From de89de6e0cf4b1eb13f27137cf2aa40d287aabdf Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Mon, 31 Aug 2009 17:00:59 -0400 Subject: [PATCH] ext4: Restore wbc->range_start in ext4_da_writepages() To solve a lock inversion problem, we implement part of the range_cyclic algorithm in ext4_da_writepages(). (See commit 2acf2c26 for more details.) As part of that change wbc->range_start was modified by ext4's writepages function, which causes its callers to get confused since they aren't expecting the filesystem to modify it. The simplest fix is to save and restore wbc->range_start in ext4_da_writepages. Signed-off-by: "Theodore Ts'o" --- fs/ext4/inode.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index d61fb523308f..ff659e757578 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -2749,6 +2749,7 @@ static int ext4_da_writepages(struct address_space *mapping, long pages_skipped; int range_cyclic, cycled = 1, io_done = 0; int needed_blocks, ret = 0, nr_to_writebump = 0; + loff_t range_start = wbc->range_start; struct ext4_sb_info *sbi = EXT4_SB(mapping->host->i_sb); trace_ext4_da_writepages(inode, wbc); @@ -2917,6 +2918,7 @@ out_writepages: if (!no_nrwrite_index_update) wbc->no_nrwrite_index_update = 0; wbc->nr_to_write -= nr_to_writebump; + wbc->range_start = range_start; trace_ext4_da_writepages_result(inode, wbc, ret, pages_written); return ret; } -- 2.30.2