From 5e86bdda41534e17621d5a071b294943cae4376e Mon Sep 17 00:00:00 2001 From: "zhangyi (F)" Date: Sat, 23 Mar 2019 11:56:01 -0400 Subject: [PATCH] ext4: cleanup bh release code in ext4_ind_remove_space() Currently, we are releasing the indirect buffer where we are done with it in ext4_ind_remove_space(), so we can see the brelse() and BUFFER_TRACE() everywhere. It seems fragile and hard to read, and we may probably forget to release the buffer some day. This patch cleans up the code by putting of the code which releases the buffers to the end of the function. Signed-off-by: zhangyi (F) Signed-off-by: Theodore Ts'o Reviewed-by: Jan Kara --- fs/ext4/indirect.c | 47 ++++++++++++++++++++++------------------------ 1 file changed, 22 insertions(+), 25 deletions(-) diff --git a/fs/ext4/indirect.c b/fs/ext4/indirect.c index 02c39524bda2..2024d3fa5504 100644 --- a/fs/ext4/indirect.c +++ b/fs/ext4/indirect.c @@ -1222,6 +1222,7 @@ int ext4_ind_remove_space(handle_t *handle, struct inode *inode, ext4_lblk_t offsets[4], offsets2[4]; Indirect chain[4], chain2[4]; Indirect *partial, *partial2; + Indirect *p = NULL, *p2 = NULL; ext4_lblk_t max_block; __le32 nr = 0, nr2 = 0; int n = 0, n2 = 0; @@ -1263,7 +1264,7 @@ int ext4_ind_remove_space(handle_t *handle, struct inode *inode, } - partial = ext4_find_shared(inode, n, offsets, chain, &nr); + partial = p = ext4_find_shared(inode, n, offsets, chain, &nr); if (nr) { if (partial == chain) { /* Shared branch grows from the inode */ @@ -1288,13 +1289,11 @@ int ext4_ind_remove_space(handle_t *handle, struct inode *inode, partial->p + 1, (__le32 *)partial->bh->b_data+addr_per_block, (chain+n-1) - partial); - BUFFER_TRACE(partial->bh, "call brelse"); - brelse(partial->bh); partial--; } end_range: - partial2 = ext4_find_shared(inode, n2, offsets2, chain2, &nr2); + partial2 = p2 = ext4_find_shared(inode, n2, offsets2, chain2, &nr2); if (nr2) { if (partial2 == chain2) { /* @@ -1324,16 +1323,14 @@ int ext4_ind_remove_space(handle_t *handle, struct inode *inode, (__le32 *)partial2->bh->b_data, partial2->p, (chain2+n2-1) - partial2); - BUFFER_TRACE(partial2->bh, "call brelse"); - brelse(partial2->bh); partial2--; } goto do_indirects; } /* Punch happened within the same level (n == n2) */ - partial = ext4_find_shared(inode, n, offsets, chain, &nr); - partial2 = ext4_find_shared(inode, n2, offsets2, chain2, &nr2); + partial = p = ext4_find_shared(inode, n, offsets, chain, &nr); + partial2 = p2 = ext4_find_shared(inode, n2, offsets2, chain2, &nr2); /* Free top, but only if partial2 isn't its subtree. */ if (nr) { @@ -1390,15 +1387,7 @@ int ext4_ind_remove_space(handle_t *handle, struct inode *inode, partial->p + 1, partial2->p, (chain+n-1) - partial); - while (partial > chain) { - BUFFER_TRACE(partial->bh, "call brelse"); - brelse(partial->bh); - } - while (partial2 > chain2) { - BUFFER_TRACE(partial2->bh, "call brelse"); - brelse(partial2->bh); - } - return 0; + goto cleanup; } /* @@ -1413,8 +1402,6 @@ int ext4_ind_remove_space(handle_t *handle, struct inode *inode, partial->p + 1, (__le32 *)partial->bh->b_data+addr_per_block, (chain+n-1) - partial); - BUFFER_TRACE(partial->bh, "call brelse"); - brelse(partial->bh); partial--; } if (partial2 > chain2 && depth2 <= depth) { @@ -1422,11 +1409,21 @@ int ext4_ind_remove_space(handle_t *handle, struct inode *inode, (__le32 *)partial2->bh->b_data, partial2->p, (chain2+n2-1) - partial2); - BUFFER_TRACE(partial2->bh, "call brelse"); - brelse(partial2->bh); partial2--; } } + +cleanup: + while (p && p > chain) { + BUFFER_TRACE(p->bh, "call brelse"); + brelse(p->bh); + p--; + } + while (p2 && p2 > chain2) { + BUFFER_TRACE(p2->bh, "call brelse"); + brelse(p2->bh); + p2--; + } return 0; do_indirects: @@ -1434,7 +1431,7 @@ int ext4_ind_remove_space(handle_t *handle, struct inode *inode, switch (offsets[0]) { default: if (++n >= n2) - return 0; + break; nr = i_data[EXT4_IND_BLOCK]; if (nr) { ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 1); @@ -1443,7 +1440,7 @@ int ext4_ind_remove_space(handle_t *handle, struct inode *inode, /* fall through */ case EXT4_IND_BLOCK: if (++n >= n2) - return 0; + break; nr = i_data[EXT4_DIND_BLOCK]; if (nr) { ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 2); @@ -1452,7 +1449,7 @@ int ext4_ind_remove_space(handle_t *handle, struct inode *inode, /* fall through */ case EXT4_DIND_BLOCK: if (++n >= n2) - return 0; + break; nr = i_data[EXT4_TIND_BLOCK]; if (nr) { ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 3); @@ -1462,5 +1459,5 @@ int ext4_ind_remove_space(handle_t *handle, struct inode *inode, case EXT4_TIND_BLOCK: ; } - return 0; + goto cleanup; }