lookup_one_len() does not support idmapped mounts and does permission
checking on the non-mapped uids. This means that cachefiles cannot
correctly use idmapped mounts as a backing store.
This patch changes to use lookup_one() and lookup_one_positive_unlocked(),
passing the relevant vfsmount so idmapping can be honoured.
This requires passing the name in a qstr. This is easily done with
QSTR() as the name is always nul terminated, and often strlen is used
anyway. ->d_name_len is removed as no longer useful.
Note that there are still many places where cachefiles uses
nop_mnt_idmap so more work is needed to properly support idmapped
mounts.
Signed-off-by: NeilBrown <neil@xxxxxxxxxx>
---
fs/cachefiles/internal.h | 1 -
fs/cachefiles/key.c | 1 -
fs/cachefiles/namei.c | 14 +++++++-------
3 files changed, 7 insertions(+), 9 deletions(-)
diff --git a/fs/cachefiles/internal.h b/fs/cachefiles/internal.h
index 38c236e38cef..b62cd3e9a18e 100644
--- a/fs/cachefiles/internal.h
+++ b/fs/cachefiles/internal.h
@@ -71,7 +71,6 @@ struct cachefiles_object {
int debug_id;
spinlock_t lock;
refcount_t ref;
- u8 d_name_len; /* Length of filename */
enum cachefiles_content content_info:8; /* Info about content presence */
unsigned long flags;
#define CACHEFILES_OBJECT_USING_TMPFILE 0 /* Have an unlinked tmpfile */
diff --git a/fs/cachefiles/key.c b/fs/cachefiles/key.c
index bf935e25bdbe..4927b533b9ae 100644
--- a/fs/cachefiles/key.c
+++ b/fs/cachefiles/key.c
@@ -132,7 +132,6 @@ bool cachefiles_cook_key(struct cachefiles_object *object)
success:
name[len] = 0;
object->d_name = name;
- object->d_name_len = len;
_leave(" = %s", object->d_name);
return true;
}
diff --git a/fs/cachefiles/namei.c b/fs/cachefiles/namei.c
index 83a60126de0f..a440a2ff5d41 100644
--- a/fs/cachefiles/namei.c
+++ b/fs/cachefiles/namei.c
@@ -98,7 +98,7 @@ struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,
retry:
ret = cachefiles_inject_read_error();
if (ret == 0)
- subdir = lookup_one_len(dirname, dir, strlen(dirname));
+ subdir = lookup_one(cache->mnt, QSTR(dirname), dir);
else
subdir = ERR_PTR(ret);
trace_cachefiles_lookup(NULL, dir, subdir);
@@ -337,7 +337,7 @@ int cachefiles_bury_object(struct cachefiles_cache *cache,
return -EIO;
}
- grave = lookup_one_len(nbuffer, cache->graveyard, strlen(nbuffer));
+ grave = lookup_one(cache->mnt, QSTR(nbuffer), cache->graveyard);
if (IS_ERR(grave)) {
unlock_rename(cache->graveyard, dir);
trace_cachefiles_vfs_error(object, d_inode(cache->graveyard),
@@ -629,8 +629,8 @@ bool cachefiles_look_up_object(struct cachefiles_object *object)
/* Look up path "cache/vol/fanout/file". */
ret = cachefiles_inject_read_error();
if (ret == 0)
- dentry = lookup_positive_unlocked(object->d_name, fan,
- object->d_name_len);
+ dentry = lookup_one_positive_unlocked(volume->cache->mnt,
+ QSTR(object->d_name), fan);
else
dentry = ERR_PTR(ret);
trace_cachefiles_lookup(object, fan, dentry);
@@ -682,7 +682,7 @@ bool cachefiles_commit_tmpfile(struct cachefiles_cache *cache,
inode_lock_nested(d_inode(fan), I_MUTEX_PARENT);
ret = cachefiles_inject_read_error();
if (ret == 0)
- dentry = lookup_one_len(object->d_name, fan, object->d_name_len);
+ dentry = lookup_one(cache->mnt, QSTR(object->d_name), fan);
else
dentry = ERR_PTR(ret);
if (IS_ERR(dentry)) {
@@ -701,7 +701,7 @@ bool cachefiles_commit_tmpfile(struct cachefiles_cache *cache,
dput(dentry);
ret = cachefiles_inject_read_error();
if (ret == 0)
- dentry = lookup_one_len(object->d_name, fan, object->d_name_len);
+ dentry = lookup_one(cache->mnt, QSTR(object->d_name), fan);
else
dentry = ERR_PTR(ret);
if (IS_ERR(dentry)) {
@@ -750,7 +750,7 @@ static struct dentry *cachefiles_lookup_for_cull(struct cachefiles_cache *cache,
inode_lock_nested(d_inode(dir), I_MUTEX_PARENT);
- victim = lookup_one_len(filename, dir, strlen(filename));
+ victim = lookup_one(cache->mnt, QSTR(filename), dir);
if (IS_ERR(victim))
goto lookup_error;
if (d_is_negative(victim))
--
2.48.1
