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authorAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>2009-01-05 21:49:55 -0500
committerTheodore Ts'o <tytso@mit.edu>2009-01-05 21:49:55 -0500
commit2ccb5fb9f113dae969d1ae9b6c10e80fa34f8cd3 (patch)
treed9dc5bca94748d4173a7783e963d20b5a75f8db8 /fs/ext4/balloc.c
parent393418676a7602e1d7d3f6e560159c65c8cbd50e (diff)
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.c25
1 files changed, 23 insertions, 2 deletions
diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
index 1b26b68aa42..6bba06b09dd 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__,