From 2ccb5fb9f113dae969d1ae9b6c10e80fa34f8cd3 Mon Sep 17 00:00:00 2001 From: Aneesh Kumar K.V Date: Mon, 5 Jan 2009 21:49:55 -0500 Subject: 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 Signed-off-by: "Theodore Ts'o" Cc: stable@kernel.org --- fs/ext4/mballoc.c | 24 ++++++++++++++++++++++-- 1 file changed, 22 insertions(+), 2 deletions(-) (limited to 'fs/ext4/mballoc.c') diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index aac33590ac64..18a52d39d094 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -794,22 +794,42 @@ static int ext4_mb_init_cache(struct page *page, char *incore) if (bh[i] == NULL) goto out; - if (buffer_uptodate(bh[i]) && - !(desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) + if (bitmap_uptodate(bh[i])) continue; lock_buffer(bh[i]); + if (bitmap_uptodate(bh[i])) { + unlock_buffer(bh[i]); + continue; + } spin_lock(sb_bgl_lock(EXT4_SB(sb), first_group + i)); if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) { ext4_init_block_bitmap(sb, bh[i], first_group + i, desc); + set_bitmap_uptodate(bh[i]); set_buffer_uptodate(bh[i]); spin_unlock(sb_bgl_lock(EXT4_SB(sb), first_group + i)); unlock_buffer(bh[i]); continue; } spin_unlock(sb_bgl_lock(EXT4_SB(sb), first_group + i)); + if (buffer_uptodate(bh[i])) { + /* + * if not uninit if bh is uptodate, + * bitmap is also uptodate + */ + set_bitmap_uptodate(bh[i]); + unlock_buffer(bh[i]); + continue; + } get_bh(bh[i]); + /* + * 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[i]); bh[i]->b_end_io = end_buffer_read_sync; submit_bh(READ, bh[i]); mb_debug("read bitmap for group %u\n", first_group + i); -- cgit v1.2.3-55-g7522