From 9810446836ab5a4b34a749bb77f3eb5836f982cc Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Sat, 15 Aug 2015 11:30:31 -0400 Subject: ext4: simplify some code in read_mmp_block() My static check complains because we have: if (!*bh) return -ENOMEM; if (*bh) { The second check is unnecessary. I've simplified this code by moving the "if (!*bh)" checks around. Also Andreas Dilger says we should probably print a warning if sb_getblk() fails. [ Restructured the code so that we print a warning message as well if the mmp block doesn't check out, and to print the error code to disambiguate between the error cases. - TYT ] Reviewed-by: Andreas Dilger Signed-off-by: Dan Carpenter Signed-off-by: Theodore Ts'o --- fs/ext4/mmp.c | 46 +++++++++++++++++++++++++--------------------- 1 file changed, 25 insertions(+), 21 deletions(-) (limited to 'fs/ext4/mmp.c') diff --git a/fs/ext4/mmp.c b/fs/ext4/mmp.c index 8313ca3324ec..048c52af2fb6 100644 --- a/fs/ext4/mmp.c +++ b/fs/ext4/mmp.c @@ -69,6 +69,7 @@ static int read_mmp_block(struct super_block *sb, struct buffer_head **bh, ext4_fsblk_t mmp_block) { struct mmp_struct *mmp; + int ret; if (*bh) clear_buffer_uptodate(*bh); @@ -76,33 +77,36 @@ static int read_mmp_block(struct super_block *sb, struct buffer_head **bh, /* This would be sb_bread(sb, mmp_block), except we need to be sure * that the MD RAID device cache has been bypassed, and that the read * is not blocked in the elevator. */ - if (!*bh) + if (!*bh) { *bh = sb_getblk(sb, mmp_block); - if (!*bh) - return -ENOMEM; - if (*bh) { - get_bh(*bh); - lock_buffer(*bh); - (*bh)->b_end_io = end_buffer_read_sync; - submit_bh(READ_SYNC | REQ_META | REQ_PRIO, *bh); - wait_on_buffer(*bh); - if (!buffer_uptodate(*bh)) { - brelse(*bh); - *bh = NULL; + if (!*bh) { + ret = -ENOMEM; + goto warn_exit; } } - if (unlikely(!*bh)) { - ext4_warning(sb, "Error while reading MMP block %llu", - mmp_block); - return -EIO; + + get_bh(*bh); + lock_buffer(*bh); + (*bh)->b_end_io = end_buffer_read_sync; + submit_bh(READ_SYNC | REQ_META | REQ_PRIO, *bh); + wait_on_buffer(*bh); + if (!buffer_uptodate(*bh)) { + brelse(*bh); + *bh = NULL; + ret = -EIO; + goto warn_exit; } mmp = (struct mmp_struct *)((*bh)->b_data); - if (le32_to_cpu(mmp->mmp_magic) != EXT4_MMP_MAGIC || - !ext4_mmp_csum_verify(sb, mmp)) - return -EINVAL; - - return 0; + if (le32_to_cpu(mmp->mmp_magic) == EXT4_MMP_MAGIC && + ext4_mmp_csum_verify(sb, mmp)) + return 0; + ret = -EINVAL; + +warn_exit: + ext4_warning(sb, "Error %d while reading MMP block %llu", + ret, mmp_block); + return ret; } /* -- cgit v1.2.3