From 29bc9cea0e13dc8043c249f5f232b9e0c441ae24 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Wed, 7 Dec 2022 12:27:10 +0100 Subject: [PATCH] ext4: move percpu_rwsem protection into ext4_writepages() Move protection by percpu_rwsem from ext4_do_writepages() to ext4_writepages(). We will not want to grab this protection during transaction commits as that would be prone to deadlocks and the protection is not needed. Move the shutdown state checking as well since we want to be able to complete commit while the shutdown is in progress. Reviewed-by: Ritesh Harjani (IBM) Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20221207112722.22220-7-jack@suse.cz Signed-off-by: Theodore Ts'o --- fs/ext4/inode.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index a023cca..3aa01a9 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -2727,10 +2727,6 @@ static int ext4_do_writepages(struct mpage_da_data *mpd) struct blk_plug plug; bool give_up_on_write = false; - if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb)))) - return -EIO; - - percpu_down_read(&sbi->s_writepages_rwsem); trace_ext4_writepages(inode, wbc); /* @@ -2940,20 +2936,28 @@ unplug: out_writepages: trace_ext4_writepages_result(inode, wbc, ret, nr_to_write - wbc->nr_to_write); - percpu_up_read(&sbi->s_writepages_rwsem); return ret; } static int ext4_writepages(struct address_space *mapping, struct writeback_control *wbc) { + struct super_block *sb = mapping->host->i_sb; struct mpage_da_data mpd = { .inode = mapping->host, .wbc = wbc, .can_map = 1, }; + int ret; + + if (unlikely(ext4_forced_shutdown(EXT4_SB(sb)))) + return -EIO; - return ext4_do_writepages(&mpd); + percpu_down_read(&EXT4_SB(sb)->s_writepages_rwsem); + ret = ext4_do_writepages(&mpd); + percpu_up_read(&EXT4_SB(sb)->s_writepages_rwsem); + + return ret; } static int ext4_dax_writepages(struct address_space *mapping, -- 2.7.4