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-rw-r--r--Documentation/filesystems/porting.rst13
-rw-r--r--fs/namei.c61
-rw-r--r--fs/nfs/dir.c3
-rw-r--r--fs/smb/server/vfs.c26
4 files changed, 46 insertions, 57 deletions
diff --git a/Documentation/filesystems/porting.rst b/Documentation/filesystems/porting.rst
index 2ead47e20677..3ed3f39ecf71 100644
--- a/Documentation/filesystems/porting.rst
+++ b/Documentation/filesystems/porting.rst
@@ -1165,3 +1165,16 @@ magic.
kern_path_locked() and user_path_locked() no longer return a negative
dentry so this doesn't need to be checked. If the name cannot be found,
ERR_PTR(-ENOENT) is returned.
+
+** recommend**
+
+lookup_one_qstr_excl() is changed to return errors in more cases, so
+these conditions don't require explicit checks:
+
+ - if LOOKUP_CREATE is NOT given, then the dentry won't be negative,
+ ERR_PTR(-ENOENT) is returned instead
+ - if LOOKUP_EXCL IS given, then the dentry won't be positive,
+ ERR_PTR(-EEXIST) is rreturned instread
+
+LOOKUP_EXCL now means "target must not exist". It can be combined with
+LOOK_CREATE or LOOKUP_RENAME_TARGET.
diff --git a/fs/namei.c b/fs/namei.c
index fb6da3ca0ca5..b7cdca902803 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1670,6 +1670,8 @@ static struct dentry *lookup_dcache(const struct qstr *name,
* dentries - as the matter of fact, this only gets called
* when directory is guaranteed to have no in-lookup children
* at all.
+ * Will return -ENOENT if name isn't found and LOOKUP_CREATE wasn't passed.
+ * Will return -EEXIST if name is found and LOOKUP_EXCL was passed.
*/
struct dentry *lookup_one_qstr_excl(const struct qstr *name,
struct dentry *base,
@@ -1680,7 +1682,7 @@ struct dentry *lookup_one_qstr_excl(const struct qstr *name,
struct inode *dir = base->d_inode;
if (dentry)
- return dentry;
+ goto found;
/* Don't create child dentry for a dead directory. */
if (unlikely(IS_DEADDIR(dir)))
@@ -1695,6 +1697,17 @@ struct dentry *lookup_one_qstr_excl(const struct qstr *name,
dput(dentry);
dentry = old;
}
+found:
+ if (IS_ERR(dentry))
+ return dentry;
+ if (d_is_negative(dentry) && !(flags & LOOKUP_CREATE)) {
+ dput(dentry);
+ return ERR_PTR(-ENOENT);
+ }
+ if (d_is_positive(dentry) && (flags & LOOKUP_EXCL)) {
+ dput(dentry);
+ return ERR_PTR(-EEXIST);
+ }
return dentry;
}
EXPORT_SYMBOL(lookup_one_qstr_excl);
@@ -2741,10 +2754,6 @@ static struct dentry *__kern_path_locked(int dfd, struct filename *name, struct
}
inode_lock_nested(path->dentry->d_inode, I_MUTEX_PARENT);
d = lookup_one_qstr_excl(&last, path->dentry, 0);
- if (!IS_ERR(d) && d_is_negative(d)) {
- dput(d);
- d = ERR_PTR(-ENOENT);
- }
if (IS_ERR(d)) {
inode_unlock(path->dentry->d_inode);
path_put(path);
@@ -4082,27 +4091,13 @@ static struct dentry *filename_create(int dfd, struct filename *name,
* '/', and a directory wasn't requested.
*/
if (last.name[last.len] && !want_dir)
- create_flags = 0;
+ create_flags &= ~LOOKUP_CREATE;
inode_lock_nested(path->dentry->d_inode, I_MUTEX_PARENT);
dentry = lookup_one_qstr_excl(&last, path->dentry,
reval_flag | create_flags);
if (IS_ERR(dentry))
goto unlock;
- error = -EEXIST;
- if (d_is_positive(dentry))
- goto fail;
-
- /*
- * Special case - lookup gave negative, but... we had foo/bar/
- * From the vfs_mknod() POV we just have a negative dentry -
- * all is fine. Let's be bastards - you had / on the end, you've
- * been asking for (non-existent) directory. -ENOENT for you.
- */
- if (unlikely(!create_flags)) {
- error = -ENOENT;
- goto fail;
- }
if (unlikely(err2)) {
error = err2;
goto fail;
@@ -4449,10 +4444,6 @@ retry:
error = PTR_ERR(dentry);
if (IS_ERR(dentry))
goto exit3;
- if (!dentry->d_inode) {
- error = -ENOENT;
- goto exit4;
- }
error = security_path_rmdir(&path, dentry);
if (error)
goto exit4;
@@ -4583,7 +4574,7 @@ retry_deleg:
if (!IS_ERR(dentry)) {
/* Why not before? Because we want correct error value */
- if (last.name[last.len] || d_is_negative(dentry))
+ if (last.name[last.len])
goto slashes;
inode = dentry->d_inode;
ihold(inode);
@@ -4617,9 +4608,7 @@ exit1:
return error;
slashes:
- if (d_is_negative(dentry))
- error = -ENOENT;
- else if (d_is_dir(dentry))
+ if (d_is_dir(dentry))
error = -EISDIR;
else
error = -ENOTDIR;
@@ -5119,7 +5108,8 @@ int do_renameat2(int olddfd, struct filename *from, int newdfd,
struct qstr old_last, new_last;
int old_type, new_type;
struct inode *delegated_inode = NULL;
- unsigned int lookup_flags = 0, target_flags = LOOKUP_RENAME_TARGET;
+ unsigned int lookup_flags = 0, target_flags =
+ LOOKUP_RENAME_TARGET | LOOKUP_CREATE;
bool should_retry = false;
int error = -EINVAL;
@@ -5132,6 +5122,8 @@ int do_renameat2(int olddfd, struct filename *from, int newdfd,
if (flags & RENAME_EXCHANGE)
target_flags = 0;
+ if (flags & RENAME_NOREPLACE)
+ target_flags |= LOOKUP_EXCL;
retry:
error = filename_parentat(olddfd, from, lookup_flags, &old_path,
@@ -5173,23 +5165,12 @@ retry_deleg:
error = PTR_ERR(old_dentry);
if (IS_ERR(old_dentry))
goto exit3;
- /* source must exist */
- error = -ENOENT;
- if (d_is_negative(old_dentry))
- goto exit4;
new_dentry = lookup_one_qstr_excl(&new_last, new_path.dentry,
lookup_flags | target_flags);
error = PTR_ERR(new_dentry);
if (IS_ERR(new_dentry))
goto exit4;
- error = -EEXIST;
- if ((flags & RENAME_NOREPLACE) && d_is_positive(new_dentry))
- goto exit5;
if (flags & RENAME_EXCHANGE) {
- error = -ENOENT;
- if (d_is_negative(new_dentry))
- goto exit5;
-
if (!d_is_dir(new_dentry)) {
error = -ENOTDIR;
if (new_last.name[new_last.len])
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 2b04038b0e40..56cf16a72334 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1532,7 +1532,8 @@ static int nfs_is_exclusive_create(struct inode *dir, unsigned int flags)
{
if (NFS_PROTO(dir)->version == 2)
return 0;
- return flags & LOOKUP_EXCL;
+ return (flags & (LOOKUP_CREATE | LOOKUP_EXCL)) ==
+ (LOOKUP_CREATE | LOOKUP_EXCL);
}
/*
diff --git a/fs/smb/server/vfs.c b/fs/smb/server/vfs.c
index 6890016e1923..fe29acef5872 100644
--- a/fs/smb/server/vfs.c
+++ b/fs/smb/server/vfs.c
@@ -113,11 +113,6 @@ static int ksmbd_vfs_path_lookup_locked(struct ksmbd_share_config *share_conf,
if (IS_ERR(d))
goto err_out;
- if (d_is_negative(d)) {
- dput(d);
- goto err_out;
- }
-
path->dentry = d;
path->mnt = mntget(parent_path->mnt);
@@ -693,6 +688,7 @@ int ksmbd_vfs_rename(struct ksmbd_work *work, const struct path *old_path,
struct ksmbd_file *parent_fp;
int new_type;
int err, lookup_flags = LOOKUP_NO_SYMLINKS;
+ int target_lookup_flags = LOOKUP_RENAME_TARGET;
if (ksmbd_override_fsids(work))
return -ENOMEM;
@@ -703,6 +699,14 @@ int ksmbd_vfs_rename(struct ksmbd_work *work, const struct path *old_path,
goto revert_fsids;
}
+ /*
+ * explicitly handle file overwrite case, for compatibility with
+ * filesystems that may not support rename flags (e.g: fuse)
+ */
+ if (flags & RENAME_NOREPLACE)
+ target_lookup_flags |= LOOKUP_EXCL;
+ flags &= ~(RENAME_NOREPLACE);
+
retry:
err = vfs_path_parent_lookup(to, lookup_flags | LOOKUP_BENEATH,
&new_path, &new_last, &new_type,
@@ -743,7 +747,7 @@ retry:
}
new_dentry = lookup_one_qstr_excl(&new_last, new_path.dentry,
- lookup_flags | LOOKUP_RENAME_TARGET);
+ lookup_flags | target_lookup_flags);
if (IS_ERR(new_dentry)) {
err = PTR_ERR(new_dentry);
goto out3;
@@ -754,16 +758,6 @@ retry:
goto out4;
}
- /*
- * explicitly handle file overwrite case, for compatibility with
- * filesystems that may not support rename flags (e.g: fuse)
- */
- if ((flags & RENAME_NOREPLACE) && d_is_positive(new_dentry)) {
- err = -EEXIST;
- goto out4;
- }
- flags &= ~(RENAME_NOREPLACE);
-
if (old_child == trap) {
err = -EINVAL;
goto out4;
generated by cgit (git 2.34.1) at 2025-07-23 15:03:06 +0000