ext4: do not set posix acls on xattr inodes

We don't need acls on xattr inodes because they are not directly
accessible from user mode.

Besides lockdep complains about recursive locking of xattr_sem as seen
below.

  =============================================
  [ INFO: possible recursive locking detected ]
  4.11.0-rc8+ #402 Not tainted
  ---------------------------------------------
  python/1894 is trying to acquire lock:
   (&ei->xattr_sem){++++..}, at: [<ffffffff804878a6>] ext4_xattr_get+0x66/0x270

  but task is already holding lock:
   (&ei->xattr_sem){++++..}, at: [<ffffffff80489500>] ext4_xattr_set_handle+0xa0/0x5d0

  other info that might help us debug this:
   Possible unsafe locking scenario:

         CPU0
         ----
    lock(&ei->xattr_sem);
    lock(&ei->xattr_sem);

   *** DEADLOCK ***

   May be due to missing lock nesting notation

  3 locks held by python/1894:
   #0:  (sb_writers#10){.+.+.+}, at: [<ffffffff803d829f>] mnt_want_write+0x1f/0x50
   #1:  (&sb->s_type->i_mutex_key#15){+.+...}, at: [<ffffffff803dda27>] vfs_setxattr+0x57/0xb0
   #2:  (&ei->xattr_sem){++++..}, at: [<ffffffff80489500>] ext4_xattr_set_handle+0xa0/0x5d0

  stack backtrace:
  CPU: 0 PID: 1894 Comm: python Not tainted 4.11.0-rc8+ #402
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
  Call Trace:
   dump_stack+0x67/0x99
   __lock_acquire+0x5f3/0x1830
   lock_acquire+0xb5/0x1d0
   down_read+0x2f/0x60
   ext4_xattr_get+0x66/0x270
   ext4_get_acl+0x43/0x1e0
   get_acl+0x72/0xf0
   posix_acl_create+0x5e/0x170
   ext4_init_acl+0x21/0xc0
   __ext4_new_inode+0xffd/0x16b0
   ext4_xattr_set_entry+0x5ea/0xb70
   ext4_xattr_block_set+0x1b5/0x970
   ext4_xattr_set_handle+0x351/0x5d0
   ext4_xattr_set+0x124/0x180
   ext4_xattr_user_set+0x34/0x40
   __vfs_setxattr+0x66/0x80
   __vfs_setxattr_noperm+0x69/0x1c0
   vfs_setxattr+0xa2/0xb0
   setxattr+0x129/0x160
   path_setxattr+0x87/0xb0
   SyS_setxattr+0xf/0x20
   entry_SYSCALL_64_fastpath+0x18/0xad

Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 41e26ad86fc30048a833ee118ed77c1c5fe27436..bc80082a2375409c5890ac75a0df70264b23c28e 100644 (file)
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -2411,16 +2411,17 @@ extern int ext4fs_dirhash(const char *name, int len, struct
 /* ialloc.c */
 extern struct inode *__ext4_new_inode(handle_t *, struct inode *, umode_t,
                                      const struct qstr *qstr, __u32 goal,
-                                     uid_t *owner, int handle_type,
-                                     unsigned int line_no, int nblocks);
+                                     uid_t *owner, __u32 i_flags,
+                                     int handle_type, unsigned int line_no,
+                                     int nblocks);
 
-#define ext4_new_inode(handle, dir, mode, qstr, goal, owner) \
+#define ext4_new_inode(handle, dir, mode, qstr, goal, owner, i_flags) \
        __ext4_new_inode((handle), (dir), (mode), (qstr), (goal), (owner), \
-                        0, 0, 0)
+                        i_flags, 0, 0, 0)
 #define ext4_new_inode_start_handle(dir, mode, qstr, goal, owner, \
                                    type, nblocks)                  \
        __ext4_new_inode(NULL, (dir), (mode), (qstr), (goal), (owner), \
-                        (type), __LINE__, (nblocks))
+                        0, (type), __LINE__, (nblocks))
 
 
 extern void ext4_free_inode(handle_t *, struct inode *);

diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index e2eb3cc068204ee29b40ebdafcde5a2b2a3efbbc..fb1b3df17f6e05ae24b294d00eafd3a9bec98e73 100644 (file)
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -742,8 +742,9 @@ out:
  */
 struct inode *__ext4_new_inode(handle_t *handle, struct inode *dir,
                               umode_t mode, const struct qstr *qstr,
-                              __u32 goal, uid_t *owner, int handle_type,
-                              unsigned int line_no, int nblocks)
+                              __u32 goal, uid_t *owner, __u32 i_flags,
+                              int handle_type, unsigned int line_no,
+                              int nblocks)
 {
        struct super_block *sb;
        struct buffer_head *inode_bitmap_bh = NULL;
@@ -1052,6 +1053,7 @@ got:
        /* Don't inherit extent flag from directory, amongst others. */
        ei->i_flags =
                ext4_mask_flags(mode, EXT4_I(dir)->i_flags & EXT4_FL_INHERITED);
+       ei->i_flags |= i_flags;
        ei->i_file_acl = 0;
        ei->i_dtime = 0;
        ei->i_block_group = group;
@@ -1108,9 +1110,11 @@ got:
                        goto fail_free_drop;
        }
 
-       err = ext4_init_acl(handle, inode, dir);
-       if (err)
-               goto fail_free_drop;
+       if (!(ei->i_flags & EXT4_EA_INODE_FL)) {
+               err = ext4_init_acl(handle, inode, dir);
+               if (err)
+                       goto fail_free_drop;
+       }
 
        err = ext4_init_security(handle, inode, dir, qstr);
        if (err)

diff --git a/fs/ext4/migrate.c b/fs/ext4/migrate.c
index 364ea4d4a94377d2763f0abc66298a323e5b14ef..cf5181b62df17ef203e6068d99e51c9bb34e5199 100644 (file)
--- a/fs/ext4/migrate.c
+++ b/fs/ext4/migrate.c
@@ -475,7 +475,7 @@ int ext4_ext_migrate(struct inode *inode)
        owner[0] = i_uid_read(inode);
        owner[1] = i_gid_read(inode);
        tmp_inode = ext4_new_inode(handle, d_inode(inode->i_sb->s_root),
-                                  S_IFREG, NULL, goal, owner);
+                                  S_IFREG, NULL, goal, owner, 0);
        if (IS_ERR(tmp_inode)) {
                retval = PTR_ERR(tmp_inode);
                ext4_journal_stop(handle);

diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index 02b0462fec62009449a08e9f3e578f7927ba74d8..df032f50436bd60cff0b6a8f0286ccdb35b4319f 100644 (file)
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -830,7 +830,8 @@ static struct inode *ext4_xattr_inode_create(handle_t *handle,
         * in the same group, or nearby one.
         */
        ea_inode = ext4_new_inode(handle, inode->i_sb->s_root->d_inode,
-                                 S_IFREG | 0600, NULL, inode->i_ino + 1, NULL);
+                                 S_IFREG | 0600, NULL, inode->i_ino + 1, NULL,
+                                 EXT4_EA_INODE_FL);
        if (!IS_ERR(ea_inode)) {
                ea_inode->i_op = &ext4_file_inode_operations;
                ea_inode->i_fop = &ext4_file_operations;