fs: scale inode alias list
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 <npiggin@kernel.dk>
This commit is contained in:
parent
2fd6b7f507
commit
b23fb0a603
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@ -271,9 +271,11 @@ static struct dentry *v9fs_dentry_from_dir_inode(struct inode *inode)
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struct dentry *dentry;
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spin_lock(&dcache_lock);
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spin_lock(&dcache_inode_lock);
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/* Directory should have only one entry. */
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BUG_ON(S_ISDIR(inode->i_mode) && !list_is_singular(&inode->i_dentry));
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dentry = list_entry(inode->i_dentry.next, struct dentry, d_alias);
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spin_unlock(&dcache_inode_lock);
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spin_unlock(&dcache_lock);
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return dentry;
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}
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@ -129,6 +129,7 @@ affs_fix_dcache(struct dentry *dentry, u32 entry_ino)
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struct list_head *head, *next;
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spin_lock(&dcache_lock);
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spin_lock(&dcache_inode_lock);
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head = &inode->i_dentry;
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next = head->next;
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while (next != head) {
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@ -139,6 +140,7 @@ affs_fix_dcache(struct dentry *dentry, u32 entry_ino)
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}
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next = next->next;
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}
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spin_unlock(&dcache_inode_lock);
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spin_unlock(&dcache_lock);
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}
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@ -810,12 +810,15 @@ inode_has_hashed_dentries(struct inode *inode)
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struct dentry *dentry;
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spin_lock(&dcache_lock);
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spin_lock(&dcache_inode_lock);
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list_for_each_entry(dentry, &inode->i_dentry, d_alias) {
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if (!d_unhashed(dentry) || IS_ROOT(dentry)) {
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spin_unlock(&dcache_inode_lock);
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spin_unlock(&dcache_lock);
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return true;
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}
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}
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spin_unlock(&dcache_inode_lock);
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spin_unlock(&dcache_lock);
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return false;
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}
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66
fs/dcache.c
66
fs/dcache.c
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@ -37,6 +37,8 @@
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/*
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* Usage:
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* dcache_inode_lock protects:
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* - i_dentry, d_alias, d_inode
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* dcache_hash_lock protects:
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* - the dcache hash table, s_anon lists
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* dcache_lru_lock protects:
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@ -49,12 +51,14 @@
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* - d_unhashed()
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* - d_parent and d_subdirs
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* - childrens' d_child and d_parent
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* - d_alias, d_inode
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*
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* Ordering:
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* dcache_lock
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* dentry->d_lock
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* dcache_lru_lock
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* dcache_hash_lock
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* dcache_inode_lock
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* dentry->d_lock
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* dcache_lru_lock
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* dcache_hash_lock
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*
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* If there is an ancestor relationship:
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* dentry->d_parent->...->d_parent->d_lock
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@ -70,11 +74,13 @@
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int sysctl_vfs_cache_pressure __read_mostly = 100;
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EXPORT_SYMBOL_GPL(sysctl_vfs_cache_pressure);
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__cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_inode_lock);
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static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_hash_lock);
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static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_lru_lock);
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__cacheline_aligned_in_smp DEFINE_SPINLOCK(dcache_lock);
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__cacheline_aligned_in_smp DEFINE_SEQLOCK(rename_lock);
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EXPORT_SYMBOL(dcache_inode_lock);
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EXPORT_SYMBOL(dcache_lock);
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static struct kmem_cache *dentry_cache __read_mostly;
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@ -154,6 +160,7 @@ static void d_free(struct dentry *dentry)
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*/
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static void dentry_iput(struct dentry * dentry)
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__releases(dentry->d_lock)
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__releases(dcache_inode_lock)
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__releases(dcache_lock)
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{
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struct inode *inode = dentry->d_inode;
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@ -161,6 +168,7 @@ static void dentry_iput(struct dentry * dentry)
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dentry->d_inode = NULL;
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list_del_init(&dentry->d_alias);
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spin_unlock(&dentry->d_lock);
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spin_unlock(&dcache_inode_lock);
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spin_unlock(&dcache_lock);
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if (!inode->i_nlink)
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fsnotify_inoderemove(inode);
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@ -170,6 +178,7 @@ static void dentry_iput(struct dentry * dentry)
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iput(inode);
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} else {
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spin_unlock(&dentry->d_lock);
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spin_unlock(&dcache_inode_lock);
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spin_unlock(&dcache_lock);
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}
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}
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@ -231,6 +240,7 @@ static void dentry_lru_move_tail(struct dentry *dentry)
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static struct dentry *d_kill(struct dentry *dentry, struct dentry *parent)
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__releases(dentry->d_lock)
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__releases(parent->d_lock)
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__releases(dcache_inode_lock)
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__releases(dcache_lock)
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{
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list_del(&dentry->d_u.d_child);
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@ -332,13 +342,18 @@ repeat:
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* want to reduce dcache_lock anyway so this will
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* get improved.
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*/
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drop1:
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spin_unlock(&dentry->d_lock);
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goto repeat;
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}
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if (parent && !spin_trylock(&parent->d_lock)) {
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spin_unlock(&dentry->d_lock);
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if (!spin_trylock(&dcache_inode_lock)) {
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drop2:
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spin_unlock(&dcache_lock);
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goto repeat;
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goto drop1;
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}
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if (parent && !spin_trylock(&parent->d_lock)) {
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spin_unlock(&dcache_inode_lock);
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goto drop2;
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}
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}
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dentry->d_count--;
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@ -369,6 +384,7 @@ repeat:
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spin_unlock(&dentry->d_lock);
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if (parent)
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spin_unlock(&parent->d_lock);
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spin_unlock(&dcache_inode_lock);
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spin_unlock(&dcache_lock);
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return;
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@ -558,7 +574,9 @@ struct dentry *d_find_alias(struct inode *inode)
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if (!list_empty(&inode->i_dentry)) {
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spin_lock(&dcache_lock);
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spin_lock(&dcache_inode_lock);
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de = __d_find_alias(inode, 0);
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spin_unlock(&dcache_inode_lock);
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spin_unlock(&dcache_lock);
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}
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return de;
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@ -574,18 +592,21 @@ void d_prune_aliases(struct inode *inode)
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struct dentry *dentry;
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restart:
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spin_lock(&dcache_lock);
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spin_lock(&dcache_inode_lock);
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list_for_each_entry(dentry, &inode->i_dentry, d_alias) {
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spin_lock(&dentry->d_lock);
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if (!dentry->d_count) {
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__dget_locked_dlock(dentry);
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__d_drop(dentry);
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spin_unlock(&dentry->d_lock);
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spin_unlock(&dcache_inode_lock);
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spin_unlock(&dcache_lock);
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dput(dentry);
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goto restart;
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}
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spin_unlock(&dentry->d_lock);
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}
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spin_unlock(&dcache_inode_lock);
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spin_unlock(&dcache_lock);
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}
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EXPORT_SYMBOL(d_prune_aliases);
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@ -601,6 +622,7 @@ EXPORT_SYMBOL(d_prune_aliases);
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static void prune_one_dentry(struct dentry *dentry, struct dentry *parent)
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__releases(dentry->d_lock)
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__releases(parent->d_lock)
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__releases(dcache_inode_lock)
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__releases(dcache_lock)
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{
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__d_drop(dentry);
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@ -612,6 +634,7 @@ static void prune_one_dentry(struct dentry *dentry, struct dentry *parent)
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*/
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while (dentry) {
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spin_lock(&dcache_lock);
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spin_lock(&dcache_inode_lock);
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again:
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spin_lock(&dentry->d_lock);
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if (IS_ROOT(dentry))
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@ -627,6 +650,7 @@ again:
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if (parent)
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spin_unlock(&parent->d_lock);
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spin_unlock(&dentry->d_lock);
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spin_unlock(&dcache_inode_lock);
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spin_unlock(&dcache_lock);
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return;
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}
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@ -676,8 +700,9 @@ relock:
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spin_unlock(&dcache_lru_lock);
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prune_one_dentry(dentry, parent);
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/* dcache_lock and dentry->d_lock dropped */
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/* dcache_lock, dcache_inode_lock and dentry->d_lock dropped */
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spin_lock(&dcache_lock);
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spin_lock(&dcache_inode_lock);
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spin_lock(&dcache_lru_lock);
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}
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}
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@ -699,6 +724,7 @@ static void __shrink_dcache_sb(struct super_block *sb, int *count, int flags)
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int cnt = *count;
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spin_lock(&dcache_lock);
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spin_lock(&dcache_inode_lock);
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relock:
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spin_lock(&dcache_lru_lock);
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while (!list_empty(&sb->s_dentry_lru)) {
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@ -737,8 +763,8 @@ relock:
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if (!list_empty(&referenced))
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list_splice(&referenced, &sb->s_dentry_lru);
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spin_unlock(&dcache_lru_lock);
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spin_unlock(&dcache_inode_lock);
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spin_unlock(&dcache_lock);
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}
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/**
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@ -832,12 +858,14 @@ void shrink_dcache_sb(struct super_block *sb)
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LIST_HEAD(tmp);
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spin_lock(&dcache_lock);
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spin_lock(&dcache_inode_lock);
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spin_lock(&dcache_lru_lock);
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while (!list_empty(&sb->s_dentry_lru)) {
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list_splice_init(&sb->s_dentry_lru, &tmp);
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shrink_dentry_list(&tmp);
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}
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spin_unlock(&dcache_lru_lock);
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spin_unlock(&dcache_inode_lock);
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spin_unlock(&dcache_lock);
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}
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EXPORT_SYMBOL(shrink_dcache_sb);
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@ -1255,9 +1283,11 @@ EXPORT_SYMBOL(d_alloc_name);
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/* the caller must hold dcache_lock */
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static void __d_instantiate(struct dentry *dentry, struct inode *inode)
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{
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spin_lock(&dentry->d_lock);
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if (inode)
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list_add(&dentry->d_alias, &inode->i_dentry);
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dentry->d_inode = inode;
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spin_unlock(&dentry->d_lock);
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fsnotify_d_instantiate(dentry, inode);
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}
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@ -1280,7 +1310,9 @@ void d_instantiate(struct dentry *entry, struct inode * inode)
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{
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BUG_ON(!list_empty(&entry->d_alias));
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spin_lock(&dcache_lock);
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spin_lock(&dcache_inode_lock);
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__d_instantiate(entry, inode);
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spin_unlock(&dcache_inode_lock);
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spin_unlock(&dcache_lock);
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security_d_instantiate(entry, inode);
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}
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@ -1341,7 +1373,9 @@ struct dentry *d_instantiate_unique(struct dentry *entry, struct inode *inode)
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BUG_ON(!list_empty(&entry->d_alias));
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spin_lock(&dcache_lock);
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spin_lock(&dcache_inode_lock);
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result = __d_instantiate_unique(entry, inode);
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spin_unlock(&dcache_inode_lock);
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spin_unlock(&dcache_lock);
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if (!result) {
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@ -1432,8 +1466,10 @@ struct dentry *d_obtain_alias(struct inode *inode)
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tmp->d_parent = tmp; /* make sure dput doesn't croak */
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spin_lock(&dcache_lock);
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spin_lock(&dcache_inode_lock);
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res = __d_find_alias(inode, 0);
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if (res) {
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spin_unlock(&dcache_inode_lock);
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spin_unlock(&dcache_lock);
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dput(tmp);
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goto out_iput;
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@ -1450,6 +1486,7 @@ struct dentry *d_obtain_alias(struct inode *inode)
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hlist_add_head(&tmp->d_hash, &inode->i_sb->s_anon);
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spin_unlock(&dcache_hash_lock);
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spin_unlock(&tmp->d_lock);
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spin_unlock(&dcache_inode_lock);
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spin_unlock(&dcache_lock);
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return tmp;
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@ -1482,9 +1519,11 @@ struct dentry *d_splice_alias(struct inode *inode, struct dentry *dentry)
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if (inode && S_ISDIR(inode->i_mode)) {
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spin_lock(&dcache_lock);
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spin_lock(&dcache_inode_lock);
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new = __d_find_alias(inode, 1);
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if (new) {
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BUG_ON(!(new->d_flags & DCACHE_DISCONNECTED));
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spin_unlock(&dcache_inode_lock);
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spin_unlock(&dcache_lock);
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security_d_instantiate(new, inode);
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d_move(new, dentry);
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@ -1492,6 +1531,7 @@ struct dentry *d_splice_alias(struct inode *inode, struct dentry *dentry)
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} else {
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/* already taking dcache_lock, so d_add() by hand */
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__d_instantiate(dentry, inode);
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spin_unlock(&dcache_inode_lock);
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spin_unlock(&dcache_lock);
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security_d_instantiate(dentry, inode);
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d_rehash(dentry);
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@ -1566,8 +1606,10 @@ struct dentry *d_add_ci(struct dentry *dentry, struct inode *inode,
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* already has a dentry.
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*/
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spin_lock(&dcache_lock);
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spin_lock(&dcache_inode_lock);
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if (!S_ISDIR(inode->i_mode) || list_empty(&inode->i_dentry)) {
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__d_instantiate(found, inode);
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spin_unlock(&dcache_inode_lock);
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spin_unlock(&dcache_lock);
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security_d_instantiate(found, inode);
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return found;
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@ -1579,6 +1621,7 @@ struct dentry *d_add_ci(struct dentry *dentry, struct inode *inode,
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*/
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new = list_entry(inode->i_dentry.next, struct dentry, d_alias);
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dget_locked(new);
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spin_unlock(&dcache_inode_lock);
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spin_unlock(&dcache_lock);
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security_d_instantiate(found, inode);
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d_move(new, found);
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@ -1797,6 +1840,7 @@ void d_delete(struct dentry * dentry)
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* Are we the only user?
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*/
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spin_lock(&dcache_lock);
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spin_lock(&dcache_inode_lock);
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spin_lock(&dentry->d_lock);
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isdir = S_ISDIR(dentry->d_inode->i_mode);
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if (dentry->d_count == 1) {
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@ -1810,6 +1854,7 @@ void d_delete(struct dentry * dentry)
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__d_drop(dentry);
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spin_unlock(&dentry->d_lock);
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spin_unlock(&dcache_inode_lock);
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spin_unlock(&dcache_lock);
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fsnotify_nameremove(dentry, isdir);
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@ -2067,6 +2112,7 @@ struct dentry *d_ancestor(struct dentry *p1, struct dentry *p2)
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*/
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static struct dentry *__d_unalias(struct dentry *dentry, struct dentry *alias)
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__releases(dcache_lock)
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__releases(dcache_inode_lock)
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{
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struct mutex *m1 = NULL, *m2 = NULL;
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struct dentry *ret;
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@ -2092,6 +2138,7 @@ out_unalias:
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d_move_locked(alias, dentry);
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ret = alias;
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out_err:
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spin_unlock(&dcache_inode_lock);
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spin_unlock(&dcache_lock);
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if (m2)
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mutex_unlock(m2);
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@ -2153,6 +2200,7 @@ struct dentry *d_materialise_unique(struct dentry *dentry, struct inode *inode)
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BUG_ON(!d_unhashed(dentry));
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spin_lock(&dcache_lock);
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spin_lock(&dcache_inode_lock);
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if (!inode) {
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actual = dentry;
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@ -2196,6 +2244,7 @@ found:
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_d_rehash(actual);
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spin_unlock(&dcache_hash_lock);
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spin_unlock(&actual->d_lock);
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spin_unlock(&dcache_inode_lock);
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spin_unlock(&dcache_lock);
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out_nolock:
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if (actual == dentry) {
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@ -2207,6 +2256,7 @@ out_nolock:
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return actual;
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shouldnt_be_hashed:
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spin_unlock(&dcache_inode_lock);
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spin_unlock(&dcache_lock);
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BUG();
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}
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@ -48,8 +48,10 @@ find_acceptable_alias(struct dentry *result,
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return result;
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spin_lock(&dcache_lock);
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spin_lock(&dcache_inode_lock);
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list_for_each_entry(dentry, &result->d_inode->i_dentry, d_alias) {
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dget_locked(dentry);
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spin_unlock(&dcache_inode_lock);
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spin_unlock(&dcache_lock);
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if (toput)
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dput(toput);
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@ -58,8 +60,10 @@ find_acceptable_alias(struct dentry *result,
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return dentry;
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}
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spin_lock(&dcache_lock);
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spin_lock(&dcache_inode_lock);
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toput = dentry;
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}
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spin_unlock(&dcache_inode_lock);
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spin_unlock(&dcache_lock);
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if (toput)
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@ -64,7 +64,11 @@ static int nfs_superblock_set_dummy_root(struct super_block *sb, struct inode *i
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* Oops, since the test for IS_ROOT() will fail.
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*/
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spin_lock(&dcache_lock);
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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;
|
||||
|
|
|
@ -60,6 +60,7 @@ void __fsnotify_update_child_dentry_flags(struct inode *inode)
|
|||
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_flags(struct inode *inode)
|
|||
}
|
||||
spin_unlock(&alias->d_lock);
|
||||
}
|
||||
spin_unlock(&dcache_inode_lock);
|
||||
spin_unlock(&dcache_lock);
|
||||
}
|
||||
|
||||
|
|
|
@ -170,7 +170,7 @@ struct dentry *ocfs2_find_local_alias(struct inode *inode,
|
|||
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(struct inode *inode,
|
|||
dentry = NULL;
|
||||
}
|
||||
|
||||
spin_unlock(&dcache_inode_lock);
|
||||
spin_unlock(&dcache_lock);
|
||||
|
||||
return dentry;
|
||||
|
|
|
@ -181,6 +181,7 @@ struct dentry_operations {
|
|||
|
||||
#define DCACHE_CANT_MOUNT 0x0100
|
||||
|
||||
extern spinlock_t dcache_inode_lock;
|
||||
extern spinlock_t dcache_lock;
|
||||
extern seqlock_t rename_lock;
|
||||
|
||||
|
|
Loading…
Reference in New Issue