diff options
| author | Mateusz Guzik <mjguzik@gmail.com> | 2024-11-20 12:20:34 +0100 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2024-12-22 11:29:50 +0100 |
| commit | ea382199071931d19aac5f688b543e07360e2b64 (patch) | |
| tree | 375c9ad796a10c2e2abd39b3a766196f354a050b /fs/proc/namespaces.c | |
| parent | 135ec43eb29c68ed26e2d10f221d43f7d9139a8f (diff) | |
vfs: support caching symlink lengths in inodes
When utilized it dodges strlen() in vfs_readlink(), giving about 1.5%
speed up when issuing readlink on /initrd.img on ext4.
Filesystems opt in by calling inode_set_cached_link() when creating an
inode.
The size is stored in a new union utilizing the same space as i_devices,
thus avoiding growing the struct or taking up any more space.
Churn-wise the current readlink_copy() helper is patched to accept the
size instead of calculating it.
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Link: https://lore.kernel.org/r/20241120112037.822078-2-mjguzik@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
Diffstat (limited to 'fs/proc/namespaces.c')
| -rw-r--r-- | fs/proc/namespaces.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/proc/namespaces.c b/fs/proc/namespaces.c index 8e159fc78c0a..c610224faf10 100644 --- a/fs/proc/namespaces.c +++ b/fs/proc/namespaces.c @@ -83,7 +83,7 @@ static int proc_ns_readlink(struct dentry *dentry, char __user *buffer, int bufl if (ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) { res = ns_get_name(name, sizeof(name), task, ns_ops); if (res >= 0) - res = readlink_copy(buffer, buflen, name); + res = readlink_copy(buffer, buflen, name, strlen(name)); } put_task_struct(task); return res; |