/*
* Usage:
* dcache->d_inode->i_lock protects:
- * - i_dentry, d_alias, d_inode of aliases
+ * - i_dentry, d_u.d_alias, d_inode of aliases
* dcache_hash_bucket lock protects:
* - the dcache hash table
* s_anon bl list spinlock protects:
* - d_unhashed()
* - d_parent and d_subdirs
* - childrens' d_child and d_parent
- * - d_alias, d_inode
+ * - d_u.d_alias, d_inode
*
* Ordering:
* dentry->d_inode->i_lock
{
struct dentry *dentry = container_of(head, struct dentry, d_u.d_rcu);
- WARN_ON(!list_empty(&dentry->d_alias));
if (dname_external(dentry))
kfree(dentry->d_name.name);
kmem_cache_free(dentry_cache, dentry);
*/
static void d_free(struct dentry *dentry)
{
+ WARN_ON(!list_empty(&dentry->d_u.d_alias));
BUG_ON(dentry->d_count);
this_cpu_dec(nr_dentry);
if (dentry->d_op && dentry->d_op->d_release)
struct inode *inode = dentry->d_inode;
if (inode) {
dentry->d_inode = NULL;
- list_del_init(&dentry->d_alias);
+ list_del_init(&dentry->d_u.d_alias);
spin_unlock(&dentry->d_lock);
spin_unlock(&inode->i_lock);
if (!inode->i_nlink)
{
struct inode *inode = dentry->d_inode;
dentry->d_inode = NULL;
- list_del_init(&dentry->d_alias);
+ list_del_init(&dentry->d_u.d_alias);
dentry_rcuwalk_barrier(dentry);
spin_unlock(&dentry->d_lock);
spin_unlock(&inode->i_lock);
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--;
}
}
}
-static void dentry_lru_move_tail(struct dentry *dentry)
+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);
}
__releases(parent->d_lock)
__releases(dentry->d_inode->i_lock)
{
- list_del(&dentry->d_u.d_child);
+ __list_del_entry(&dentry->d_child);
/*
- * Inform try_to_ascend() that we are no longer attached to the
+ * Inform ascending readers that we are no longer attached to the
* dentry tree
*/
- dentry->d_flags |= DCACHE_DISCONNECTED;
+ dentry->d_flags |= DCACHE_DENTRY_KILLED;
if (parent)
spin_unlock(&parent->d_lock);
dentry_iput(dentry);
again:
discon_alias = NULL;
- list_for_each_entry(alias, &inode->i_dentry, d_alias) {
+ list_for_each_entry(alias, &inode->i_dentry, d_u.d_alias) {
spin_lock(&alias->d_lock);
if (S_ISDIR(inode->i_mode) || !d_unhashed(alias)) {
if (IS_ROOT(alias) &&
struct dentry *dentry;
restart:
spin_lock(&inode->i_lock);
- list_for_each_entry(dentry, &inode->i_dentry, d_alias) {
+ list_for_each_entry(dentry, &inode->i_dentry, d_u.d_alias) {
spin_lock(&dentry->d_lock);
if (!dentry->d_count) {
__dget_dlock(dentry);
}
/**
- * __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)
{
struct dentry *dentry;
LIST_HEAD(referenced);
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 (!--count)
break;
shrink_dentry_list(&tmp);
}
-/**
- * prune_dcache_sb - shrink the dcache
- * @sb: superblock
- * @nr_to_scan: number of entries to try to free
- *
- * Attempt to shrink the superblock dcache LRU by @nr_to_scan entries. This is
- * done when we need more memory an called from the superblock shrinker
- * function.
- *
- * This function may fail to free any resources if all the dentries are in
- * use.
- */
-void prune_dcache_sb(struct super_block *sb, int nr_to_scan)
-{
- __shrink_dcache_sb(sb, nr_to_scan, DCACHE_REFERENCED);
-}
-
/**
* shrink_dcache_sb - shrink dcache for a superblock
* @sb: superblock
/* descend to the first leaf in the current subtree */
while (!list_empty(&dentry->d_subdirs))
dentry = list_entry(dentry->d_subdirs.next,
- struct dentry, d_u.d_child);
+ struct dentry, d_child);
/* consume the dentries from this leaf up through its parents
* until we find one with children or run out altogether */
if (IS_ROOT(dentry)) {
parent = NULL;
- list_del(&dentry->d_u.d_child);
+ list_del(&dentry->d_child);
} else {
parent = dentry->d_parent;
parent->d_count--;
- list_del(&dentry->d_u.d_child);
+ list_del(&dentry->d_child);
}
inode = dentry->d_inode;
if (inode) {
dentry->d_inode = NULL;
- list_del_init(&dentry->d_alias);
+ list_del_init(&dentry->d_u.d_alias);
if (dentry->d_op && dentry->d_op->d_iput)
dentry->d_op->d_iput(dentry, inode);
else
} while (list_empty(&dentry->d_subdirs));
dentry = list_entry(dentry->d_subdirs.next,
- struct dentry, d_u.d_child);
+ struct dentry, d_child);
}
}
}
}
-/*
- * 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.
resume:
while (next != &this_parent->d_subdirs) {
struct list_head *tmp = next;
- struct dentry *dentry = list_entry(tmp, struct dentry, d_u.d_child);
+ struct dentry *dentry = list_entry(tmp, struct dentry, d_child);
next = tmp->next;
spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
/*
* All done at this level ... ascend and resume the search.
*/
+ rcu_read_lock();
+ascend:
if (this_parent != parent) {
struct dentry *child = this_parent;
- this_parent = try_to_ascend(this_parent, locked, seq);
- if (!this_parent)
+ this_parent = child->d_parent;
+
+ spin_unlock(&child->d_lock);
+ spin_lock(&this_parent->d_lock);
+
+ /* might go back up the wrong parent if we have had a rename */
+ if (!locked && read_seqretry(&rename_lock, seq))
goto rename_retry;
- next = child->d_u.d_child.next;
+ /* go into the first sibling still alive */
+ do {
+ next = child->d_child.next;
+ if (next == &this_parent->d_subdirs)
+ goto ascend;
+ child = list_entry(next, struct dentry, d_child);
+ } while (unlikely(child->d_flags & DCACHE_DENTRY_KILLED));
+ rcu_read_unlock();
goto resume;
}
- spin_unlock(&this_parent->d_lock);
if (!locked && read_seqretry(&rename_lock, seq))
goto rename_retry;
+ spin_unlock(&this_parent->d_lock);
+ rcu_read_unlock();
if (locked)
write_sequnlock(&rename_lock);
return 0; /* No mount points found in tree */
positive:
if (!locked && read_seqretry(&rename_lock, seq))
- goto rename_retry;
+ goto rename_retry_unlocked;
if (locked)
write_sequnlock(&rename_lock);
return 1;
rename_retry:
+ spin_unlock(&this_parent->d_lock);
+ rcu_read_unlock();
+ if (locked)
+ goto again;
+rename_retry_unlocked:
locked = 1;
write_seqlock(&rename_lock);
goto again;
* 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;
resume:
while (next != &this_parent->d_subdirs) {
struct list_head *tmp = next;
- struct dentry *dentry = list_entry(tmp, struct dentry, d_u.d_child);
+ struct dentry *dentry = list_entry(tmp, struct dentry, d_child);
next = tmp->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
*/
if (found && need_resched()) {
spin_unlock(&dentry->d_lock);
+ rcu_read_lock();
goto out;
}
/*
* All done at this level ... ascend and resume the search.
*/
+ rcu_read_lock();
+ascend:
if (this_parent != parent) {
struct dentry *child = this_parent;
- this_parent = try_to_ascend(this_parent, locked, seq);
- if (!this_parent)
+ this_parent = child->d_parent;
+
+ spin_unlock(&child->d_lock);
+ spin_lock(&this_parent->d_lock);
+
+ /* might go back up the wrong parent if we have had a rename */
+ if (!locked && read_seqretry(&rename_lock, seq))
goto rename_retry;
- next = child->d_u.d_child.next;
+ /* go into the first sibling still alive */
+ do {
+ next = child->d_child.next;
+ if (next == &this_parent->d_subdirs)
+ goto ascend;
+ child = list_entry(next, struct dentry, d_child);
+ } while (unlikely(child->d_flags & DCACHE_DENTRY_KILLED));
+ rcu_read_unlock();
goto resume;
}
out:
- spin_unlock(&this_parent->d_lock);
if (!locked && read_seqretry(&rename_lock, seq))
goto rename_retry;
+ spin_unlock(&this_parent->d_lock);
+ rcu_read_unlock();
if (locked)
write_sequnlock(&rename_lock);
return found;
rename_retry:
+ spin_unlock(&this_parent->d_lock);
+ rcu_read_unlock();
if (found)
return found;
+ if (locked)
+ goto again;
locked = 1;
write_seqlock(&rename_lock);
goto again;
*
* 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);
+ cond_resched();
+ }
}
EXPORT_SYMBOL(shrink_dcache_parent);
INIT_HLIST_BL_NODE(&dentry->d_hash);
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);
+ INIT_LIST_HEAD(&dentry->d_u.d_alias);
+ INIT_LIST_HEAD(&dentry->d_child);
d_set_d_op(dentry, dentry->d_sb->s_d_op);
this_cpu_inc(nr_dentry);
struct dentry *dentry = __d_alloc(parent->d_sb, name);
if (!dentry)
return NULL;
-
+ dentry->d_flags |= DCACHE_RCUACCESS;
spin_lock(&parent->d_lock);
/*
* don't need child lock because it is not subject
*/
__dget_dlock(parent);
dentry->d_parent = parent;
- list_add(&dentry->d_u.d_child, &parent->d_subdirs);
+ list_add(&dentry->d_child, &parent->d_subdirs);
spin_unlock(&parent->d_lock);
return dentry;
if (inode) {
if (unlikely(IS_AUTOMOUNT(inode)))
dentry->d_flags |= DCACHE_NEED_AUTOMOUNT;
- list_add(&dentry->d_alias, &inode->i_dentry);
+ list_add(&dentry->d_u.d_alias, &inode->i_dentry);
}
dentry->d_inode = inode;
dentry_rcuwalk_barrier(dentry);
void d_instantiate(struct dentry *entry, struct inode * inode)
{
- BUG_ON(!list_empty(&entry->d_alias));
+ BUG_ON(!list_empty(&entry->d_u.d_alias));
if (inode)
spin_lock(&inode->i_lock);
__d_instantiate(entry, inode);
return NULL;
}
- list_for_each_entry(alias, &inode->i_dentry, d_alias) {
+ list_for_each_entry(alias, &inode->i_dentry, d_u.d_alias) {
struct qstr *qstr = &alias->d_name;
/*
{
struct dentry *result;
- BUG_ON(!list_empty(&entry->d_alias));
+ BUG_ON(!list_empty(&entry->d_u.d_alias));
if (inode)
spin_lock(&inode->i_lock);
if (list_empty(&inode->i_dentry))
return NULL;
- alias = list_first_entry(&inode->i_dentry, struct dentry, d_alias);
+ alias = list_first_entry(&inode->i_dentry, struct dentry, d_u.d_alias);
__dget(alias);
return alias;
}
*/
struct dentry *d_obtain_alias(struct inode *inode)
{
- static const struct qstr anonstring = { .name = "" };
+ static const struct qstr anonstring = { .name = "/", .len = 1 };
struct dentry *tmp;
struct dentry *res;
spin_lock(&tmp->d_lock);
tmp->d_inode = inode;
tmp->d_flags |= DCACHE_DISCONNECTED;
- list_add(&tmp->d_alias, &inode->i_dentry);
+ list_add(&tmp->d_u.d_alias, &inode->i_dentry);
hlist_bl_lock(&tmp->d_sb->s_anon);
hlist_bl_add_head(&tmp->d_hash, &tmp->d_sb->s_anon);
hlist_bl_unlock(&tmp->d_sb->s_anon);
struct dentry *child;
spin_lock(&dparent->d_lock);
- list_for_each_entry(child, &dparent->d_subdirs, d_u.d_child) {
+ list_for_each_entry(child, &dparent->d_subdirs, d_child) {
if (dentry == child) {
spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
__dget_dlock(dentry);
{
BUG_ON(!d_unhashed(entry));
hlist_bl_lock(b);
- entry->d_flags |= DCACHE_RCUACCESS;
hlist_bl_add_head_rcu(&entry->d_hash, b);
hlist_bl_unlock(b);
}
/* Unhash the target: dput() will then get rid of it */
__d_drop(target);
- list_del(&dentry->d_u.d_child);
- list_del(&target->d_u.d_child);
+ list_del(&dentry->d_child);
+ list_del(&target->d_child);
/* Switch the names.. */
switch_names(dentry, target);
/* ... and switch the parents */
if (IS_ROOT(dentry)) {
+ dentry->d_flags |= DCACHE_RCUACCESS;
dentry->d_parent = target->d_parent;
target->d_parent = target;
- INIT_LIST_HEAD(&target->d_u.d_child);
+ INIT_LIST_HEAD(&target->d_child);
} else {
swap(dentry->d_parent, target->d_parent);
/* And add them back to the (new) parent lists */
- list_add(&target->d_u.d_child, &target->d_parent->d_subdirs);
+ list_add(&target->d_child, &target->d_parent->d_subdirs);
}
- list_add(&dentry->d_u.d_child, &dentry->d_parent->d_subdirs);
+ list_add(&dentry->d_child, &dentry->d_parent->d_subdirs);
write_seqcount_end(&target->d_seq);
write_seqcount_end(&dentry->d_seq);
switch_names(dentry, anon);
swap(dentry->d_name.hash, anon->d_name.hash);
+ dentry->d_flags |= DCACHE_RCUACCESS;
dentry->d_parent = (aparent == anon) ? dentry : aparent;
- list_del(&dentry->d_u.d_child);
+ list_del(&dentry->d_child);
if (!IS_ROOT(dentry))
- list_add(&dentry->d_u.d_child, &dentry->d_parent->d_subdirs);
+ list_add(&dentry->d_child, &dentry->d_parent->d_subdirs);
else
- INIT_LIST_HEAD(&dentry->d_u.d_child);
+ INIT_LIST_HEAD(&dentry->d_child);
anon->d_parent = (dparent == dentry) ? anon : dparent;
- list_del(&anon->d_u.d_child);
+ list_del(&anon->d_child);
if (!IS_ROOT(anon))
- list_add(&anon->d_u.d_child, &anon->d_parent->d_subdirs);
+ list_add(&anon->d_child, &anon->d_parent->d_subdirs);
else
- INIT_LIST_HEAD(&anon->d_u.d_child);
+ INIT_LIST_HEAD(&anon->d_child);
write_seqcount_end(&dentry->d_seq);
write_seqcount_end(&anon->d_seq);
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? */
goto found;
} else {
/* Nope, but we must(!) avoid directory
- * aliasing */
+ * aliasing. This drops inode->i_lock */
actual = __d_unalias(inode, dentry, alias);
}
write_sequnlock(&rename_lock);
/**
* 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;
+ char *orig_buffer = *buffer;
+ int orig_len = *buflen;
bool slash = false;
int error = 0;
- br_read_lock(vfsmount_lock);
while (dentry != root->dentry || vfsmnt != root->mnt) {
struct dentry * parent;
if (dentry == vfsmnt->mnt_root || IS_ROOT(dentry)) {
+ /* Escaped? */
+ if (dentry != vfsmnt->mnt_root) {
+ *buffer = orig_buffer;
+ *buflen = orig_len;
+ slash = false;
+ error = 3;
+ goto global_root;
+ }
/* Global root? */
if (vfsmnt->mnt_parent == vfsmnt) {
goto global_root;
dentry = parent;
}
-out:
if (!error && !slash)
error = prepend(buffer, buflen, "/", 1);
- br_read_unlock(vfsmount_lock);
return error;
global_root:
WARN(1, "Root dentry has weird name <%.*s>\n",
(int) dentry->d_name.len, dentry->d_name.name);
}
- root->mnt = vfsmnt;
- root->dentry = dentry;
- goto out;
+ if (!slash)
+ error = prepend(buffer, buflen, "/", 1);
+ if (!error)
+ error = vfsmnt->mnt_ns ? 1 : 2;
+ return error;
}
/**
* __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;
int error;
prepend(&res, &buflen, "\0", 1);
+ br_read_lock(vfsmount_lock);
write_seqlock(&rename_lock);
error = prepend_path(path, root, &res, &buflen);
write_sequnlock(&rename_lock);
+ br_read_unlock(vfsmount_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);
+ br_read_lock(vfsmount_lock);
+ write_seqlock(&rename_lock);
+ error = prepend_path(path, &root, &res, &buflen);
+ write_sequnlock(&rename_lock);
+ br_read_unlock(vfsmount_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;
/*
return path->dentry->d_op->d_dname(path->dentry, buf, buflen);
get_fs_root(current->fs, &root);
+ br_read_lock(vfsmount_lock);
write_seqlock(&rename_lock);
- tmp = root;
- error = path_with_deleted(path, &tmp, &res, &buflen);
- if (error)
- res = ERR_PTR(error);
+ error = path_with_deleted(path, &root, &res, &buflen);
write_sequnlock(&rename_lock);
+ br_read_unlock(vfsmount_lock);
+ if (error < 0)
+ res = ERR_PTR(error);
path_put(&root);
return res;
}
{
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);
get_fs_root_and_pwd(current->fs, &root, &pwd);
error = -ENOENT;
+ br_read_lock(vfsmount_lock);
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);
+ br_read_unlock(vfsmount_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;
}
} else {
write_sequnlock(&rename_lock);
+ br_read_unlock(vfsmount_lock);
}
out:
resume:
while (next != &this_parent->d_subdirs) {
struct list_head *tmp = next;
- struct dentry *dentry = list_entry(tmp, struct dentry, d_u.d_child);
+ struct dentry *dentry = list_entry(tmp, struct dentry, d_child);
next = tmp->next;
spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
}
spin_unlock(&dentry->d_lock);
}
+ rcu_read_lock();
+ascend:
if (this_parent != root) {
struct dentry *child = this_parent;
if (!(this_parent->d_flags & DCACHE_GENOCIDE)) {
this_parent->d_flags |= DCACHE_GENOCIDE;
this_parent->d_count--;
}
- this_parent = try_to_ascend(this_parent, locked, seq);
- if (!this_parent)
+ this_parent = child->d_parent;
+
+ spin_unlock(&child->d_lock);
+ spin_lock(&this_parent->d_lock);
+
+ /* might go back up the wrong parent if we have had a rename */
+ if (!locked && read_seqretry(&rename_lock, seq))
goto rename_retry;
- next = child->d_u.d_child.next;
+ /* go into the first sibling still alive */
+ do {
+ next = child->d_child.next;
+ if (next == &this_parent->d_subdirs)
+ goto ascend;
+ child = list_entry(next, struct dentry, d_child);
+ } while (unlikely(child->d_flags & DCACHE_DENTRY_KILLED));
+ rcu_read_unlock();
goto resume;
}
- spin_unlock(&this_parent->d_lock);
if (!locked && read_seqretry(&rename_lock, seq))
goto rename_retry;
+ spin_unlock(&this_parent->d_lock);
+ rcu_read_unlock();
if (locked)
write_sequnlock(&rename_lock);
return;
rename_retry:
+ spin_unlock(&this_parent->d_lock);
+ rcu_read_unlock();
+ if (locked)
+ goto again;
locked = 1;
write_seqlock(&rename_lock);
goto again;
git.openpandora.org / pandora-kernel.git / blobdiff