Overlayfs does not cache ACL's to avoid double caching with all its
problems. Instead it just calls the underlying filesystem's
i_op->get_acl(), which will return the cached value, if possible.
In rcu path walk, however, get_cached_acl_rcu() is employed to get the
value from the cache, which will fail on overlayfs resulting in dropping
out of rcu walk mode. This can result in a big performance hit in certain
situations.
Add a flags argument to the ->get_acl() callback, and allow
get_cached_acl_rcu() to call the ->get_acl() method with LOOKUP_RCU.
Don't do this for the generic case of a cache miss, only in case of
ACL_DONT_CACHE.
Reported-by: garyhuang <[email protected]>
Signed-off-by: Miklos Szeredi <[email protected]>
---
fs/9p/acl.c | 2 +-
fs/9p/acl.h | 2 +-
fs/bad_inode.c | 2 +-
fs/btrfs/acl.c | 2 +-
fs/btrfs/ctree.h | 2 +-
fs/ceph/acl.c | 2 +-
fs/ceph/super.h | 2 +-
fs/erofs/xattr.c | 2 +-
fs/erofs/xattr.h | 2 +-
fs/ext2/acl.c | 2 +-
fs/ext2/acl.h | 2 +-
fs/ext4/acl.c | 2 +-
fs/ext4/acl.h | 2 +-
fs/f2fs/acl.c | 2 +-
fs/f2fs/acl.h | 2 +-
fs/fuse/acl.c | 2 +-
fs/fuse/fuse_i.h | 2 +-
fs/gfs2/acl.c | 2 +-
fs/gfs2/acl.h | 2 +-
fs/jffs2/acl.c | 2 +-
fs/jffs2/acl.h | 2 +-
fs/jfs/acl.c | 2 +-
fs/jfs/jfs_acl.h | 2 +-
fs/nfs/nfs3_fs.h | 2 +-
fs/nfs/nfs3acl.c | 2 +-
fs/ocfs2/acl.c | 2 +-
fs/ocfs2/acl.h | 2 +-
fs/orangefs/acl.c | 2 +-
fs/orangefs/orangefs-kernel.h | 2 +-
fs/overlayfs/inode.c | 6 +++++-
fs/overlayfs/overlayfs.h | 2 +-
fs/posix_acl.c | 10 ++++++++--
fs/reiserfs/acl.h | 2 +-
fs/reiserfs/xattr_acl.c | 2 +-
fs/xfs/xfs_acl.c | 2 +-
fs/xfs/xfs_acl.h | 4 ++--
include/linux/fs.h | 2 +-
37 files changed, 49 insertions(+), 39 deletions(-)
diff --git a/fs/9p/acl.c b/fs/9p/acl.c
index bb1b286c49ae..48d0a8fcc038 100644
--- a/fs/9p/acl.c
+++ b/fs/9p/acl.c
@@ -97,7 +97,7 @@ static struct posix_acl *v9fs_get_cached_acl(struct inode *inode, int type)
return acl;
}
-struct posix_acl *v9fs_iop_get_acl(struct inode *inode, int type)
+struct posix_acl *v9fs_iop_get_acl(struct inode *inode, int type, int flags)
{
struct v9fs_session_info *v9ses;
diff --git a/fs/9p/acl.h b/fs/9p/acl.h
index e4f7e882272b..7b31cef9ef5a 100644
--- a/fs/9p/acl.h
+++ b/fs/9p/acl.h
@@ -16,7 +16,7 @@
#ifdef CONFIG_9P_FS_POSIX_ACL
extern int v9fs_get_acl(struct inode *, struct p9_fid *);
-extern struct posix_acl *v9fs_iop_get_acl(struct inode *inode, int type);
+extern struct posix_acl *v9fs_iop_get_acl(struct inode *inode, int type, int flags);
extern int v9fs_acl_chmod(struct inode *, struct p9_fid *);
extern int v9fs_set_create_acl(struct inode *, struct p9_fid *,
struct posix_acl *, struct posix_acl *);
diff --git a/fs/bad_inode.c b/fs/bad_inode.c
index 48e16144c1f7..dd34decddaa6 100644
--- a/fs/bad_inode.c
+++ b/fs/bad_inode.c
@@ -121,7 +121,7 @@ static const char *bad_inode_get_link(struct dentry *dentry,
return ERR_PTR(-EIO);
}
-static struct posix_acl *bad_inode_get_acl(struct inode *inode, int type)
+static struct posix_acl *bad_inode_get_acl(struct inode *inode, int type, int flags)
{
return ERR_PTR(-EIO);
}
diff --git a/fs/btrfs/acl.c b/fs/btrfs/acl.c
index d95eb5c8cb37..1d70bfd31ac1 100644
--- a/fs/btrfs/acl.c
+++ b/fs/btrfs/acl.c
@@ -16,7 +16,7 @@
#include "btrfs_inode.h"
#include "xattr.h"
-struct posix_acl *btrfs_get_acl(struct inode *inode, int type)
+struct posix_acl *btrfs_get_acl(struct inode *inode, int type, int flags)
{
int size;
const char *name;
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 9ae776ab3967..a450e5fc9df8 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -3639,7 +3639,7 @@ static inline int __btrfs_fs_compat_ro(struct btrfs_fs_info *fs_info, u64 flag)
/* acl.c */
#ifdef CONFIG_BTRFS_FS_POSIX_ACL
-struct posix_acl *btrfs_get_acl(struct inode *inode, int type);
+struct posix_acl *btrfs_get_acl(struct inode *inode, int type, int flags);
int btrfs_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
struct posix_acl *acl, int type);
int btrfs_init_acl(struct btrfs_trans_handle *trans,
diff --git a/fs/ceph/acl.c b/fs/ceph/acl.c
index 529af59d9fd3..2b72b03b0586 100644
--- a/fs/ceph/acl.c
+++ b/fs/ceph/acl.c
@@ -29,7 +29,7 @@ static inline void ceph_set_cached_acl(struct inode *inode,
spin_unlock(&ci->i_ceph_lock);
}
-struct posix_acl *ceph_get_acl(struct inode *inode, int type)
+struct posix_acl *ceph_get_acl(struct inode *inode, int type, int flags)
{
int size;
unsigned int retry_cnt = 0;
diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index c48bb30c8d70..c12712c80668 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -1066,7 +1066,7 @@ void ceph_release_acl_sec_ctx(struct ceph_acl_sec_ctx *as_ctx);
/* acl.c */
#ifdef CONFIG_CEPH_FS_POSIX_ACL
-struct posix_acl *ceph_get_acl(struct inode *, int);
+struct posix_acl *ceph_get_acl(struct inode *, int, int);
int ceph_set_acl(struct user_namespace *mnt_userns,
struct inode *inode, struct posix_acl *acl, int type);
int ceph_pre_init_acls(struct inode *dir, umode_t *mode,
diff --git a/fs/erofs/xattr.c b/fs/erofs/xattr.c
index 47314a26767a..84c971690292 100644
--- a/fs/erofs/xattr.c
+++ b/fs/erofs/xattr.c
@@ -674,7 +674,7 @@ ssize_t erofs_listxattr(struct dentry *dentry,
}
#ifdef CONFIG_EROFS_FS_POSIX_ACL
-struct posix_acl *erofs_get_acl(struct inode *inode, int type)
+struct posix_acl *erofs_get_acl(struct inode *inode, int type, int flags)
{
struct posix_acl *acl;
int prefix, rc;
diff --git a/fs/erofs/xattr.h b/fs/erofs/xattr.h
index 815304bd335f..5e4b917cc6a7 100644
--- a/fs/erofs/xattr.h
+++ b/fs/erofs/xattr.h
@@ -81,7 +81,7 @@ static inline int erofs_getxattr(struct inode *inode, int index,
#endif /* !CONFIG_EROFS_FS_XATTR */
#ifdef CONFIG_EROFS_FS_POSIX_ACL
-struct posix_acl *erofs_get_acl(struct inode *inode, int type);
+struct posix_acl *erofs_get_acl(struct inode *inode, int type, int flags);
#else
#define erofs_get_acl (NULL)
#endif
diff --git a/fs/ext2/acl.c b/fs/ext2/acl.c
index b9a9db98e94b..1dc220f205b3 100644
--- a/fs/ext2/acl.c
+++ b/fs/ext2/acl.c
@@ -141,7 +141,7 @@ ext2_acl_to_disk(const struct posix_acl *acl, size_t *size)
* inode->i_mutex: don't care
*/
struct posix_acl *
-ext2_get_acl(struct inode *inode, int type)
+ext2_get_acl(struct inode *inode, int type, int flags)
{
int name_index;
char *value = NULL;
diff --git a/fs/ext2/acl.h b/fs/ext2/acl.h
index 917db5f6630a..0bd53a953831 100644
--- a/fs/ext2/acl.h
+++ b/fs/ext2/acl.h
@@ -55,7 +55,7 @@ static inline int ext2_acl_count(size_t size)
#ifdef CONFIG_EXT2_FS_POSIX_ACL
/* acl.c */
-extern struct posix_acl *ext2_get_acl(struct inode *inode, int type);
+extern struct posix_acl *ext2_get_acl(struct inode *inode, int type, int flags);
extern int ext2_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
struct posix_acl *acl, int type);
extern int ext2_init_acl (struct inode *, struct inode *);
diff --git a/fs/ext4/acl.c b/fs/ext4/acl.c
index c5eaffccecc3..b2b06a80eb8b 100644
--- a/fs/ext4/acl.c
+++ b/fs/ext4/acl.c
@@ -142,7 +142,7 @@ ext4_acl_to_disk(const struct posix_acl *acl, size_t *size)
* inode->i_mutex: don't care
*/
struct posix_acl *
-ext4_get_acl(struct inode *inode, int type)
+ext4_get_acl(struct inode *inode, int type, int flags)
{
int name_index;
char *value = NULL;
diff --git a/fs/ext4/acl.h b/fs/ext4/acl.h
index 84b8942a57f2..b349365c7b33 100644
--- a/fs/ext4/acl.h
+++ b/fs/ext4/acl.h
@@ -55,7 +55,7 @@ static inline int ext4_acl_count(size_t size)
#ifdef CONFIG_EXT4_FS_POSIX_ACL
/* acl.c */
-struct posix_acl *ext4_get_acl(struct inode *inode, int type);
+struct posix_acl *ext4_get_acl(struct inode *inode, int type, int flags);
int ext4_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
struct posix_acl *acl, int type);
extern int ext4_init_acl(handle_t *, struct inode *, struct inode *);
diff --git a/fs/f2fs/acl.c b/fs/f2fs/acl.c
index 965037a9c205..ae86df5e1472 100644
--- a/fs/f2fs/acl.c
+++ b/fs/f2fs/acl.c
@@ -195,7 +195,7 @@ static struct posix_acl *__f2fs_get_acl(struct inode *inode, int type,
return acl;
}
-struct posix_acl *f2fs_get_acl(struct inode *inode, int type)
+struct posix_acl *f2fs_get_acl(struct inode *inode, int type, int flags)
{
return __f2fs_get_acl(inode, type, NULL);
}
diff --git a/fs/f2fs/acl.h b/fs/f2fs/acl.h
index 986fd1bc780b..3b7b0deb2845 100644
--- a/fs/f2fs/acl.h
+++ b/fs/f2fs/acl.h
@@ -33,7 +33,7 @@ struct f2fs_acl_header {
#ifdef CONFIG_F2FS_FS_POSIX_ACL
-extern struct posix_acl *f2fs_get_acl(struct inode *, int);
+extern struct posix_acl *f2fs_get_acl(struct inode *, int, int);
extern int f2fs_set_acl(struct user_namespace *, struct inode *,
struct posix_acl *, int);
extern int f2fs_init_acl(struct inode *, struct inode *, struct page *,
diff --git a/fs/fuse/acl.c b/fs/fuse/acl.c
index e9c0f916349d..1ec289668d73 100644
--- a/fs/fuse/acl.c
+++ b/fs/fuse/acl.c
@@ -11,7 +11,7 @@
#include <linux/posix_acl.h>
#include <linux/posix_acl_xattr.h>
-struct posix_acl *fuse_get_acl(struct inode *inode, int type)
+struct posix_acl *fuse_get_acl(struct inode *inode, int type, int flags)
{
struct fuse_conn *fc = get_fuse_conn(inode);
int size;
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 63d97a15ffde..8f34101c5c62 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -1180,7 +1180,7 @@ extern const struct xattr_handler *fuse_acl_xattr_handlers[];
extern const struct xattr_handler *fuse_no_acl_xattr_handlers[];
struct posix_acl;
-struct posix_acl *fuse_get_acl(struct inode *inode, int type);
+struct posix_acl *fuse_get_acl(struct inode *inode, int type, int flags);
int fuse_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
struct posix_acl *acl, int type);
diff --git a/fs/gfs2/acl.c b/fs/gfs2/acl.c
index 9165d70ead07..3455cb2079b9 100644
--- a/fs/gfs2/acl.c
+++ b/fs/gfs2/acl.c
@@ -57,7 +57,7 @@ static struct posix_acl *__gfs2_get_acl(struct inode *inode, int type)
return acl;
}
-struct posix_acl *gfs2_get_acl(struct inode *inode, int type)
+struct posix_acl *gfs2_get_acl(struct inode *inode, int type, int flags)
{
struct gfs2_inode *ip = GFS2_I(inode);
struct gfs2_holder gh;
diff --git a/fs/gfs2/acl.h b/fs/gfs2/acl.h
index eccc6a43326c..cdf8f12089de 100644
--- a/fs/gfs2/acl.h
+++ b/fs/gfs2/acl.h
@@ -11,7 +11,7 @@
#define GFS2_ACL_MAX_ENTRIES(sdp) ((300 << (sdp)->sd_sb.sb_bsize_shift) >> 12)
-extern struct posix_acl *gfs2_get_acl(struct inode *inode, int type);
+extern struct posix_acl *gfs2_get_acl(struct inode *inode, int type, int flags);
extern int __gfs2_set_acl(struct inode *inode, struct posix_acl *acl, int type);
extern int gfs2_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
struct posix_acl *acl, int type);
diff --git a/fs/jffs2/acl.c b/fs/jffs2/acl.c
index 55a79df70d24..3eade65c95eb 100644
--- a/fs/jffs2/acl.c
+++ b/fs/jffs2/acl.c
@@ -173,7 +173,7 @@ static void *jffs2_acl_to_medium(const struct posix_acl *acl, size_t *size)
return ERR_PTR(-EINVAL);
}
-struct posix_acl *jffs2_get_acl(struct inode *inode, int type)
+struct posix_acl *jffs2_get_acl(struct inode *inode, int type, int flags)
{
struct posix_acl *acl;
char *value = NULL;
diff --git a/fs/jffs2/acl.h b/fs/jffs2/acl.h
index 62c50da9d493..afd6f924aacb 100644
--- a/fs/jffs2/acl.h
+++ b/fs/jffs2/acl.h
@@ -27,7 +27,7 @@ struct jffs2_acl_header {
#ifdef CONFIG_JFFS2_FS_POSIX_ACL
-struct posix_acl *jffs2_get_acl(struct inode *inode, int type);
+struct posix_acl *jffs2_get_acl(struct inode *inode, int type, int flags);
int jffs2_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
struct posix_acl *acl, int type);
extern int jffs2_init_acl_pre(struct inode *, struct inode *, umode_t *);
diff --git a/fs/jfs/acl.c b/fs/jfs/acl.c
index 43c285c3d2a7..b8a459cc649f 100644
--- a/fs/jfs/acl.c
+++ b/fs/jfs/acl.c
@@ -14,7 +14,7 @@
#include "jfs_xattr.h"
#include "jfs_acl.h"
-struct posix_acl *jfs_get_acl(struct inode *inode, int type)
+struct posix_acl *jfs_get_acl(struct inode *inode, int type, int flags)
{
struct posix_acl *acl;
char *ea_name;
diff --git a/fs/jfs/jfs_acl.h b/fs/jfs/jfs_acl.h
index 7ae389a7a366..e86997d1f123 100644
--- a/fs/jfs/jfs_acl.h
+++ b/fs/jfs/jfs_acl.h
@@ -7,7 +7,7 @@
#ifdef CONFIG_JFS_POSIX_ACL
-struct posix_acl *jfs_get_acl(struct inode *inode, int type);
+struct posix_acl *jfs_get_acl(struct inode *inode, int type, int flags);
int jfs_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
struct posix_acl *acl, int type);
int jfs_init_acl(tid_t, struct inode *, struct inode *);
diff --git a/fs/nfs/nfs3_fs.h b/fs/nfs/nfs3_fs.h
index c8a192802dda..0f3ba2f3b8da 100644
--- a/fs/nfs/nfs3_fs.h
+++ b/fs/nfs/nfs3_fs.h
@@ -11,7 +11,7 @@
* nfs3acl.c
*/
#ifdef CONFIG_NFS_V3_ACL
-extern struct posix_acl *nfs3_get_acl(struct inode *inode, int type);
+extern struct posix_acl *nfs3_get_acl(struct inode *inode, int type, int flags);
extern int nfs3_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
struct posix_acl *acl, int type);
extern int nfs3_proc_setacls(struct inode *inode, struct posix_acl *acl,
diff --git a/fs/nfs/nfs3acl.c b/fs/nfs/nfs3acl.c
index bb386a691e69..f78ad2f6a80a 100644
--- a/fs/nfs/nfs3acl.c
+++ b/fs/nfs/nfs3acl.c
@@ -44,7 +44,7 @@ static void nfs3_abort_get_acl(struct posix_acl **p)
cmpxchg(p, sentinel, ACL_NOT_CACHED);
}
-struct posix_acl *nfs3_get_acl(struct inode *inode, int type)
+struct posix_acl *nfs3_get_acl(struct inode *inode, int type, int flags)
{
struct nfs_server *server = NFS_SERVER(inode);
struct page *pages[NFSACL_MAXPAGES] = { };
diff --git a/fs/ocfs2/acl.c b/fs/ocfs2/acl.c
index 5259badabb56..2d0db332bd0e 100644
--- a/fs/ocfs2/acl.c
+++ b/fs/ocfs2/acl.c
@@ -291,7 +291,7 @@ int ocfs2_iop_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
return status;
}
-struct posix_acl *ocfs2_iop_get_acl(struct inode *inode, int type)
+struct posix_acl *ocfs2_iop_get_acl(struct inode *inode, int type, int flags)
{
struct ocfs2_super *osb;
struct buffer_head *di_bh = NULL;
diff --git a/fs/ocfs2/acl.h b/fs/ocfs2/acl.h
index 4e86450917b2..b75028c4ab4b 100644
--- a/fs/ocfs2/acl.h
+++ b/fs/ocfs2/acl.h
@@ -18,7 +18,7 @@ struct ocfs2_acl_entry {
__le32 e_id;
};
-struct posix_acl *ocfs2_iop_get_acl(struct inode *inode, int type);
+struct posix_acl *ocfs2_iop_get_acl(struct inode *inode, int type, int flags);
int ocfs2_iop_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
struct posix_acl *acl, int type);
extern int ocfs2_acl_chmod(struct inode *, struct buffer_head *);
diff --git a/fs/orangefs/acl.c b/fs/orangefs/acl.c
index 18852b9ed82b..7c61a21cfcb2 100644
--- a/fs/orangefs/acl.c
+++ b/fs/orangefs/acl.c
@@ -10,7 +10,7 @@
#include "orangefs-bufmap.h"
#include <linux/posix_acl_xattr.h>
-struct posix_acl *orangefs_get_acl(struct inode *inode, int type)
+struct posix_acl *orangefs_get_acl(struct inode *inode, int type, int flags)
{
struct posix_acl *acl;
int ret;
diff --git a/fs/orangefs/orangefs-kernel.h b/fs/orangefs/orangefs-kernel.h
index 0e6b97682e41..370bd89c670f 100644
--- a/fs/orangefs/orangefs-kernel.h
+++ b/fs/orangefs/orangefs-kernel.h
@@ -106,7 +106,7 @@ enum orangefs_vfs_op_states {
extern int orangefs_init_acl(struct inode *inode, struct inode *dir);
extern const struct xattr_handler *orangefs_xattr_handlers[];
-extern struct posix_acl *orangefs_get_acl(struct inode *inode, int type);
+extern struct posix_acl *orangefs_get_acl(struct inode *inode, int type, int flags);
extern int orangefs_set_acl(struct user_namespace *mnt_userns,
struct inode *inode, struct posix_acl *acl,
int type);
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index 003cf83bf78a..994ce7ecebae 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -11,6 +11,7 @@
#include <linux/posix_acl.h>
#include <linux/ratelimit.h>
#include <linux/fiemap.h>
+#include <linux/namei.h>
#include "overlayfs.h"
@@ -450,7 +451,7 @@ ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size)
return res;
}
-struct posix_acl *ovl_get_acl(struct inode *inode, int type)
+struct posix_acl *ovl_get_acl(struct inode *inode, int type, int flags)
{
struct inode *realinode = ovl_inode_real(inode);
const struct cred *old_cred;
@@ -459,6 +460,9 @@ struct posix_acl *ovl_get_acl(struct inode *inode, int type)
if (!IS_ENABLED(CONFIG_FS_POSIX_ACL) || !IS_POSIXACL(realinode))
return NULL;
+ if (flags & LOOKUP_RCU)
+ return get_cached_acl_rcu(realinode, type);
+
old_cred = ovl_override_creds(inode->i_sb);
acl = get_acl(realinode, type);
revert_creds(old_cred);
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index 95cff83786a5..d2284fe67978 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -456,7 +456,7 @@ int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char *name,
int ovl_xattr_get(struct dentry *dentry, struct inode *inode, const char *name,
void *value, size_t size);
ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size);
-struct posix_acl *ovl_get_acl(struct inode *inode, int type);
+struct posix_acl *ovl_get_acl(struct inode *inode, int type, int flags);
int ovl_update_time(struct inode *inode, struct timespec64 *ts, int flags);
bool ovl_is_private_xattr(struct super_block *sb, const char *name);
diff --git a/fs/posix_acl.c b/fs/posix_acl.c
index f3309a7edb49..4d1c6c266cf0 100644
--- a/fs/posix_acl.c
+++ b/fs/posix_acl.c
@@ -22,6 +22,7 @@
#include <linux/xattr.h>
#include <linux/export.h>
#include <linux/user_namespace.h>
+#include <linux/namei.h>
static struct posix_acl **acl_by_type(struct inode *inode, int type)
{
@@ -56,7 +57,12 @@ EXPORT_SYMBOL(get_cached_acl);
struct posix_acl *get_cached_acl_rcu(struct inode *inode, int type)
{
- return rcu_dereference(*acl_by_type(inode, type));
+ struct posix_acl *acl = rcu_dereference(*acl_by_type(inode, type));
+
+ if (acl == ACL_DONT_CACHE)
+ acl = inode->i_op->get_acl(inode, type, LOOKUP_RCU);
+
+ return acl;
}
EXPORT_SYMBOL(get_cached_acl_rcu);
@@ -138,7 +144,7 @@ struct posix_acl *get_acl(struct inode *inode, int type)
set_cached_acl(inode, type, NULL);
return NULL;
}
- acl = inode->i_op->get_acl(inode, type);
+ acl = inode->i_op->get_acl(inode, type, 0);
if (IS_ERR(acl)) {
/*
diff --git a/fs/reiserfs/acl.h b/fs/reiserfs/acl.h
index fd58618da360..bf10841b892d 100644
--- a/fs/reiserfs/acl.h
+++ b/fs/reiserfs/acl.h
@@ -48,7 +48,7 @@ static inline int reiserfs_acl_count(size_t size)
}
#ifdef CONFIG_REISERFS_FS_POSIX_ACL
-struct posix_acl *reiserfs_get_acl(struct inode *inode, int type);
+struct posix_acl *reiserfs_get_acl(struct inode *inode, int type, int flags);
int reiserfs_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
struct posix_acl *acl, int type);
int reiserfs_acl_chmod(struct inode *inode);
diff --git a/fs/reiserfs/xattr_acl.c b/fs/reiserfs/xattr_acl.c
index a9547144a099..377507a1c7b8 100644
--- a/fs/reiserfs/xattr_acl.c
+++ b/fs/reiserfs/xattr_acl.c
@@ -190,7 +190,7 @@ static void *reiserfs_posix_acl_to_disk(const struct posix_acl *acl, size_t * si
* inode->i_mutex: down
* BKL held [before 2.5.x]
*/
-struct posix_acl *reiserfs_get_acl(struct inode *inode, int type)
+struct posix_acl *reiserfs_get_acl(struct inode *inode, int type, int flags)
{
char *name, *value;
struct posix_acl *acl;
diff --git a/fs/xfs/xfs_acl.c b/fs/xfs/xfs_acl.c
index d02bef24b32b..27e6e6525cd3 100644
--- a/fs/xfs/xfs_acl.c
+++ b/fs/xfs/xfs_acl.c
@@ -125,7 +125,7 @@ xfs_acl_to_disk(struct xfs_acl *aclp, const struct posix_acl *acl)
}
struct posix_acl *
-xfs_get_acl(struct inode *inode, int type)
+xfs_get_acl(struct inode *inode, int type, int flags)
{
struct xfs_inode *ip = XFS_I(inode);
struct xfs_mount *mp = ip->i_mount;
diff --git a/fs/xfs/xfs_acl.h b/fs/xfs/xfs_acl.h
index 7bdb3a4ed798..38f933f2e281 100644
--- a/fs/xfs/xfs_acl.h
+++ b/fs/xfs/xfs_acl.h
@@ -10,13 +10,13 @@ struct inode;
struct posix_acl;
#ifdef CONFIG_XFS_POSIX_ACL
-extern struct posix_acl *xfs_get_acl(struct inode *inode, int type);
+extern struct posix_acl *xfs_get_acl(struct inode *inode, int type, int flags);
extern int xfs_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
struct posix_acl *acl, int type);
extern int __xfs_set_acl(struct inode *inode, struct posix_acl *acl, int type);
void xfs_forget_acl(struct inode *inode, const char *name);
#else
-static inline struct posix_acl *xfs_get_acl(struct inode *inode, int type)
+static inline struct posix_acl *xfs_get_acl(struct inode *inode, int type, int flags)
{
return NULL;
}
diff --git a/include/linux/fs.h b/include/linux/fs.h
index ec8f3ddf4a6a..1683f16f3b06 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1931,7 +1931,7 @@ struct inode_operations {
struct dentry * (*lookup) (struct inode *,struct dentry *, unsigned int);
const char * (*get_link) (struct dentry *, struct inode *, struct delayed_call *);
int (*permission) (struct user_namespace *, struct inode *, int);
- struct posix_acl * (*get_acl)(struct inode *, int);
+ struct posix_acl * (*get_acl)(struct inode *, int, int);
int (*readlink) (struct dentry *, char __user *,int);
--
2.30.2
On Tue, Mar 23, 2021 at 5:07 PM Miklos Szeredi <[email protected]> wrote:
>
> Overlayfs does not cache ACL's to avoid double caching with all its
> problems. Instead it just calls the underlying filesystem's
> i_op->get_acl(), which will return the cached value, if possible.
>
> In rcu path walk, however, get_cached_acl_rcu() is employed to get the
> value from the cache, which will fail on overlayfs resulting in dropping
> out of rcu walk mode. This can result in a big performance hit in certain
> situations.
>
> Add a flags argument to the ->get_acl() callback, and allow
> get_cached_acl_rcu() to call the ->get_acl() method with LOOKUP_RCU.
>
> Don't do this for the generic case of a cache miss, only in case of
> ACL_DONT_CACHE.
>
> Reported-by: garyhuang <[email protected]>
> Signed-off-by: Miklos Szeredi <[email protected]>
Hi Al,
Could you please apply this patch?
It's fairly trivial, but unfortunately adds a fair bit of API churn.
Thanks,
Miklos