ext4: Use new buffer_head flag to check uninit group bitmaps initialization From: Aneesh Kumar K.V 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/balloc.c | 25 +++++++++++++++++++++++-- fs/ext4/ext4.h | 18 ++++++++++++++++++ fs/ext4/ialloc.c | 24 ++++++++++++++++++++++-- fs/ext4/mballoc.c | 24 ++++++++++++++++++++++-- 4 files changed, 85 insertions(+), 6 deletions(-) diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c index 3cae4c6..c00023f 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__, diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 0844969..9cc8b93 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -19,6 +19,7 @@ #include #include #include +#include #include "ext4_i.h" /* @@ -1357,6 +1358,23 @@ extern int ext4_get_blocks_wrap(handle_t *handle, struct inode *inode, extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, __u64 start, __u64 len); +/* + * Add new method to test wether block and inode bitmaps are properly + * initialized. With uninit_bg reading the block from disk is not enough + * to mark the bitmap uptodate. We need to also zero-out the bitmap + */ +#define BH_BITMAP_UPTODATE BH_JBDPrivateStart + +static inline int bitmap_uptodate(struct buffer_head *bh) +{ + return (buffer_uptodate(bh) && + test_bit(BH_BITMAP_UPTODATE, &(bh)->b_state)); +} +static inline void set_bitmap_uptodate(struct buffer_head *bh) +{ + set_bit(BH_BITMAP_UPTODATE, &(bh)->b_state); +} + #endif /* __KERNEL__ */ #endif /* _EXT4_H */ diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c index d1ccae5..1627868 100644 --- a/fs/ext4/ialloc.c +++ b/fs/ext4/ialloc.c @@ -115,20 +115,40 @@ ext4_read_inode_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_INODE_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_INODE_UNINIT)) { ext4_init_inode_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__, diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 259eef7..5d4105d 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);