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