Add a new lock, dcache_inode_lock, to protect the inode's i_dentry list from concurrent modification. d_alias is also protected by d_lock. Signed-off-by: Nick Piggin --- fs/9p/vfs_inode.c | 2 + fs/affs/amigaffs.c | 2 + fs/cifs/inode.c | 3 ++ fs/dcache.c | 66 +++++++++++++++++++++++++++++++++++++++++++------ fs/exportfs/expfs.c | 4 ++ fs/nfs/getroot.c | 4 ++ fs/notify/fsnotify.c | 2 + fs/ocfs2/dcache.c | 3 +- include/linux/dcache.h | 1 9 files changed, 78 insertions(+), 9 deletions(-) Index: linux-2.6/fs/dcache.c =================================================================== --- linux-2.6.orig/fs/dcache.c 2010-11-17 00:52:37.000000000 +1100 +++ linux-2.6/fs/dcache.c 2010-11-17 01:05:43.000000000 +1100 @@ -37,6 +37,8 @@ /* * Usage: + * dcache_inode_lock protects: + * - i_dentry, d_alias, d_inode * dcache_hash_lock protects: * - the dcache hash table * dcache_lru_lock protects: @@ -49,12 +51,14 @@ * - d_unhashed() * - d_parent and d_subdirs * - childrens' d_child and d_parent + * - d_alias, d_inode * * Ordering: * dcache_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 @@ -70,11 +74,13 @@ int sysctl_vfs_cache_pressure __read_mostly = 100; EXPORT_SYMBOL_GPL(sysctl_vfs_cache_pressure); +__cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_inode_lock); __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(dcache_inode_lock); EXPORT_SYMBOL(dcache_hash_lock); EXPORT_SYMBOL(dcache_lock); @@ -148,6 +154,7 @@ 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; @@ -155,6 +162,7 @@ static void dentry_iput(struct dentry * dentry->d_inode = NULL; 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); @@ -164,6 +172,7 @@ static void dentry_iput(struct dentry * iput(inode); } else { spin_unlock(&dentry->d_lock); + spin_unlock(&dcache_inode_lock); spin_unlock(&dcache_lock); } } @@ -225,6 +234,7 @@ static void dentry_lru_move_tail(struct 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) { list_del(&dentry->d_u.d_child); @@ -290,13 +300,18 @@ void dput(struct dentry *dentry) * want to reduce dcache_lock anyway so this will * get improved. */ +drop1: spin_unlock(&dentry->d_lock); goto repeat; } - if (parent && !spin_trylock(&parent->d_lock)) { - spin_unlock(&dentry->d_lock); + if (!spin_trylock(&dcache_inode_lock)) { +drop2: spin_unlock(&dcache_lock); - goto repeat; + goto drop1; + } + if (parent && !spin_trylock(&parent->d_lock)) { + spin_unlock(&dcache_inode_lock); + goto drop2; } } dentry->d_count--; @@ -327,6 +342,7 @@ void dput(struct dentry *dentry) spin_unlock(&dentry->d_lock); if (parent) spin_unlock(&parent->d_lock); + spin_unlock(&dcache_inode_lock); spin_unlock(&dcache_lock); return; @@ -521,7 +537,9 @@ struct dentry *d_find_alias(struct inode 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; @@ -537,18 +555,21 @@ 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); if (!dentry->d_count) { __dget_locked_dlock(dentry); __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); @@ -564,6 +585,7 @@ EXPORT_SYMBOL(d_prune_aliases); 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); @@ -575,6 +597,7 @@ static void prune_one_dentry(struct dent */ while (dentry) { spin_lock(&dcache_lock); + spin_lock(&dcache_inode_lock); again: spin_lock(&dentry->d_lock); if (IS_ROOT(dentry)) @@ -590,6 +613,7 @@ static void prune_one_dentry(struct dent if (parent) spin_unlock(&parent->d_lock); spin_unlock(&dentry->d_lock); + spin_unlock(&dcache_inode_lock); spin_unlock(&dcache_lock); return; } @@ -639,8 +663,9 @@ static void shrink_dentry_list(struct li spin_unlock(&dcache_lru_lock); prune_one_dentry(dentry, parent); - /* dcache_lock and dentry->d_lock dropped */ + /* dcache_lock, dcache_inode_lock and dentry->d_lock dropped */ spin_lock(&dcache_lock); + spin_lock(&dcache_inode_lock); spin_lock(&dcache_lru_lock); } } @@ -662,6 +687,7 @@ static void __shrink_dcache_sb(struct su int cnt = *count; spin_lock(&dcache_lock); + spin_lock(&dcache_inode_lock); relock: spin_lock(&dcache_lru_lock); while (!list_empty(&sb->s_dentry_lru)) { @@ -700,8 +726,8 @@ static void __shrink_dcache_sb(struct su if (!list_empty(&referenced)) list_splice(&referenced, &sb->s_dentry_lru); spin_unlock(&dcache_lru_lock); + spin_unlock(&dcache_inode_lock); spin_unlock(&dcache_lock); - } /** @@ -795,12 +821,14 @@ void shrink_dcache_sb(struct super_block LIST_HEAD(tmp); spin_lock(&dcache_lock); + spin_lock(&dcache_inode_lock); spin_lock(&dcache_lru_lock); while (!list_empty(&sb->s_dentry_lru)) { list_splice_init(&sb->s_dentry_lru, &tmp); shrink_dentry_list(&tmp); } spin_unlock(&dcache_lru_lock); + spin_unlock(&dcache_inode_lock); spin_unlock(&dcache_lock); } EXPORT_SYMBOL(shrink_dcache_sb); @@ -1221,9 +1249,11 @@ 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); if (inode) list_add(&dentry->d_alias, &inode->i_dentry); dentry->d_inode = inode; + spin_unlock(&dentry->d_lock); fsnotify_d_instantiate(dentry, inode); } @@ -1246,7 +1276,9 @@ void d_instantiate(struct dentry *entry, { 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); } @@ -1307,7 +1339,9 @@ struct dentry *d_instantiate_unique(stru 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) { @@ -1398,8 +1432,10 @@ struct dentry *d_obtain_alias(struct ino 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; @@ -1416,6 +1452,7 @@ struct dentry *d_obtain_alias(struct ino hlist_add_head(&tmp->d_hash, &inode->i_sb->s_anon); spin_unlock(&dcache_hash_lock); spin_unlock(&tmp->d_lock); + spin_unlock(&dcache_inode_lock); spin_unlock(&dcache_lock); return tmp; @@ -1448,9 +1485,11 @@ struct dentry *d_splice_alias(struct ino 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); @@ -1458,6 +1497,7 @@ struct dentry *d_splice_alias(struct ino } else { /* already taking dcache_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); @@ -1532,8 +1572,10 @@ struct dentry *d_add_ci(struct dentry *d * 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; @@ -1545,6 +1587,7 @@ struct dentry *d_add_ci(struct dentry *d */ 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); @@ -1763,6 +1806,7 @@ 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); if (dentry->d_count == 1) { @@ -1776,6 +1820,7 @@ void d_delete(struct dentry * dentry) __d_drop(dentry); spin_unlock(&dentry->d_lock); + spin_unlock(&dcache_inode_lock); spin_unlock(&dcache_lock); fsnotify_nameremove(dentry, isdir); @@ -2003,6 +2048,7 @@ struct dentry *d_ancestor(struct dentry */ static struct dentry *__d_unalias(struct dentry *dentry, struct dentry *alias) __releases(dcache_lock) + __releases(dcache_inode_lock) { struct mutex *m1 = NULL, *m2 = NULL; struct dentry *ret; @@ -2028,6 +2074,7 @@ static struct dentry *__d_unalias(struct d_move_locked(alias, dentry); ret = alias; out_err: + spin_unlock(&dcache_inode_lock); spin_unlock(&dcache_lock); if (m2) mutex_unlock(m2); @@ -2093,6 +2140,7 @@ struct dentry *d_materialise_unique(stru BUG_ON(!d_unhashed(dentry)); spin_lock(&dcache_lock); + spin_lock(&dcache_inode_lock); if (!inode) { actual = dentry; @@ -2136,6 +2184,7 @@ struct dentry *d_materialise_unique(stru _d_rehash(actual); spin_unlock(&dcache_hash_lock); spin_unlock(&actual->d_lock); + spin_unlock(&dcache_inode_lock); spin_unlock(&dcache_lock); out_nolock: if (actual == dentry) { @@ -2147,6 +2196,7 @@ struct dentry *d_materialise_unique(stru return actual; shouldnt_be_hashed: + spin_unlock(&dcache_inode_lock); spin_unlock(&dcache_lock); BUG(); } Index: linux-2.6/include/linux/dcache.h =================================================================== --- linux-2.6.orig/include/linux/dcache.h 2010-11-17 00:52:37.000000000 +1100 +++ linux-2.6/include/linux/dcache.h 2010-11-17 01:05:43.000000000 +1100 @@ -181,6 +181,7 @@ struct dentry_operations { #define DCACHE_CANT_MOUNT 0x0100 +extern spinlock_t dcache_inode_lock; extern spinlock_t dcache_hash_lock; extern spinlock_t dcache_lock; extern seqlock_t rename_lock; Index: linux-2.6/fs/exportfs/expfs.c =================================================================== --- linux-2.6.orig/fs/exportfs/expfs.c 2010-11-17 00:50:49.000000000 +1100 +++ linux-2.6/fs/exportfs/expfs.c 2010-11-17 01:05:42.000000000 +1100 @@ -48,8 +48,10 @@ find_acceptable_alias(struct dentry *res 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); @@ -58,8 +60,10 @@ find_acceptable_alias(struct dentry *res return dentry; } spin_lock(&dcache_lock); + spin_lock(&dcache_inode_lock); toput = dentry; } + spin_unlock(&dcache_inode_lock); spin_unlock(&dcache_lock); if (toput) Index: linux-2.6/fs/affs/amigaffs.c =================================================================== --- linux-2.6.orig/fs/affs/amigaffs.c 2010-11-17 00:50:49.000000000 +1100 +++ linux-2.6/fs/affs/amigaffs.c 2010-11-17 01:05:42.000000000 +1100 @@ -129,6 +129,7 @@ affs_fix_dcache(struct dentry *dentry, u struct list_head *head, *next; spin_lock(&dcache_lock); + spin_lock(&dcache_inode_lock); head = &inode->i_dentry; next = head->next; while (next != head) { @@ -139,6 +140,7 @@ affs_fix_dcache(struct dentry *dentry, u } next = next->next; } + spin_unlock(&dcache_inode_lock); spin_unlock(&dcache_lock); } Index: linux-2.6/fs/ocfs2/dcache.c =================================================================== --- linux-2.6.orig/fs/ocfs2/dcache.c 2010-11-17 00:52:37.000000000 +1100 +++ linux-2.6/fs/ocfs2/dcache.c 2010-11-17 01:05:42.000000000 +1100 @@ -170,7 +170,7 @@ struct dentry *ocfs2_find_local_alias(st 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); @@ -188,6 +188,7 @@ struct dentry *ocfs2_find_local_alias(st dentry = NULL; } + spin_unlock(&dcache_inode_lock); spin_unlock(&dcache_lock); return dentry; Index: linux-2.6/fs/nfs/getroot.c =================================================================== --- linux-2.6.orig/fs/nfs/getroot.c 2010-11-17 00:50:49.000000000 +1100 +++ linux-2.6/fs/nfs/getroot.c 2010-11-17 01:05:42.000000000 +1100 @@ -64,7 +64,11 @@ static int nfs_superblock_set_dummy_root * 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; Index: linux-2.6/fs/notify/fsnotify.c =================================================================== --- linux-2.6.orig/fs/notify/fsnotify.c 2010-11-17 00:52:37.000000000 +1100 +++ linux-2.6/fs/notify/fsnotify.c 2010-11-17 01:05:42.000000000 +1100 @@ -60,6 +60,7 @@ void __fsnotify_update_child_dentry_flag 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 */ list_for_each_entry(alias, &inode->i_dentry, d_alias) { @@ -82,6 +83,7 @@ void __fsnotify_update_child_dentry_flag } spin_unlock(&alias->d_lock); } + spin_unlock(&dcache_inode_lock); spin_unlock(&dcache_lock); } Index: linux-2.6/fs/9p/vfs_inode.c =================================================================== --- linux-2.6.orig/fs/9p/vfs_inode.c 2010-11-17 00:50:49.000000000 +1100 +++ linux-2.6/fs/9p/vfs_inode.c 2010-11-17 01:05:42.000000000 +1100 @@ -271,9 +271,11 @@ static struct dentry *v9fs_dentry_from_d 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; } Index: linux-2.6/fs/cifs/inode.c =================================================================== --- linux-2.6.orig/fs/cifs/inode.c 2010-11-17 00:50:49.000000000 +1100 +++ linux-2.6/fs/cifs/inode.c 2010-11-17 01:05:42.000000000 +1100 @@ -805,12 +805,15 @@ inode_has_hashed_dentries(struct 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; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/