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Diffstat (limited to 'fs/dcache.c')
-rw-r--r--fs/dcache.c214
1 files changed, 77 insertions, 137 deletions
diff --git a/fs/dcache.c b/fs/dcache.c
index 19153a0a810c..87bdb5329c3c 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -337,23 +337,6 @@ static void dentry_lru_del(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);
@@ -486,11 +469,13 @@ relock:
if (ref)
dentry->d_count--;
/*
- * 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 (dentry->d_flags & DCACHE_OP_PRUNE)
+ dentry->d_op->d_prune(dentry);
+
+ dentry_lru_del(dentry);
/* if it was on the hash then remove it */
__d_drop(dentry);
return d_kill(dentry, parent);
@@ -675,11 +660,10 @@ EXPORT_SYMBOL(dget_parent);
static struct dentry *__d_find_alias(struct inode *inode, int want_discon)
{
struct dentry *alias, *discon_alias;
- struct hlist_node *p;
again:
discon_alias = NULL;
- hlist_for_each_entry(alias, p, &inode->i_dentry, d_alias) {
+ hlist_for_each_entry(alias, &inode->i_dentry, d_alias) {
spin_lock(&alias->d_lock);
if (S_ISDIR(inode->i_mode) || !d_unhashed(alias)) {
if (IS_ROOT(alias) &&
@@ -730,10 +714,9 @@ EXPORT_SYMBOL(d_find_alias);
void d_prune_aliases(struct inode *inode)
{
struct dentry *dentry;
- struct hlist_node *p;
restart:
spin_lock(&inode->i_lock);
- hlist_for_each_entry(dentry, p, &inode->i_dentry, d_alias) {
+ hlist_for_each_entry(dentry, &inode->i_dentry, d_alias) {
spin_lock(&dentry->d_lock);
if (!dentry->d_count) {
__dget_dlock(dentry);
@@ -921,11 +904,13 @@ static void shrink_dcache_for_umount_subtree(struct dentry *dentry)
struct inode *inode;
/*
- * remove the dentry from the lru, and inform
- * the fs that this dentry is about to be
+ * inform the fs that this dentry is about to be
* unhashed and destroyed.
*/
- dentry_lru_prune(dentry);
+ if (dentry->d_flags & DCACHE_OP_PRUNE)
+ dentry->d_op->d_prune(dentry);
+
+ dentry_lru_del(dentry);
__d_shrink(dentry);
if (dentry->d_count != 0) {
@@ -1232,8 +1217,10 @@ void shrink_dcache_parent(struct dentry * parent)
LIST_HEAD(dispose);
int found;
- while ((found = select_parent(parent, &dispose)) != 0)
+ while ((found = select_parent(parent, &dispose)) != 0) {
shrink_dentry_list(&dispose);
+ cond_resched();
+ }
}
EXPORT_SYMBOL(shrink_dcache_parent);
@@ -1358,6 +1345,7 @@ void d_set_d_op(struct dentry *dentry, const struct dentry_operations *op)
WARN_ON_ONCE(dentry->d_flags & (DCACHE_OP_HASH |
DCACHE_OP_COMPARE |
DCACHE_OP_REVALIDATE |
+ DCACHE_OP_WEAK_REVALIDATE |
DCACHE_OP_DELETE ));
dentry->d_op = op;
if (!op)
@@ -1368,6 +1356,8 @@ void d_set_d_op(struct dentry *dentry, const struct dentry_operations *op)
dentry->d_flags |= DCACHE_OP_COMPARE;
if (op->d_revalidate)
dentry->d_flags |= DCACHE_OP_REVALIDATE;
+ if (op->d_weak_revalidate)
+ dentry->d_flags |= DCACHE_OP_WEAK_REVALIDATE;
if (op->d_delete)
dentry->d_flags |= DCACHE_OP_DELETE;
if (op->d_prune)
@@ -1440,14 +1430,13 @@ static struct dentry *__d_instantiate_unique(struct dentry *entry,
int len = entry->d_name.len;
const char *name = entry->d_name.name;
unsigned int hash = entry->d_name.hash;
- struct hlist_node *p;
if (!inode) {
__d_instantiate(entry, NULL);
return NULL;
}
- hlist_for_each_entry(alias, p, &inode->i_dentry, d_alias) {
+ hlist_for_each_entry(alias, &inode->i_dentry, d_alias) {
/*
* Don't need alias->d_lock here, because aliases with
* d_parent == entry->d_parent are not subject to name or
@@ -1623,6 +1612,10 @@ EXPORT_SYMBOL(d_obtain_alias);
* If a dentry was found and moved, then it is returned. Otherwise NULL
* is returned. This matches the expected return value of ->lookup.
*
+ * Cluster filesystems may call this function with a negative, hashed dentry.
+ * In that case, we know that the inode will be a regular file, and also this
+ * will only occur during atomic_open. So we need to check for the dentry
+ * being already hashed only in the final case.
*/
struct dentry *d_splice_alias(struct inode *inode, struct dentry *dentry)
{
@@ -1647,8 +1640,11 @@ struct dentry *d_splice_alias(struct inode *inode, struct dentry *dentry)
security_d_instantiate(dentry, inode);
d_rehash(dentry);
}
- } else
- d_add(dentry, inode);
+ } else {
+ d_instantiate(dentry, inode);
+ if (d_unhashed(dentry))
+ d_rehash(dentry);
+ }
return new;
}
EXPORT_SYMBOL(d_splice_alias);
@@ -1672,7 +1668,6 @@ EXPORT_SYMBOL(d_splice_alias);
struct dentry *d_add_ci(struct dentry *dentry, struct inode *inode,
struct qstr *name)
{
- int error;
struct dentry *found;
struct dentry *new;
@@ -1681,10 +1676,12 @@ struct dentry *d_add_ci(struct dentry *dentry, struct inode *inode,
* if not go ahead and create it now.
*/
found = d_hash_and_lookup(dentry->d_parent, name);
+ if (unlikely(IS_ERR(found)))
+ goto err_out;
if (!found) {
new = d_alloc(dentry->d_parent, name);
if (!new) {
- error = -ENOMEM;
+ found = ERR_PTR(-ENOMEM);
goto err_out;
}
@@ -1725,7 +1722,7 @@ struct dentry *d_add_ci(struct dentry *dentry, struct inode *inode,
err_out:
iput(inode);
- return ERR_PTR(error);
+ return found;
}
EXPORT_SYMBOL(d_add_ci);
@@ -1733,7 +1730,7 @@ EXPORT_SYMBOL(d_add_ci);
* Do the slow-case of the dentry name compare.
*
* Unlike the dentry_cmp() function, we need to atomically
- * load the name, length and inode information, so that the
+ * load the name and length information, so that the
* filesystem can rely on them, and can use the 'name' and
* 'len' information without worrying about walking off the
* end of memory etc.
@@ -1751,22 +1748,18 @@ enum slow_d_compare {
static noinline enum slow_d_compare slow_dentry_cmp(
const struct dentry *parent,
- struct inode *inode,
struct dentry *dentry,
unsigned int seq,
const struct qstr *name)
{
int tlen = dentry->d_name.len;
const char *tname = dentry->d_name.name;
- struct inode *i = dentry->d_inode;
if (read_seqcount_retry(&dentry->d_seq, seq)) {
cpu_relax();
return D_COMP_SEQRETRY;
}
- if (parent->d_op->d_compare(parent, inode,
- dentry, i,
- tlen, tname, name))
+ if (parent->d_op->d_compare(parent, dentry, tlen, tname, name))
return D_COMP_NOMATCH;
return D_COMP_OK;
}
@@ -1776,7 +1769,6 @@ static noinline enum slow_d_compare slow_dentry_cmp(
* @parent: parent dentry
* @name: qstr of name we wish to find
* @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
*
* __d_lookup_rcu is the dcache lookup function for rcu-walk name
@@ -1803,7 +1795,7 @@ static noinline enum slow_d_compare slow_dentry_cmp(
*/
struct dentry *__d_lookup_rcu(const struct dentry *parent,
const struct qstr *name,
- unsigned *seqp, struct inode *inode)
+ unsigned *seqp)
{
u64 hashlen = name->hash_len;
const unsigned char *str = name->name;
@@ -1837,11 +1829,10 @@ struct dentry *__d_lookup_rcu(const struct dentry *parent,
seqretry:
/*
* The dentry sequence count protects us from concurrent
- * renames, and thus protects inode, parent and name fields.
+ * renames, and thus protects parent and name fields.
*
* The caller must perform a seqcount check in order
- * to do anything useful with the returned dentry,
- * including using the 'd_inode' pointer.
+ * to do anything useful with the returned dentry.
*
* NOTE! We do a "raw" seqcount_begin here. That means that
* we don't wait for the sequence count to stabilize if it
@@ -1855,12 +1846,12 @@ seqretry:
continue;
if (d_unhashed(dentry))
continue;
- *seqp = seq;
if (unlikely(parent->d_flags & DCACHE_OP_COMPARE)) {
if (dentry->d_name.hash != hashlen_hash(hashlen))
continue;
- switch (slow_dentry_cmp(parent, inode, dentry, seq, name)) {
+ *seqp = seq;
+ switch (slow_dentry_cmp(parent, dentry, seq, name)) {
case D_COMP_OK:
return dentry;
case D_COMP_NOMATCH:
@@ -1872,6 +1863,7 @@ seqretry:
if (dentry->d_name.hash_len != hashlen)
continue;
+ *seqp = seq;
if (!dentry_cmp(dentry, str, hashlen_len(hashlen)))
return dentry;
}
@@ -1889,7 +1881,7 @@ seqretry:
* dentry is returned. The caller must use dput to free the entry when it has
* finished using it. %NULL is returned if the dentry does not exist.
*/
-struct dentry *d_lookup(struct dentry *parent, struct qstr *name)
+struct dentry *d_lookup(const struct dentry *parent, const struct qstr *name)
{
struct dentry *dentry;
unsigned seq;
@@ -1919,7 +1911,7 @@ EXPORT_SYMBOL(d_lookup);
*
* __d_lookup callers must be commented.
*/
-struct dentry *__d_lookup(struct dentry *parent, struct qstr *name)
+struct dentry *__d_lookup(const struct dentry *parent, const struct qstr *name)
{
unsigned int len = name->len;
unsigned int hash = name->hash;
@@ -1969,9 +1961,7 @@ struct dentry *__d_lookup(struct dentry *parent, struct qstr *name)
if (parent->d_flags & DCACHE_OP_COMPARE) {
int tlen = dentry->d_name.len;
const char *tname = dentry->d_name.name;
- if (parent->d_op->d_compare(parent, parent->d_inode,
- dentry, dentry->d_inode,
- tlen, tname, name))
+ if (parent->d_op->d_compare(parent, dentry, tlen, tname, name))
goto next;
} else {
if (dentry->d_name.len != len)
@@ -1997,12 +1987,10 @@ next:
* @dir: Directory to search in
* @name: qstr of name we wish to find
*
- * On hash failure or on lookup failure NULL is returned.
+ * On lookup failure NULL is returned; on bad name - ERR_PTR(-error)
*/
struct dentry *d_hash_and_lookup(struct dentry *dir, struct qstr *name)
{
- struct dentry *dentry = NULL;
-
/*
* Check for a fs-specific hash function. Note that we must
* calculate the standard hash first, as the d_op->d_hash()
@@ -2010,13 +1998,13 @@ struct dentry *d_hash_and_lookup(struct dentry *dir, struct qstr *name)
*/
name->hash = full_name_hash(name->name, name->len);
if (dir->d_flags & DCACHE_OP_HASH) {
- if (dir->d_op->d_hash(dir, dir->d_inode, name) < 0)
- goto out;
+ int err = dir->d_op->d_hash(dir, name);
+ if (unlikely(err < 0))
+ return ERR_PTR(err);
}
- dentry = d_lookup(dir, name);
-out:
- return dentry;
+ return d_lookup(dir, name);
}
+EXPORT_SYMBOL(d_hash_and_lookup);
/**
* d_validate - verify dentry provided from insecure source (deprecated)
@@ -2394,7 +2382,7 @@ out_err:
*/
static void __d_materialise_dentry(struct dentry *dentry, struct dentry *anon)
{
- struct dentry *dparent, *aparent;
+ struct dentry *dparent;
dentry_lock_for_move(anon, dentry);
@@ -2402,24 +2390,14 @@ static void __d_materialise_dentry(struct dentry *dentry, struct dentry *anon)
write_seqcount_begin(&anon->d_seq);
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))
- list_add(&dentry->d_u.d_child, &dentry->d_parent->d_subdirs);
- else
- INIT_LIST_HEAD(&dentry->d_u.d_child);
-
- anon->d_parent = (dparent == dentry) ? anon : dparent;
- list_del(&anon->d_u.d_child);
- if (!IS_ROOT(anon))
- list_add(&anon->d_u.d_child, &anon->d_parent->d_subdirs);
- else
- INIT_LIST_HEAD(&anon->d_u.d_child);
+ dentry->d_parent = dentry;
+ list_del_init(&dentry->d_u.d_child);
+ anon->d_parent = dparent;
+ list_move(&anon->d_u.d_child, &dparent->d_subdirs);
write_seqcount_end(&dentry->d_seq);
write_seqcount_end(&anon->d_seq);
@@ -2552,7 +2530,6 @@ static int prepend_path(const struct path *path,
bool slash = false;
int error = 0;
- br_read_lock(&vfsmount_lock);
while (dentry != root->dentry || vfsmnt != root->mnt) {
struct dentry * parent;
@@ -2582,8 +2559,6 @@ static int prepend_path(const struct path *path,
if (!error && !slash)
error = prepend(buffer, buflen, "/", 1);
-out:
- br_read_unlock(&vfsmount_lock);
return error;
global_root:
@@ -2600,7 +2575,7 @@ global_root:
error = prepend(buffer, buflen, "/", 1);
if (!error)
error = is_mounted(vfsmnt) ? 1 : 2;
- goto out;
+ return error;
}
/**
@@ -2627,9 +2602,11 @@ char *__d_path(const struct path *path,
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 < 0)
return ERR_PTR(error);
@@ -2646,9 +2623,11 @@ char *d_absolute_path(const struct path *path,
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;
@@ -2712,47 +2691,18 @@ char *d_path(const struct path *path, char *buf, int buflen)
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);
error = path_with_deleted(path, &root, &res, &buflen);
+ write_sequnlock(&rename_lock);
+ br_read_unlock(&vfsmount_lock);
if (error < 0)
res = ERR_PTR(error);
- write_sequnlock(&rename_lock);
path_put(&root);
return res;
}
EXPORT_SYMBOL(d_path);
-/**
- * d_path_with_unreachable - return the path of a dentry
- * @path: path to report
- * @buf: buffer to return value in
- * @buflen: buffer length
- *
- * The difference from d_path() is that this prepends "(unreachable)"
- * to paths which are unreachable from the current process' root.
- */
-char *d_path_with_unreachable(const struct path *path, char *buf, int buflen)
-{
- char *res = buf + buflen;
- struct path root;
- int error;
-
- if (path->dentry->d_op && path->dentry->d_op->d_dname)
- return path->dentry->d_op->d_dname(path->dentry, buf, buflen);
-
- get_fs_root(current->fs, &root);
- write_seqlock(&rename_lock);
- error = path_with_deleted(path, &root, &res, &buflen);
- if (error > 0)
- error = prepend_unreachable(&res, &buflen);
- write_sequnlock(&rename_lock);
- path_put(&root);
- if (error)
- res = ERR_PTR(error);
-
- return res;
-}
-
/*
* Helper function for dentry_operations.d_dname() members
*/
@@ -2871,6 +2821,7 @@ SYSCALL_DEFINE2(getcwd, char __user *, buf, unsigned long, size)
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;
@@ -2880,6 +2831,7 @@ SYSCALL_DEFINE2(getcwd, char __user *, buf, unsigned long, size)
prepend(&cwd, &buflen, "\0", 1);
error = prepend_path(&pwd, &root, &cwd, &buflen);
write_sequnlock(&rename_lock);
+ br_read_unlock(&vfsmount_lock);
if (error < 0)
goto out;
@@ -2900,6 +2852,7 @@ SYSCALL_DEFINE2(getcwd, char __user *, buf, unsigned long, size)
}
} else {
write_sequnlock(&rename_lock);
+ br_read_unlock(&vfsmount_lock);
}
out:
@@ -3015,34 +2968,21 @@ rename_retry:
goto again;
}
-/**
- * find_inode_number - check for dentry with name
- * @dir: directory to check
- * @name: Name to find.
- *
- * Check whether a dentry already exists for the given name,
- * and return the inode number if it has an inode. Otherwise
- * 0 is returned.
- *
- * This routine is used to post-process directory listings for
- * filesystems using synthetic inode numbers, and is necessary
- * to keep getcwd() working.
- */
-
-ino_t find_inode_number(struct dentry *dir, struct qstr *name)
+void d_tmpfile(struct dentry *dentry, struct inode *inode)
{
- struct dentry * dentry;
- ino_t ino = 0;
-
- dentry = d_hash_and_lookup(dir, name);
- if (dentry) {
- if (dentry->d_inode)
- ino = dentry->d_inode->i_ino;
- dput(dentry);
- }
- return ino;
+ inode_dec_link_count(inode);
+ BUG_ON(dentry->d_name.name != dentry->d_iname ||
+ !hlist_unhashed(&dentry->d_alias) ||
+ !d_unlinked(dentry));
+ spin_lock(&dentry->d_parent->d_lock);
+ spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
+ dentry->d_name.len = sprintf(dentry->d_iname, "#%llu",
+ (unsigned long long)inode->i_ino);
+ spin_unlock(&dentry->d_lock);
+ spin_unlock(&dentry->d_parent->d_lock);
+ d_instantiate(dentry, inode);
}
-EXPORT_SYMBOL(find_inode_number);
+EXPORT_SYMBOL(d_tmpfile);
static __initdata unsigned long dhash_entries;
static int __init set_dhash_entries(char *str)
generated by cgit v1.2.3 (git 2.39.0) at 2025-12-11 21:25:58 +0300