#include <linux/init.h>
#include <linux/hash.h>
#include <linux/cache.h>
-#include <linux/module.h>
+#include <linux/export.h>
#include <linux/mount.h>
#include <linux/file.h>
#include <asm/uaccess.h>
#include <linux/hardirq.h>
#include <linux/bit_spinlock.h>
#include <linux/rculist_bl.h>
+#include <linux/prefetch.h>
+#include <linux/ratelimit.h>
#include "internal.h"
+#include "mount.h"
/*
* Usage:
static unsigned int d_hash_mask __read_mostly;
static unsigned int d_hash_shift __read_mostly;
-struct dcache_hash_bucket {
- struct hlist_bl_head head;
-};
-static struct dcache_hash_bucket *dentry_hashtable __read_mostly;
+static struct hlist_bl_head *dentry_hashtable __read_mostly;
-static inline struct dcache_hash_bucket *d_hash(struct dentry *parent,
- unsigned long hash)
+static inline struct hlist_bl_head *d_hash(const struct dentry *parent,
+ unsigned int hash)
{
- hash += ((unsigned long) parent ^ GOLDEN_RATIO_PRIME) / L1_CACHE_BYTES;
- hash = hash ^ ((hash ^ GOLDEN_RATIO_PRIME) >> D_HASHBITS);
+ hash += (unsigned long) parent / L1_CACHE_BYTES;
+ hash = hash + (hash >> D_HASHBITS);
return dentry_hashtable + (hash & D_HASHMASK);
}
-static inline void spin_lock_bucket(struct dcache_hash_bucket *b)
-{
- bit_spin_lock(0, (unsigned long *)&b->head.first);
-}
-
-static inline void spin_unlock_bucket(struct dcache_hash_bucket *b)
-{
- __bit_spin_unlock(0, (unsigned long *)&b->head.first);
-}
-
/* Statistics gathering. */
struct dentry_stat_t dentry_stat = {
.age_limit = 45,
}
#endif
+/*
+ * Compare 2 name strings, return 0 if they match, otherwise non-zero.
+ * The strings are both count bytes long, and count is non-zero.
+ */
+#ifdef CONFIG_DCACHE_WORD_ACCESS
+
+#include <asm/word-at-a-time.h>
+/*
+ * NOTE! 'cs' and 'scount' come from a dentry, so it has a
+ * aligned allocation for this particular component. We don't
+ * strictly need the load_unaligned_zeropad() safety, but it
+ * doesn't hurt either.
+ *
+ * In contrast, 'ct' and 'tcount' can be from a pathname, and do
+ * need the careful unaligned handling.
+ */
+static inline int dentry_cmp(const unsigned char *cs, size_t scount,
+ const unsigned char *ct, size_t tcount)
+{
+ unsigned long a,b,mask;
+
+ if (unlikely(scount != tcount))
+ return 1;
+
+ for (;;) {
+ a = load_unaligned_zeropad(cs);
+ b = load_unaligned_zeropad(ct);
+ if (tcount < sizeof(unsigned long))
+ break;
+ if (unlikely(a != b))
+ return 1;
+ cs += sizeof(unsigned long);
+ ct += sizeof(unsigned long);
+ tcount -= sizeof(unsigned long);
+ if (!tcount)
+ return 0;
+ }
+ mask = ~(~0ul << tcount*8);
+ return unlikely(!!((a ^ b) & mask));
+}
+
+#else
+
+static inline int dentry_cmp(const unsigned char *cs, size_t scount,
+ const unsigned char *ct, size_t tcount)
+{
+ if (scount != tcount)
+ return 1;
+
+ do {
+ if (*cs != *ct)
+ return 1;
+ cs++;
+ ct++;
+ tcount--;
+ } while (tcount);
+ return 0;
+}
+
+#endif
+
static void __d_free(struct rcu_head *head)
{
struct dentry *dentry = container_of(head, struct dentry, d_u.d_rcu);
if (dentry->d_op && dentry->d_op->d_release)
dentry->d_op->d_release(dentry);
- /* if dentry was never inserted into hash, immediate free is OK */
- if (hlist_bl_unhashed(&dentry->d_hash))
+ /* if dentry was never visible to RCU, immediate free is OK */
+ if (!(dentry->d_flags & DCACHE_RCUACCESS))
__d_free(&dentry->d_u.d_rcu);
else
call_rcu(&dentry->d_u.d_rcu, __d_free);
/**
* dentry_rcuwalk_barrier - invalidate in-progress rcu-walk lookups
+ * @dentry: the target dentry
* After this call, in-progress rcu-walk path lookup will fail. This
* should be called after unhashing, and after changing d_inode (if
* the dentry has not already been unhashed).
}
/*
- * dentry_lru_(add|del|move_tail) must be called with d_lock held.
+ * dentry_lru_(add|del|prune|move_tail) must be called with d_lock held.
*/
static void dentry_lru_add(struct dentry *dentry)
{
static void __dentry_lru_del(struct dentry *dentry)
{
list_del_init(&dentry->d_lru);
+ dentry->d_flags &= ~DCACHE_SHRINK_LIST;
dentry->d_sb->s_nr_dentry_unused--;
dentry_stat.nr_unused--;
}
+/*
+ * Remove a dentry with references from the LRU.
+ */
static void dentry_lru_del(struct dentry *dentry)
{
if (!list_empty(&dentry->d_lru)) {
}
}
-static void dentry_lru_move_tail(struct dentry *dentry)
+/*
+ * Remove a dentry that is unreferenced and about to be pruned
+ * (unhashed and destroyed) from the LRU, and inform the file system.
+ * This wrapper should be called _prior_ to unhashing a victim dentry.
+ */
+static void dentry_lru_prune(struct dentry *dentry)
+{
+ if (!list_empty(&dentry->d_lru)) {
+ if (dentry->d_flags & DCACHE_OP_PRUNE)
+ dentry->d_op->d_prune(dentry);
+
+ spin_lock(&dcache_lru_lock);
+ __dentry_lru_del(dentry);
+ spin_unlock(&dcache_lru_lock);
+ }
+}
+
+static void dentry_lru_move_list(struct dentry *dentry, struct list_head *list)
{
spin_lock(&dcache_lru_lock);
if (list_empty(&dentry->d_lru)) {
- list_add_tail(&dentry->d_lru, &dentry->d_sb->s_dentry_lru);
+ list_add_tail(&dentry->d_lru, list);
dentry->d_sb->s_nr_dentry_unused++;
dentry_stat.nr_unused++;
} else {
- list_move_tail(&dentry->d_lru, &dentry->d_sb->s_dentry_lru);
+ list_move_tail(&dentry->d_lru, list);
}
spin_unlock(&dcache_lru_lock);
}
/**
* d_kill - kill dentry and return parent
* @dentry: dentry to kill
+ * @parent: parent dentry
*
* The dentry must already be unhashed and removed from the LRU.
*
__releases(parent->d_lock)
__releases(dentry->d_inode->i_lock)
{
- dentry->d_parent = NULL;
list_del(&dentry->d_u.d_child);
+ /*
+ * Inform try_to_ascend() that we are no longer attached to the
+ * dentry tree
+ */
+ dentry->d_flags |= DCACHE_DISCONNECTED;
if (parent)
spin_unlock(&parent->d_lock);
dentry_iput(dentry);
return parent;
}
+/*
+ * Unhash a dentry without inserting an RCU walk barrier or checking that
+ * dentry->d_lock is locked. The caller must take care of that, if
+ * appropriate.
+ */
+static void __d_shrink(struct dentry *dentry)
+{
+ if (!d_unhashed(dentry)) {
+ struct hlist_bl_head *b;
+ if (unlikely(dentry->d_flags & DCACHE_DISCONNECTED))
+ b = &dentry->d_sb->s_anon;
+ else
+ b = d_hash(dentry->d_parent, dentry->d_name.hash);
+
+ hlist_bl_lock(b);
+ __hlist_bl_del(&dentry->d_hash);
+ dentry->d_hash.pprev = NULL;
+ hlist_bl_unlock(b);
+ }
+}
+
/**
* d_drop - drop a dentry
* @dentry: dentry to drop
*/
void __d_drop(struct dentry *dentry)
{
- if (!(dentry->d_flags & DCACHE_UNHASHED)) {
- if (unlikely(dentry->d_flags & DCACHE_DISCONNECTED)) {
- bit_spin_lock(0,
- (unsigned long *)&dentry->d_sb->s_anon.first);
- dentry->d_flags |= DCACHE_UNHASHED;
- hlist_bl_del_init(&dentry->d_hash);
- __bit_spin_unlock(0,
- (unsigned long *)&dentry->d_sb->s_anon.first);
- } else {
- struct dcache_hash_bucket *b;
- b = d_hash(dentry->d_parent, dentry->d_name.hash);
- spin_lock_bucket(b);
- /*
- * We may not actually need to put DCACHE_UNHASHED
- * manipulations under the hash lock, but follow
- * the principle of least surprise.
- */
- dentry->d_flags |= DCACHE_UNHASHED;
- hlist_bl_del_rcu(&dentry->d_hash);
- spin_unlock_bucket(b);
- dentry_rcuwalk_barrier(dentry);
- }
+ if (!d_unhashed(dentry)) {
+ __d_shrink(dentry);
+ dentry_rcuwalk_barrier(dentry);
}
}
EXPORT_SYMBOL(__d_drop);
EXPORT_SYMBOL(d_drop);
/*
+ * d_clear_need_lookup - drop a dentry from cache and clear the need lookup flag
+ * @dentry: dentry to drop
+ *
+ * This is called when we do a lookup on a placeholder dentry that needed to be
+ * looked up. The dentry should have been hashed in order for it to be found by
+ * the lookup code, but now needs to be unhashed while we do the actual lookup
+ * and clear the DCACHE_NEED_LOOKUP flag.
+ */
+void d_clear_need_lookup(struct dentry *dentry)
+{
+ spin_lock(&dentry->d_lock);
+ __d_drop(dentry);
+ dentry->d_flags &= ~DCACHE_NEED_LOOKUP;
+ spin_unlock(&dentry->d_lock);
+}
+EXPORT_SYMBOL(d_clear_need_lookup);
+
+/*
* Finish off a dentry we've decided to kill.
* dentry->d_lock must be held, returns with it unlocked.
* If ref is non-zero, then decrement the refcount too.
if (ref)
dentry->d_count--;
- /* if dentry was on the d_lru list delete it from there */
- dentry_lru_del(dentry);
+ /*
+ * if dentry was on the d_lru list delete it from there.
+ * inform the fs via d_prune that this dentry is about to be
+ * unhashed and destroyed.
+ */
+ dentry_lru_prune(dentry);
/* if it was on the hash then remove it */
__d_drop(dentry);
return d_kill(dentry, parent);
if (d_unhashed(dentry))
goto kill_it;
- /* Otherwise leave it cached and ensure it's on the LRU */
- dentry->d_flags |= DCACHE_REFERENCED;
+ /*
+ * If this dentry needs lookup, don't set the referenced flag so that it
+ * is more likely to be cleaned up by the dcache shrinker in case of
+ * memory pressure.
+ */
+ if (!d_need_lookup(dentry))
+ dentry->d_flags |= DCACHE_REFERENCED;
dentry_lru_add(dentry);
dentry->d_count--;
* would make it unreachable from the root,
* we might still populate it if it was a
* working directory or similar).
+ * We also need to leave mountpoints alone,
+ * directory or not.
*/
- if (dentry->d_count > 1) {
- if (dentry->d_inode && S_ISDIR(dentry->d_inode->i_mode)) {
+ if (dentry->d_count > 1 && dentry->d_inode) {
+ if (S_ISDIR(dentry->d_inode->i_mode) || d_mountpoint(dentry)) {
spin_unlock(&dentry->d_lock);
return -EBUSY;
}
*/
rcu_read_lock();
ret = dentry->d_parent;
- if (!ret) {
- rcu_read_unlock();
- goto out;
- }
spin_lock(&ret->d_lock);
if (unlikely(ret != dentry->d_parent)) {
spin_unlock(&ret->d_lock);
BUG_ON(!ret->d_count);
ret->d_count++;
spin_unlock(&ret->d_lock);
-out:
return ret;
}
EXPORT_SYMBOL(dget_parent);
}
/**
- * __shrink_dcache_sb - shrink the dentry LRU on a given superblock
- * @sb: superblock to shrink dentry LRU.
- * @count: number of entries to prune
- * @flags: flags to control the dentry processing
+ * prune_dcache_sb - shrink the dcache
+ * @sb: superblock
+ * @count: number of entries to try to free
+ *
+ * Attempt to shrink the superblock dcache LRU by @count entries. This is
+ * done when we need more memory an called from the superblock shrinker
+ * function.
*
- * If flags contains DCACHE_REFERENCED reference dentries will not be pruned.
+ * This function may fail to free any resources if all the dentries are in
+ * use.
*/
-static void __shrink_dcache_sb(struct super_block *sb, int *count, int flags)
+void prune_dcache_sb(struct super_block *sb, int count)
{
- /* called from prune_dcache() and shrink_dcache_parent() */
struct dentry *dentry;
LIST_HEAD(referenced);
LIST_HEAD(tmp);
- int cnt = *count;
relock:
spin_lock(&dcache_lru_lock);
goto relock;
}
- /*
- * If we are honouring the DCACHE_REFERENCED flag and the
- * dentry has this flag set, don't free it. Clear the flag
- * and put it back on the LRU.
- */
- if (flags & DCACHE_REFERENCED &&
- dentry->d_flags & DCACHE_REFERENCED) {
+ if (dentry->d_flags & DCACHE_REFERENCED) {
dentry->d_flags &= ~DCACHE_REFERENCED;
list_move(&dentry->d_lru, &referenced);
spin_unlock(&dentry->d_lock);
} else {
list_move_tail(&dentry->d_lru, &tmp);
+ dentry->d_flags |= DCACHE_SHRINK_LIST;
spin_unlock(&dentry->d_lock);
- if (!--cnt)
+ if (!--count)
break;
}
cond_resched_lock(&dcache_lru_lock);
spin_unlock(&dcache_lru_lock);
shrink_dentry_list(&tmp);
-
- *count = cnt;
-}
-
-/**
- * prune_dcache - shrink the dcache
- * @count: number of entries to try to free
- *
- * Shrink the dcache. This is done when we need more memory, or simply when we
- * need to unmount something (at which point we need to unuse all dentries).
- *
- * This function may fail to free any resources if all the dentries are in use.
- */
-static void prune_dcache(int count)
-{
- struct super_block *sb, *p = NULL;
- int w_count;
- int unused = dentry_stat.nr_unused;
- int prune_ratio;
- int pruned;
-
- if (unused == 0 || count == 0)
- return;
- if (count >= unused)
- prune_ratio = 1;
- else
- prune_ratio = unused / count;
- spin_lock(&sb_lock);
- list_for_each_entry(sb, &super_blocks, s_list) {
- if (list_empty(&sb->s_instances))
- continue;
- if (sb->s_nr_dentry_unused == 0)
- continue;
- sb->s_count++;
- /* Now, we reclaim unused dentrins with fairness.
- * We reclaim them same percentage from each superblock.
- * We calculate number of dentries to scan on this sb
- * as follows, but the implementation is arranged to avoid
- * overflows:
- * number of dentries to scan on this sb =
- * count * (number of dentries on this sb /
- * number of dentries in the machine)
- */
- spin_unlock(&sb_lock);
- if (prune_ratio != 1)
- w_count = (sb->s_nr_dentry_unused / prune_ratio) + 1;
- else
- w_count = sb->s_nr_dentry_unused;
- pruned = w_count;
- /*
- * We need to be sure this filesystem isn't being unmounted,
- * otherwise we could race with generic_shutdown_super(), and
- * end up holding a reference to an inode while the filesystem
- * is unmounted. So we try to get s_umount, and make sure
- * s_root isn't NULL.
- */
- if (down_read_trylock(&sb->s_umount)) {
- if ((sb->s_root != NULL) &&
- (!list_empty(&sb->s_dentry_lru))) {
- __shrink_dcache_sb(sb, &w_count,
- DCACHE_REFERENCED);
- pruned -= w_count;
- }
- up_read(&sb->s_umount);
- }
- spin_lock(&sb_lock);
- if (p)
- __put_super(p);
- count -= pruned;
- p = sb;
- /* more work left to do? */
- if (count <= 0)
- break;
- }
- if (p)
- __put_super(p);
- spin_unlock(&sb_lock);
}
/**
static void shrink_dcache_for_umount_subtree(struct dentry *dentry)
{
struct dentry *parent;
- unsigned detached = 0;
BUG_ON(!IS_ROOT(dentry));
- /* detach this root from the system */
- spin_lock(&dentry->d_lock);
- dentry_lru_del(dentry);
- __d_drop(dentry);
- spin_unlock(&dentry->d_lock);
-
for (;;) {
/* descend to the first leaf in the current subtree */
- while (!list_empty(&dentry->d_subdirs)) {
- struct dentry *loop;
-
- /* this is a branch with children - detach all of them
- * from the system in one go */
- spin_lock(&dentry->d_lock);
- list_for_each_entry(loop, &dentry->d_subdirs,
- d_u.d_child) {
- spin_lock_nested(&loop->d_lock,
- DENTRY_D_LOCK_NESTED);
- dentry_lru_del(loop);
- __d_drop(loop);
- spin_unlock(&loop->d_lock);
- }
- spin_unlock(&dentry->d_lock);
-
- /* move to the first child */
+ while (!list_empty(&dentry->d_subdirs))
dentry = list_entry(dentry->d_subdirs.next,
struct dentry, d_u.d_child);
- }
/* consume the dentries from this leaf up through its parents
* until we find one with children or run out altogether */
do {
struct inode *inode;
+ /*
+ * remove the dentry from the lru, and inform
+ * the fs that this dentry is about to be
+ * unhashed and destroyed.
+ */
+ dentry_lru_prune(dentry);
+ __d_shrink(dentry);
+
if (dentry->d_count != 0) {
printk(KERN_ERR
"BUG: Dentry %p{i=%lx,n=%s}"
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);
}
- detached++;
-
inode = dentry->d_inode;
if (inode) {
dentry->d_inode = NULL;
dentry = sb->s_root;
sb->s_root = NULL;
- spin_lock(&dentry->d_lock);
dentry->d_count--;
- spin_unlock(&dentry->d_lock);
shrink_dcache_for_umount_subtree(dentry);
while (!hlist_bl_empty(&sb->s_anon)) {
}
/*
+ * This tries to ascend one level of parenthood, but
+ * we can race with renaming, so we need to re-check
+ * the parenthood after dropping the lock and check
+ * that the sequence number still matches.
+ */
+static struct dentry *try_to_ascend(struct dentry *old, int locked, unsigned seq)
+{
+ struct dentry *new = old->d_parent;
+
+ rcu_read_lock();
+ spin_unlock(&old->d_lock);
+ spin_lock(&new->d_lock);
+
+ /*
+ * might go back up the wrong parent if we have had a rename
+ * or deletion
+ */
+ if (new != old->d_parent ||
+ (old->d_flags & DCACHE_DISCONNECTED) ||
+ (!locked && read_seqretry(&rename_lock, seq))) {
+ spin_unlock(&new->d_lock);
+ new = NULL;
+ }
+ rcu_read_unlock();
+ return new;
+}
+
+
+/*
* Search for at least 1 mount point in the dentry's subdirs.
* We descend to the next level whenever the d_subdirs
* list is non-empty and continue searching.
* All done at this level ... ascend and resume the search.
*/
if (this_parent != parent) {
- struct dentry *tmp;
- struct dentry *child;
-
- tmp = this_parent->d_parent;
- rcu_read_lock();
- spin_unlock(&this_parent->d_lock);
- child = this_parent;
- this_parent = tmp;
- spin_lock(&this_parent->d_lock);
- /* might go back up the wrong parent if we have had a rename
- * or deletion */
- if (this_parent != child->d_parent ||
- (!locked && read_seqretry(&rename_lock, seq))) {
- spin_unlock(&this_parent->d_lock);
- rcu_read_unlock();
+ struct dentry *child = this_parent;
+ this_parent = try_to_ascend(this_parent, locked, seq);
+ if (!this_parent)
goto rename_retry;
- }
- rcu_read_unlock();
next = child->d_u.d_child.next;
goto resume;
}
* drop the lock and return early due to latency
* constraints.
*/
-static int select_parent(struct dentry * parent)
+static int select_parent(struct dentry *parent, struct list_head *dispose)
{
struct dentry *this_parent;
struct list_head *next;
spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
- /*
- * move only zero ref count dentries to the end
- * of the unused list for prune_dcache
+ /*
+ * move only zero ref count dentries to the dispose list.
+ *
+ * Those which are presently on the shrink list, being processed
+ * by shrink_dentry_list(), shouldn't be moved. Otherwise the
+ * loop in shrink_dcache_parent() might not make any progress
+ * and loop forever.
*/
- if (!dentry->d_count) {
- dentry_lru_move_tail(dentry);
- found++;
- } else {
+ if (dentry->d_count) {
dentry_lru_del(dentry);
+ } else if (!(dentry->d_flags & DCACHE_SHRINK_LIST)) {
+ dentry_lru_move_list(dentry, dispose);
+ dentry->d_flags |= DCACHE_SHRINK_LIST;
+ found++;
}
-
/*
* We can return to the caller if we have found some (this
* ensures forward progress). We'll be coming back to find
* All done at this level ... ascend and resume the search.
*/
if (this_parent != parent) {
- struct dentry *tmp;
- struct dentry *child;
-
- tmp = this_parent->d_parent;
- rcu_read_lock();
- spin_unlock(&this_parent->d_lock);
- child = this_parent;
- this_parent = tmp;
- spin_lock(&this_parent->d_lock);
- /* might go back up the wrong parent if we have had a rename
- * or deletion */
- if (this_parent != child->d_parent ||
- (!locked && read_seqretry(&rename_lock, seq))) {
- spin_unlock(&this_parent->d_lock);
- rcu_read_unlock();
+ struct dentry *child = this_parent;
+ this_parent = try_to_ascend(this_parent, locked, seq);
+ if (!this_parent)
goto rename_retry;
- }
- rcu_read_unlock();
next = child->d_u.d_child.next;
goto resume;
}
*
* Prune the dcache to remove unused children of the parent dentry.
*/
-
void shrink_dcache_parent(struct dentry * parent)
{
- struct super_block *sb = parent->d_sb;
+ LIST_HEAD(dispose);
int found;
- while ((found = select_parent(parent)) != 0)
- __shrink_dcache_sb(sb, &found, 0);
+ while ((found = select_parent(parent, &dispose)) != 0)
+ shrink_dentry_list(&dispose);
}
EXPORT_SYMBOL(shrink_dcache_parent);
-/*
- * Scan `nr' dentries and return the number which remain.
- *
- * We need to avoid reentering the filesystem if the caller is performing a
- * GFP_NOFS allocation attempt. One example deadlock is:
- *
- * ext2_new_block->getblk->GFP->shrink_dcache_memory->prune_dcache->
- * prune_one_dentry->dput->dentry_iput->iput->inode->i_sb->s_op->put_inode->
- * ext2_discard_prealloc->ext2_free_blocks->lock_super->DEADLOCK.
- *
- * In this case we return -1 to tell the caller that we baled.
- */
-static int shrink_dcache_memory(struct shrinker *shrink, int nr, gfp_t gfp_mask)
-{
- if (nr) {
- if (!(gfp_mask & __GFP_FS))
- return -1;
- prune_dcache(nr);
- }
-
- return (dentry_stat.nr_unused / 100) * sysctl_vfs_cache_pressure;
-}
-
-static struct shrinker dcache_shrinker = {
- .shrink = shrink_dcache_memory,
- .seeks = DEFAULT_SEEKS,
-};
-
/**
- * d_alloc - allocate a dcache entry
- * @parent: parent of entry to allocate
+ * __d_alloc - allocate a dcache entry
+ * @sb: filesystem it will belong to
* @name: qstr of the name
*
* Allocates a dentry. It returns %NULL if there is insufficient memory
* copied and the copy passed in may be reused after this call.
*/
-struct dentry *d_alloc(struct dentry * parent, const struct qstr *name)
+struct dentry *__d_alloc(struct super_block *sb, const struct qstr *name)
{
struct dentry *dentry;
char *dname;
dname[name->len] = 0;
dentry->d_count = 1;
- dentry->d_flags = DCACHE_UNHASHED;
+ dentry->d_flags = 0;
spin_lock_init(&dentry->d_lock);
seqcount_init(&dentry->d_seq);
dentry->d_inode = NULL;
- dentry->d_parent = NULL;
- dentry->d_sb = NULL;
+ dentry->d_parent = dentry;
+ dentry->d_sb = sb;
dentry->d_op = NULL;
dentry->d_fsdata = NULL;
INIT_HLIST_BL_NODE(&dentry->d_hash);
INIT_LIST_HEAD(&dentry->d_subdirs);
INIT_LIST_HEAD(&dentry->d_alias);
INIT_LIST_HEAD(&dentry->d_u.d_child);
-
- if (parent) {
- spin_lock(&parent->d_lock);
- /*
- * don't need child lock because it is not subject
- * to concurrency here
- */
- __dget_dlock(parent);
- dentry->d_parent = parent;
- dentry->d_sb = parent->d_sb;
- d_set_d_op(dentry, dentry->d_sb->s_d_op);
- list_add(&dentry->d_u.d_child, &parent->d_subdirs);
- spin_unlock(&parent->d_lock);
- }
+ d_set_d_op(dentry, dentry->d_sb->s_d_op);
this_cpu_inc(nr_dentry);
return dentry;
}
+
+/**
+ * d_alloc - allocate a dcache entry
+ * @parent: parent of entry to allocate
+ * @name: qstr of the name
+ *
+ * Allocates a dentry. It returns %NULL if there is insufficient memory
+ * available. On a success the dentry is returned. The name passed in is
+ * copied and the copy passed in may be reused after this call.
+ */
+struct dentry *d_alloc(struct dentry * parent, const struct qstr *name)
+{
+ struct dentry *dentry = __d_alloc(parent->d_sb, name);
+ if (!dentry)
+ return NULL;
+
+ spin_lock(&parent->d_lock);
+ /*
+ * don't need child lock because it is not subject
+ * to concurrency here
+ */
+ __dget_dlock(parent);
+ dentry->d_parent = parent;
+ list_add(&dentry->d_u.d_child, &parent->d_subdirs);
+ spin_unlock(&parent->d_lock);
+
+ return dentry;
+}
EXPORT_SYMBOL(d_alloc);
struct dentry *d_alloc_pseudo(struct super_block *sb, const struct qstr *name)
{
- struct dentry *dentry = d_alloc(NULL, name);
- if (dentry) {
- dentry->d_sb = sb;
- d_set_d_op(dentry, dentry->d_sb->s_d_op);
- dentry->d_parent = dentry;
+ struct dentry *dentry = __d_alloc(sb, name);
+ if (dentry)
dentry->d_flags |= DCACHE_DISCONNECTED;
- }
return dentry;
}
EXPORT_SYMBOL(d_alloc_pseudo);
void d_set_d_op(struct dentry *dentry, const struct dentry_operations *op)
{
- BUG_ON(dentry->d_op);
- BUG_ON(dentry->d_flags & (DCACHE_OP_HASH |
+ WARN_ON_ONCE(dentry->d_op);
+ WARN_ON_ONCE(dentry->d_flags & (DCACHE_OP_HASH |
DCACHE_OP_COMPARE |
DCACHE_OP_REVALIDATE |
DCACHE_OP_DELETE ));
dentry->d_flags |= DCACHE_OP_REVALIDATE;
if (op->d_delete)
dentry->d_flags |= DCACHE_OP_DELETE;
+ if (op->d_prune)
+ dentry->d_flags |= DCACHE_OP_PRUNE;
}
EXPORT_SYMBOL(d_set_d_op);
static void __d_instantiate(struct dentry *dentry, struct inode *inode)
{
spin_lock(&dentry->d_lock);
- if (inode)
+ if (inode) {
+ if (unlikely(IS_AUTOMOUNT(inode)))
+ dentry->d_flags |= DCACHE_NEED_AUTOMOUNT;
list_add(&dentry->d_alias, &inode->i_dentry);
+ }
dentry->d_inode = inode;
dentry_rcuwalk_barrier(dentry);
spin_unlock(&dentry->d_lock);
EXPORT_SYMBOL(d_instantiate_unique);
-/**
- * d_alloc_root - allocate root dentry
- * @root_inode: inode to allocate the root for
- *
- * Allocate a root ("/") dentry for the inode given. The inode is
- * instantiated and returned. %NULL is returned if there is insufficient
- * memory or the inode passed is %NULL.
- */
-
-struct dentry * d_alloc_root(struct inode * root_inode)
+struct dentry *d_make_root(struct inode *root_inode)
{
struct dentry *res = NULL;
if (root_inode) {
static const struct qstr name = { .name = "/", .len = 1 };
- res = d_alloc(NULL, &name);
- if (res) {
- res->d_sb = root_inode->i_sb;
- d_set_d_op(res, res->d_sb->s_d_op);
- res->d_parent = res;
+ res = __d_alloc(root_inode->i_sb, &name);
+ if (res)
d_instantiate(res, root_inode);
- }
+ else
+ iput(root_inode);
}
return res;
}
-EXPORT_SYMBOL(d_alloc_root);
+EXPORT_SYMBOL(d_make_root);
+
+static struct dentry * __d_find_any_alias(struct inode *inode)
+{
+ struct dentry *alias;
+
+ if (list_empty(&inode->i_dentry))
+ return NULL;
+ alias = list_first_entry(&inode->i_dentry, struct dentry, d_alias);
+ __dget(alias);
+ return alias;
+}
+
+/**
+ * d_find_any_alias - find any alias for a given inode
+ * @inode: inode to find an alias for
+ *
+ * If any aliases exist for the given inode, take and return a
+ * reference for one of them. If no aliases exist, return %NULL.
+ */
+struct dentry *d_find_any_alias(struct inode *inode)
+{
+ struct dentry *de;
+
+ spin_lock(&inode->i_lock);
+ de = __d_find_any_alias(inode);
+ spin_unlock(&inode->i_lock);
+ return de;
+}
+EXPORT_SYMBOL(d_find_any_alias);
/**
* d_obtain_alias - find or allocate a dentry for a given inode
if (IS_ERR(inode))
return ERR_CAST(inode);
- res = d_find_alias(inode);
+ res = d_find_any_alias(inode);
if (res)
goto out_iput;
- tmp = d_alloc(NULL, &anonstring);
+ tmp = __d_alloc(inode->i_sb, &anonstring);
if (!tmp) {
res = ERR_PTR(-ENOMEM);
goto out_iput;
}
- tmp->d_parent = tmp; /* make sure dput doesn't croak */
-
spin_lock(&inode->i_lock);
- res = __d_find_alias(inode, 0);
+ res = __d_find_any_alias(inode);
if (res) {
spin_unlock(&inode->i_lock);
dput(tmp);
/* attach a disconnected dentry */
spin_lock(&tmp->d_lock);
- tmp->d_sb = inode->i_sb;
- d_set_d_op(tmp, tmp->d_sb->s_d_op);
tmp->d_inode = inode;
tmp->d_flags |= DCACHE_DISCONNECTED;
list_add(&tmp->d_alias, &inode->i_dentry);
- bit_spin_lock(0, (unsigned long *)&tmp->d_sb->s_anon.first);
- tmp->d_flags &= ~DCACHE_UNHASHED;
+ hlist_bl_lock(&tmp->d_sb->s_anon);
hlist_bl_add_head(&tmp->d_hash, &tmp->d_sb->s_anon);
- __bit_spin_unlock(0, (unsigned long *)&tmp->d_sb->s_anon.first);
+ hlist_bl_unlock(&tmp->d_sb->s_anon);
spin_unlock(&tmp->d_lock);
spin_unlock(&inode->i_lock);
+ security_d_instantiate(tmp, inode);
return tmp;
out_iput:
+ if (res && !IS_ERR(res))
+ security_d_instantiate(res, inode);
iput(inode);
return res;
}
{
struct dentry *new = NULL;
+ if (IS_ERR(inode))
+ return ERR_CAST(inode);
+
if (inode && S_ISDIR(inode->i_mode)) {
spin_lock(&inode->i_lock);
new = __d_find_alias(inode, 1);
}
/*
- * Negative dentry: instantiate it unless the inode is a directory and
- * already has a dentry.
+ * We are going to instantiate this dentry, unhash it and clear the
+ * lookup flag so we can do that.
*/
- spin_lock(&inode->i_lock);
- if (!S_ISDIR(inode->i_mode) || list_empty(&inode->i_dentry)) {
- __d_instantiate(found, inode);
- spin_unlock(&inode->i_lock);
- security_d_instantiate(found, inode);
- return found;
- }
+ if (unlikely(d_need_lookup(found)))
+ d_clear_need_lookup(found);
/*
- * In case a directory already has a (disconnected) entry grab a
- * reference to it, move it in place and use it.
+ * Negative dentry: instantiate it unless the inode is a directory and
+ * already has a dentry.
*/
- new = list_entry(inode->i_dentry.next, struct dentry, d_alias);
- __dget(new);
- spin_unlock(&inode->i_lock);
- security_d_instantiate(found, inode);
- d_move(new, found);
- iput(inode);
- dput(found);
- return new;
+ new = d_splice_alias(inode, found);
+ if (new) {
+ dput(found);
+ found = new;
+ }
+ return found;
err_out:
iput(inode);
* __d_lookup_rcu - search for a dentry (racy, store-free)
* @parent: parent dentry
* @name: qstr of name we wish to find
- * @seq: returns d_seq value at the point where the dentry was found
+ * @seqp: returns d_seq value at the point where the dentry was found
* @inode: returns dentry->d_inode when the inode was found valid.
* Returns: dentry, or NULL
*
* child is looked up. Thus, an interlocking stepping of sequence lock checks
* is formed, giving integrity down the path walk.
*/
-struct dentry *__d_lookup_rcu(struct dentry *parent, struct qstr *name,
- unsigned *seq, struct inode **inode)
+struct dentry *__d_lookup_rcu(const struct dentry *parent,
+ const struct qstr *name,
+ unsigned *seqp, struct inode **inode)
{
unsigned int len = name->len;
unsigned int hash = name->hash;
const unsigned char *str = name->name;
- struct dcache_hash_bucket *b = d_hash(parent, hash);
+ struct hlist_bl_head *b = d_hash(parent, hash);
struct hlist_bl_node *node;
struct dentry *dentry;
* false-negative result. d_lookup() protects against concurrent
* renames using rename_lock seqlock.
*
- * See Documentation/vfs/dcache-locking.txt for more details.
+ * See Documentation/filesystems/path-lookup.txt for more details.
*/
- hlist_bl_for_each_entry_rcu(dentry, node, &b->head, d_hash) {
+ hlist_bl_for_each_entry_rcu(dentry, node, b, d_hash) {
+ unsigned seq;
struct inode *i;
const char *tname;
int tlen;
continue;
seqretry:
- *seq = read_seqcount_begin(&dentry->d_seq);
+ seq = read_seqcount_begin(&dentry->d_seq);
if (dentry->d_parent != parent)
continue;
if (d_unhashed(dentry))
tname = dentry->d_name.name;
i = dentry->d_inode;
prefetch(tname);
- if (i)
- prefetch(i);
/*
* This seqcount check is required to ensure name and
* len are loaded atomically, so as not to walk off the
* edge of memory when walking. If we could load this
* atomically some other way, we could drop this check.
*/
- if (read_seqcount_retry(&dentry->d_seq, *seq))
+ if (read_seqcount_retry(&dentry->d_seq, seq))
goto seqretry;
- if (parent->d_flags & DCACHE_OP_COMPARE) {
+ if (unlikely(parent->d_flags & DCACHE_OP_COMPARE)) {
if (parent->d_op->d_compare(parent, *inode,
dentry, i,
tlen, tname, name))
* order to do anything useful with the returned dentry
* anyway.
*/
+ *seqp = seq;
*inode = i;
return dentry;
}
unsigned int len = name->len;
unsigned int hash = name->hash;
const unsigned char *str = name->name;
- struct dcache_hash_bucket *b = d_hash(parent, hash);
+ struct hlist_bl_head *b = d_hash(parent, hash);
struct hlist_bl_node *node;
struct dentry *found = NULL;
struct dentry *dentry;
* false-negative result. d_lookup() protects against concurrent
* renames using rename_lock seqlock.
*
- * See Documentation/vfs/dcache-locking.txt for more details.
+ * See Documentation/filesystems/path-lookup.txt for more details.
*/
rcu_read_lock();
- hlist_bl_for_each_entry_rcu(dentry, node, &b->head, d_hash) {
+ hlist_bl_for_each_entry_rcu(dentry, node, b, d_hash) {
const char *tname;
int tlen;
/**
* d_validate - verify dentry provided from insecure source (deprecated)
* @dentry: The dentry alleged to be valid child of @dparent
- * @parent: The parent dentry (known to be valid)
+ * @dparent: The parent dentry (known to be valid)
*
* An insecure source has sent us a dentry, here we verify it and dget() it.
* This is used by ncpfs in its readdir implementation.
}
EXPORT_SYMBOL(d_delete);
-static void __d_rehash(struct dentry * entry, struct dcache_hash_bucket *b)
+static void __d_rehash(struct dentry * entry, struct hlist_bl_head *b)
{
BUG_ON(!d_unhashed(entry));
- spin_lock_bucket(b);
- entry->d_flags &= ~DCACHE_UNHASHED;
- hlist_bl_add_head_rcu(&entry->d_hash, &b->head);
- spin_unlock_bucket(b);
+ hlist_bl_lock(b);
+ entry->d_flags |= DCACHE_RCUACCESS;
+ hlist_bl_add_head_rcu(&entry->d_hash, b);
+ hlist_bl_unlock(b);
}
static void _d_rehash(struct dentry * entry)
*/
void dentry_update_name_case(struct dentry *dentry, struct qstr *name)
{
- BUG_ON(!mutex_is_locked(&dentry->d_inode->i_mutex));
+ BUG_ON(!mutex_is_locked(&dentry->d_parent->d_inode->i_mutex));
BUG_ON(dentry->d_name.len != name->len); /* d_lookup gives this */
spin_lock(&dentry->d_lock);
* The hash value has to match the hash queue that the dentry is on..
*/
/*
- * d_move - 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.
+ * dcache entries should not be moved in this way. Caller must hold
+ * rename_lock, the i_mutex of the source and target directories,
+ * and the sb->s_vfs_rename_mutex if they differ. See lock_rename().
*/
-void d_move(struct dentry * dentry, struct dentry * target)
+static void __d_move(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);
-
dentry_lock_for_move(dentry, target);
write_seqcount_begin(&dentry->d_seq);
spin_unlock(&target->d_lock);
fsnotify_d_move(dentry);
spin_unlock(&dentry->d_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. See the locking
+ * requirements for __d_move.
+ */
+void d_move(struct dentry *dentry, struct dentry *target)
+{
+ write_seqlock(&rename_lock);
+ __d_move(dentry, target);
write_sequnlock(&rename_lock);
}
EXPORT_SYMBOL(d_move);
* 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 inode->i_lock
+ * dentry->d_parent->d_inode->i_mutex, inode->i_lock and rename_lock
*
* Note: If ever the locking in lock_rename() changes, then please
* remember to update this too...
if (alias->d_parent == dentry->d_parent)
goto out_unalias;
- /* Check for loops */
- ret = ERR_PTR(-ELOOP);
- if (d_ancestor(alias, dentry))
- goto out_err;
-
/* See lock_rename() */
ret = ERR_PTR(-EBUSY);
if (!mutex_trylock(&dentry->d_sb->s_vfs_rename_mutex))
goto out_err;
m2 = &alias->d_parent->d_inode->i_mutex;
out_unalias:
- d_move(alias, dentry);
+ __d_move(alias, dentry);
ret = alias;
out_err:
spin_unlock(&inode->i_lock);
* @inode: inode to bind to the dentry, to which aliases may be attached
*
* Introduces an dentry into the tree, substituting an extant disconnected
- * root directory alias in its place if there is one
+ * root directory alias in its place if there is one. Caller must hold the
+ * i_mutex of the parent directory.
*/
struct dentry *d_materialise_unique(struct dentry *dentry, struct inode *inode)
{
alias = __d_find_alias(inode, 0);
if (alias) {
actual = alias;
- /* Is this an anonymous mountpoint that we could splice
- * into our tree? */
- if (IS_ROOT(alias)) {
+ write_seqlock(&rename_lock);
+
+ if (d_ancestor(alias, dentry)) {
+ /* Check for loops */
+ actual = ERR_PTR(-ELOOP);
+ spin_unlock(&inode->i_lock);
+ } else if (IS_ROOT(alias)) {
+ /* Is this an anonymous mountpoint that we
+ * could splice into our tree? */
__d_materialise_dentry(dentry, alias);
+ write_sequnlock(&rename_lock);
__d_drop(alias);
goto found;
+ } else {
+ /* Nope, but we must(!) avoid directory
+ * aliasing. This drops inode->i_lock */
+ actual = __d_unalias(inode, dentry, alias);
}
- /* Nope, but we must(!) avoid directory aliasing */
- actual = __d_unalias(inode, dentry, alias);
- if (IS_ERR(actual))
+ write_sequnlock(&rename_lock);
+ if (IS_ERR(actual)) {
+ if (PTR_ERR(actual) == -ELOOP)
+ pr_warn_ratelimited(
+ "VFS: Lookup of '%s' in %s %s"
+ " would have caused loop\n",
+ dentry->d_name.name,
+ inode->i_sb->s_type->name,
+ inode->i_sb->s_id);
dput(alias);
+ }
goto out_nolock;
}
}
/**
* prepend_path - Prepend path string to a buffer
* @path: the dentry/vfsmount to report
- * @root: root vfsmnt/dentry (may be modified by this function)
+ * @root: root vfsmnt/dentry
* @buffer: pointer to the end of the buffer
* @buflen: pointer to buffer length
*
* Caller holds the rename_lock.
- *
- * If path is not reachable from the supplied root, then the value of
- * root is changed (without modifying refcounts).
*/
-static int prepend_path(const struct path *path, struct path *root,
+static int prepend_path(const struct path *path,
+ const struct path *root,
char **buffer, int *buflen)
{
struct dentry *dentry = path->dentry;
struct vfsmount *vfsmnt = path->mnt;
+ struct mount *mnt = real_mount(vfsmnt);
bool slash = false;
int error = 0;
if (dentry == vfsmnt->mnt_root || IS_ROOT(dentry)) {
/* Global root? */
- if (vfsmnt->mnt_parent == vfsmnt) {
+ if (!mnt_has_parent(mnt))
goto global_root;
- }
- dentry = vfsmnt->mnt_mountpoint;
- vfsmnt = vfsmnt->mnt_parent;
+ dentry = mnt->mnt_mountpoint;
+ mnt = mnt->mnt_parent;
+ vfsmnt = &mnt->mnt;
continue;
}
parent = dentry->d_parent;
dentry = parent;
}
-out:
if (!error && !slash)
error = prepend(buffer, buflen, "/", 1);
+out:
br_read_unlock(vfsmount_lock);
return error;
WARN(1, "Root dentry has weird name <%.*s>\n",
(int) dentry->d_name.len, dentry->d_name.name);
}
- root->mnt = vfsmnt;
- root->dentry = dentry;
+ if (!slash)
+ error = prepend(buffer, buflen, "/", 1);
+ if (!error)
+ error = real_mount(vfsmnt)->mnt_ns ? 1 : 2;
goto out;
}
/**
* __d_path - return the path of a dentry
* @path: the dentry/vfsmount to report
- * @root: root vfsmnt/dentry (may be modified by this function)
+ * @root: root vfsmnt/dentry
* @buf: buffer to return value in
* @buflen: buffer length
*
*
* "buflen" should be positive.
*
- * If path is not reachable from the supplied root, then the value of
- * root is changed (without modifying refcounts).
+ * If the path is not reachable from the supplied root, return %NULL.
*/
-char *__d_path(const struct path *path, struct path *root,
+char *__d_path(const struct path *path,
+ const struct path *root,
char *buf, int buflen)
{
char *res = buf + buflen;
error = prepend_path(path, root, &res, &buflen);
write_sequnlock(&rename_lock);
- if (error)
+ if (error < 0)
+ return ERR_PTR(error);
+ if (error > 0)
+ return NULL;
+ return res;
+}
+
+char *d_absolute_path(const struct path *path,
+ char *buf, int buflen)
+{
+ struct path root = {};
+ char *res = buf + buflen;
+ int error;
+
+ prepend(&res, &buflen, "\0", 1);
+ write_seqlock(&rename_lock);
+ error = prepend_path(path, &root, &res, &buflen);
+ write_sequnlock(&rename_lock);
+
+ if (error > 1)
+ error = -EINVAL;
+ if (error < 0)
return ERR_PTR(error);
return res;
}
/*
* same as __d_path but appends "(deleted)" for unlinked files.
*/
-static int path_with_deleted(const struct path *path, struct path *root,
- char **buf, int *buflen)
+static int path_with_deleted(const struct path *path,
+ const struct path *root,
+ char **buf, int *buflen)
{
prepend(buf, buflen, "\0", 1);
if (d_unlinked(path->dentry)) {
{
char *res = buf + buflen;
struct path root;
- struct path tmp;
int error;
/*
get_fs_root(current->fs, &root);
write_seqlock(&rename_lock);
- tmp = root;
- error = path_with_deleted(path, &tmp, &res, &buflen);
- if (error)
+ error = path_with_deleted(path, &root, &res, &buflen);
+ if (error < 0)
res = ERR_PTR(error);
write_sequnlock(&rename_lock);
path_put(&root);
{
char *res = buf + buflen;
struct path root;
- struct path tmp;
int error;
if (path->dentry->d_op && path->dentry->d_op->d_dname)
get_fs_root(current->fs, &root);
write_seqlock(&rename_lock);
- tmp = root;
- error = path_with_deleted(path, &tmp, &res, &buflen);
- if (!error && !path_equal(&tmp, &root))
+ error = path_with_deleted(path, &root, &res, &buflen);
+ if (error > 0)
error = prepend_unreachable(&res, &buflen);
write_sequnlock(&rename_lock);
path_put(&root);
write_seqlock(&rename_lock);
if (!d_unlinked(pwd.dentry)) {
unsigned long len;
- struct path tmp = root;
char *cwd = page + PAGE_SIZE;
int buflen = PAGE_SIZE;
prepend(&cwd, &buflen, "\0", 1);
- error = prepend_path(&pwd, &tmp, &cwd, &buflen);
+ error = prepend_path(&pwd, &root, &cwd, &buflen);
write_sequnlock(&rename_lock);
- if (error)
+ if (error < 0)
goto out;
/* Unreachable from current root */
- if (!path_equal(&tmp, &root)) {
+ if (error > 0) {
error = prepend_unreachable(&cwd, &buflen);
if (error)
goto out;
return result;
}
-int path_is_under(struct path *path1, struct path *path2)
-{
- struct vfsmount *mnt = path1->mnt;
- struct dentry *dentry = path1->dentry;
- int res;
-
- br_read_lock(vfsmount_lock);
- if (mnt != path2->mnt) {
- for (;;) {
- if (mnt->mnt_parent == mnt) {
- br_read_unlock(vfsmount_lock);
- return 0;
- }
- if (mnt->mnt_parent == path2->mnt)
- break;
- mnt = mnt->mnt_parent;
- }
- dentry = mnt->mnt_mountpoint;
- }
- res = is_subdir(dentry, path2->dentry);
- br_read_unlock(vfsmount_lock);
- return res;
-}
-EXPORT_SYMBOL(path_is_under);
-
void d_genocide(struct dentry *root)
{
struct dentry *this_parent;
spin_unlock(&dentry->d_lock);
}
if (this_parent != root) {
- struct dentry *tmp;
- struct dentry *child;
-
- tmp = this_parent->d_parent;
+ struct dentry *child = this_parent;
if (!(this_parent->d_flags & DCACHE_GENOCIDE)) {
this_parent->d_flags |= DCACHE_GENOCIDE;
this_parent->d_count--;
}
- rcu_read_lock();
- spin_unlock(&this_parent->d_lock);
- child = this_parent;
- this_parent = tmp;
- spin_lock(&this_parent->d_lock);
- /* might go back up the wrong parent if we have had a rename
- * or deletion */
- if (this_parent != child->d_parent ||
- (!locked && read_seqretry(&rename_lock, seq))) {
- spin_unlock(&this_parent->d_lock);
- rcu_read_unlock();
+ this_parent = try_to_ascend(this_parent, locked, seq);
+ if (!this_parent)
goto rename_retry;
- }
- rcu_read_unlock();
next = child->d_u.d_child.next;
goto resume;
}
static void __init dcache_init_early(void)
{
- int loop;
+ unsigned int loop;
/* If hashes are distributed across NUMA nodes, defer
* hash allocation until vmalloc space is available.
dentry_hashtable =
alloc_large_system_hash("Dentry cache",
- sizeof(struct dcache_hash_bucket),
+ sizeof(struct hlist_bl_head),
dhash_entries,
13,
HASH_EARLY,
&d_hash_mask,
0);
- for (loop = 0; loop < (1 << d_hash_shift); loop++)
- INIT_HLIST_BL_HEAD(&dentry_hashtable[loop].head);
+ for (loop = 0; loop < (1U << d_hash_shift); loop++)
+ INIT_HLIST_BL_HEAD(dentry_hashtable + loop);
}
static void __init dcache_init(void)
{
- int loop;
+ unsigned int loop;
/*
* A constructor could be added for stable state like the lists,
*/
dentry_cache = KMEM_CACHE(dentry,
SLAB_RECLAIM_ACCOUNT|SLAB_PANIC|SLAB_MEM_SPREAD);
-
- register_shrinker(&dcache_shrinker);
/* Hash may have been set up in dcache_init_early */
if (!hashdist)
dentry_hashtable =
alloc_large_system_hash("Dentry cache",
- sizeof(struct dcache_hash_bucket),
+ sizeof(struct hlist_bl_head),
dhash_entries,
13,
0,
&d_hash_mask,
0);
- for (loop = 0; loop < (1 << d_hash_shift); loop++)
- INIT_HLIST_BL_HEAD(&dentry_hashtable[loop].head);
+ for (loop = 0; loop < (1U << d_hash_shift); loop++)
+ INIT_HLIST_BL_HEAD(dentry_hashtable + loop);
}
/* SLAB cache for __getname() consumers */
projects / linux-flexiantxendom0-3.2.10.git / blobdiff