diff options
| -rw-r--r-- | fs/ext4/ext4.h | 5 | ||||
| -rw-r--r-- | fs/ext4/super.c | 62 |
2 files changed, 67 insertions, 0 deletions
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 3e31371795cb..199afbf27510 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -2823,6 +2823,11 @@ extern int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count); /* super.c */ extern struct buffer_head *ext4_sb_bread(struct super_block *sb, sector_t block, int op_flags); +extern void ext4_read_bh_nowait(struct buffer_head *bh, int op_flags, + bh_end_io_t *end_io); +extern int ext4_read_bh(struct buffer_head *bh, int op_flags, + bh_end_io_t *end_io); +extern int ext4_read_bh_lock(struct buffer_head *bh, int op_flags, bool wait); extern int ext4_seq_options_show(struct seq_file *seq, void *offset); extern int ext4_calculate_overhead(struct super_block *sb); extern void ext4_superblock_csum_set(struct super_block *sb); diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 6937ab4dfa67..4cfa95abe9dc 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -141,6 +141,68 @@ MODULE_ALIAS_FS("ext3"); MODULE_ALIAS("ext3"); #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type) + +static inline void __ext4_read_bh(struct buffer_head *bh, int op_flags, + bh_end_io_t *end_io) +{ + /* + * buffer's verified bit is no longer valid after reading from + * disk again due to write out error, clear it to make sure we + * recheck the buffer contents. + */ + clear_buffer_verified(bh); + + bh->b_end_io = end_io ? end_io : end_buffer_read_sync; + get_bh(bh); + submit_bh(REQ_OP_READ, op_flags, bh); +} + +void ext4_read_bh_nowait(struct buffer_head *bh, int op_flags, + bh_end_io_t *end_io) +{ + BUG_ON(!buffer_locked(bh)); + + if (ext4_buffer_uptodate(bh)) { + unlock_buffer(bh); + return; + } + __ext4_read_bh(bh, op_flags, end_io); +} + +int ext4_read_bh(struct buffer_head *bh, int op_flags, bh_end_io_t *end_io) +{ + BUG_ON(!buffer_locked(bh)); + + if (ext4_buffer_uptodate(bh)) { + unlock_buffer(bh); + return 0; + } + + __ext4_read_bh(bh, op_flags, end_io); + + wait_on_buffer(bh); + if (buffer_uptodate(bh)) + return 0; + return -EIO; +} + +int ext4_read_bh_lock(struct buffer_head *bh, int op_flags, bool wait) +{ + if (trylock_buffer(bh)) { + if (wait) + return ext4_read_bh(bh, op_flags, NULL); + ext4_read_bh_nowait(bh, op_flags, NULL); + return 0; + } + if (wait) { + wait_on_buffer(bh); + if (buffer_uptodate(bh)) + return 0; + return -EIO; + } + return 0; +} + /* * This works like sb_bread() except it uses ERR_PTR for error * returns. Currently with sb_bread it's impossible to distinguish |