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Diffstat (limited to 'fs/namei.c')
-rw-r--r--fs/namei.c110
1 files changed, 43 insertions, 67 deletions
diff --git a/fs/namei.c b/fs/namei.c
index 6a82fb7e2127..ecb0b439747e 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1449,9 +1449,8 @@ static int follow_dotdot(struct nameidata *nd)
}
/*
- * This looks up the name in dcache, possibly revalidates the old dentry and
- * allocates a new one if not found or not valid. In the need_lookup argument
- * returns whether i_op->lookup is necessary.
+ * This looks up the name in dcache and possibly revalidates the found dentry.
+ * NULL is returned if the dentry does not exist in the cache.
*/
static struct dentry *lookup_dcache(const struct qstr *name,
struct dentry *dir,
@@ -1890,9 +1889,9 @@ static inline unsigned int fold_hash(unsigned long x, unsigned long y)
* payload bytes, to match the way that hash_name() iterates until it
* finds the delimiter after the name.
*/
-unsigned int full_name_hash(const char *name, unsigned int len)
+unsigned int full_name_hash(const void *salt, const char *name, unsigned int len)
{
- unsigned long a, x = 0, y = 0;
+ unsigned long a, x = 0, y = (unsigned long)salt;
for (;;) {
if (!len)
@@ -1911,15 +1910,19 @@ done:
EXPORT_SYMBOL(full_name_hash);
/* Return the "hash_len" (hash and length) of a null-terminated string */
-u64 hashlen_string(const char *name)
+u64 hashlen_string(const void *salt, const char *name)
{
- unsigned long a = 0, x = 0, y = 0, adata, mask, len;
+ unsigned long a = 0, x = 0, y = (unsigned long)salt;
+ unsigned long adata, mask, len;
const struct word_at_a_time constants = WORD_AT_A_TIME_CONSTANTS;
- len = -sizeof(unsigned long);
+ len = 0;
+ goto inside;
+
do {
HASH_MIX(x, y, a);
len += sizeof(unsigned long);
+inside:
a = load_unaligned_zeropad(name+len);
} while (!has_zero(a, &adata, &constants));
@@ -1935,15 +1938,19 @@ EXPORT_SYMBOL(hashlen_string);
* Calculate the length and hash of the path component, and
* return the "hash_len" as the result.
*/
-static inline u64 hash_name(const char *name)
+static inline u64 hash_name(const void *salt, const char *name)
{
- unsigned long a = 0, b, x = 0, y = 0, adata, bdata, mask, len;
+ unsigned long a = 0, b, x = 0, y = (unsigned long)salt;
+ unsigned long adata, bdata, mask, len;
const struct word_at_a_time constants = WORD_AT_A_TIME_CONSTANTS;
- len = -sizeof(unsigned long);
+ len = 0;
+ goto inside;
+
do {
HASH_MIX(x, y, a);
len += sizeof(unsigned long);
+inside:
a = load_unaligned_zeropad(name+len);
b = a ^ REPEAT_BYTE('/');
} while (!(has_zero(a, &adata, &constants) | has_zero(b, &bdata, &constants)));
@@ -1959,9 +1966,9 @@ static inline u64 hash_name(const char *name)
#else /* !CONFIG_DCACHE_WORD_ACCESS: Slow, byte-at-a-time version */
/* Return the hash of a string of known length */
-unsigned int full_name_hash(const char *name, unsigned int len)
+unsigned int full_name_hash(const void *salt, const char *name, unsigned int len)
{
- unsigned long hash = init_name_hash();
+ unsigned long hash = init_name_hash(salt);
while (len--)
hash = partial_name_hash((unsigned char)*name++, hash);
return end_name_hash(hash);
@@ -1969,9 +1976,9 @@ unsigned int full_name_hash(const char *name, unsigned int len)
EXPORT_SYMBOL(full_name_hash);
/* Return the "hash_len" (hash and length) of a null-terminated string */
-u64 hashlen_string(const char *name)
+u64 hashlen_string(const void *salt, const char *name)
{
- unsigned long hash = init_name_hash();
+ unsigned long hash = init_name_hash(salt);
unsigned long len = 0, c;
c = (unsigned char)*name;
@@ -1988,9 +1995,9 @@ EXPORT_SYMBOL(hashlen_string);
* We know there's a real path component here of at least
* one character.
*/
-static inline u64 hash_name(const char *name)
+static inline u64 hash_name(const void *salt, const char *name)
{
- unsigned long hash = init_name_hash();
+ unsigned long hash = init_name_hash(salt);
unsigned long len = 0, c;
c = (unsigned char)*name;
@@ -2030,7 +2037,7 @@ static int link_path_walk(const char *name, struct nameidata *nd)
if (err)
return err;
- hash_len = hash_name(name);
+ hash_len = hash_name(nd->path.dentry, name);
type = LAST_NORM;
if (name[0] == '.') switch (hashlen_len(hash_len)) {
@@ -2436,7 +2443,7 @@ struct dentry *lookup_one_len(const char *name, struct dentry *base, int len)
this.name = name;
this.len = len;
- this.hash = full_name_hash(name, len);
+ this.hash = full_name_hash(base, name, len);
if (!len)
return ERR_PTR(-EACCES);
@@ -2489,7 +2496,7 @@ struct dentry *lookup_one_len_unlocked(const char *name,
this.name = name;
this.len = len;
- this.hash = full_name_hash(name, len);
+ this.hash = full_name_hash(base, name, len);
if (!len)
return ERR_PTR(-EACCES);
@@ -3030,9 +3037,13 @@ static int atomic_open(struct nameidata *nd, struct dentry *dentry,
}
if (*opened & FILE_CREATED)
fsnotify_create(dir, dentry);
- path->dentry = dentry;
- path->mnt = nd->path.mnt;
- return 1;
+ if (unlikely(d_is_negative(dentry))) {
+ error = -ENOENT;
+ } else {
+ path->dentry = dentry;
+ path->mnt = nd->path.mnt;
+ return 1;
+ }
}
}
dput(dentry);
@@ -3201,9 +3212,7 @@ static int do_last(struct nameidata *nd,
int acc_mode = op->acc_mode;
unsigned seq;
struct inode *inode;
- struct path save_parent = { .dentry = NULL, .mnt = NULL };
struct path path;
- bool retried = false;
int error;
nd->flags &= ~LOOKUP_PARENT;
@@ -3246,7 +3255,6 @@ static int do_last(struct nameidata *nd,
return -EISDIR;
}
-retry_lookup:
if (open_flag & (O_CREAT | O_TRUNC | O_WRONLY | O_RDWR)) {
error = mnt_want_write(nd->path.mnt);
if (!error)
@@ -3298,6 +3306,10 @@ retry_lookup:
got_write = false;
}
+ error = follow_managed(&path, nd);
+ if (unlikely(error < 0))
+ return error;
+
if (unlikely(d_is_negative(path.dentry))) {
path_to_nameidata(&path, nd);
return -ENOENT;
@@ -3313,10 +3325,6 @@ retry_lookup:
return -EEXIST;
}
- error = follow_managed(&path, nd);
- if (unlikely(error < 0))
- return error;
-
seq = 0; /* out of RCU mode, so the value doesn't matter */
inode = d_backing_inode(path.dentry);
finish_lookup:
@@ -3327,23 +3335,14 @@ finish_lookup:
if (unlikely(error))
return error;
- if ((nd->flags & LOOKUP_RCU) || nd->path.mnt != path.mnt) {
- path_to_nameidata(&path, nd);
- } else {
- save_parent.dentry = nd->path.dentry;
- save_parent.mnt = mntget(path.mnt);
- nd->path.dentry = path.dentry;
-
- }
+ path_to_nameidata(&path, nd);
nd->inode = inode;
nd->seq = seq;
/* Why this, you ask? _Now_ we might have grown LOOKUP_JUMPED... */
finish_open:
error = complete_walk(nd);
- if (error) {
- path_put(&save_parent);
+ if (error)
return error;
- }
audit_inode(nd->name, nd->path.dentry, 0);
error = -EISDIR;
if ((open_flag & O_CREAT) && d_is_dir(nd->path.dentry))
@@ -3366,13 +3365,9 @@ finish_open_created:
goto out;
BUG_ON(*opened & FILE_OPENED); /* once it's opened, it's opened */
error = vfs_open(&nd->path, file, current_cred());
- if (!error) {
- *opened |= FILE_OPENED;
- } else {
- if (error == -EOPENSTALE)
- goto stale_open;
+ if (error)
goto out;
- }
+ *opened |= FILE_OPENED;
opened:
error = open_check_o_direct(file);
if (!error)
@@ -3388,26 +3383,7 @@ out:
}
if (got_write)
mnt_drop_write(nd->path.mnt);
- path_put(&save_parent);
return error;
-
-stale_open:
- /* If no saved parent or already retried then can't retry */
- if (!save_parent.dentry || retried)
- goto out;
-
- BUG_ON(save_parent.dentry != dir);
- path_put(&nd->path);
- nd->path = save_parent;
- nd->inode = dir->d_inode;
- save_parent.mnt = NULL;
- save_parent.dentry = NULL;
- if (got_write) {
- mnt_drop_write(nd->path.mnt);
- got_write = false;
- }
- retried = true;
- goto retry_lookup;
}
static int do_tmpfile(struct nameidata *nd, unsigned flags,
@@ -4359,7 +4335,7 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
* Check source == target.
* On overlayfs need to look at underlying inodes.
*/
- if (vfs_select_inode(old_dentry, 0) == vfs_select_inode(new_dentry, 0))
+ if (d_real_inode(old_dentry) == d_real_inode(new_dentry))
return 0;
error = may_delete(old_dir, old_dentry, is_dir);
generated by cgit v1.2.3 (git 2.39.0) at 2025-09-23 16:53:41 +0300