diff options
| author | Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> | 2009-01-06 03:49:55 +0100 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2009-01-06 03:49:55 +0100 |
| commit | 2ccb5fb9f113dae969d1ae9b6c10e80fa34f8cd3 (patch) | |
| tree | d9dc5bca94748d4173a7783e963d20b5a75f8db8 /fs/ext4/balloc.c | |
| parent | ext4: Fix the race between read_inode_bitmap() and ext4_new_inode() (diff) | |
| download | linux-2ccb5fb9f113dae969d1ae9b6c10e80fa34f8cd3.tar.xz linux-2ccb5fb9f113dae969d1ae9b6c10e80fa34f8cd3.zip | |
ext4: Use new buffer_head flag to check uninit group bitmaps initialization
For uninit block group, the on-disk bitmap is not initialized. That
implies we cannot depend on the uptodate flag on the bitmap
buffer_head to find bitmap validity. Use a new buffer_head flag which
would be set after we properly initialize the bitmap. This also
prevents (re-)initializing the uninit group bitmap every time we call
ext4_read_block_bitmap().
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
Diffstat (limited to 'fs/ext4/balloc.c')
| -rw-r--r-- | fs/ext4/balloc.c | 25 |
1 files changed, 23 insertions, 2 deletions
diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c index 1b26b68aa428..6bba06b09dd1 100644 --- a/fs/ext4/balloc.c +++ b/fs/ext4/balloc.c @@ -320,20 +320,41 @@ ext4_read_block_bitmap(struct super_block *sb, ext4_group_t block_group) block_group, bitmap_blk); return NULL; } - if (buffer_uptodate(bh) && - !(desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) + + if (bitmap_uptodate(bh)) return bh; lock_buffer(bh); + if (bitmap_uptodate(bh)) { + unlock_buffer(bh); + return bh; + } spin_lock(sb_bgl_lock(EXT4_SB(sb), block_group)); if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) { ext4_init_block_bitmap(sb, bh, block_group, desc); + set_bitmap_uptodate(bh); set_buffer_uptodate(bh); spin_unlock(sb_bgl_lock(EXT4_SB(sb), block_group)); unlock_buffer(bh); return bh; } spin_unlock(sb_bgl_lock(EXT4_SB(sb), block_group)); + if (buffer_uptodate(bh)) { + /* + * if not uninit if bh is uptodate, + * bitmap is also uptodate + */ + set_bitmap_uptodate(bh); + unlock_buffer(bh); + return bh; + } + /* + * submit the buffer_head for read. We can + * safely mark the bitmap as uptodate now. + * We do it here so the bitmap uptodate bit + * get set with buffer lock held. + */ + set_bitmap_uptodate(bh); if (bh_submit_read(bh) < 0) { put_bh(bh); ext4_error(sb, __func__, |