ext4: Use bitops to read/modify i_flags in struct ext4_inode_info

At several places we modify EXT4_I(inode)->i_flags without holding
i_mutex (ext4_do_update_inode, ...). These modifications are racy and
we can lose updates to i_flags. So convert handling of i_flags to use
bitops which are atomic.

https://bugzilla.kernel.org/show_bug.cgi?id=15792

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 5 insertions, 5 deletions

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 91c3873970e4..42d8ce91adbd 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -3498,7 +3498,7 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
                         map->m_flags |= EXT4_MAP_UNINIT;
         }
 
-        if (unlikely(EXT4_I(inode)->i_flags & EXT4_EOFBLOCKS_FL)) {
+        if (unlikely(ext4_test_inode_flag(inode, EXT4_INODE_EOFBLOCKS))) {
                 if (unlikely(!eh->eh_entries)) {
                         EXT4_ERROR_INODE(inode,
                                          "eh->eh_entries == 0 ee_block %d",
@@ -3509,7 +3509,7 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
                 last_ex = EXT_LAST_EXTENT(eh);
                 if (map->m_lblk + ar.len > le32_to_cpu(last_ex->ee_block)
                     + ext4_ext_get_actual_len(last_ex))
-                        EXT4_I(inode)->i_flags &= ~EXT4_EOFBLOCKS_FL;
+                        ext4_clear_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
         }
         err = ext4_ext_insert_extent(handle, inode, path, &newex, flags);
         if (err) {
@@ -3650,7 +3650,7 @@ static void ext4_falloc_update_inode(struct inode *inode,
                  * can proceed even if the new size is the same as i_size.
                  */
                 if (new_size > i_size_read(inode))
-                        EXT4_I(inode)->i_flags |= EXT4_EOFBLOCKS_FL;
+                        ext4_set_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
         }
 
 }
@@ -3677,7 +3677,7 @@ long ext4_fallocate(struct inode *inode, int mode, loff_t offset, loff_t len)
          * currently supporting (pre)allocate mode for extent-based
          * files _only_
          */
-        if (!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL))
+        if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
                 return -EOPNOTSUPP;
 
         /* preallocation to directories is currently not supported */
@@ -3922,7 +3922,7 @@ int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
         int error = 0;
 
         /* fallback to generic here if not in extents fmt */
-        if (!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL))
+        if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
                 return generic_block_fiemap(inode, fieinfo, start, len,
                         ext4_get_block);