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-rw-r--r--fs/autofs4/autofs_i.h11
-rw-r--r--fs/autofs4/expire.c127
-rw-r--r--fs/autofs4/root.c18
-rw-r--r--fs/ceph/dir.c6
-rw-r--r--fs/ceph/inode.c8
-rw-r--r--fs/coda/cache.c2
-rw-r--r--fs/dcache.c248
-rw-r--r--fs/libfs.c24
-rw-r--r--fs/ncpfs/dir.c3
-rw-r--r--fs/ncpfs/ncplib_kernel.h4
-rw-r--r--fs/notify/fsnotify.c4
11 files changed, 302 insertions, 153 deletions
diff --git a/fs/autofs4/autofs_i.h b/fs/autofs4/autofs_i.h
index 3912dcf..9d2ae9b 100644
--- a/fs/autofs4/autofs_i.h
+++ b/fs/autofs4/autofs_i.h
@@ -254,6 +254,17 @@ static inline int simple_positive(struct dentry *dentry)
return dentry->d_inode && !d_unhashed(dentry);
}
+static inline void __autofs4_add_expiring(struct dentry *dentry)
+{
+ struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
+ struct autofs_info *ino = autofs4_dentry_ino(dentry);
+ if (ino) {
+ if (list_empty(&ino->expiring))
+ list_add(&ino->expiring, &sbi->expiring_list);
+ }
+ return;
+}
+
static inline void autofs4_add_expiring(struct dentry *dentry)
{
struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
diff --git a/fs/autofs4/expire.c b/fs/autofs4/expire.c
index ee64020..968c143 100644
--- a/fs/autofs4/expire.c
+++ b/fs/autofs4/expire.c
@@ -91,24 +91,64 @@ done:
}
/*
- * Calculate next entry in top down tree traversal.
- * From next_mnt in namespace.c - elegant.
+ * Calculate and dget next entry in top down tree traversal.
*/
-static struct dentry *next_dentry(struct dentry *p, struct dentry *root)
+static struct dentry *get_next_positive_dentry(struct dentry *prev,
+ struct dentry *root)
{
- struct list_head *next = p->d_subdirs.next;
+ struct list_head *next;
+ struct dentry *p, *ret;
+
+ if (prev == NULL)
+ return dget(prev);
+ spin_lock(&dcache_lock);
+relock:
+ p = prev;
+ spin_lock(&p->d_lock);
+again:
+ next = p->d_subdirs.next;
if (next == &p->d_subdirs) {
while (1) {
- if (p == root)
+ struct dentry *parent;
+
+ if (p == root) {
+ spin_unlock(&p->d_lock);
+ spin_unlock(&dcache_lock);
+ dput(prev);
return NULL;
+ }
+
+ parent = p->d_parent;
+ if (!spin_trylock(&parent->d_lock)) {
+ spin_unlock(&p->d_lock);
+ cpu_relax();
+ goto relock;
+ }
+ spin_unlock(&p->d_lock);
next = p->d_u.d_child.next;
- if (next != &p->d_parent->d_subdirs)
+ p = parent;
+ if (next != &parent->d_subdirs)
break;
- p = p->d_parent;
}
}
- return list_entry(next, struct dentry, d_u.d_child);
+ ret = list_entry(next, struct dentry, d_u.d_child);
+
+ spin_lock_nested(&ret->d_lock, DENTRY_D_LOCK_NESTED);
+ /* Negative dentry - try next */
+ if (!simple_positive(ret)) {
+ spin_unlock(&ret->d_lock);
+ p = ret;
+ goto again;
+ }
+ dget_dlock(ret);
+ spin_unlock(&ret->d_lock);
+ spin_unlock(&p->d_lock);
+ spin_unlock(&dcache_lock);
+
+ dput(prev);
+
+ return ret;
}
/*
@@ -158,22 +198,11 @@ static int autofs4_tree_busy(struct vfsmount *mnt,
if (!simple_positive(top))
return 1;
- spin_lock(&dcache_lock);
- for (p = top; p; p = next_dentry(p, top)) {
- spin_lock(&p->d_lock);
- /* Negative dentry - give up */
- if (!simple_positive(p)) {
- spin_unlock(&p->d_lock);
- continue;
- }
-
+ p = NULL;
+ while ((p = get_next_positive_dentry(p, top))) {
DPRINTK("dentry %p %.*s",
p, (int) p->d_name.len, p->d_name.name);
- p = dget_dlock(p);
- spin_unlock(&p->d_lock);
- spin_unlock(&dcache_lock);
-
/*
* Is someone visiting anywhere in the subtree ?
* If there's no mount we need to check the usage
@@ -208,10 +237,7 @@ static int autofs4_tree_busy(struct vfsmount *mnt,
return 1;
}
}
- dput(p);
- spin_lock(&dcache_lock);
}
- spin_unlock(&dcache_lock);
/* Timeout of a tree mount is ultimately determined by its top dentry */
if (!autofs4_can_expire(top, timeout, do_now))
@@ -230,36 +256,21 @@ static struct dentry *autofs4_check_leaves(struct vfsmount *mnt,
DPRINTK("parent %p %.*s",
parent, (int)parent->d_name.len, parent->d_name.name);
- spin_lock(&dcache_lock);
- for (p = parent; p; p = next_dentry(p, parent)) {
- spin_lock(&p->d_lock);
- /* Negative dentry - give up */
- if (!simple_positive(p)) {
- spin_unlock(&p->d_lock);
- continue;
- }
-
+ p = NULL;
+ while ((p = get_next_positive_dentry(p, parent))) {
DPRINTK("dentry %p %.*s",
p, (int) p->d_name.len, p->d_name.name);
- p = dget_dlock(p);
- spin_unlock(&p->d_lock);
- spin_unlock(&dcache_lock);
-
if (d_mountpoint(p)) {
/* Can we umount this guy */
if (autofs4_mount_busy(mnt, p))
- goto cont;
+ continue;
/* Can we expire this guy */
if (autofs4_can_expire(p, timeout, do_now))
return p;
}
-cont:
- dput(p);
- spin_lock(&dcache_lock);
}
- spin_unlock(&dcache_lock);
return NULL;
}
@@ -310,8 +321,8 @@ struct dentry *autofs4_expire_indirect(struct super_block *sb,
{
unsigned long timeout;
struct dentry *root = sb->s_root;
+ struct dentry *dentry;
struct dentry *expired = NULL;
- struct list_head *next;
int do_now = how & AUTOFS_EXP_IMMEDIATE;
int exp_leaves = how & AUTOFS_EXP_LEAVES;
struct autofs_info *ino;
@@ -323,26 +334,8 @@ struct dentry *autofs4_expire_indirect(struct super_block *sb,
now = jiffies;
timeout = sbi->exp_timeout;
- spin_lock(&dcache_lock);
- next = root->d_subdirs.next;
-
- /* On exit from the loop expire is set to a dgot dentry
- * to expire or it's NULL */
- while ( next != &root->d_subdirs ) {
- struct dentry *dentry = list_entry(next, struct dentry, d_u.d_child);
-
- /* Negative dentry - give up */
- spin_lock(&dentry->d_lock);
- if (!simple_positive(dentry)) {
- next = next->next;
- spin_unlock(&dentry->d_lock);
- continue;
- }
-
- dentry = dget_dlock(dentry);
- spin_unlock(&dentry->d_lock);
- spin_unlock(&dcache_lock);
-
+ dentry = NULL;
+ while ((dentry = get_next_positive_dentry(dentry, root))) {
spin_lock(&sbi->fs_lock);
ino = autofs4_dentry_ino(dentry);
@@ -405,11 +398,7 @@ struct dentry *autofs4_expire_indirect(struct super_block *sb,
}
next:
spin_unlock(&sbi->fs_lock);
- dput(dentry);
- spin_lock(&dcache_lock);
- next = next->next;
}
- spin_unlock(&dcache_lock);
return NULL;
found:
@@ -420,7 +409,11 @@ found:
init_completion(&ino->expire_complete);
spin_unlock(&sbi->fs_lock);
spin_lock(&dcache_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);
return expired;
}
diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c
index 7922509..7a9ed6b 100644
--- a/fs/autofs4/root.c
+++ b/fs/autofs4/root.c
@@ -143,10 +143,13 @@ static int autofs4_dir_open(struct inode *inode, struct file *file)
* it.
*/
spin_lock(&dcache_lock);
+ spin_lock(&dentry->d_lock);
if (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) {
+ spin_unlock(&dentry->d_lock);
spin_unlock(&dcache_lock);
return -ENOENT;
}
+ spin_unlock(&dentry->d_lock);
spin_unlock(&dcache_lock);
out:
@@ -253,7 +256,9 @@ static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd)
lookup_type = autofs4_need_mount(nd->flags);
spin_lock(&sbi->fs_lock);
spin_lock(&dcache_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(&sbi->fs_lock);
goto follow;
@@ -266,6 +271,7 @@ 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(&sbi->fs_lock);
@@ -275,6 +281,7 @@ static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd)
goto follow;
}
+ spin_unlock(&dentry->d_lock);
spin_unlock(&dcache_lock);
spin_unlock(&sbi->fs_lock);
follow:
@@ -347,10 +354,12 @@ static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd)
/* Check for a non-mountpoint directory with no contents */
spin_lock(&dcache_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);
/* The daemon never causes a mount to trigger */
@@ -367,6 +376,7 @@ static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd)
return status;
}
+ spin_unlock(&dentry->d_lock);
spin_unlock(&dcache_lock);
return 1;
@@ -776,12 +786,16 @@ static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry)
return -EACCES;
spin_lock(&dcache_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);
return -ENOTEMPTY;
}
- autofs4_add_expiring(dentry);
- spin_lock(&dentry->d_lock);
+ __autofs4_add_expiring(dentry);
+ spin_unlock(&sbi->lookup_lock);
__d_drop(dentry);
spin_unlock(&dentry->d_lock);
spin_unlock(&dcache_lock);
diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index 571f270..2c924e8 100644
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -113,6 +113,7 @@ static int __dcache_readdir(struct file *filp,
last);
spin_lock(&dcache_lock);
+ spin_lock(&parent->d_lock);
/* start at beginning? */
if (filp->f_pos == 2 || last == NULL ||
@@ -136,7 +137,7 @@ more:
fi->at_end = 1;
goto out_unlock;
}
- spin_lock(&dentry->d_lock);
+ spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
if (!d_unhashed(dentry) && dentry->d_inode &&
ceph_snap(dentry->d_inode) != CEPH_SNAPDIR &&
ceph_ino(dentry->d_inode) != CEPH_INO_CEPH &&
@@ -154,6 +155,7 @@ 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,
@@ -188,10 +190,12 @@ more:
}
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)
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index bb68c79..2c69444 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -842,11 +842,13 @@ static void ceph_set_dentry_offset(struct dentry *dn)
spin_unlock(&inode->i_lock);
spin_lock(&dcache_lock);
- spin_lock(&dn->d_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);
dout("set_dentry_offset %p %lld (%p %p)\n", dn, di->offset,
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);
}
@@ -1232,9 +1234,11 @@ retry_lookup:
} else {
/* reorder parent's d_subdirs */
spin_lock(&dcache_lock);
- spin_lock(&dn->d_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);
}
diff --git a/fs/coda/cache.c b/fs/coda/cache.c
index 9060f08..859393f 100644
--- a/fs/coda/cache.c
+++ b/fs/coda/cache.c
@@ -94,6 +94,7 @@ static void coda_flag_children(struct dentry *parent, int flag)
struct dentry *de;
spin_lock(&dcache_lock);
+ spin_lock(&parent->d_lock);
list_for_each(child, &parent->d_subdirs)
{
de = list_entry(child, struct dentry, d_u.d_child);
@@ -102,6 +103,7 @@ static void coda_flag_children(struct dentry *parent, int flag)
continue;
coda_flag_inode(de->d_inode, flag);
}
+ spin_unlock(&parent->d_lock);
spin_unlock(&dcache_lock);
return;
}
diff --git a/fs/dcache.c b/fs/dcache.c
index ee127f9..a661247 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -47,6 +47,8 @@
* - d_lru
* - d_count
* - d_unhashed()
+ * - d_parent and d_subdirs
+ * - childrens' d_child and d_parent
*
* Ordering:
* dcache_lock
@@ -223,24 +225,22 @@ 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 must be held by caller, are dropped by d_kill.
+ * dcache_lock and d_lock and d_parent->d_lock must be held by caller, and
+ * are dropped by d_kill.
*/
-static struct dentry *d_kill(struct dentry *dentry)
+static struct dentry *d_kill(struct dentry *dentry, struct dentry *parent)
__releases(dentry->d_lock)
+ __releases(parent->d_lock)
__releases(dcache_lock)
{
- struct dentry *parent;
-
list_del(&dentry->d_u.d_child);
+ if (parent)
+ spin_unlock(&parent->d_lock);
dentry_iput(dentry);
/*
* dentry_iput drops the locks, at which point nobody (except
* transient RCU lookups) can reach this dentry.
*/
- if (IS_ROOT(dentry))
- parent = NULL;
- else
- parent = dentry->d_parent;
d_free(dentry);
return parent;
}
@@ -312,6 +312,7 @@ EXPORT_SYMBOL(d_drop);
void dput(struct dentry *dentry)
{
+ struct dentry *parent;
if (!dentry)
return;
@@ -319,6 +320,10 @@ repeat:
if (dentry->d_count == 1)
might_sleep();
spin_lock(&dentry->d_lock);
+ if (IS_ROOT(dentry))
+ parent = NULL;
+ else
+ parent = dentry->d_parent;
if (dentry->d_count == 1) {
if (!spin_trylock(&dcache_lock)) {
/*
@@ -330,10 +335,17 @@ repeat:
spin_unlock(&dentry->d_lock);
goto repeat;
}
+ if (parent && !spin_trylock(&parent->d_lock)) {
+ spin_unlock(&dentry->d_lock);
+ spin_unlock(&dcache_lock);
+ goto repeat;
+ }
}
dentry->d_count--;
if (dentry->d_count) {
spin_unlock(&dentry->d_lock);
+ if (parent)
+ spin_unlock(&parent->d_lock);
spin_unlock(&dcache_lock);
return;
}
@@ -355,6 +367,8 @@ repeat:
dentry_lru_add(dentry);
spin_unlock(&dentry->d_lock);
+ if (parent)
+ spin_unlock(&parent->d_lock);
spin_unlock(&dcache_lock);
return;
@@ -363,7 +377,7 @@ unhash_it:
kill_it:
/* if dentry was on the d_lru list delete it from there */
dentry_lru_del(dentry);
- dentry = d_kill(dentry);
+ dentry = d_kill(dentry, parent);
if (dentry)
goto repeat;
}
@@ -584,12 +598,13 @@ EXPORT_SYMBOL(d_prune_aliases);
* quadratic behavior of shrink_dcache_parent(), but is also expected
* to be beneficial in reducing dentry cache fragmentation.
*/
-static void prune_one_dentry(struct dentry * dentry)
+static void prune_one_dentry(struct dentry *dentry, struct dentry *parent)
__releases(dentry->d_lock)
+ __releases(parent->d_lock)
__releases(dcache_lock)
{
__d_drop(dentry);
- dentry = d_kill(dentry);
+ dentry = d_kill(dentry, parent);
/*
* Prune ancestors. Locking is simpler than in dput(),
@@ -597,9 +612,20 @@ static void prune_one_dentry(struct dentry * dentry)
*/
while (dentry) {
spin_lock(&dcache_lock);
+again:
spin_lock(&dentry->d_lock);
+ if (IS_ROOT(dentry))
+ parent = NULL;
+ else
+ parent = dentry->d_parent;
+ if (parent && !spin_trylock(&parent->d_lock)) {
+ spin_unlock(&dentry->d_lock);
+ goto again;
+ }
dentry->d_count--;
if (dentry->d_count) {
+ if (parent)
+ spin_unlock(&parent->d_lock);
spin_unlock(&dentry->d_lock);
spin_unlock(&dcache_lock);
return;
@@ -607,7 +633,7 @@ static void prune_one_dentry(struct dentry * dentry)
dentry_lru_del(dentry);
__d_drop(dentry);
- dentry = d_kill(dentry);
+ dentry = d_kill(dentry, parent);
}
}
@@ -616,29 +642,40 @@ static void shrink_dentry_list(struct list_head *list)
struct dentry *dentry;
while (!list_empty(list)) {
+ struct dentry *parent;
+
dentry = list_entry(list->prev, struct dentry, d_lru);
if (!spin_trylock(&dentry->d_lock)) {
+relock:
spin_unlock(&dcache_lru_lock);
cpu_relax();
spin_lock(&dcache_lru_lock);
continue;
}
- __dentry_lru_del(dentry);
-
/*
* We found an inuse dentry which was not removed from
* the LRU because of laziness during lookup. Do not free
* it - just keep it off the LRU list.
*/
if (dentry->d_count) {
+ __dentry_lru_del(dentry);
spin_unlock(&dentry->d_lock);
continue;
}
+ if (IS_ROOT(dentry))
+ parent = NULL;
+ else
+ parent = dentry->d_parent;
+ if (parent && !spin_trylock(&parent->d_lock)) {
+ spin_unlock(&dentry->d_lock);
+ goto relock;
+ }
+ __dentry_lru_del(dentry);
spin_unlock(&dcache_lru_lock);
- prune_one_dentry(dentry);
+ prune_one_dentry(dentry, parent);
/* dcache_lock and dentry->d_lock dropped */
spin_lock(&dcache_lock);
spin_lock(&dcache_lru_lock);
@@ -833,14 +870,16 @@ 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) {
- spin_lock(&loop->d_lock);
+ spin_lock_nested(&loop->d_lock,
+ DENTRY_D_LOCK_NESTED);
dentry_lru_del(loop);
__d_drop(loop);
spin_unlock(&loop->d_lock);
- cond_resched_lock(&dcache_lock);
}
+ spin_unlock(&dentry->d_lock);
spin_unlock(&dcache_lock);
/* move to the first child */
@@ -868,16 +907,17 @@ static void shrink_dcache_for_umount_subtree(struct dentry *dentry)
BUG();
}
- if (IS_ROOT(dentry))
+ if (IS_ROOT(dentry)) {
parent = NULL;
- else {
+ list_del(&dentry->d_u.d_child);
+ } else {
parent = dentry->d_parent;
spin_lock(&parent->d_lock);
parent->d_count--;
+ list_del(&dentry->d_u.d_child);
spin_unlock(&parent->d_lock);
}
- list_del(&dentry->d_u.d_child);
detached++;
inode = dentry->d_inode;
@@ -958,6 +998,7 @@ int have_submounts(struct dentry *parent)
spin_lock(&dcache_lock);
if (d_mountpoint(parent))
goto positive;
+ spin_lock(&this_parent->d_lock);
repeat:
next = this_parent->d_subdirs.next;
resume:
@@ -965,22 +1006,34 @@ resume:
struct list_head *tmp = next;
struct dentry *dentry = list_entry(tmp, struct dentry, d_u.d_child);
next = tmp->next;
+
+ spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
/* Have we found a mount point ? */
- if (d_mountpoint(dentry))
+ if (d_mountpoint(dentry)) {
+ spin_unlock(&dentry->d_lock);
+ spin_unlock(&this_parent->d_lock);
goto positive;
+ }
if (!list_empty(&dentry->d_subdirs)) {
+ spin_unlock(&this_parent->d_lock);
+ spin_release(&dentry->d_lock.dep_map, 1, _RET_IP_);
this_parent = dentry;
+ spin_acquire(&this_parent->d_lock.dep_map, 0, 1, _RET_IP_);
goto repeat;
}
+ spin_unlock(&dentry->d_lock);
}
/*
* All done at this level ... ascend and resume the search.
*/
if (this_parent != parent) {
next = this_parent->d_u.d_child.next;
+ spin_unlock(&this_parent->d_lock);
this_parent = this_parent->d_parent;
+ spin_lock(&this_parent->d_lock);
goto resume;
}
+ spin_unlock(&this_parent->d_lock);
spin_unlock(&dcache_lock);
return 0; /* No mount points found in tree */
positive:
@@ -1010,6 +1063,7 @@ static int select_parent(struct dentry * parent)
int found = 0;
spin_lock(&dcache_lock);
+ spin_lock(&this_parent->d_lock);
repeat:
next = this_parent->d_subdirs.next;
resume:
@@ -1017,8 +1071,9 @@ resume:
struct list_head *tmp = next;
struct dentry *dentry = list_entry(tmp, struct dentry, d_u.d_child);
next = tmp->next;
+ BUG_ON(this_parent == dentry);
- spin_lock(&dentry->d_lock);
+ spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
/*
* move only zero ref count dentries to the end
@@ -1031,33 +1086,44 @@ resume:
dentry_lru_del(dentry);
}
- spin_unlock(&dentry->d_lock);
-
/*
* We can return to the caller if we have found some (this
* ensures forward progress). We'll be coming back to find
* the rest.
*/
- if (found && need_resched())
+ if (found && need_resched()) {
+ spin_unlock(&dentry->d_lock);
goto out;
+ }
/*
* Descend a level if the d_subdirs list is non-empty.
*/
if (!list_empty(&dentry->d_subdirs)) {
+ spin_unlock(&this_parent->d_lock);
+ spin_release(&dentry->d_lock.dep_map, 1, _RET_IP_);
this_parent = dentry;
+ spin_acquire(&this_parent->d_lock.dep_map, 0, 1, _RET_IP_);
goto repeat;
}
+
+ spin_unlock(&dentry->d_lock);
}
/*
* All done at this level ... ascend and resume the search.
*/
if (this_parent != parent) {
+ struct dentry *tmp;
next = this_parent->d_u.d_child.next;
- this_parent = this_parent->d_parent;
+ tmp = this_parent->d_parent;
+ spin_unlock(&this_parent->d_lock);
+ BUG_ON(tmp == this_parent);
+ this_parent = tmp;
+ spin_lock(&this_parent->d_lock);
goto resume;
}
out:
+ spin_unlock(&this_parent->d_lock);
spin_unlock(&dcache_lock);
return found;
}
@@ -1155,18 +1221,19 @@ struct dentry *d_alloc(struct dentry * parent, const struct qstr *name)
INIT_LIST_HEAD(&dentry->d_lru);
INIT_LIST_HEAD(&dentry->d_subdirs);
INIT_LIST_HEAD(&dentry->d_alias);
+ INIT_LIST_HEAD(&dentry->d_u.d_child);
if (parent) {
- dentry->d_parent = dget(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);
dentry->d_sb = parent->d_sb;
- } else {
- INIT_LIST_HEAD(&dentry->d_u.d_child);
- }
-
- spin_lock(&dcache_lock);
- if (parent)
list_add(&dentry->d_u.d_child, &parent->d_subdirs);
- spin_unlock(&dcache_lock);
+ spin_unlock(&dentry->d_lock);
+ spin_unlock(&parent->d_lock);
+ spin_unlock(&dcache_lock);
+ }
this_cpu_inc(nr_dentry);
@@ -1684,13 +1751,18 @@ 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) {
- __dget_locked(dentry);
+ spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
+ __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;
@@ -1802,17 +1874,6 @@ void dentry_update_name_case(struct dentry *dentry, struct qstr *name)
}
EXPORT_SYMBOL(dentry_update_name_case);
-/*
- * When switching names, the actual string doesn't strictly have to
- * be preserved in the target - because we're dropping the target
- * anyway. As such, we can just do a simple memcpy() to copy over
- * the new name before we switch.
- *
- * Note that we have to be a lot more careful about getting the hash
- * switched - we have to switch the hash value properly even if it
- * then no longer matches the actual (corrupted) string of the target.
- * The hash value has to match the hash queue that the dentry is on..
- */
static void switch_names(struct dentry *dentry, struct dentry *target)
{
if (dname_external(target)) {
@@ -1854,18 +1915,53 @@ static void switch_names(struct dentry *dentry, struct dentry *target)
swap(dentry->d_name.len, target->d_name.len);
}
+static void dentry_lock_for_move(struct dentry *dentry, struct dentry *target)
+{
+ /*
+ * XXXX: do we really need to take target->d_lock?
+ */
+ if (IS_ROOT(dentry) || dentry->d_parent == target->d_parent)
+ spin_lock(&target->d_parent->d_lock);
+ else {
+ if (d_ancestor(dentry->d_parent, target->d_parent)) {
+ spin_lock(&dentry->d_parent->d_lock);
+ spin_lock_nested(&target->d_parent->d_lock,
+ DENTRY_D_LOCK_NESTED);
+ } else {
+ spin_lock(&target->d_parent->d_lock);
+ spin_lock_nested(&dentry->d_parent->d_lock,
+ DENTRY_D_LOCK_NESTED);
+ }
+ }
+ if (target < dentry) {
+ spin_lock_nested(&target->d_lock, 2);
+ spin_lock_nested(&dentry->d_lock, 3);
+ } else {
+ spin_lock_nested(&dentry->d_lock, 2);
+ spin_lock_nested(&target->d_lock, 3);
+ }
+}
+
+static void dentry_unlock_parents_for_move(struct dentry *dentry,
+ struct dentry *target)
+{
+ if (target->d_parent != dentry->d_parent)
+ spin_unlock(&dentry->d_parent->d_lock);
+ if (target->d_parent != target)
+ spin_unlock(&target->d_parent->d_lock);
+}
+
/*
- * We cannibalize "target" when moving dentry on top of it,
- * because it's going to be thrown away anyway. We could be more
- * polite about it, though.
- *
- * This forceful removal will result in ugly /proc output if
- * somebody holds a file open that got deleted due to a rename.
- * We could be nicer about the deleted file, and let it show
- * up under the name it had before it was deleted rather than
- * under the original name of the file that was moved on top of it.
+ * When switching names, the actual string doesn't strictly have to
+ * be preserved in the target - because we're dropping the target
+ * anyway. As such, we can just do a simple memcpy() to copy over
+ * the new name before we switch.
+ *
+ * Note that we have to be a lot more careful about getting the hash
+ * switched - we have to switch the hash value properly even if it
+ * then no longer matches the actual (corrupted) string of the target.
+ * The hash value has to match the hash queue that the dentry is on..
*/
-
/*
* d_move_locked - move a dentry
* @dentry: entry to move
@@ -1879,20 +1975,12 @@ static void d_move_locked(struct dentry * dentry, struct dentry * target)
if (!dentry->d_inode)
printk(KERN_WARNING "VFS: moving negative dcache entry\n");
+ BUG_ON(d_ancestor(dentry, target));
+ BUG_ON(d_ancestor(target, dentry));
+
write_seqlock(&rename_lock);
- /*
- * XXXX: do we really need to take target->d_lock?
- */
- if (d_ancestor(dentry, target)) {
- spin_lock(&dentry->d_lock);
- spin_lock_nested(&target->d_lock, DENTRY_D_LOCK_NESTED);
- } else if (d_ancestor(target, dentry) || target < dentry) {
- spin_lock(&target->d_lock);
- spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
- } else {
- spin_lock(&dentry->d_lock);
- spin_lock_nested(&target->d_lock, DENTRY_D_LOCK_NESTED);
- }
+
+ dentry_lock_for_move(dentry, target);
/* Move the dentry to the target hash queue, if on different bucket */
spin_lock(&dcache_hash_lock);
@@ -1924,6 +2012,8 @@ static void d_move_locked(struct dentry * dentry, struct dentry * target)
}
list_add(&dentry->d_u.d_child, &dentry->d_parent->d_subdirs);
+
+ dentry_unlock_parents_for_move(dentry, target);
spin_unlock(&target->d_lock);
fsnotify_d_move(dentry);
spin_unlock(&dentry->d_lock);
@@ -2013,17 +2103,20 @@ out_err:
/*
* Prepare an anonymous dentry for life in the superblock's dentry tree as a
* named dentry in place of the dentry to be replaced.
+ * returns with anon->d_lock held!
*/
static void __d_materialise_dentry(struct dentry *dentry, struct dentry *anon)
{
struct dentry *dparent, *aparent;
- switch_names(dentry, anon);
- swap(dentry->d_name.hash, anon->d_name.hash);
+ dentry_lock_for_move(anon, dentry);
dparent = dentry->d_parent;
aparent = anon->d_parent;
+ switch_names(dentry, anon);
+ swap(dentry->d_name.hash, anon->d_name.hash);
+
dentry->d_parent = (aparent == anon) ? dentry : aparent;
list_del(&dentry->d_u.d_child);
if (!IS_ROOT(dentry))
@@ -2038,6 +2131,10 @@ static void __d_materialise_dentry(struct dentry *dentry, struct dentry *anon)
else
INIT_LIST_HEAD(&anon->d_u.d_child);
+ dentry_unlock_parents_for_move(anon, dentry);
+ spin_unlock(&dentry->d_lock);
+
+ /* anon->d_lock still locked, returns locked */
anon->d_flags &= ~DCACHE_DISCONNECTED;
}
@@ -2073,7 +2170,6 @@ struct dentry *d_materialise_unique(struct dentry *dentry, struct inode *inode)
/* Is this an anonymous mountpoint that we could splice
* into our tree? */
if (IS_ROOT(alias)) {
- spin_lock(&alias->d_lock);
__d_materialise_dentry(dentry, alias);
__d_drop(alias);
goto found;
@@ -2558,6 +2654,7 @@ void d_genocide(struct dentry *root)
struct list_head *next;
spin_lock(&dcache_lock);
+ spin_lock(&this_parent->d_lock);
repeat:
next = this_parent->d_subdirs.next;
resume:
@@ -2571,8 +2668,10 @@ resume:
continue;
}
if (!list_empty(&dentry->d_subdirs)) {
- spin_unlock(&dentry->d_lock);
+ spin_unlock(&this_parent->d_lock);
+ spin_release(&dentry->d_lock.dep_map, 1, _RET_IP_);
this_parent = dentry;
+ spin_acquire(&this_parent->d_lock.dep_map, 0, 1, _RET_IP_);
goto repeat;
}
dentry->d_count--;
@@ -2580,12 +2679,13 @@ resume:
}
if (this_parent != root) {
next = this_parent->d_u.d_child.next;
- spin_lock(&this_parent->d_lock);
this_parent->d_count--;
spin_unlock(&this_parent->d_lock);
this_parent = this_parent->d_parent;
+ spin_lock(&this_parent->d_lock);
goto resume;
}
+ spin_unlock(&this_parent->d_lock);
spin_unlock(&dcache_lock);
}
diff --git a/fs/libfs.c b/fs/libfs.c
index 433e713..cc47949 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -81,7 +81,8 @@ int dcache_dir_close(struct inode *inode, struct file *file)
loff_t dcache_dir_lseek(struct file *file, loff_t offset, int origin)
{
- mutex_lock(&file->f_path.dentry->d_inode->i_mutex);
+ struct dentry *dentry = file->f_path.dentry;
+ mutex_lock(&dentry->d_inode->i_mutex);
switch (origin) {
case 1:
offset += file->f_pos;
@@ -89,7 +90,7 @@ loff_t dcache_dir_lseek(struct file *file, loff_t offset, int origin)
if (offset >= 0)
break;
default:
- mutex_unlock(&file->f_path.dentry->d_inode->i_mutex);
+ mutex_unlock(&dentry->d_inode->i_mutex);
return -EINVAL;
}
if (offset != file->f_pos) {
@@ -100,22 +101,25 @@ loff_t dcache_dir_lseek(struct file *file, loff_t offset, int origin)
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);
- p = file->f_path.dentry->d_subdirs.next;
- while (n && p != &file->f_path.dentry->d_subdirs) {
+ p = dentry->d_subdirs.next;
+ while (n && p != &dentry->d_subdirs) {
struct dentry *next;
next = list_entry(p, struct dentry, d_u.d_child);
- spin_lock(&next->d_lock);
+ spin_lock_nested(&next->d_lock, DENTRY_D_LOCK_NESTED);
if (simple_positive(next))
n--;
spin_unlock(&next->d_lock);
p = p->next;
}
list_add_tail(&cursor->d_u.d_child, p);
+ spin_unlock(&dentry->d_lock);
spin_unlock(&dcache_lock);
}
}
- mutex_unlock(&file->f_path.dentry->d_inode->i_mutex);
+ mutex_unlock(&dentry->d_inode->i_mutex);
return offset;
}
@@ -156,6 +160,7 @@ int dcache_readdir(struct file * filp, void * dirent, filldir_t filldir)
/* fallthrough */
default:
spin_lock(&dcache_lock);
+ spin_lock(&dentry->d_lock);
if (filp->f_pos == 2)
list_move(q, &dentry->d_subdirs);
@@ -169,6 +174,7 @@ 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,
@@ -176,11 +182,15 @@ int dcache_readdir(struct file * filp, void * dirent, filldir_t filldir)
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 */
list_move(q, p);
+ spin_unlock(&next->d_lock);
p = q;
filp->f_pos++;
}
+ spin_unlock(&dentry->d_lock);
spin_unlock(&dcache_lock);
}
return 0;
@@ -276,6 +286,7 @@ int simple_empty(struct dentry *dentry)
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);
if (simple_positive(child)) {
@@ -286,6 +297,7 @@ int simple_empty(struct dentry *dentry)
}
ret = 1;
out:
+ spin_unlock(&dentry->d_lock);
spin_unlock(&dcache_lock);
return ret;
}
diff --git a/fs/ncpfs/dir.c b/fs/ncpfs/dir.c
index bbbf792..102278e 100644
--- a/fs/ncpfs/dir.c
+++ b/fs/ncpfs/dir.c
@@ -392,6 +392,7 @@ 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) {
dent = list_entry(next, struct dentry, d_u.d_child);
@@ -400,11 +401,13 @@ ncp_dget_fpos(struct dentry *dentry, struct dentry *parent, unsigned long fpos)
dget_locked(dent);
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;
diff --git a/fs/ncpfs/ncplib_kernel.h b/fs/ncpfs/ncplib_kernel.h
index 244d1b7..c4b718f 100644
--- a/fs/ncpfs/ncplib_kernel.h
+++ b/fs/ncpfs/ncplib_kernel.h
@@ -194,6 +194,7 @@ ncp_renew_dentries(struct dentry *parent)
struct dentry *dentry;
spin_lock(&dcache_lock);
+ spin_lock(&parent->d_lock);
next = parent->d_subdirs.next;
while (next != &parent->d_subdirs) {
dentry = list_entry(next, struct dentry, d_u.d_child);
@@ -205,6 +206,7 @@ ncp_renew_dentries(struct dentry *parent)
next = next->next;
}
+ spin_unlock(&parent->d_lock);
spin_unlock(&dcache_lock);
}
@@ -216,6 +218,7 @@ ncp_invalidate_dircache_entries(struct dentry *parent)
struct dentry *dentry;
spin_lock(&dcache_lock);
+ spin_lock(&parent->d_lock);
next = parent->d_subdirs.next;
while (next != &parent->d_subdirs) {
dentry = list_entry(next, struct dentry, d_u.d_child);
@@ -223,6 +226,7 @@ ncp_invalidate_dircache_entries(struct dentry *parent)
ncp_age_dentry(server, dentry);
next = next->next;
}
+ spin_unlock(&parent->d_lock);
spin_unlock(&dcache_lock);
}
diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c
index 20dc218..aa4f25e 100644
--- a/fs/notify/fsnotify.c
+++ b/fs/notify/fsnotify.c
@@ -68,17 +68,19 @@ void __fsnotify_update_child_dentry_flags(struct inode *inode)
/* run all of the children of the original inode and fix their
* d_flags to indicate parental interest (their parent is the
* original inode) */
+ spin_lock(&alias->d_lock);
list_for_each_entry(child, &alias->d_subdirs, d_u.d_child) {
if (!child->d_inode)
continue;
- spin_lock(&child->d_lock);
+ spin_lock_nested(&child->d_lock, DENTRY_D_LOCK_NESTED);
if (watched)
child->d_flags |= DCACHE_FSNOTIFY_PARENT_WATCHED;
else
child->d_flags &= ~DCACHE_FSNOTIFY_PARENT_WATCHED;
spin_unlock(&child->d_lock);
}
+ spin_unlock(&alias->d_lock);
}
spin_unlock(&dcache_lock);
}