From 949854d02455080d20cd3e1db28a3a18daf7599d Mon Sep 17 00:00:00 2001 From: Nick Piggin Date: Fri, 7 Jan 2011 17:49:37 +1100 Subject: fs: Use rename lock and RCU for multi-step operations The remaining usages for dcache_lock is to allow atomic, multi-step read-side operations over the directory tree by excluding modifications to the tree. Also, to walk in the leaf->root direction in the tree where we don't have a natural d_lock ordering. This could be accomplished by taking every d_lock, but this would mean a huge number of locks and actually gets very tricky. Solve this instead by using the rename seqlock for multi-step read-side operations, retry in case of a rename so we don't walk up the wrong parent. Concurrent dentry insertions are not serialised against. Concurrent deletes are tricky when walking up the directory: our parent might have been deleted when dropping locks so also need to check and retry for that. We can also use the rename lock in cases where livelock is a worry (and it is introduced in subsequent patch). Signed-off-by: Nick Piggin --- fs/nfs/namespace.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) (limited to 'fs/nfs/namespace.c') diff --git a/fs/nfs/namespace.c b/fs/nfs/namespace.c index db6aa3673cf..78c0ebb0b07 100644 --- a/fs/nfs/namespace.c +++ b/fs/nfs/namespace.c @@ -49,11 +49,17 @@ char *nfs_path(const char *base, const struct dentry *dentry, char *buffer, ssize_t buflen) { - char *end = buffer+buflen; + char *end; int namelen; + unsigned seq; +rename_retry: + end = buffer+buflen; *--end = '\0'; buflen--; + + seq = read_seqbegin(&rename_lock); + rcu_read_lock(); spin_lock(&dcache_lock); while (!IS_ROOT(dentry) && dentry != droot) { namelen = dentry->d_name.len; @@ -66,6 +72,9 @@ char *nfs_path(const char *base, dentry = dentry->d_parent; } spin_unlock(&dcache_lock); + rcu_read_unlock(); + if (read_seqretry(&rename_lock, seq)) + goto rename_retry; if (*end != '/') { if (--buflen < 0) goto Elong; @@ -83,6 +92,9 @@ char *nfs_path(const char *base, return end; Elong_unlock: spin_unlock(&dcache_lock); + rcu_read_unlock(); + if (read_seqretry(&rename_lock, seq)) + goto rename_retry; Elong: return ERR_PTR(-ENAMETOOLONG); } -- cgit v1.2.3-70-g09d2 From b5c84bf6f6fa3a7dfdcb556023a62953574b60ee Mon Sep 17 00:00:00 2001 From: Nick Piggin Date: Fri, 7 Jan 2011 17:49:38 +1100 Subject: fs: dcache remove dcache_lock dcache_lock no longer protects anything. remove it. Signed-off-by: Nick Piggin --- Documentation/filesystems/Locking | 16 +-- Documentation/filesystems/dentry-locking.txt | 40 ++++--- Documentation/filesystems/porting | 8 +- arch/powerpc/platforms/cell/spufs/inode.c | 5 +- drivers/infiniband/hw/ipath/ipath_fs.c | 6 +- drivers/infiniband/hw/qib/qib_fs.c | 3 - drivers/staging/pohmelfs/path_entry.c | 2 - drivers/staging/smbfs/cache.c | 4 - drivers/usb/core/inode.c | 3 - fs/9p/vfs_inode.c | 2 - fs/affs/amigaffs.c | 2 - fs/autofs4/autofs_i.h | 3 + fs/autofs4/expire.c | 10 +- fs/autofs4/root.c | 44 ++++---- fs/autofs4/waitq.c | 7 +- fs/ceph/dir.c | 6 +- fs/ceph/inode.c | 4 - fs/cifs/inode.c | 3 - fs/coda/cache.c | 2 - fs/configfs/configfs_internal.h | 2 - fs/configfs/inode.c | 6 +- fs/dcache.c | 160 ++++----------------------- fs/exportfs/expfs.c | 4 - fs/libfs.c | 8 -- fs/namei.c | 9 +- fs/ncpfs/dir.c | 3 - fs/ncpfs/ncplib_kernel.h | 4 - fs/nfs/dir.c | 3 - fs/nfs/getroot.c | 2 - fs/nfs/namespace.c | 3 - fs/notify/fsnotify.c | 2 - fs/ocfs2/dcache.c | 2 - include/linux/dcache.h | 5 +- include/linux/fs.h | 6 +- include/linux/fsnotify.h | 2 - include/linux/fsnotify_backend.h | 11 +- include/linux/namei.h | 1 - kernel/cgroup.c | 6 - mm/filemap.c | 3 - security/selinux/selinuxfs.c | 4 - 40 files changed, 109 insertions(+), 307 deletions(-) (limited to 'fs/nfs/namespace.c') diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking index a15ee207b44..bdad6414dfa 100644 --- a/Documentation/filesystems/Locking +++ b/Documentation/filesystems/Locking @@ -21,14 +21,14 @@ prototypes: char *(*d_dname)((struct dentry *dentry, char *buffer, int buflen); locking rules: - dcache_lock rename_lock ->d_lock may block -d_revalidate: no no no yes -d_hash no no no no -d_compare: no yes no no -d_delete: yes no yes no -d_release: no no no yes -d_iput: no no no yes -d_dname: no no no no + rename_lock ->d_lock may block +d_revalidate: no no yes +d_hash no no no +d_compare: yes no no +d_delete: no yes no +d_release: no no yes +d_iput: no no yes +d_dname: no no no --------------------------- inode_operations --------------------------- prototypes: diff --git a/Documentation/filesystems/dentry-locking.txt b/Documentation/filesystems/dentry-locking.txt index 79334ed5daa..30b6a40f565 100644 --- a/Documentation/filesystems/dentry-locking.txt +++ b/Documentation/filesystems/dentry-locking.txt @@ -31,6 +31,7 @@ significant change is the way d_lookup traverses the hash chain, it doesn't acquire the dcache_lock for this and rely on RCU to ensure that the dentry has not been *freed*. +dcache_lock no longer exists, dentry locking is explained in fs/dcache.c Dcache locking details ====================== @@ -50,14 +51,12 @@ Safe lock-free look-up of dcache hash table Dcache is a complex data structure with the hash table entries also linked together in other lists. In 2.4 kernel, dcache_lock protected -all the lists. We applied RCU only on hash chain walking. The rest of -the lists are still protected by dcache_lock. Some of the important -changes are : +all the lists. RCU dentry hash walking works like this: 1. The deletion from hash chain is done using hlist_del_rcu() macro which doesn't initialize next pointer of the deleted dentry and this allows us to walk safely lock-free while a deletion is - happening. + happening. This is a standard hlist_rcu iteration. 2. Insertion of a dentry into the hash table is done using hlist_add_head_rcu() which take care of ordering the writes - the @@ -66,19 +65,18 @@ changes are : which has since been replaced by hlist_for_each_entry_rcu(), while walking the hash chain. The only requirement is that all initialization to the dentry must be done before - hlist_add_head_rcu() since we don't have dcache_lock protection - while traversing the hash chain. This isn't different from the - existing code. - -3. The dentry looked up without holding dcache_lock by cannot be - returned for walking if it is unhashed. It then may have a NULL - d_inode or other bogosity since RCU doesn't protect the other - fields in the dentry. We therefore use a flag DCACHE_UNHASHED to - indicate unhashed dentries and use this in conjunction with a - per-dentry lock (d_lock). Once looked up without the dcache_lock, - we acquire the per-dentry lock (d_lock) and check if the dentry is - unhashed. If so, the look-up is failed. If not, the reference count - of the dentry is increased and the dentry is returned. + hlist_add_head_rcu() since we don't have lock protection + while traversing the hash chain. + +3. The dentry looked up without holding locks cannot be returned for + walking if it is unhashed. It then may have a NULL d_inode or other + bogosity since RCU doesn't protect the other fields in the dentry. We + therefore use a flag DCACHE_UNHASHED to indicate unhashed dentries + and use this in conjunction with a per-dentry lock (d_lock). Once + looked up without locks, we acquire the per-dentry lock (d_lock) and + check if the dentry is unhashed. If so, the look-up is failed. If not, + the reference count of the dentry is increased and the dentry is + returned. 4. Once a dentry is looked up, it must be ensured during the path walk for that component it doesn't go away. In pre-2.5.10 code, this was @@ -86,10 +84,10 @@ changes are : In some sense, dcache_rcu path walking looks like the pre-2.5.10 version. -5. All dentry hash chain updates must take the dcache_lock as well as - the per-dentry lock in that order. dput() does this to ensure that - a dentry that has just been looked up in another CPU doesn't get - deleted before dget() can be done on it. +5. All dentry hash chain updates must take the per-dentry lock (see + fs/dcache.c). This excludes dput() to ensure that a dentry that has + been looked up concurrently does not get deleted before dget() can + take a ref. 6. There are several ways to do reference counting of RCU protected objects. One such example is in ipv4 route cache where deferred diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting index 9fd31940a8e..1eb76959d09 100644 --- a/Documentation/filesystems/porting +++ b/Documentation/filesystems/porting @@ -216,7 +216,6 @@ had ->revalidate()) add calls in ->follow_link()/->readlink(). ->d_parent changes are not protected by BKL anymore. Read access is safe if at least one of the following is true: * filesystem has no cross-directory rename() - * dcache_lock is held * we know that parent had been locked (e.g. we are looking at ->d_parent of ->lookup() argument). * we are called from ->rename(). @@ -340,3 +339,10 @@ look at examples of other filesystems) for guidance. .d_hash() calling convention and locking rules are significantly changed. Read updated documentation in Documentation/filesystems/vfs.txt (and look at examples of other filesystems) for guidance. + +--- +[mandatory] + dcache_lock is gone, replaced by fine grained locks. See fs/dcache.c +for details of what locks to replace dcache_lock with in order to protect +particular things. Most of the time, a filesystem only needs ->d_lock, which +protects *all* the dcache state of a given dentry. diff --git a/arch/powerpc/platforms/cell/spufs/inode.c b/arch/powerpc/platforms/cell/spufs/inode.c index 5aef1a7f5e4..2662b50ea8d 100644 --- a/arch/powerpc/platforms/cell/spufs/inode.c +++ b/arch/powerpc/platforms/cell/spufs/inode.c @@ -159,21 +159,18 @@ static void spufs_prune_dir(struct dentry *dir) mutex_lock(&dir->d_inode->i_mutex); list_for_each_entry_safe(dentry, tmp, &dir->d_subdirs, d_u.d_child) { - spin_lock(&dcache_lock); spin_lock(&dentry->d_lock); if (!(d_unhashed(dentry)) && dentry->d_inode) { dget_locked_dlock(dentry); __d_drop(dentry); spin_unlock(&dentry->d_lock); simple_unlink(dir->d_inode, dentry); - /* XXX: what is dcache_lock protecting here? Other + /* XXX: what was dcache_lock protecting here? Other * filesystems (IB, configfs) release dcache_lock * before unlink */ - spin_unlock(&dcache_lock); dput(dentry); } else { spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); } } shrink_dcache_parent(dir); diff --git a/drivers/infiniband/hw/ipath/ipath_fs.c b/drivers/infiniband/hw/ipath/ipath_fs.c index 18aee04a841..925e88227de 100644 --- a/drivers/infiniband/hw/ipath/ipath_fs.c +++ b/drivers/infiniband/hw/ipath/ipath_fs.c @@ -277,18 +277,14 @@ static int remove_file(struct dentry *parent, char *name) goto bail; } - spin_lock(&dcache_lock); spin_lock(&tmp->d_lock); if (!(d_unhashed(tmp) && tmp->d_inode)) { dget_locked_dlock(tmp); __d_drop(tmp); spin_unlock(&tmp->d_lock); - spin_unlock(&dcache_lock); simple_unlink(parent->d_inode, tmp); - } else { + } else spin_unlock(&tmp->d_lock); - spin_unlock(&dcache_lock); - } ret = 0; bail: diff --git a/drivers/infiniband/hw/qib/qib_fs.c b/drivers/infiniband/hw/qib/qib_fs.c index fe4b242f009..49af4a6538b 100644 --- a/drivers/infiniband/hw/qib/qib_fs.c +++ b/drivers/infiniband/hw/qib/qib_fs.c @@ -453,17 +453,14 @@ static int remove_file(struct dentry *parent, char *name) goto bail; } - spin_lock(&dcache_lock); spin_lock(&tmp->d_lock); if (!(d_unhashed(tmp) && tmp->d_inode)) { dget_locked_dlock(tmp); __d_drop(tmp); spin_unlock(&tmp->d_lock); - spin_unlock(&dcache_lock); simple_unlink(parent->d_inode, tmp); } else { spin_unlock(&tmp->d_lock); - spin_unlock(&dcache_lock); } ret = 0; diff --git a/drivers/staging/pohmelfs/path_entry.c b/drivers/staging/pohmelfs/path_entry.c index bbe42f42ca8..400a9fc386a 100644 --- a/drivers/staging/pohmelfs/path_entry.c +++ b/drivers/staging/pohmelfs/path_entry.c @@ -101,7 +101,6 @@ rename_retry: d = first; seq = read_seqbegin(&rename_lock); rcu_read_lock(); - spin_lock(&dcache_lock); if (!IS_ROOT(d) && d_unhashed(d)) len += UNHASHED_OBSCURE_STRING_SIZE; /* Obscure " (deleted)" string */ @@ -110,7 +109,6 @@ rename_retry: len += d->d_name.len + 1; /* Plus slash */ d = d->d_parent; } - spin_unlock(&dcache_lock); rcu_read_unlock(); if (read_seqretry(&rename_lock, seq)) goto rename_retry; diff --git a/drivers/staging/smbfs/cache.c b/drivers/staging/smbfs/cache.c index 920434b6c07..75dfd403fb9 100644 --- a/drivers/staging/smbfs/cache.c +++ b/drivers/staging/smbfs/cache.c @@ -62,7 +62,6 @@ smb_invalidate_dircache_entries(struct dentry *parent) struct list_head *next; struct dentry *dentry; - spin_lock(&dcache_lock); spin_lock(&parent->d_lock); next = parent->d_subdirs.next; while (next != &parent->d_subdirs) { @@ -72,7 +71,6 @@ smb_invalidate_dircache_entries(struct dentry *parent) next = next->next; } spin_unlock(&parent->d_lock); - spin_unlock(&dcache_lock); } /* @@ -98,7 +96,6 @@ smb_dget_fpos(struct dentry *dentry, struct dentry *parent, unsigned long fpos) } /* If a pointer is invalid, we search the dentry. */ - spin_lock(&dcache_lock); spin_lock(&parent->d_lock); next = parent->d_subdirs.next; while (next != &parent->d_subdirs) { @@ -115,7 +112,6 @@ smb_dget_fpos(struct dentry *dentry, struct dentry *parent, unsigned long fpos) dent = NULL; out_unlock: spin_unlock(&parent->d_lock); - spin_unlock(&dcache_lock); return dent; } diff --git a/drivers/usb/core/inode.c b/drivers/usb/core/inode.c index 89a0e836658..1b125c224dc 100644 --- a/drivers/usb/core/inode.c +++ b/drivers/usb/core/inode.c @@ -343,7 +343,6 @@ static int usbfs_empty (struct dentry *dentry) { struct list_head *list; - spin_lock(&dcache_lock); spin_lock(&dentry->d_lock); list_for_each(list, &dentry->d_subdirs) { struct dentry *de = list_entry(list, struct dentry, d_u.d_child); @@ -352,13 +351,11 @@ static int usbfs_empty (struct dentry *dentry) if (usbfs_positive(de)) { spin_unlock(&de->d_lock); spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); return 0; } spin_unlock(&de->d_lock); } spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); return 1; } diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c index 47dfd5d29a6..1073bca8488 100644 --- a/fs/9p/vfs_inode.c +++ b/fs/9p/vfs_inode.c @@ -270,13 +270,11 @@ static struct dentry *v9fs_dentry_from_dir_inode(struct inode *inode) { struct dentry *dentry; - spin_lock(&dcache_lock); spin_lock(&dcache_inode_lock); /* Directory should have only one entry. */ BUG_ON(S_ISDIR(inode->i_mode) && !list_is_singular(&inode->i_dentry)); dentry = list_entry(inode->i_dentry.next, struct dentry, d_alias); spin_unlock(&dcache_inode_lock); - spin_unlock(&dcache_lock); return dentry; } diff --git a/fs/affs/amigaffs.c b/fs/affs/amigaffs.c index 2321cc92d44..600101a21ba 100644 --- a/fs/affs/amigaffs.c +++ b/fs/affs/amigaffs.c @@ -128,7 +128,6 @@ affs_fix_dcache(struct dentry *dentry, u32 entry_ino) void *data = dentry->d_fsdata; struct list_head *head, *next; - spin_lock(&dcache_lock); spin_lock(&dcache_inode_lock); head = &inode->i_dentry; next = head->next; @@ -141,7 +140,6 @@ affs_fix_dcache(struct dentry *dentry, u32 entry_ino) next = next->next; } spin_unlock(&dcache_inode_lock); - spin_unlock(&dcache_lock); } diff --git a/fs/autofs4/autofs_i.h b/fs/autofs4/autofs_i.h index 9d2ae9b30d9..0fffe1c24ce 100644 --- a/fs/autofs4/autofs_i.h +++ b/fs/autofs4/autofs_i.h @@ -16,6 +16,7 @@ #include #include #include +#include #include /* This is the range of ioctl() numbers we claim as ours */ @@ -60,6 +61,8 @@ do { \ current->pid, __func__, ##args); \ } while (0) +extern spinlock_t autofs4_lock; + /* Unified info structure. This is pointed to by both the dentry and inode structures. Each file in the filesystem has an instance of this structure. It holds a reference to the dentry, so dentries are never diff --git a/fs/autofs4/expire.c b/fs/autofs4/expire.c index 968c1434af6..2f7951d67d1 100644 --- a/fs/autofs4/expire.c +++ b/fs/autofs4/expire.c @@ -102,7 +102,7 @@ static struct dentry *get_next_positive_dentry(struct dentry *prev, if (prev == NULL) return dget(prev); - spin_lock(&dcache_lock); + spin_lock(&autofs4_lock); relock: p = prev; spin_lock(&p->d_lock); @@ -114,7 +114,7 @@ again: if (p == root) { spin_unlock(&p->d_lock); - spin_unlock(&dcache_lock); + spin_unlock(&autofs4_lock); dput(prev); return NULL; } @@ -144,7 +144,7 @@ again: dget_dlock(ret); spin_unlock(&ret->d_lock); spin_unlock(&p->d_lock); - spin_unlock(&dcache_lock); + spin_unlock(&autofs4_lock); dput(prev); @@ -408,13 +408,13 @@ found: ino->flags |= AUTOFS_INF_EXPIRING; init_completion(&ino->expire_complete); spin_unlock(&sbi->fs_lock); - spin_lock(&dcache_lock); + spin_lock(&autofs4_lock); spin_lock(&expired->d_parent->d_lock); spin_lock_nested(&expired->d_lock, DENTRY_D_LOCK_NESTED); list_move(&expired->d_parent->d_subdirs, &expired->d_u.d_child); spin_unlock(&expired->d_lock); spin_unlock(&expired->d_parent->d_lock); - spin_unlock(&dcache_lock); + spin_unlock(&autofs4_lock); return expired; } diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c index 7a9ed6b8829..10ca68a96dc 100644 --- a/fs/autofs4/root.c +++ b/fs/autofs4/root.c @@ -23,6 +23,8 @@ #include "autofs_i.h" +DEFINE_SPINLOCK(autofs4_lock); + static int autofs4_dir_symlink(struct inode *,struct dentry *,const char *); static int autofs4_dir_unlink(struct inode *,struct dentry *); static int autofs4_dir_rmdir(struct inode *,struct dentry *); @@ -142,15 +144,15 @@ static int autofs4_dir_open(struct inode *inode, struct file *file) * autofs file system so just let the libfs routines handle * it. */ - spin_lock(&dcache_lock); + spin_lock(&autofs4_lock); spin_lock(&dentry->d_lock); if (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) { spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); + spin_unlock(&autofs4_lock); return -ENOENT; } spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); + spin_unlock(&autofs4_lock); out: return dcache_dir_open(inode, file); @@ -255,11 +257,11 @@ static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd) /* We trigger a mount for almost all flags */ lookup_type = autofs4_need_mount(nd->flags); spin_lock(&sbi->fs_lock); - spin_lock(&dcache_lock); + spin_lock(&autofs4_lock); spin_lock(&dentry->d_lock); if (!(lookup_type || ino->flags & AUTOFS_INF_PENDING)) { spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); + spin_unlock(&autofs4_lock); spin_unlock(&sbi->fs_lock); goto follow; } @@ -272,7 +274,7 @@ static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd) if (ino->flags & AUTOFS_INF_PENDING || (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs))) { spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); + spin_unlock(&autofs4_lock); spin_unlock(&sbi->fs_lock); status = try_to_fill_dentry(dentry, nd->flags); @@ -282,7 +284,7 @@ static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd) goto follow; } spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); + spin_unlock(&autofs4_lock); spin_unlock(&sbi->fs_lock); follow: /* @@ -353,14 +355,14 @@ static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd) return 0; /* Check for a non-mountpoint directory with no contents */ - spin_lock(&dcache_lock); + spin_lock(&autofs4_lock); spin_lock(&dentry->d_lock); if (S_ISDIR(dentry->d_inode->i_mode) && !d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) { DPRINTK("dentry=%p %.*s, emptydir", dentry, dentry->d_name.len, dentry->d_name.name); spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); + spin_unlock(&autofs4_lock); /* The daemon never causes a mount to trigger */ if (oz_mode) @@ -377,7 +379,7 @@ static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd) return status; } spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); + spin_unlock(&autofs4_lock); return 1; } @@ -432,7 +434,7 @@ static struct dentry *autofs4_lookup_active(struct dentry *dentry) const unsigned char *str = name->name; struct list_head *p, *head; - spin_lock(&dcache_lock); + spin_lock(&autofs4_lock); spin_lock(&sbi->lookup_lock); head = &sbi->active_list; list_for_each(p, head) { @@ -465,14 +467,14 @@ static struct dentry *autofs4_lookup_active(struct dentry *dentry) dget_dlock(active); spin_unlock(&active->d_lock); spin_unlock(&sbi->lookup_lock); - spin_unlock(&dcache_lock); + spin_unlock(&autofs4_lock); return active; } next: spin_unlock(&active->d_lock); } spin_unlock(&sbi->lookup_lock); - spin_unlock(&dcache_lock); + spin_unlock(&autofs4_lock); return NULL; } @@ -487,7 +489,7 @@ static struct dentry *autofs4_lookup_expiring(struct dentry *dentry) const unsigned char *str = name->name; struct list_head *p, *head; - spin_lock(&dcache_lock); + spin_lock(&autofs4_lock); spin_lock(&sbi->lookup_lock); head = &sbi->expiring_list; list_for_each(p, head) { @@ -520,14 +522,14 @@ static struct dentry *autofs4_lookup_expiring(struct dentry *dentry) dget_dlock(expiring); spin_unlock(&expiring->d_lock); spin_unlock(&sbi->lookup_lock); - spin_unlock(&dcache_lock); + spin_unlock(&autofs4_lock); return expiring; } next: spin_unlock(&expiring->d_lock); } spin_unlock(&sbi->lookup_lock); - spin_unlock(&dcache_lock); + spin_unlock(&autofs4_lock); return NULL; } @@ -763,12 +765,12 @@ static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry) dir->i_mtime = CURRENT_TIME; - spin_lock(&dcache_lock); + spin_lock(&autofs4_lock); autofs4_add_expiring(dentry); spin_lock(&dentry->d_lock); __d_drop(dentry); spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); + spin_unlock(&autofs4_lock); return 0; } @@ -785,20 +787,20 @@ static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry) if (!autofs4_oz_mode(sbi)) return -EACCES; - spin_lock(&dcache_lock); + spin_lock(&autofs4_lock); spin_lock(&sbi->lookup_lock); spin_lock(&dentry->d_lock); if (!list_empty(&dentry->d_subdirs)) { spin_unlock(&dentry->d_lock); spin_unlock(&sbi->lookup_lock); - spin_unlock(&dcache_lock); + spin_unlock(&autofs4_lock); return -ENOTEMPTY; } __autofs4_add_expiring(dentry); spin_unlock(&sbi->lookup_lock); __d_drop(dentry); spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); + spin_unlock(&autofs4_lock); if (atomic_dec_and_test(&ino->count)) { p_ino = autofs4_dentry_ino(dentry->d_parent); diff --git a/fs/autofs4/waitq.c b/fs/autofs4/waitq.c index 4be8f778a41..c5f8459c905 100644 --- a/fs/autofs4/waitq.c +++ b/fs/autofs4/waitq.c @@ -194,14 +194,15 @@ static int autofs4_getpath(struct autofs_sb_info *sbi, rename_retry: buf = *name; len = 0; + seq = read_seqbegin(&rename_lock); rcu_read_lock(); - spin_lock(&dcache_lock); + spin_lock(&autofs4_lock); for (tmp = dentry ; tmp != root ; tmp = tmp->d_parent) len += tmp->d_name.len + 1; if (!len || --len > NAME_MAX) { - spin_unlock(&dcache_lock); + spin_unlock(&autofs4_lock); rcu_read_unlock(); if (read_seqretry(&rename_lock, seq)) goto rename_retry; @@ -217,7 +218,7 @@ rename_retry: p -= tmp->d_name.len; strncpy(p, tmp->d_name.name, tmp->d_name.len); } - spin_unlock(&dcache_lock); + spin_unlock(&autofs4_lock); rcu_read_unlock(); if (read_seqretry(&rename_lock, seq)) goto rename_retry; diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c index 2c924e8d85f..58abc3da611 100644 --- a/fs/ceph/dir.c +++ b/fs/ceph/dir.c @@ -112,7 +112,6 @@ static int __dcache_readdir(struct file *filp, dout("__dcache_readdir %p at %llu (last %p)\n", dir, filp->f_pos, last); - spin_lock(&dcache_lock); spin_lock(&parent->d_lock); /* start at beginning? */ @@ -156,7 +155,6 @@ more: dget_dlock(dentry); spin_unlock(&dentry->d_lock); spin_unlock(&parent->d_lock); - spin_unlock(&dcache_lock); dout(" %llu (%llu) dentry %p %.*s %p\n", di->offset, filp->f_pos, dentry, dentry->d_name.len, dentry->d_name.name, dentry->d_inode); @@ -182,21 +180,19 @@ more: filp->f_pos++; - /* make sure a dentry wasn't dropped while we didn't have dcache_lock */ + /* make sure a dentry wasn't dropped while we didn't have parent lock */ if (!ceph_i_test(dir, CEPH_I_COMPLETE)) { dout(" lost I_COMPLETE on %p; falling back to mds\n", dir); err = -EAGAIN; goto out; } - spin_lock(&dcache_lock); spin_lock(&parent->d_lock); p = p->prev; /* advance to next dentry */ goto more; out_unlock: spin_unlock(&parent->d_lock); - spin_unlock(&dcache_lock); out: if (last) dput(last); diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c index 2c694447336..2a48cafc174 100644 --- a/fs/ceph/inode.c +++ b/fs/ceph/inode.c @@ -841,7 +841,6 @@ static void ceph_set_dentry_offset(struct dentry *dn) di->offset = ceph_inode(inode)->i_max_offset++; spin_unlock(&inode->i_lock); - spin_lock(&dcache_lock); spin_lock(&dir->d_lock); spin_lock_nested(&dn->d_lock, DENTRY_D_LOCK_NESTED); list_move(&dn->d_u.d_child, &dir->d_subdirs); @@ -849,7 +848,6 @@ static void ceph_set_dentry_offset(struct dentry *dn) dn->d_u.d_child.prev, dn->d_u.d_child.next); spin_unlock(&dn->d_lock); spin_unlock(&dir->d_lock); - spin_unlock(&dcache_lock); } /* @@ -1233,13 +1231,11 @@ retry_lookup: goto retry_lookup; } else { /* reorder parent's d_subdirs */ - spin_lock(&dcache_lock); spin_lock(&parent->d_lock); spin_lock_nested(&dn->d_lock, DENTRY_D_LOCK_NESTED); list_move(&dn->d_u.d_child, &parent->d_subdirs); spin_unlock(&dn->d_lock); spin_unlock(&parent->d_lock); - spin_unlock(&dcache_lock); } di = dn->d_fsdata; diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c index 003698365ec..99b9a2cc14b 100644 --- a/fs/cifs/inode.c +++ b/fs/cifs/inode.c @@ -809,17 +809,14 @@ inode_has_hashed_dentries(struct inode *inode) { struct dentry *dentry; - spin_lock(&dcache_lock); spin_lock(&dcache_inode_lock); list_for_each_entry(dentry, &inode->i_dentry, d_alias) { if (!d_unhashed(dentry) || IS_ROOT(dentry)) { spin_unlock(&dcache_inode_lock); - spin_unlock(&dcache_lock); return true; } } spin_unlock(&dcache_inode_lock); - spin_unlock(&dcache_lock); return false; } diff --git a/fs/coda/cache.c b/fs/coda/cache.c index 859393fca2b..5525e1c660f 100644 --- a/fs/coda/cache.c +++ b/fs/coda/cache.c @@ -93,7 +93,6 @@ static void coda_flag_children(struct dentry *parent, int flag) struct list_head *child; struct dentry *de; - spin_lock(&dcache_lock); spin_lock(&parent->d_lock); list_for_each(child, &parent->d_subdirs) { @@ -104,7 +103,6 @@ static void coda_flag_children(struct dentry *parent, int flag) coda_flag_inode(de->d_inode, flag); } spin_unlock(&parent->d_lock); - spin_unlock(&dcache_lock); return; } diff --git a/fs/configfs/configfs_internal.h b/fs/configfs/configfs_internal.h index e58b4c30e21..026cf68553a 100644 --- a/fs/configfs/configfs_internal.h +++ b/fs/configfs/configfs_internal.h @@ -120,7 +120,6 @@ static inline struct config_item *configfs_get_config_item(struct dentry *dentry { struct config_item * item = NULL; - spin_lock(&dcache_lock); spin_lock(&dentry->d_lock); if (!d_unhashed(dentry)) { struct configfs_dirent * sd = dentry->d_fsdata; @@ -131,7 +130,6 @@ static inline struct config_item *configfs_get_config_item(struct dentry *dentry item = config_item_get(sd->s_element); } spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); return item; } diff --git a/fs/configfs/inode.c b/fs/configfs/inode.c index 79b37765d8f..fb3a55fff82 100644 --- a/fs/configfs/inode.c +++ b/fs/configfs/inode.c @@ -250,18 +250,14 @@ void configfs_drop_dentry(struct configfs_dirent * sd, struct dentry * parent) struct dentry * dentry = sd->s_dentry; if (dentry) { - spin_lock(&dcache_lock); spin_lock(&dentry->d_lock); if (!(d_unhashed(dentry) && dentry->d_inode)) { dget_locked_dlock(dentry); __d_drop(dentry); spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); simple_unlink(parent->d_inode, dentry); - } else { + } else spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); - } } } diff --git a/fs/dcache.c b/fs/dcache.c index a9bc4ecc21e..0dbae053b66 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -54,11 +54,10 @@ * - d_alias, d_inode * * Ordering: - * dcache_lock - * dcache_inode_lock - * dentry->d_lock - * dcache_lru_lock - * dcache_hash_lock + * dcache_inode_lock + * dentry->d_lock + * dcache_lru_lock + * dcache_hash_lock * * If there is an ancestor relationship: * dentry->d_parent->...->d_parent->d_lock @@ -77,12 +76,10 @@ EXPORT_SYMBOL_GPL(sysctl_vfs_cache_pressure); __cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_inode_lock); static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_hash_lock); static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_lru_lock); -__cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_lock); __cacheline_aligned_in_smp DEFINE_SEQLOCK(rename_lock); EXPORT_SYMBOL(rename_lock); EXPORT_SYMBOL(dcache_inode_lock); -EXPORT_SYMBOL(dcache_lock); static struct kmem_cache *dentry_cache __read_mostly; @@ -139,7 +136,7 @@ static void __d_free(struct rcu_head *head) } /* - * no dcache_lock, please. + * no locks, please. */ static void d_free(struct dentry *dentry) { @@ -162,7 +159,6 @@ static void d_free(struct dentry *dentry) static void dentry_iput(struct dentry * dentry) __releases(dentry->d_lock) __releases(dcache_inode_lock) - __releases(dcache_lock) { struct inode *inode = dentry->d_inode; if (inode) { @@ -170,7 +166,6 @@ static void dentry_iput(struct dentry * dentry) list_del_init(&dentry->d_alias); spin_unlock(&dentry->d_lock); spin_unlock(&dcache_inode_lock); - spin_unlock(&dcache_lock); if (!inode->i_nlink) fsnotify_inoderemove(inode); if (dentry->d_op && dentry->d_op->d_iput) @@ -180,7 +175,6 @@ static void dentry_iput(struct dentry * dentry) } else { spin_unlock(&dentry->d_lock); spin_unlock(&dcache_inode_lock); - spin_unlock(&dcache_lock); } } @@ -235,14 +229,13 @@ static void dentry_lru_move_tail(struct dentry *dentry) * * If this is the root of the dentry tree, return NULL. * - * dcache_lock and d_lock and d_parent->d_lock must be held by caller, and - * are dropped by d_kill. + * dentry->d_lock and parent->d_lock must be held by caller, and are dropped by + * d_kill. */ static struct dentry *d_kill(struct dentry *dentry, struct dentry *parent) __releases(dentry->d_lock) __releases(parent->d_lock) __releases(dcache_inode_lock) - __releases(dcache_lock) { dentry->d_parent = NULL; list_del(&dentry->d_u.d_child); @@ -285,11 +278,9 @@ EXPORT_SYMBOL(__d_drop); void d_drop(struct dentry *dentry) { - spin_lock(&dcache_lock); spin_lock(&dentry->d_lock); __d_drop(dentry); spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); } EXPORT_SYMBOL(d_drop); @@ -337,21 +328,10 @@ repeat: else parent = dentry->d_parent; if (dentry->d_count == 1) { - if (!spin_trylock(&dcache_lock)) { - /* - * Something of a livelock possibility we could avoid - * by taking dcache_lock and trying again, but we - * want to reduce dcache_lock anyway so this will - * get improved. - */ -drop1: - spin_unlock(&dentry->d_lock); - goto repeat; - } if (!spin_trylock(&dcache_inode_lock)) { drop2: - spin_unlock(&dcache_lock); - goto drop1; + spin_unlock(&dentry->d_lock); + goto repeat; } if (parent && !spin_trylock(&parent->d_lock)) { spin_unlock(&dcache_inode_lock); @@ -363,7 +343,6 @@ drop2: spin_unlock(&dentry->d_lock); if (parent) spin_unlock(&parent->d_lock); - spin_unlock(&dcache_lock); return; } @@ -387,7 +366,6 @@ drop2: if (parent) spin_unlock(&parent->d_lock); spin_unlock(&dcache_inode_lock); - spin_unlock(&dcache_lock); return; unhash_it: @@ -418,11 +396,9 @@ int d_invalidate(struct dentry * dentry) /* * If it's already been dropped, return OK. */ - spin_lock(&dcache_lock); spin_lock(&dentry->d_lock); if (d_unhashed(dentry)) { spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); return 0; } /* @@ -431,9 +407,7 @@ int d_invalidate(struct dentry * dentry) */ if (!list_empty(&dentry->d_subdirs)) { spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); shrink_dcache_parent(dentry); - spin_lock(&dcache_lock); spin_lock(&dentry->d_lock); } @@ -450,19 +424,17 @@ int d_invalidate(struct dentry * dentry) if (dentry->d_count > 1) { if (dentry->d_inode && S_ISDIR(dentry->d_inode->i_mode)) { spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); return -EBUSY; } } __d_drop(dentry); spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); return 0; } EXPORT_SYMBOL(d_invalidate); -/* This must be called with dcache_lock and d_lock held */ +/* This must be called with d_lock held */ static inline struct dentry * __dget_locked_dlock(struct dentry *dentry) { dentry->d_count++; @@ -470,7 +442,7 @@ static inline struct dentry * __dget_locked_dlock(struct dentry *dentry) return dentry; } -/* This should be called _only_ with dcache_lock held */ +/* This must be called with d_lock held */ static inline struct dentry * __dget_locked(struct dentry *dentry) { spin_lock(&dentry->d_lock); @@ -575,11 +547,9 @@ struct dentry *d_find_alias(struct inode *inode) struct dentry *de = NULL; if (!list_empty(&inode->i_dentry)) { - spin_lock(&dcache_lock); spin_lock(&dcache_inode_lock); de = __d_find_alias(inode, 0); spin_unlock(&dcache_inode_lock); - spin_unlock(&dcache_lock); } return de; } @@ -593,7 +563,6 @@ void d_prune_aliases(struct inode *inode) { struct dentry *dentry; restart: - spin_lock(&dcache_lock); spin_lock(&dcache_inode_lock); list_for_each_entry(dentry, &inode->i_dentry, d_alias) { spin_lock(&dentry->d_lock); @@ -602,14 +571,12 @@ restart: __d_drop(dentry); spin_unlock(&dentry->d_lock); spin_unlock(&dcache_inode_lock); - spin_unlock(&dcache_lock); dput(dentry); goto restart; } spin_unlock(&dentry->d_lock); } spin_unlock(&dcache_inode_lock); - spin_unlock(&dcache_lock); } EXPORT_SYMBOL(d_prune_aliases); @@ -625,17 +592,14 @@ static void prune_one_dentry(struct dentry *dentry, struct dentry *parent) __releases(dentry->d_lock) __releases(parent->d_lock) __releases(dcache_inode_lock) - __releases(dcache_lock) { __d_drop(dentry); dentry = d_kill(dentry, parent); /* - * Prune ancestors. Locking is simpler than in dput(), - * because dcache_lock needs to be taken anyway. + * Prune ancestors. */ while (dentry) { - spin_lock(&dcache_lock); spin_lock(&dcache_inode_lock); again: spin_lock(&dentry->d_lock); @@ -653,7 +617,6 @@ again: spin_unlock(&parent->d_lock); spin_unlock(&dentry->d_lock); spin_unlock(&dcache_inode_lock); - spin_unlock(&dcache_lock); return; } @@ -702,8 +665,7 @@ relock: spin_unlock(&dcache_lru_lock); prune_one_dentry(dentry, parent); - /* dcache_lock, dcache_inode_lock and dentry->d_lock dropped */ - spin_lock(&dcache_lock); + /* dcache_inode_lock and dentry->d_lock dropped */ spin_lock(&dcache_inode_lock); spin_lock(&dcache_lru_lock); } @@ -725,7 +687,6 @@ static void __shrink_dcache_sb(struct super_block *sb, int *count, int flags) LIST_HEAD(tmp); int cnt = *count; - spin_lock(&dcache_lock); spin_lock(&dcache_inode_lock); relock: spin_lock(&dcache_lru_lock); @@ -766,7 +727,6 @@ relock: list_splice(&referenced, &sb->s_dentry_lru); spin_unlock(&dcache_lru_lock); spin_unlock(&dcache_inode_lock); - spin_unlock(&dcache_lock); } /** @@ -788,7 +748,6 @@ static void prune_dcache(int count) if (unused == 0 || count == 0) return; - spin_lock(&dcache_lock); if (count >= unused) prune_ratio = 1; else @@ -825,11 +784,9 @@ static void prune_dcache(int count) if (down_read_trylock(&sb->s_umount)) { if ((sb->s_root != NULL) && (!list_empty(&sb->s_dentry_lru))) { - spin_unlock(&dcache_lock); __shrink_dcache_sb(sb, &w_count, DCACHE_REFERENCED); pruned -= w_count; - spin_lock(&dcache_lock); } up_read(&sb->s_umount); } @@ -845,7 +802,6 @@ static void prune_dcache(int count) if (p) __put_super(p); spin_unlock(&sb_lock); - spin_unlock(&dcache_lock); } /** @@ -859,7 +815,6 @@ void shrink_dcache_sb(struct super_block *sb) { LIST_HEAD(tmp); - spin_lock(&dcache_lock); spin_lock(&dcache_inode_lock); spin_lock(&dcache_lru_lock); while (!list_empty(&sb->s_dentry_lru)) { @@ -868,7 +823,6 @@ void shrink_dcache_sb(struct super_block *sb) } spin_unlock(&dcache_lru_lock); spin_unlock(&dcache_inode_lock); - spin_unlock(&dcache_lock); } EXPORT_SYMBOL(shrink_dcache_sb); @@ -885,12 +839,10 @@ static void shrink_dcache_for_umount_subtree(struct dentry *dentry) BUG_ON(!IS_ROOT(dentry)); /* detach this root from the system */ - spin_lock(&dcache_lock); spin_lock(&dentry->d_lock); dentry_lru_del(dentry); __d_drop(dentry); spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); for (;;) { /* descend to the first leaf in the current subtree */ @@ -899,7 +851,6 @@ static void shrink_dcache_for_umount_subtree(struct dentry *dentry) /* this is a branch with children - detach all of them * from the system in one go */ - spin_lock(&dcache_lock); spin_lock(&dentry->d_lock); list_for_each_entry(loop, &dentry->d_subdirs, d_u.d_child) { @@ -910,7 +861,6 @@ static void shrink_dcache_for_umount_subtree(struct dentry *dentry) spin_unlock(&loop->d_lock); } spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); /* move to the first child */ dentry = list_entry(dentry->d_subdirs.next, @@ -977,8 +927,7 @@ static void shrink_dcache_for_umount_subtree(struct dentry *dentry) /* * destroy the dentries attached to a superblock on unmounting - * - we don't need to use dentry->d_lock, and only need dcache_lock when - * removing the dentry from the system lists and hashes because: + * - we don't need to use dentry->d_lock because: * - the superblock is detached from all mountings and open files, so the * dentry trees will not be rearranged by the VFS * - s_umount is write-locked, so the memory pressure shrinker will ignore @@ -1029,7 +978,6 @@ rename_retry: this_parent = parent; seq = read_seqbegin(&rename_lock); - spin_lock(&dcache_lock); if (d_mountpoint(parent)) goto positive; spin_lock(&this_parent->d_lock); @@ -1075,7 +1023,6 @@ resume: if (this_parent != child->d_parent || read_seqretry(&rename_lock, seq)) { spin_unlock(&this_parent->d_lock); - spin_unlock(&dcache_lock); rcu_read_unlock(); goto rename_retry; } @@ -1084,12 +1031,10 @@ resume: goto resume; } spin_unlock(&this_parent->d_lock); - spin_unlock(&dcache_lock); if (read_seqretry(&rename_lock, seq)) goto rename_retry; return 0; /* No mount points found in tree */ positive: - spin_unlock(&dcache_lock); if (read_seqretry(&rename_lock, seq)) goto rename_retry; return 1; @@ -1121,7 +1066,6 @@ rename_retry: this_parent = parent; seq = read_seqbegin(&rename_lock); - spin_lock(&dcache_lock); spin_lock(&this_parent->d_lock); repeat: next = this_parent->d_subdirs.next; @@ -1185,7 +1129,6 @@ resume: if (this_parent != child->d_parent || read_seqretry(&rename_lock, seq)) { spin_unlock(&this_parent->d_lock); - spin_unlock(&dcache_lock); rcu_read_unlock(); goto rename_retry; } @@ -1195,7 +1138,6 @@ resume: } out: spin_unlock(&this_parent->d_lock); - spin_unlock(&dcache_lock); if (read_seqretry(&rename_lock, seq)) goto rename_retry; return found; @@ -1297,7 +1239,6 @@ struct dentry *d_alloc(struct dentry * parent, const struct qstr *name) INIT_LIST_HEAD(&dentry->d_u.d_child); if (parent) { - spin_lock(&dcache_lock); spin_lock(&parent->d_lock); spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED); dentry->d_parent = dget_dlock(parent); @@ -1305,7 +1246,6 @@ struct dentry *d_alloc(struct dentry * parent, const struct qstr *name) list_add(&dentry->d_u.d_child, &parent->d_subdirs); spin_unlock(&dentry->d_lock); spin_unlock(&parent->d_lock); - spin_unlock(&dcache_lock); } this_cpu_inc(nr_dentry); @@ -1325,7 +1265,6 @@ struct dentry *d_alloc_name(struct dentry *parent, const char *name) } EXPORT_SYMBOL(d_alloc_name); -/* the caller must hold dcache_lock */ static void __d_instantiate(struct dentry *dentry, struct inode *inode) { spin_lock(&dentry->d_lock); @@ -1354,11 +1293,9 @@ static void __d_instantiate(struct dentry *dentry, struct inode *inode) void d_instantiate(struct dentry *entry, struct inode * inode) { BUG_ON(!list_empty(&entry->d_alias)); - spin_lock(&dcache_lock); spin_lock(&dcache_inode_lock); __d_instantiate(entry, inode); spin_unlock(&dcache_inode_lock); - spin_unlock(&dcache_lock); security_d_instantiate(entry, inode); } EXPORT_SYMBOL(d_instantiate); @@ -1422,11 +1359,9 @@ struct dentry *d_instantiate_unique(struct dentry *entry, struct inode *inode) BUG_ON(!list_empty(&entry->d_alias)); - spin_lock(&dcache_lock); spin_lock(&dcache_inode_lock); result = __d_instantiate_unique(entry, inode); spin_unlock(&dcache_inode_lock); - spin_unlock(&dcache_lock); if (!result) { security_d_instantiate(entry, inode); @@ -1515,12 +1450,11 @@ struct dentry *d_obtain_alias(struct inode *inode) } tmp->d_parent = tmp; /* make sure dput doesn't croak */ - spin_lock(&dcache_lock); + spin_lock(&dcache_inode_lock); res = __d_find_alias(inode, 0); if (res) { spin_unlock(&dcache_inode_lock); - spin_unlock(&dcache_lock); dput(tmp); goto out_iput; } @@ -1538,7 +1472,6 @@ struct dentry *d_obtain_alias(struct inode *inode) spin_unlock(&tmp->d_lock); spin_unlock(&dcache_inode_lock); - spin_unlock(&dcache_lock); return tmp; out_iput: @@ -1568,21 +1501,18 @@ struct dentry *d_splice_alias(struct inode *inode, struct dentry *dentry) struct dentry *new = NULL; if (inode && S_ISDIR(inode->i_mode)) { - spin_lock(&dcache_lock); spin_lock(&dcache_inode_lock); new = __d_find_alias(inode, 1); if (new) { BUG_ON(!(new->d_flags & DCACHE_DISCONNECTED)); spin_unlock(&dcache_inode_lock); - spin_unlock(&dcache_lock); security_d_instantiate(new, inode); d_move(new, dentry); iput(inode); } else { - /* already taking dcache_lock, so d_add() by hand */ + /* already taking dcache_inode_lock, so d_add() by hand */ __d_instantiate(dentry, inode); spin_unlock(&dcache_inode_lock); - spin_unlock(&dcache_lock); security_d_instantiate(dentry, inode); d_rehash(dentry); } @@ -1655,12 +1585,10 @@ struct dentry *d_add_ci(struct dentry *dentry, struct inode *inode, * Negative dentry: instantiate it unless the inode is a directory and * already has a dentry. */ - spin_lock(&dcache_lock); spin_lock(&dcache_inode_lock); if (!S_ISDIR(inode->i_mode) || list_empty(&inode->i_dentry)) { __d_instantiate(found, inode); spin_unlock(&dcache_inode_lock); - spin_unlock(&dcache_lock); security_d_instantiate(found, inode); return found; } @@ -1672,7 +1600,6 @@ struct dentry *d_add_ci(struct dentry *dentry, struct inode *inode, new = list_entry(inode->i_dentry.next, struct dentry, d_alias); dget_locked(new); spin_unlock(&dcache_inode_lock); - spin_unlock(&dcache_lock); security_d_instantiate(found, inode); d_move(new, found); iput(inode); @@ -1843,7 +1770,6 @@ int d_validate(struct dentry *dentry, struct dentry *dparent) { struct dentry *child; - spin_lock(&dcache_lock); spin_lock(&dparent->d_lock); list_for_each_entry(child, &dparent->d_subdirs, d_u.d_child) { if (dentry == child) { @@ -1851,12 +1777,10 @@ int d_validate(struct dentry *dentry, struct dentry *dparent) __dget_locked_dlock(dentry); spin_unlock(&dentry->d_lock); spin_unlock(&dparent->d_lock); - spin_unlock(&dcache_lock); return 1; } } spin_unlock(&dparent->d_lock); - spin_unlock(&dcache_lock); return 0; } @@ -1889,7 +1813,6 @@ void d_delete(struct dentry * dentry) /* * Are we the only user? */ - spin_lock(&dcache_lock); spin_lock(&dcache_inode_lock); spin_lock(&dentry->d_lock); isdir = S_ISDIR(dentry->d_inode->i_mode); @@ -1905,7 +1828,6 @@ void d_delete(struct dentry * dentry) spin_unlock(&dentry->d_lock); spin_unlock(&dcache_inode_lock); - spin_unlock(&dcache_lock); fsnotify_nameremove(dentry, isdir); } @@ -1932,13 +1854,11 @@ static void _d_rehash(struct dentry * entry) void d_rehash(struct dentry * entry) { - spin_lock(&dcache_lock); spin_lock(&entry->d_lock); spin_lock(&dcache_hash_lock); _d_rehash(entry); spin_unlock(&dcache_hash_lock); spin_unlock(&entry->d_lock); - spin_unlock(&dcache_lock); } EXPORT_SYMBOL(d_rehash); @@ -1961,11 +1881,9 @@ void dentry_update_name_case(struct dentry *dentry, struct qstr *name) BUG_ON(!mutex_is_locked(&dentry->d_inode->i_mutex)); BUG_ON(dentry->d_name.len != name->len); /* d_lookup gives this */ - spin_lock(&dcache_lock); spin_lock(&dentry->d_lock); memcpy((unsigned char *)dentry->d_name.name, name->name, name->len); spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); } EXPORT_SYMBOL(dentry_update_name_case); @@ -2058,14 +1976,14 @@ static void dentry_unlock_parents_for_move(struct dentry *dentry, * The hash value has to match the hash queue that the dentry is on.. */ /* - * d_move_locked - move a dentry + * d_move - move a dentry * @dentry: entry to move * @target: new dentry * * Update the dcache to reflect the move of a file name. Negative * dcache entries should not be moved in this way. */ -static void d_move_locked(struct dentry * dentry, struct dentry * target) +void d_move(struct dentry * dentry, struct dentry * target) { if (!dentry->d_inode) printk(KERN_WARNING "VFS: moving negative dcache entry\n"); @@ -2114,22 +2032,6 @@ static void d_move_locked(struct dentry * dentry, struct dentry * target) spin_unlock(&dentry->d_lock); write_sequnlock(&rename_lock); } - -/** - * d_move - move a dentry - * @dentry: entry to move - * @target: new dentry - * - * Update the dcache to reflect the move of a file name. Negative - * dcache entries should not be moved in this way. - */ - -void d_move(struct dentry * dentry, struct dentry * target) -{ - spin_lock(&dcache_lock); - d_move_locked(dentry, target); - spin_unlock(&dcache_lock); -} EXPORT_SYMBOL(d_move); /** @@ -2155,13 +2057,12 @@ struct dentry *d_ancestor(struct dentry *p1, struct dentry *p2) * This helper attempts to cope with remotely renamed directories * * It assumes that the caller is already holding - * dentry->d_parent->d_inode->i_mutex and the dcache_lock + * dentry->d_parent->d_inode->i_mutex and the dcache_inode_lock * * Note: If ever the locking in lock_rename() changes, then please * remember to update this too... */ static struct dentry *__d_unalias(struct dentry *dentry, struct dentry *alias) - __releases(dcache_lock) __releases(dcache_inode_lock) { struct mutex *m1 = NULL, *m2 = NULL; @@ -2185,11 +2086,10 @@ static struct dentry *__d_unalias(struct dentry *dentry, struct dentry *alias) goto out_err; m2 = &alias->d_parent->d_inode->i_mutex; out_unalias: - d_move_locked(alias, dentry); + d_move(alias, dentry); ret = alias; out_err: spin_unlock(&dcache_inode_lock); - spin_unlock(&dcache_lock); if (m2) mutex_unlock(m2); if (m1) @@ -2249,7 +2149,6 @@ struct dentry *d_materialise_unique(struct dentry *dentry, struct inode *inode) BUG_ON(!d_unhashed(dentry)); - spin_lock(&dcache_lock); spin_lock(&dcache_inode_lock); if (!inode) { @@ -2295,7 +2194,6 @@ found: spin_unlock(&dcache_hash_lock); spin_unlock(&actual->d_lock); spin_unlock(&dcache_inode_lock); - spin_unlock(&dcache_lock); out_nolock: if (actual == dentry) { security_d_instantiate(dentry, inode); @@ -2307,7 +2205,6 @@ out_nolock: shouldnt_be_hashed: spin_unlock(&dcache_inode_lock); - spin_unlock(&dcache_lock); BUG(); } EXPORT_SYMBOL_GPL(d_materialise_unique); @@ -2421,11 +2318,9 @@ char *__d_path(const struct path *path, struct path *root, int error; prepend(&res, &buflen, "\0", 1); - spin_lock(&dcache_lock); write_seqlock(&rename_lock); error = prepend_path(path, root, &res, &buflen); write_sequnlock(&rename_lock); - spin_unlock(&dcache_lock); if (error) return ERR_PTR(error); @@ -2487,14 +2382,12 @@ char *d_path(const struct path *path, char *buf, int buflen) return path->dentry->d_op->d_dname(path->dentry, buf, buflen); get_fs_root(current->fs, &root); - spin_lock(&dcache_lock); write_seqlock(&rename_lock); tmp = root; error = path_with_deleted(path, &tmp, &res, &buflen); if (error) res = ERR_PTR(error); write_sequnlock(&rename_lock); - spin_unlock(&dcache_lock); path_put(&root); return res; } @@ -2520,14 +2413,12 @@ char *d_path_with_unreachable(const struct path *path, char *buf, int buflen) return path->dentry->d_op->d_dname(path->dentry, buf, buflen); get_fs_root(current->fs, &root); - spin_lock(&dcache_lock); write_seqlock(&rename_lock); tmp = root; error = path_with_deleted(path, &tmp, &res, &buflen); if (!error && !path_equal(&tmp, &root)) error = prepend_unreachable(&res, &buflen); write_sequnlock(&rename_lock); - spin_unlock(&dcache_lock); path_put(&root); if (error) res = ERR_PTR(error); @@ -2594,11 +2485,9 @@ char *dentry_path_raw(struct dentry *dentry, char *buf, int buflen) { char *retval; - spin_lock(&dcache_lock); write_seqlock(&rename_lock); retval = __dentry_path(dentry, buf, buflen); write_sequnlock(&rename_lock); - spin_unlock(&dcache_lock); return retval; } @@ -2609,7 +2498,6 @@ char *dentry_path(struct dentry *dentry, char *buf, int buflen) char *p = NULL; char *retval; - spin_lock(&dcache_lock); write_seqlock(&rename_lock); if (d_unlinked(dentry)) { p = buf + buflen; @@ -2619,12 +2507,10 @@ char *dentry_path(struct dentry *dentry, char *buf, int buflen) } retval = __dentry_path(dentry, buf, buflen); write_sequnlock(&rename_lock); - spin_unlock(&dcache_lock); if (!IS_ERR(retval) && p) *p = '/'; /* restore '/' overriden with '\0' */ return retval; Elong: - spin_unlock(&dcache_lock); return ERR_PTR(-ENAMETOOLONG); } @@ -2658,7 +2544,6 @@ SYSCALL_DEFINE2(getcwd, char __user *, buf, unsigned long, size) get_fs_root_and_pwd(current->fs, &root, &pwd); error = -ENOENT; - spin_lock(&dcache_lock); write_seqlock(&rename_lock); if (!d_unlinked(pwd.dentry)) { unsigned long len; @@ -2669,7 +2554,6 @@ SYSCALL_DEFINE2(getcwd, char __user *, buf, unsigned long, size) prepend(&cwd, &buflen, "\0", 1); error = prepend_path(&pwd, &tmp, &cwd, &buflen); write_sequnlock(&rename_lock); - spin_unlock(&dcache_lock); if (error) goto out; @@ -2690,7 +2574,6 @@ SYSCALL_DEFINE2(getcwd, char __user *, buf, unsigned long, size) } } else { write_sequnlock(&rename_lock); - spin_unlock(&dcache_lock); } out: @@ -2776,7 +2659,6 @@ void d_genocide(struct dentry *root) rename_retry: this_parent = root; seq = read_seqbegin(&rename_lock); - spin_lock(&dcache_lock); spin_lock(&this_parent->d_lock); repeat: next = this_parent->d_subdirs.next; @@ -2823,7 +2705,6 @@ resume: if (this_parent != child->d_parent || read_seqretry(&rename_lock, seq)) { spin_unlock(&this_parent->d_lock); - spin_unlock(&dcache_lock); rcu_read_unlock(); goto rename_retry; } @@ -2832,7 +2713,6 @@ resume: goto resume; } spin_unlock(&this_parent->d_lock); - spin_unlock(&dcache_lock); if (read_seqretry(&rename_lock, seq)) goto rename_retry; } diff --git a/fs/exportfs/expfs.c b/fs/exportfs/expfs.c index 84b8c460a78..53a5c08fb63 100644 --- a/fs/exportfs/expfs.c +++ b/fs/exportfs/expfs.c @@ -47,24 +47,20 @@ find_acceptable_alias(struct dentry *result, if (acceptable(context, result)) return result; - spin_lock(&dcache_lock); spin_lock(&dcache_inode_lock); list_for_each_entry(dentry, &result->d_inode->i_dentry, d_alias) { dget_locked(dentry); spin_unlock(&dcache_inode_lock); - spin_unlock(&dcache_lock); if (toput) dput(toput); if (dentry != result && acceptable(context, dentry)) { dput(result); return dentry; } - spin_lock(&dcache_lock); spin_lock(&dcache_inode_lock); toput = dentry; } spin_unlock(&dcache_inode_lock); - spin_unlock(&dcache_lock); if (toput) dput(toput); diff --git a/fs/libfs.c b/fs/libfs.c index cc4794914b5..28b36663c44 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -100,7 +100,6 @@ loff_t dcache_dir_lseek(struct file *file, loff_t offset, int origin) struct dentry *cursor = file->private_data; loff_t n = file->f_pos - 2; - spin_lock(&dcache_lock); spin_lock(&dentry->d_lock); /* d_lock not required for cursor */ list_del(&cursor->d_u.d_child); @@ -116,7 +115,6 @@ loff_t dcache_dir_lseek(struct file *file, loff_t offset, int origin) } list_add_tail(&cursor->d_u.d_child, p); spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); } } mutex_unlock(&dentry->d_inode->i_mutex); @@ -159,7 +157,6 @@ int dcache_readdir(struct file * filp, void * dirent, filldir_t filldir) i++; /* fallthrough */ default: - spin_lock(&dcache_lock); spin_lock(&dentry->d_lock); if (filp->f_pos == 2) list_move(q, &dentry->d_subdirs); @@ -175,13 +172,11 @@ int dcache_readdir(struct file * filp, void * dirent, filldir_t filldir) spin_unlock(&next->d_lock); spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); if (filldir(dirent, next->d_name.name, next->d_name.len, filp->f_pos, next->d_inode->i_ino, dt_type(next->d_inode)) < 0) return 0; - spin_lock(&dcache_lock); spin_lock(&dentry->d_lock); spin_lock_nested(&next->d_lock, DENTRY_D_LOCK_NESTED); /* next is still alive */ @@ -191,7 +186,6 @@ int dcache_readdir(struct file * filp, void * dirent, filldir_t filldir) filp->f_pos++; } spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); } return 0; } @@ -285,7 +279,6 @@ int simple_empty(struct dentry *dentry) struct dentry *child; int ret = 0; - spin_lock(&dcache_lock); spin_lock(&dentry->d_lock); list_for_each_entry(child, &dentry->d_subdirs, d_u.d_child) { spin_lock_nested(&child->d_lock, DENTRY_D_LOCK_NESTED); @@ -298,7 +291,6 @@ int simple_empty(struct dentry *dentry) ret = 1; out: spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); return ret; } diff --git a/fs/namei.c b/fs/namei.c index cbfa5fb3107..5642bc2be41 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -612,8 +612,8 @@ int follow_up(struct path *path) return 1; } -/* no need for dcache_lock, as serialization is taken care in - * namespace.c +/* + * serialization is taken care of in namespace.c */ static int __follow_mount(struct path *path) { @@ -645,9 +645,6 @@ static void follow_mount(struct path *path) } } -/* no need for dcache_lock, as serialization is taken care in - * namespace.c - */ int follow_down(struct path *path) { struct vfsmount *mounted; @@ -2131,12 +2128,10 @@ void dentry_unhash(struct dentry *dentry) { dget(dentry); shrink_dcache_parent(dentry); - spin_lock(&dcache_lock); spin_lock(&dentry->d_lock); if (dentry->d_count == 2) __d_drop(dentry); spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); } int vfs_rmdir(struct inode *dir, struct dentry *dentry) diff --git a/fs/ncpfs/dir.c b/fs/ncpfs/dir.c index 102278ed38b..de15c533311 100644 --- a/fs/ncpfs/dir.c +++ b/fs/ncpfs/dir.c @@ -391,7 +391,6 @@ ncp_dget_fpos(struct dentry *dentry, struct dentry *parent, unsigned long fpos) } /* If a pointer is invalid, we search the dentry. */ - spin_lock(&dcache_lock); spin_lock(&parent->d_lock); next = parent->d_subdirs.next; while (next != &parent->d_subdirs) { @@ -402,13 +401,11 @@ ncp_dget_fpos(struct dentry *dentry, struct dentry *parent, unsigned long fpos) else dent = NULL; spin_unlock(&parent->d_lock); - spin_unlock(&dcache_lock); goto out; } next = next->next; } spin_unlock(&parent->d_lock); - spin_unlock(&dcache_lock); return NULL; out: diff --git a/fs/ncpfs/ncplib_kernel.h b/fs/ncpfs/ncplib_kernel.h index c4b718ff9a6..1220df75ff2 100644 --- a/fs/ncpfs/ncplib_kernel.h +++ b/fs/ncpfs/ncplib_kernel.h @@ -193,7 +193,6 @@ ncp_renew_dentries(struct dentry *parent) struct list_head *next; struct dentry *dentry; - spin_lock(&dcache_lock); spin_lock(&parent->d_lock); next = parent->d_subdirs.next; while (next != &parent->d_subdirs) { @@ -207,7 +206,6 @@ ncp_renew_dentries(struct dentry *parent) next = next->next; } spin_unlock(&parent->d_lock); - spin_unlock(&dcache_lock); } static inline void @@ -217,7 +215,6 @@ ncp_invalidate_dircache_entries(struct dentry *parent) struct list_head *next; struct dentry *dentry; - spin_lock(&dcache_lock); spin_lock(&parent->d_lock); next = parent->d_subdirs.next; while (next != &parent->d_subdirs) { @@ -227,7 +224,6 @@ ncp_invalidate_dircache_entries(struct dentry *parent) next = next->next; } spin_unlock(&parent->d_lock); - spin_unlock(&dcache_lock); } struct ncp_cache_head { diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index 12de824edb5..eb77471b882 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -1718,11 +1718,9 @@ static int nfs_unlink(struct inode *dir, struct dentry *dentry) dfprintk(VFS, "NFS: unlink(%s/%ld, %s)\n", dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); - spin_lock(&dcache_lock); spin_lock(&dentry->d_lock); if (dentry->d_count > 1) { spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); /* Start asynchronous writeout of the inode */ write_inode_now(dentry->d_inode, 0); error = nfs_sillyrename(dir, dentry); @@ -1733,7 +1731,6 @@ static int nfs_unlink(struct inode *dir, struct dentry *dentry) need_rehash = 1; } spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); error = nfs_safe_remove(dentry); if (!error || error == -ENOENT) { nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); diff --git a/fs/nfs/getroot.c b/fs/nfs/getroot.c index 850f67d5f0a..b3e36c3430d 100644 --- a/fs/nfs/getroot.c +++ b/fs/nfs/getroot.c @@ -63,13 +63,11 @@ static int nfs_superblock_set_dummy_root(struct super_block *sb, struct inode *i * This again causes shrink_dcache_for_umount_subtree() to * Oops, since the test for IS_ROOT() will fail. */ - spin_lock(&dcache_lock); spin_lock(&dcache_inode_lock); spin_lock(&sb->s_root->d_lock); list_del_init(&sb->s_root->d_alias); spin_unlock(&sb->s_root->d_lock); spin_unlock(&dcache_inode_lock); - spin_unlock(&dcache_lock); } return 0; } diff --git a/fs/nfs/namespace.c b/fs/nfs/namespace.c index 78c0ebb0b07..74aaf3963c1 100644 --- a/fs/nfs/namespace.c +++ b/fs/nfs/namespace.c @@ -60,7 +60,6 @@ rename_retry: seq = read_seqbegin(&rename_lock); rcu_read_lock(); - spin_lock(&dcache_lock); while (!IS_ROOT(dentry) && dentry != droot) { namelen = dentry->d_name.len; buflen -= namelen + 1; @@ -71,7 +70,6 @@ rename_retry: *--end = '/'; dentry = dentry->d_parent; } - spin_unlock(&dcache_lock); rcu_read_unlock(); if (read_seqretry(&rename_lock, seq)) goto rename_retry; @@ -91,7 +89,6 @@ rename_retry: memcpy(end, base, namelen); return end; Elong_unlock: - spin_unlock(&dcache_lock); rcu_read_unlock(); if (read_seqretry(&rename_lock, seq)) goto rename_retry; diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c index ae769fc9b66..9be6ec1f36d 100644 --- a/fs/notify/fsnotify.c +++ b/fs/notify/fsnotify.c @@ -59,7 +59,6 @@ void __fsnotify_update_child_dentry_flags(struct inode *inode) /* determine if the children should tell inode about their events */ watched = fsnotify_inode_watches_children(inode); - spin_lock(&dcache_lock); spin_lock(&dcache_inode_lock); /* run all of the dentries associated with this inode. Since this is a * directory, there damn well better only be one item on this list */ @@ -84,7 +83,6 @@ void __fsnotify_update_child_dentry_flags(struct inode *inode) spin_unlock(&alias->d_lock); } spin_unlock(&dcache_inode_lock); - spin_unlock(&dcache_lock); } /* Notify this dentry's parent about a child's events. */ diff --git a/fs/ocfs2/dcache.c b/fs/ocfs2/dcache.c index c31b5c647ac..b7de749bdd1 100644 --- a/fs/ocfs2/dcache.c +++ b/fs/ocfs2/dcache.c @@ -169,7 +169,6 @@ struct dentry *ocfs2_find_local_alias(struct inode *inode, struct list_head *p; struct dentry *dentry = NULL; - spin_lock(&dcache_lock); spin_lock(&dcache_inode_lock); list_for_each(p, &inode->i_dentry) { dentry = list_entry(p, struct dentry, d_alias); @@ -189,7 +188,6 @@ struct dentry *ocfs2_find_local_alias(struct inode *inode, } spin_unlock(&dcache_inode_lock); - spin_unlock(&dcache_lock); return dentry; } diff --git a/include/linux/dcache.h b/include/linux/dcache.h index c963ebada92..a2ceb94b0e3 100644 --- a/include/linux/dcache.h +++ b/include/linux/dcache.h @@ -183,7 +183,6 @@ struct dentry_operations { #define DCACHE_GENOCIDE 0x0200 extern spinlock_t dcache_inode_lock; -extern spinlock_t dcache_lock; extern seqlock_t rename_lock; static inline int dname_external(struct dentry *dentry) @@ -296,8 +295,8 @@ extern char *dentry_path(struct dentry *, char *, int); * destroyed when it has references. dget() should never be * called for dentries with zero reference counter. For these cases * (preferably none, functions in dcache.c are sufficient for normal - * needs and they take necessary precautions) you should hold dcache_lock - * and call dget_locked() instead of dget(). + * needs and they take necessary precautions) you should hold d_lock + * and call dget_dlock() instead of dget(). */ static inline struct dentry *dget_dlock(struct dentry *dentry) { diff --git a/include/linux/fs.h b/include/linux/fs.h index 090f0eacde2..296cf2fde94 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1378,7 +1378,7 @@ struct super_block { #else struct list_head s_files; #endif - /* s_dentry_lru and s_nr_dentry_unused are protected by dcache_lock */ + /* s_dentry_lru, s_nr_dentry_unused protected by dcache.c lru locks */ struct list_head s_dentry_lru; /* unused dentry lru */ int s_nr_dentry_unused; /* # of dentry on lru */ @@ -2446,6 +2446,10 @@ static inline ino_t parent_ino(struct dentry *dentry) { ino_t res; + /* + * Don't strictly need d_lock here? If the parent ino could change + * then surely we'd have a deeper race in the caller? + */ spin_lock(&dentry->d_lock); res = dentry->d_parent->d_inode->i_ino; spin_unlock(&dentry->d_lock); diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h index b10bcdeaef7..2a53f10712b 100644 --- a/include/linux/fsnotify.h +++ b/include/linux/fsnotify.h @@ -17,7 +17,6 @@ /* * fsnotify_d_instantiate - instantiate a dentry for inode - * Called with dcache_lock held. */ static inline void fsnotify_d_instantiate(struct dentry *dentry, struct inode *inode) @@ -62,7 +61,6 @@ static inline int fsnotify_perm(struct file *file, int mask) /* * fsnotify_d_move - dentry has been moved - * Called with dcache_lock and dentry->d_lock held. */ static inline void fsnotify_d_move(struct dentry *dentry) { diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h index 7380763595d..69ad89b5048 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h @@ -329,9 +329,15 @@ static inline void __fsnotify_update_dcache_flags(struct dentry *dentry) { struct dentry *parent; - assert_spin_locked(&dcache_lock); assert_spin_locked(&dentry->d_lock); + /* + * Serialisation of setting PARENT_WATCHED on the dentries is provided + * by d_lock. If inotify_inode_watched changes after we have taken + * d_lock, the following __fsnotify_update_child_dentry_flags call will + * find our entry, so it will spin until we complete here, and update + * us with the new state. + */ parent = dentry->d_parent; if (parent->d_inode && fsnotify_inode_watches_children(parent->d_inode)) dentry->d_flags |= DCACHE_FSNOTIFY_PARENT_WATCHED; @@ -341,15 +347,12 @@ static inline void __fsnotify_update_dcache_flags(struct dentry *dentry) /* * fsnotify_d_instantiate - instantiate a dentry for inode - * Called with dcache_lock held. */ static inline void __fsnotify_d_instantiate(struct dentry *dentry, struct inode *inode) { if (!inode) return; - assert_spin_locked(&dcache_lock); - spin_lock(&dentry->d_lock); __fsnotify_update_dcache_flags(dentry); spin_unlock(&dentry->d_lock); diff --git a/include/linux/namei.h b/include/linux/namei.h index 05b441d9364..aec730b5393 100644 --- a/include/linux/namei.h +++ b/include/linux/namei.h @@ -41,7 +41,6 @@ enum {LAST_NORM, LAST_ROOT, LAST_DOT, LAST_DOTDOT, LAST_BIND}; * - require a directory * - ending slashes ok even for nonexistent files * - internal "there are more path components" flag - * - locked when lookup done with dcache_lock held * - dentry cache is untrusted; force a real lookup */ #define LOOKUP_FOLLOW 1 diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 7b4705b51d4..1864cb6a6a5 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -876,7 +876,6 @@ static void cgroup_clear_directory(struct dentry *dentry) struct list_head *node; BUG_ON(!mutex_is_locked(&dentry->d_inode->i_mutex)); - spin_lock(&dcache_lock); spin_lock(&dentry->d_lock); node = dentry->d_subdirs.next; while (node != &dentry->d_subdirs) { @@ -891,18 +890,15 @@ static void cgroup_clear_directory(struct dentry *dentry) dget_locked_dlock(d); spin_unlock(&d->d_lock); spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); d_delete(d); simple_unlink(dentry->d_inode, d); dput(d); - spin_lock(&dcache_lock); spin_lock(&dentry->d_lock); } else spin_unlock(&d->d_lock); node = dentry->d_subdirs.next; } spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); } /* @@ -914,14 +910,12 @@ static void cgroup_d_remove_dir(struct dentry *dentry) cgroup_clear_directory(dentry); - spin_lock(&dcache_lock); parent = dentry->d_parent; spin_lock(&parent->d_lock); spin_lock(&dentry->d_lock); list_del_init(&dentry->d_u.d_child); spin_unlock(&dentry->d_lock); spin_unlock(&parent->d_lock); - spin_unlock(&dcache_lock); remove_dir(dentry); } diff --git a/mm/filemap.c b/mm/filemap.c index 6b9aee20f24..ca389394fa2 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -102,9 +102,6 @@ * ->inode_lock (zap_pte_range->set_page_dirty) * ->private_lock (zap_pte_range->__set_page_dirty_buffers) * - * ->task->proc_lock - * ->dcache_lock (proc_pid_lookup) - * * (code doesn't rely on that order, so you could switch it around) * ->tasklist_lock (memory_failure, collect_procs_ao) * ->i_mmap_lock diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c index 017ec096446..2285d693f29 100644 --- a/security/selinux/selinuxfs.c +++ b/security/selinux/selinuxfs.c @@ -1145,7 +1145,6 @@ static void sel_remove_entries(struct dentry *de) { struct list_head *node; - spin_lock(&dcache_lock); spin_lock(&de->d_lock); node = de->d_subdirs.next; while (node != &de->d_subdirs) { @@ -1158,11 +1157,9 @@ static void sel_remove_entries(struct dentry *de) dget_locked_dlock(d); spin_unlock(&de->d_lock); spin_unlock(&d->d_lock); - spin_unlock(&dcache_lock); d_delete(d); simple_unlink(de->d_inode, d); dput(d); - spin_lock(&dcache_lock); spin_lock(&de->d_lock); } else spin_unlock(&d->d_lock); @@ -1170,7 +1167,6 @@ static void sel_remove_entries(struct dentry *de) } spin_unlock(&de->d_lock); - spin_unlock(&dcache_lock); } #define BOOL_DIR_NAME "booleans" -- cgit v1.2.3-70-g09d2