[PATCH] fs: add porting notes about readlink_copy()

[PATCH] fs: add porting notes about readlink_copy()

[Mateusz Guzik]

Calling convention has changed in  ea382199071931d1 ("vfs: support caching symlink lengths in inodes")

Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
---
 Documentation/filesystems/porting.rst | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/Documentation/filesystems/porting.rst b/Documentation/filesystems/porting.rst
index 3397937ed838..bd4128ccbb67 100644
--- a/Documentation/filesystems/porting.rst
+++ b/Documentation/filesystems/porting.rst
@@ -1334,3 +1334,13 @@ end_creating() and the parent will be unlocked precisely when necessary.
 
 kill_litter_super() is gone; convert to DCACHE_PERSISTENT use (as all
 in-tree filesystems have done).
+
+---
+
+**mandatory**
+
+readlink_copy() now requires link length as the 4th argument. Said length needs
+to match what strlen() would return if it was ran on the string.
+
+However, if the string is freely accessible for the duration of inode's
+lifetime, consider using inode_set_cached_link() instead.
-- 
2.43.0

Re: [PATCH] fs: add porting notes about readlink_copy()

[Christian Brauner]

On Tue, 03 Feb 2026 14:00:31 +0100, Mateusz Guzik wrote:
> Calling convention has changed in  ea382199071931d1 ("vfs: support caching symlink lengths in inodes")
> 
> 

Applied to the vfs-7.0.misc branch of the vfs/vfs.git tree.
Patches in the vfs-7.0.misc branch should appear in linux-next soon.

Please report any outstanding bugs that were missed during review in a
new review to the original patch series allowing us to drop it.

It's encouraged to provide Acked-bys and Reviewed-bys even though the
patch has now been applied. If possible patch trailers will be updated.

Note that commit hashes shown below are subject to change due to rebase,
trailer updates or similar. If in doubt, please check the listed branch.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git
branch: vfs-7.0.misc

[1/1] fs: add porting notes about readlink_copy()
      https://git.kernel.org/vfs/vfs/c/dedfae78f009