[PATCH v5 03/14] VFS: tidy up do_unlinkat()

NeilBrown
2025-11-06T00:54:38Z

From: NeilBrown <neil@brown.name>

The simplification of locking in the previous patch opens up some room
for tidying up do_unlinkat()

- change all "exit" labels to describe what will happen at the label.
- always goto an exit label on an error - unwrap the "if (!IS_ERR())" branch.
- Move the "slashes" handing inline, but mark it as unlikely()
- simplify use of the "inode" variable - we no longer need to test for NULL.

Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: NeilBrown <neil@brown.name>
---
fs/namei.c | 55 ++++++++++++++++++++++++++----------------------------
1 file changed, 26 insertions(+), 29 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 231e1ffd4b8d..93c5fce2d814 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -4755,65 +4755,62 @@ int do_unlinkat(int dfd, struct filename *name)
struct path path;
struct qstr last;
int type;
- struct inode *inode = NULL;
+ struct inode *inode;
struct inode *delegated_inode = NULL;
unsigned int lookup_flags = 0;
retry:
error = filename_parentat(dfd, name, lookup_flags, &path, &last, &type);
if (error)
- goto exit1;
+ goto exit_putname;

error = -EISDIR;
if (type != LAST_NORM)
- goto exit2;
+ goto exit_path_put;

error = mnt_want_write(path.mnt);
if (error)
- goto exit2;
+ goto exit_path_put;
retry_deleg:
dentry = start_dirop(path.dentry, &last, lookup_flags);
error = PTR_ERR(dentry);
- if (!IS_ERR(dentry)) {
+ if (IS_ERR(dentry))
+ goto exit_drop_write;

- /* Why not before? Because we want correct error value */
- if (last.name[last.len])
- goto slashes;
- inode = dentry->d_inode;
- ihold(inode);
- error = security_path_unlink(&path, dentry);
- if (error)
- goto exit3;
- error = vfs_unlink(mnt_idmap(path.mnt), path.dentry->d_inode,
- dentry, &delegated_inode);
-exit3:
+ /* Why not before? Because we want correct error value */
+ if (unlikely(last.name[last.len])) {
+ if (d_is_dir(dentry))
+ error = -EISDIR;
+ else
+ error = -ENOTDIR;
end_dirop(dentry);
+ goto exit_drop_write;
}
- if (inode)
- iput(inode); /* truncate the inode here */
- inode = NULL;
+ inode = dentry->d_inode;
+ ihold(inode);
+ error = security_path_unlink(&path, dentry);
+ if (error)
+ goto exit_end_dirop;
+ error = vfs_unlink(mnt_idmap(path.mnt), path.dentry->d_inode,
+ dentry, &delegated_inode);
+exit_end_dirop:
+ end_dirop(dentry);
+ iput(inode); /* truncate the inode here */
if (delegated_inode) {
error = break_deleg_wait(&delegated_inode);
if (!error)
goto retry_deleg;
}
+exit_drop_write:
mnt_drop_write(path.mnt);
-exit2:
+exit_path_put:
path_put(&path);
if (retry_estale(error, lookup_flags)) {
lookup_flags |= LOOKUP_REVAL;
- inode = NULL;
goto retry;
}
-exit1:
+exit_putname:
putname(name);
return error;
-
-slashes:
- if (d_is_dir(dentry))
- error = -EISDIR;
- else
- error = -ENOTDIR;
- goto exit3;
}

SYSCALL_DEFINE3(unlinkat, int, dfd, const char __user *, pathname, int, flag)
--
2.50.0.107.gf914562f5916.dirty