Messages in this thread Patch in this message | | | From | Chao Yu <> | Subject | [PATCH 1/2] f2fs: reduce region of cp_rwsem covered in f2fs_do_collapse | Date | Thu, 16 Jul 2015 18:18:11 +0800 |
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In f2fs_do_collapse, region cp_rwsem covered is large, since it will be held until all blocks are left shifted, so if we try to collapse small area at the beginning of large file, checkpoint who want to grab writer's lock of cp_rwsem will be delayed for long time.
In order to avoid this condition, altering to lock/unlock cp_rwsem each shift operation.
Signed-off-by: Chao Yu <chao2.yu@samsung.com> --- fs/f2fs/file.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-)
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 963cee0..852535f 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -800,11 +800,11 @@ static int f2fs_do_collapse(struct inode *inode, pgoff_t start, pgoff_t end) pgoff_t nrpages = (i_size_read(inode) + PAGE_SIZE - 1) / PAGE_SIZE; int ret = 0; - f2fs_lock_op(sbi); - for (; end < nrpages; start++, end++) { block_t new_addr, old_addr; + f2fs_lock_op(sbi); + set_new_dnode(&dn, inode, NULL, NULL, 0); ret = get_dnode_of_data(&dn, end, LOOKUP_NODE_RA); if (ret && ret != -ENOENT) { @@ -820,13 +820,16 @@ static int f2fs_do_collapse(struct inode *inode, pgoff_t start, pgoff_t end) if (new_addr == NULL_ADDR) { set_new_dnode(&dn, inode, NULL, NULL, 0); ret = get_dnode_of_data(&dn, start, LOOKUP_NODE_RA); - if (ret && ret != -ENOENT) + if (ret && ret != -ENOENT) { goto out; - else if (ret == -ENOENT) + } else if (ret == -ENOENT) { + f2fs_unlock_op(sbi); continue; + } if (dn.data_blkaddr == NULL_ADDR) { f2fs_put_dnode(&dn); + f2fs_unlock_op(sbi); continue; } else { truncate_data_blocks_range(&dn, 1); @@ -865,8 +868,9 @@ static int f2fs_do_collapse(struct inode *inode, pgoff_t start, pgoff_t end) f2fs_put_dnode(&dn); } + f2fs_unlock_op(sbi); } - ret = 0; + return 0; out: f2fs_unlock_op(sbi); return ret; -- 2.4.2
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