred = vp->v_cred;
+ vp->v_cred = NOCRED;
+ vp->v_authorized_actions = 0;
+ vp->v_cred_timestamp = 0;
}
- if (name && *name) {
- if (name_len == 0)
- name_len = strlen(name);
- vp->v_name = add_name_locked(name, name_len, name_hashval, 0);
+ if ( (flags & VNODE_UPDATE_NAME) ) {
+ vname = vp->v_name;
+ vp->v_name = tname;
}
- }
- if (flags & VNODE_UPDATE_PARENT) {
- if (dvp != vp && dvp != vp->v_parent) {
- old_parentvp = vp->v_parent;
- vp->v_parent = dvp;
- dvp = NULLVP;
+ if (flags & VNODE_UPDATE_PARENT) {
+ if (dvp != vp && dvp != vp->v_parent) {
+ old_parentvp = vp->v_parent;
+ vp->v_parent = dvp;
+ dvp = NULLVP;
- if (old_parentvp)
- flags |= VNODE_UPDATE_CACHE;
+ if (old_parentvp)
+ flags |= VNODE_UPDATE_CACHE;
+ }
}
- }
- if (flags & VNODE_UPDATE_CACHE) {
- while ( (ncp = LIST_FIRST(&vp->v_nclinks)) )
- cache_delete(ncp, 1);
- }
- NAME_CACHE_UNLOCK();
+ if (flags & VNODE_UPDATE_CACHE) {
+ while ( (ncp = LIST_FIRST(&vp->v_nclinks)) )
+ cache_delete(ncp, 1);
+ }
+ NAME_CACHE_UNLOCK();
+ if (vname != NULL)
+ vfs_removename(vname);
+
+ if (IS_VALID_CRED(tcred))
+ kauth_cred_unref(&tcred);
+ }
if (dvp != NULLVP) {
-#if NAMEDSTREAMS
/* Back-out the ref we took if we lost a race for vp->v_parent. */
if (kusecountbumped) {
vnode_lock_spin(dvp);
--dvp->v_kusecount;
vnode_unlock(dvp);
}
-#endif
vnode_rele(dvp);
}
if (old_parentvp) {
struct uthread *ut;
-#if NAMEDSTREAMS
if (isstream) {
vnode_lock_spin(old_parentvp);
if ((old_parentvp->v_type != VDIR) && (old_parentvp->v_kusecount > 0))
--old_parentvp->v_kusecount;
vnode_unlock(old_parentvp);
}
-#endif
ut = get_bsdthread_info(current_thread());
/*
while ( (vp = old_parentvp) != NULLVP ) {
- vnode_lock(vp);
+ vnode_lock_spin(vp);
vnode_rele_internal(vp, 0, 0, 1);
/*
* we'll sit in this loop until we run into
* a parent in this chain that is not in this state
*
- * make our check and the node_rele atomic
+ * make our check and the vnode_rele atomic
* with respect to the current vnode we're working on
* by holding the vnode lock
* if vnode_rele deferred the vnode_reclaim and has put
}
-boolean_t vnode_cache_is_authorized(vnode_t vp, vfs_context_t ctx, kauth_action_t action)
+extern int bootarg_vnode_cache_defeat; /* default = 0, from bsd_init.c */
+
+boolean_t
+vnode_cache_is_authorized(vnode_t vp, vfs_context_t ctx, kauth_action_t action)
{
kauth_cred_t ucred;
boolean_t retval = FALSE;
+ /* Boot argument to defeat rights caching */
+ if (bootarg_vnode_cache_defeat)
+ return FALSE;
+
if ( (vp->v_mount->mnt_kern_flag & (MNTK_AUTH_OPAQUE | MNTK_AUTH_CACHE_TTL)) ) {
/*
* a TTL is enabled on the rights cache... handle it here
*/
int
cache_lookup_path(struct nameidata *ndp, struct componentname *cnp, vnode_t dp,
- vfs_context_t ctx, int *trailing_slash, int *dp_authorized, vnode_t last_dp)
+ vfs_context_t ctx, int *dp_authorized, vnode_t last_dp)
{
char *cp; /* pointer into pathname argument */
int vid;
kauth_cred_t ucred;
boolean_t ttl_enabled = FALSE;
struct timeval tv;
- mount_t mp;
+ mount_t mp;
unsigned int hash;
int error = 0;
+ boolean_t dotdotchecked = FALSE;
+
+#if CONFIG_TRIGGERS
+ vnode_t trigger_vp;
+#endif /* CONFIG_TRIGGERS */
ucred = vfs_context_ucred(ctx);
- *trailing_slash = 0;
+ ndp->ni_flag &= ~(NAMEI_TRAILINGSLASH);
NAME_CACHE_LOCK_SHARED();
microuptime(&tv);
}
for (;;) {
- /*
+ /*
* Search a directory.
*
* The cn_hash value is for use by cache_lookup
cp = cnp->cn_nameptr;
while (*cp && (*cp != '/')) {
- hash ^= crc32tab[((hash >> 24) ^ (unsigned char)*cp++)];
+ hash = crc32tab[((hash >> 24) ^ (unsigned char)*cp++)] ^ hash << 8;
}
/*
* the crc generator can legitimately generate
ndp->ni_pathlen--;
if (*cp == '\0') {
- *trailing_slash = 1;
+ ndp->ni_flag |= NAMEI_TRAILINGSLASH;
*ndp->ni_next = '\0';
}
}
#if CONFIG_MACF
- /*
+ /*
* Name cache provides authorization caching (see below)
* that will short circuit MAC checks in lookup().
* We must perform MAC check here. On denial
if (!(cnp->cn_flags & DONOTAUTH)) {
error = mac_vnode_check_lookup(ctx, dp, cnp);
if (error) {
- name_cache_unlock();
+ NAME_CACHE_UNLOCK();
goto errorout;
}
}
#endif /* MAC */
- if (ttl_enabled && ((tv.tv_sec - dp->v_cred_timestamp) > dp->v_mount->mnt_authcache_ttl))
+ if (ttl_enabled &&
+ (dp->v_mount->mnt_authcache_ttl == 0 ||
+ ((tv.tv_sec - dp->v_cred_timestamp) > dp->v_mount->mnt_authcache_ttl))) {
break;
+ }
/*
* NAME_CACHE_LOCK holds these fields stable
+ *
+ * We can't cache KAUTH_VNODE_SEARCHBYANYONE for root correctly
+ * so we make an ugly check for root here. root is always
+ * allowed and breaking out of here only to find out that is
+ * authorized by virtue of being root is very very expensive.
+ * However, the check for not root is valid only for filesystems
+ * which use local authorization.
+ *
+ * XXX: Remove the check for root when we can reliably set
+ * KAUTH_VNODE_SEARCHBYANYONE as root.
*/
if ((dp->v_cred != ucred || !(dp->v_authorized_actions & KAUTH_VNODE_SEARCH)) &&
- !(dp->v_authorized_actions & KAUTH_VNODE_SEARCHBYANYONE))
+ !(dp->v_authorized_actions & KAUTH_VNODE_SEARCHBYANYONE) &&
+ (ttl_enabled || !vfs_context_issuser(ctx))) {
break;
+ }
/*
* indicate that we're allowed to traverse this directory...
*dp_authorized = 1;
if ( (cnp->cn_flags & (ISLASTCN | ISDOTDOT)) ) {
- if (cnp->cn_nameiop != LOOKUP)
- break;
- if (cnp->cn_flags & (LOCKPARENT | NOCACHE))
- break;
+ if (cnp->cn_nameiop != LOOKUP)
+ break;
+ if (cnp->cn_flags & LOCKPARENT)
+ break;
+ if (cnp->cn_flags & NOCACHE)
+ break;
if (cnp->cn_flags & ISDOTDOT) {
/*
* Force directory hardlinks to go to
* file system for ".." requests.
*/
- if (dp && (dp->v_flag & VISHARDLINK)) {
+ if ((dp->v_flag & VISHARDLINK)) {
break;
}
/*
}
}
+ if ((cnp->cn_flags & CN_SKIPNAMECACHE)) {
+ /*
+ * Force lookup to go to the filesystem with
+ * all cnp fields set up.
+ */
+ break;
+ }
+
/*
* "." and ".." aren't supposed to be cached, so check
* for them before checking the cache.
*/
if (cnp->cn_namelen == 1 && cnp->cn_nameptr[0] == '.')
vp = dp;
- else if ((cnp->cn_flags & ISDOTDOT) && dp->v_parent)
- vp = dp->v_parent;
- else {
+ else if ( (cnp->cn_flags & ISDOTDOT) ) {
+ /*
+ * If this is a chrooted process, we need to check if
+ * the process is trying to break out of its chrooted
+ * jail. We do that by trying to determine if dp is
+ * a subdirectory of ndp->ni_rootdir. If we aren't
+ * able to determine that by the v_parent pointers, we
+ * will leave the fast path.
+ *
+ * Since this function may see dotdot components
+ * many times and it has the name cache lock held for
+ * the entire duration, we optimise this by doing this
+ * check only once per cache_lookup_path call.
+ * If dotdotchecked is set, it means we've done this
+ * check once already and don't need to do it again.
+ */
+ if (!dotdotchecked && (ndp->ni_rootdir != rootvnode)) {
+ vnode_t tvp = dp;
+ boolean_t defer = FALSE;
+ boolean_t is_subdir = FALSE;
+
+ defer = cache_check_vnode_issubdir(tvp,
+ ndp->ni_rootdir, &is_subdir, &tvp);
+
+ if (defer) {
+ /* defer to Filesystem */
+ break;
+ } else if (!is_subdir) {
+ /*
+ * This process is trying to break out
+ * of its chrooted jail, so all its
+ * dotdot accesses will be translated to
+ * its root directory.
+ */
+ vp = ndp->ni_rootdir;
+ } else {
+ /*
+ * All good, let this dotdot access
+ * proceed normally
+ */
+ vp = dp->v_parent;
+ }
+ dotdotchecked = TRUE;
+ } else {
+ vp = dp->v_parent;
+ }
+ } else {
if ( (vp = cache_lookup_locked(dp, cnp)) == NULLVP)
break;
- }
+ if ( (vp->v_flag & VISHARDLINK) ) {
+ /*
+ * The file system wants a VNOP_LOOKUP on this vnode
+ */
+ vp = NULL;
+ break;
+ }
+ }
if ( (cnp->cn_flags & ISLASTCN) )
break;
vp = NULL;
break;
}
- if ( (mp = vp->v_mountedhere) && ((cnp->cn_flags & NOCROSSMOUNT) == 0)) {
- if (mp->mnt_realrootvp == NULLVP || mp->mnt_generation != mount_generation ||
- mp->mnt_realrootvp_vid != mp->mnt_realrootvp->v_id)
- break;
- vp = mp->mnt_realrootvp;
+ if ( (mp = vp->v_mountedhere) && ((cnp->cn_flags & NOCROSSMOUNT) == 0)) {
+ vnode_t tmp_vp = mp->mnt_realrootvp;
+ if (tmp_vp == NULLVP || mp->mnt_generation != mount_generation ||
+ mp->mnt_realrootvp_vid != tmp_vp->v_id)
+ break;
+ vp = tmp_vp;
}
+
+#if CONFIG_TRIGGERS
+ /*
+ * After traversing all mountpoints stacked here, if we have a
+ * trigger in hand, resolve it. Note that we don't need to
+ * leave the fast path if the mount has already happened.
+ */
+ if (vp->v_resolve)
+ break;
+#endif /* CONFIG_TRIGGERS */
+
+
dp = vp;
vp = NULLVP;
* immediately w/o waiting... it always succeeds
*/
vnode_get(dp);
- } else if ( (vnode_getwithvid(dp, vid)) ) {
+ } else if ((error = vnode_getwithvid_drainok(dp, vid))) {
/*
* failure indicates the vnode
* changed identity or is being
* don't necessarily return ENOENT, though, because
* we really want to go back to disk and make sure it's
* there or not if someone else is changing this
- * vnode.
+ * vnode. That being said, the one case where we do want
+ * to return ENOENT is when the vnode's mount point is
+ * in the process of unmounting and we might cause a deadlock
+ * in our attempt to take an iocount. An ENODEV error return
+ * is from vnode_get* is an indication this but we change that
+ * ENOENT for upper layers.
*/
- error = ERECYCLE;
+ if (error == ENODEV) {
+ error = ENOENT;
+ } else {
+ error = ERECYCLE;
+ }
goto errorout;
}
}
}
if (vp != NULLVP) {
- if ( (vnode_getwithvid(vp, vvid)) ) {
+ if ( (vnode_getwithvid_drainok(vp, vvid)) ) {
vp = NULLVP;
/*
}
}
}
+
ndp->ni_dvp = dp;
ndp->ni_vp = vp;
+#if CONFIG_TRIGGERS
+ trigger_vp = vp ? vp : dp;
+ if ((error == 0) && (trigger_vp != NULLVP) && vnode_isdir(trigger_vp)) {
+ error = vnode_trigger_resolve(trigger_vp, ndp, ctx);
+ if (error) {
+ if (vp)
+ vnode_put(vp);
+ if (dp)
+ vnode_put(dp);
+ goto errorout;
+ }
+ }
+#endif /* CONFIG_TRIGGERS */
+
errorout:
/*
* If we came into cache_lookup_path after an iteration of the lookup loop that
struct namecache *ncp;
struct nchashhead *ncpp;
long namelen = cnp->cn_namelen;
- char *nameptr = cnp->cn_nameptr;
- unsigned int hashval = (cnp->cn_hash & NCHASHMASK);
- vnode_t vp;
+ unsigned int hashval = cnp->cn_hash;
+ if (nc_disabled) {
+ return NULL;
+ }
+
ncpp = NCHHASH(dvp, cnp->cn_hash);
LIST_FOREACH(ncp, ncpp, nc_hash) {
if ((ncp->nc_dvp == dvp) && (ncp->nc_hashval == hashval)) {
- if (memcmp(ncp->nc_name, nameptr, namelen) == 0 && ncp->nc_name[namelen] == 0)
+ if (strncmp(ncp->nc_name, cnp->cn_nameptr, namelen) == 0 && ncp->nc_name[namelen] == 0)
break;
}
}
}
NCHSTAT(ncs_goodhits);
- vp = ncp->nc_vp;
- if (vp && (vp->v_flag & VISHARDLINK)) {
- /*
- * The file system wants a VNOP_LOOKUP on this vnode
- */
- vp = NULL;
- }
-
- return (vp);
+ return (ncp->nc_vp);
}
+unsigned int hash_string(const char *cp, int len);
//
// Have to take a len argument because we may only need to
// hash part of a componentname.
//
-static unsigned int
+unsigned int
hash_string(const char *cp, int len)
{
unsigned hash = 0;
if (len) {
while (len--) {
- hash ^= crc32tab[((hash >> 24) ^ (unsigned char)*cp++)];
+ hash = crc32tab[((hash >> 24) ^ (unsigned char)*cp++)] ^ hash << 8;
}
} else {
while (*cp != '\0') {
- hash ^= crc32tab[((hash >> 24) ^ (unsigned char)*cp++)];
+ hash = crc32tab[((hash >> 24) ^ (unsigned char)*cp++)] ^ hash << 8;
}
}
/*
struct namecache *ncp;
struct nchashhead *ncpp;
long namelen = cnp->cn_namelen;
- char *nameptr = cnp->cn_nameptr;
- unsigned int hashval = (cnp->cn_hash & NCHASHMASK);
+ unsigned int hashval;
boolean_t have_exclusive = FALSE;
uint32_t vid;
vnode_t vp;
+ if (cnp->cn_hash == 0)
+ cnp->cn_hash = hash_string(cnp->cn_nameptr, cnp->cn_namelen);
+ hashval = cnp->cn_hash;
+
+ if (nc_disabled) {
+ return 0;
+ }
+
NAME_CACHE_LOCK_SHARED();
- ncpp = NCHHASH(dvp, cnp->cn_hash);
relook:
+ ncpp = NCHHASH(dvp, cnp->cn_hash);
LIST_FOREACH(ncp, ncpp, nc_hash) {
if ((ncp->nc_dvp == dvp) && (ncp->nc_hashval == hashval)) {
- if (memcmp(ncp->nc_name, nameptr, namelen) == 0 && ncp->nc_name[namelen] == 0)
+ if (strncmp(ncp->nc_name, cnp->cn_nameptr, namelen) == 0 && ncp->nc_name[namelen] == 0)
break;
}
}
/*
* We found a "negative" match, ENOENT notifies client of this match.
- * The nc_whiteout field records whether this is a whiteout.
*/
NCHSTAT(ncs_neghits);
- if (ncp->nc_whiteout)
- cnp->cn_flags |= ISWHITEOUT;
NAME_CACHE_UNLOCK();
return (ENOENT);
}
+const char *
+cache_enter_create(vnode_t dvp, vnode_t vp, struct componentname *cnp)
+{
+ const char *strname;
+
+ if (cnp->cn_hash == 0)
+ cnp->cn_hash = hash_string(cnp->cn_nameptr, cnp->cn_namelen);
+
+ /*
+ * grab 2 references on the string entered
+ * one for the cache_enter_locked to consume
+ * and the second to be consumed by v_name (vnode_create call point)
+ */
+ strname = add_name_internal(cnp->cn_nameptr, cnp->cn_namelen, cnp->cn_hash, TRUE, 0);
+
+ NAME_CACHE_LOCK();
+
+ cache_enter_locked(dvp, vp, cnp, strname);
+
+ NAME_CACHE_UNLOCK();
+
+ return (strname);
+}
+
/*
* Add an entry to the cache...
NAME_CACHE_LOCK();
if (dvp->v_nc_generation == gen)
- cache_enter_locked(dvp, vp, cnp);
+ (void)cache_enter_locked(dvp, vp, cnp, NULL);
NAME_CACHE_UNLOCK();
}
void
cache_enter(struct vnode *dvp, struct vnode *vp, struct componentname *cnp)
{
+ const char *strname;
+
if (cnp->cn_hash == 0)
cnp->cn_hash = hash_string(cnp->cn_nameptr, cnp->cn_namelen);
+ /*
+ * grab 1 reference on the string entered
+ * for the cache_enter_locked to consume
+ */
+ strname = add_name_internal(cnp->cn_nameptr, cnp->cn_namelen, cnp->cn_hash, FALSE, 0);
+
NAME_CACHE_LOCK();
- cache_enter_locked(dvp, vp, cnp);
+ cache_enter_locked(dvp, vp, cnp, strname);
NAME_CACHE_UNLOCK();
}
static void
-cache_enter_locked(struct vnode *dvp, struct vnode *vp, struct componentname *cnp)
+cache_enter_locked(struct vnode *dvp, struct vnode *vp, struct componentname *cnp, const char *strname)
{
struct namecache *ncp, *negp;
struct nchashhead *ncpp;
+ if (nc_disabled)
+ return;
+
/*
* if the entry is for -ve caching vp is null
*/
* someone beat us to the punch..
* this vnode is already in the cache
*/
+ if (strname != NULL)
+ vfs_removename(strname);
return;
}
/*
/*
* Allocate one more entry
*/
- ncp = (struct namecache *)_MALLOC_ZONE((u_long)sizeof *ncp, M_CACHE, M_WAITOK);
+ ncp = (struct namecache *)_MALLOC_ZONE(sizeof(*ncp), M_CACHE, M_WAITOK);
numcache++;
} else {
/*
ncp->nc_vp = vp;
ncp->nc_dvp = dvp;
ncp->nc_hashval = cnp->cn_hash;
- ncp->nc_whiteout = FALSE;
- ncp->nc_name = add_name_locked(cnp->cn_nameptr, cnp->cn_namelen, cnp->cn_hash, 0);
+
+ if (strname == NULL)
+ ncp->nc_name = add_name_internal(cnp->cn_nameptr, cnp->cn_namelen, cnp->cn_hash, FALSE, 0);
+ else
+ ncp->nc_name = strname;
+
+ //
+ // If the bytes of the name associated with the vnode differ,
+ // use the name associated with the vnode since the file system
+ // may have set that explicitly in the case of a lookup on a
+ // case-insensitive file system where the case of the looked up
+ // name differs from what is on disk. For more details, see:
+ // <rdar://problem/8044697> FSEvents doesn't always decompose diacritical unicode chars in the paths of the changed directories
+ //
+ const char *vn_name = vp ? vp->v_name : NULL;
+ unsigned int len = vn_name ? strlen(vn_name) : 0;
+ if (vn_name && ncp && ncp->nc_name && strncmp(ncp->nc_name, vn_name, len) != 0) {
+ unsigned int hash = hash_string(vn_name, len);
+
+ vfs_removename(ncp->nc_name);
+ ncp->nc_name = add_name_internal(vn_name, len, hash, FALSE, 0);
+ ncp->nc_hashval = hash;
+ }
/*
* make us the newest entry in the cache
} else {
/*
* this is a negative cache entry (vp == NULL)
- * stick it on the negative cache list
- * and record the whiteout state
+ * stick it on the negative cache list.
*/
TAILQ_INSERT_TAIL(&neghead, ncp, nc_un.nc_negentry);
- if (cnp->cn_flags & ISWHITEOUT)
- ncp->nc_whiteout = TRUE;
ncs_negtotal++;
if (ncs_negtotal > desiredNegNodes) {
* the oldest
*/
negp = TAILQ_FIRST(&neghead);
- TAILQ_REMOVE(&neghead, negp, nc_un.nc_negentry);
-
cache_delete(negp, 1);
}
}
* add us to the list of name cache entries that
* are children of dvp
*/
- LIST_INSERT_HEAD(&dvp->v_ncchildren, ncp, nc_child);
+ if (vp)
+ TAILQ_INSERT_TAIL(&dvp->v_ncchildren, ncp, nc_child);
+ else
+ TAILQ_INSERT_HEAD(&dvp->v_ncchildren, ncp, nc_child);
}
void
nchinit(void)
{
+ int i;
+
desiredNegNodes = (desiredvnodes / 10);
desiredNodes = desiredvnodes + desiredNegNodes;
init_string_table();
- /* Allocate mount list lock group attribute and group */
+ /* Allocate name cache lock group attribute and group */
namecache_lck_grp_attr= lck_grp_attr_alloc_init();
namecache_lck_grp = lck_grp_alloc_init("Name Cache", namecache_lck_grp_attr);
- /* Allocate mount list lock attribute */
+ /* Allocate name cache lock attribute */
namecache_lck_attr = lck_attr_alloc_init();
- /* Allocate mount list lock */
+ /* Allocate name cache lock */
namecache_rw_lock = lck_rw_alloc_init(namecache_lck_grp, namecache_lck_attr);
+ /* Allocate string cache lock group attribute and group */
+ strcache_lck_grp_attr= lck_grp_attr_alloc_init();
+
+ strcache_lck_grp = lck_grp_alloc_init("String Cache", strcache_lck_grp_attr);
+
+ /* Allocate string cache lock attribute */
+ strcache_lck_attr = lck_attr_alloc_init();
+
+ /* Allocate string cache lock */
+ strtable_rw_lock = lck_rw_alloc_init(strcache_lck_grp, strcache_lck_attr);
+
+ for (i = 0; i < NUM_STRCACHE_LOCKS; i++)
+ lck_mtx_init(&strcache_mtx_locks[i], strcache_lck_grp, strcache_lck_attr);
}
void
int
-resize_namecache(u_int newsize)
+resize_namecache(int newsize)
{
struct nchashhead *new_table;
struct nchashhead *old_table;
struct nchashhead *old_head, *head;
struct namecache *entry, *next;
uint32_t i, hashval;
- int dNodes, dNegNodes;
+ int dNodes, dNegNodes, nelements;
u_long new_size, old_size;
+ if (newsize < 0)
+ return EINVAL;
+
dNegNodes = (newsize / 10);
dNodes = newsize + dNegNodes;
-
// we don't support shrinking yet
- if (dNodes < desiredNodes) {
- return 0;
+ if (dNodes <= desiredNodes) {
+ return 0;
}
- new_table = hashinit(2 * dNodes, M_CACHE, &nchashmask);
+
+ if (os_mul_overflow(dNodes, 2, &nelements)) {
+ return EINVAL;
+ }
+
+ new_table = hashinit(nelements, M_CACHE, &nchashmask);
new_size = nchashmask + 1;
if (new_table == NULL) {
- return ENOMEM;
+ return ENOMEM;
}
NAME_CACHE_LOCK();
}
static void
-cache_delete(struct namecache *ncp, int age_entry)
+cache_delete(struct namecache *ncp, int free_entry)
{
NCHSTAT(ncs_deletes);
TAILQ_REMOVE(&neghead, ncp, nc_un.nc_negentry);
ncs_negtotal--;
}
- LIST_REMOVE(ncp, nc_child);
+ TAILQ_REMOVE(&(ncp->nc_dvp->v_ncchildren), ncp, nc_child);
LIST_REMOVE(ncp, nc_hash);
/*
*/
ncp->nc_hash.le_prev = NULL;
- if (age_entry) {
- /*
- * make it the next one available
- * for cache_enter's use
- */
+ vfs_removename(ncp->nc_name);
+ ncp->nc_name = NULL;
+ if (free_entry) {
TAILQ_REMOVE(&nchead, ncp, nc_entry);
- TAILQ_INSERT_HEAD(&nchead, ncp, nc_entry);
+ FREE_ZONE(ncp, sizeof(*ncp), M_CACHE);
+ numcache--;
}
- remove_name_locked(ncp->nc_name);
- ncp->nc_name = NULL;
}
struct namecache *ncp;
kauth_cred_t tcred = NULL;
- if ((LIST_FIRST(&vp->v_nclinks) == NULL) && (LIST_FIRST(&vp->v_ncchildren) == NULL) && (vp->v_cred == NOCRED))
+ if ((LIST_FIRST(&vp->v_nclinks) == NULL) &&
+ (TAILQ_FIRST(&vp->v_ncchildren) == NULL) &&
+ (vp->v_cred == NOCRED) &&
+ (vp->v_parent == NULLVP))
return;
NAME_CACHE_LOCK();
while ( (ncp = LIST_FIRST(&vp->v_nclinks)) )
cache_delete(ncp, 1);
- while ( (ncp = LIST_FIRST(&vp->v_ncchildren)) )
+ while ( (ncp = TAILQ_FIRST(&vp->v_ncchildren)) )
cache_delete(ncp, 1);
/*
void
cache_purge_negatives(vnode_t vp)
{
- struct namecache *ncp;
+ struct namecache *ncp, *next_ncp;
NAME_CACHE_LOCK();
- LIST_FOREACH(ncp, &vp->v_ncchildren, nc_child)
- if (ncp->nc_vp == NULL)
- cache_delete(ncp , 1);
+ TAILQ_FOREACH_SAFE(ncp, &vp->v_ncchildren, nc_child, next_ncp) {
+ if (ncp->nc_vp)
+ break;
+
+ cache_delete(ncp, 1);
+ }
NAME_CACHE_UNLOCK();
}
//
static LIST_HEAD(stringhead, string_t) *string_ref_table;
static u_long string_table_mask;
-static uint32_t max_chain_len=0;
-static struct stringhead *long_chain_head=NULL;
static uint32_t filled_buckets=0;
-static uint32_t num_dups=0;
-static uint32_t nstrings=0;
+
typedef struct string_t {
LIST_ENTRY(string_t) hash_chain;
} string_t;
-
-static int
+static void
resize_string_ref_table(void)
{
- struct stringhead *new_table;
- struct stringhead *old_table;
- struct stringhead *old_head, *head;
- string_t *entry, *next;
- uint32_t i, hashval;
- u_long new_mask, old_mask;
-
- new_table = hashinit((string_table_mask + 1) * 2, M_CACHE, &new_mask);
- if (new_table == NULL) {
- return ENOMEM;
- }
+ struct stringhead *new_table;
+ struct stringhead *old_table;
+ struct stringhead *old_head, *head;
+ string_t *entry, *next;
+ uint32_t i, hashval;
+ u_long new_mask, old_mask;
- // do the switch!
- old_table = string_ref_table;
- string_ref_table = new_table;
- old_mask = string_table_mask;
- string_table_mask = new_mask;
+ /*
+ * need to hold the table lock exclusively
+ * in order to grow the table... need to recheck
+ * the need to resize again after we've taken
+ * the lock exclusively in case some other thread
+ * beat us to the punch
+ */
+ lck_rw_lock_exclusive(strtable_rw_lock);
- printf("resize: max chain len %d, new table size %lu\n",
- max_chain_len, new_mask + 1);
- max_chain_len = 0;
- long_chain_head = NULL;
- filled_buckets = 0;
+ if (4 * filled_buckets < ((string_table_mask + 1) * 3)) {
+ lck_rw_done(strtable_rw_lock);
+ return;
+ }
+ new_table = hashinit((string_table_mask + 1) * 2, M_CACHE, &new_mask);
- // walk the old table and insert all the entries into
- // the new table
- //
- for(i=0; i <= old_mask; i++) {
- old_head = &old_table[i];
- for (entry=old_head->lh_first; entry != NULL; entry=next) {
- hashval = hash_string((const char *)entry->str, 0);
- head = &string_ref_table[hashval & string_table_mask];
- if (head->lh_first == NULL) {
- filled_buckets++;
- }
+ if (new_table == NULL) {
+ printf("failed to resize the hash table.\n");
+ lck_rw_done(strtable_rw_lock);
+ return;
+ }
- next = entry->hash_chain.le_next;
- LIST_INSERT_HEAD(head, entry, hash_chain);
+ // do the switch!
+ old_table = string_ref_table;
+ string_ref_table = new_table;
+ old_mask = string_table_mask;
+ string_table_mask = new_mask;
+ filled_buckets = 0;
+
+ // walk the old table and insert all the entries into
+ // the new table
+ //
+ for (i = 0; i <= old_mask; i++) {
+ old_head = &old_table[i];
+ for (entry = old_head->lh_first; entry != NULL; entry = next) {
+ hashval = hash_string((const char *)entry->str, 0);
+ head = &string_ref_table[hashval & string_table_mask];
+ if (head->lh_first == NULL) {
+ filled_buckets++;
+ }
+ next = entry->hash_chain.le_next;
+ LIST_INSERT_HEAD(head, entry, hash_chain);
+ }
}
- }
-
- FREE(old_table, M_CACHE);
+ lck_rw_done(strtable_rw_lock);
- return 0;
+ FREE(old_table, M_CACHE);
}
const char *
-vfs_addname(const char *name, size_t len, u_int hashval, u_int flags)
+vfs_addname(const char *name, uint32_t len, u_int hashval, u_int flags)
{
- const char * ptr;
-
- NAME_CACHE_LOCK();
- ptr = add_name_locked(name, len, hashval, flags);
- NAME_CACHE_UNLOCK();
-
- return(ptr);
+ return (add_name_internal(name, len, hashval, FALSE, flags));
}
+
static const char *
-add_name_locked(const char *name, size_t len, u_int hashval, __unused u_int flags)
+add_name_internal(const char *name, uint32_t len, u_int hashval, boolean_t need_extra_ref, __unused u_int flags)
{
- struct stringhead *head;
- string_t *entry;
- uint32_t chain_len = 0;
- char *ptr;
+ struct stringhead *head;
+ string_t *entry;
+ uint32_t chain_len = 0;
+ uint32_t hash_index;
+ uint32_t lock_index;
+ char *ptr;
- //
- // If the table gets more than 3/4 full, resize it
- //
- if (4*filled_buckets >= ((string_table_mask + 1) * 3)) {
- if (resize_string_ref_table() != 0) {
- printf("failed to resize the hash table.\n");
- }
- }
- if (hashval == 0) {
- hashval = hash_string(name, 0);
- }
-
- //
- // if the length already accounts for the null-byte, then
- // subtract one so later on we don't index past the end
- // of the string.
- //
- if (len > 0 && name[len-1] == '\0') {
- len--;
- }
+ if (len > MAXPATHLEN)
+ len = MAXPATHLEN;
- head = &string_ref_table[hashval & string_table_mask];
- for (entry=head->lh_first; entry != NULL; chain_len++, entry=entry->hash_chain.le_next) {
- if (memcmp(entry->str, name, len) == 0 && entry->str[len] == '\0') {
- entry->refcount++;
- num_dups++;
- break;
+ /*
+ * if the length already accounts for the null-byte, then
+ * subtract one so later on we don't index past the end
+ * of the string.
+ */
+ if (len > 0 && name[len-1] == '\0') {
+ len--;
+ }
+ if (hashval == 0) {
+ hashval = hash_string(name, len);
}
- }
- if (entry == NULL) {
- // it wasn't already there so add it.
- MALLOC(entry, string_t *, sizeof(string_t) + len + 1, M_TEMP, M_WAITOK);
+ /*
+ * take this lock 'shared' to keep the hash stable
+ * if someone else decides to grow the pool they
+ * will take this lock exclusively
+ */
+ lck_rw_lock_shared(strtable_rw_lock);
- // have to get "head" again because we could have blocked
- // in malloc and thus head could have changed.
- //
- head = &string_ref_table[hashval & string_table_mask];
- if (head->lh_first == NULL) {
- filled_buckets++;
+ /*
+ * If the table gets more than 3/4 full, resize it
+ */
+ if (4 * filled_buckets >= ((string_table_mask + 1) * 3)) {
+ lck_rw_done(strtable_rw_lock);
+
+ resize_string_ref_table();
+
+ lck_rw_lock_shared(strtable_rw_lock);
}
+ hash_index = hashval & string_table_mask;
+ lock_index = hash_index % NUM_STRCACHE_LOCKS;
+
+ head = &string_ref_table[hash_index];
- ptr = (char *)((char *)entry + sizeof(string_t));
- strncpy(ptr, name, len);
- ptr[len] = '\0';
- entry->str = ptr;
- entry->refcount = 1;
- LIST_INSERT_HEAD(head, entry, hash_chain);
+ lck_mtx_lock_spin(&strcache_mtx_locks[lock_index]);
- if (chain_len > max_chain_len) {
- max_chain_len = chain_len;
- long_chain_head = head;
+ for (entry = head->lh_first; entry != NULL; chain_len++, entry = entry->hash_chain.le_next) {
+ if (strncmp(entry->str, name, len) == 0 && entry->str[len] == 0) {
+ entry->refcount++;
+ break;
+ }
}
+ if (entry == NULL) {
+ lck_mtx_convert_spin(&strcache_mtx_locks[lock_index]);
+ /*
+ * it wasn't already there so add it.
+ */
+ MALLOC(entry, string_t *, sizeof(string_t) + len + 1, M_TEMP, M_WAITOK);
- nstrings++;
- }
+ if (head->lh_first == NULL) {
+ OSAddAtomic(1, &filled_buckets);
+ }
+ ptr = (char *)((char *)entry + sizeof(string_t));
+ strncpy(ptr, name, len);
+ ptr[len] = '\0';
+ entry->str = ptr;
+ entry->refcount = 1;
+ LIST_INSERT_HEAD(head, entry, hash_chain);
+ }
+ if (need_extra_ref == TRUE)
+ entry->refcount++;
- return (const char *)entry->str;
+ lck_mtx_unlock(&strcache_mtx_locks[lock_index]);
+ lck_rw_done(strtable_rw_lock);
+
+ return (const char *)entry->str;
}
+
int
vfs_removename(const char *nameref)
{
- int i;
+ struct stringhead *head;
+ string_t *entry;
+ uint32_t hashval;
+ uint32_t hash_index;
+ uint32_t lock_index;
+ int retval = ENOENT;
- NAME_CACHE_LOCK();
- i = remove_name_locked(nameref);
- NAME_CACHE_UNLOCK();
+ hashval = hash_string(nameref, 0);
- return(i);
-
-}
+ /*
+ * take this lock 'shared' to keep the hash stable
+ * if someone else decides to grow the pool they
+ * will take this lock exclusively
+ */
+ lck_rw_lock_shared(strtable_rw_lock);
+ /*
+ * must compute the head behind the table lock
+ * since the size and location of the table
+ * can change on the fly
+ */
+ hash_index = hashval & string_table_mask;
+ lock_index = hash_index % NUM_STRCACHE_LOCKS;
+ head = &string_ref_table[hash_index];
-static int
-remove_name_locked(const char *nameref)
-{
- struct stringhead *head;
- string_t *entry;
- uint32_t hashval;
- const char *ptr;
-
- hashval = hash_string(nameref, 0);
- head = &string_ref_table[hashval & string_table_mask];
- for (entry=head->lh_first; entry != NULL; entry=entry->hash_chain.le_next) {
- if (entry->str == nameref) {
- entry->refcount--;
- if (entry->refcount == 0) {
- LIST_REMOVE(entry, hash_chain);
- if (head->lh_first == NULL) {
- filled_buckets--;
- }
- ptr = entry->str;
- entry->str = NULL;
- nstrings--;
+ lck_mtx_lock_spin(&strcache_mtx_locks[lock_index]);
- FREE(entry, M_TEMP);
- } else {
- num_dups--;
- }
+ for (entry = head->lh_first; entry != NULL; entry = entry->hash_chain.le_next) {
+ if (entry->str == nameref) {
+ entry->refcount--;
+
+ if (entry->refcount == 0) {
+ LIST_REMOVE(entry, hash_chain);
- return 0;
+ if (head->lh_first == NULL) {
+ OSAddAtomic(-1, &filled_buckets);
+ }
+ } else {
+ entry = NULL;
+ }
+ retval = 0;
+ break;
+ }
}
- }
+ lck_mtx_unlock(&strcache_mtx_locks[lock_index]);
+ lck_rw_done(strtable_rw_lock);
+
+ if (entry != NULL)
+ FREE(entry, M_TEMP);
- return ENOENT;
+ return retval;
}
string_t *entry;
u_long i;
- NAME_CACHE_LOCK_SHARED();
+ lck_rw_lock_shared(strtable_rw_lock);
for (i = 0; i <= string_table_mask; i++) {
head = &string_ref_table[i];
printf("%6d - %s\n", entry->refcount, entry->str);
}
}
- NAME_CACHE_UNLOCK();
+ lck_rw_done(strtable_rw_lock);
}
#endif /* DUMP_STRING_TABLE */
projects / apple / xnu.git / blobdiff