From 02117b8ae9c0549500119c42375f9e15602bf47e Mon Sep 17 00:00:00 2001 From: Ritesh Harjani Date: Fri, 16 Mar 2018 18:53:53 +0530 Subject: [PATCH] f2fs: Set GF_NOFS in read_cache_page_gfp while doing f2fs_quota_read Quota code itself is serializing the operations by taking mutex_lock. It seems a below deadlock can happen if GF_NOFS is not used in f2fs_quota_read __switch_to+0x88 __schedule+0x5b0 schedule+0x78 schedule_preempt_disabled+0x20 __mutex_lock_slowpath+0xdc //mutex owner is itself mutex_lock+0x2c dquot_commit+0x30 //mutex_lock(&dqopt->dqio_mutex); dqput+0xe0 __dquot_drop+0x80 dquot_drop+0x48 f2fs_evict_inode+0x218 evict+0xa8 dispose_list+0x3c prune_icache_sb+0x58 super_cache_scan+0xf4 do_shrink_slab+0x208 shrink_slab.part.40+0xac shrink_zone+0x1b0 do_try_to_free_pages+0x25c try_to_free_pages+0x164 __alloc_pages_nodemask+0x534 do_read_cache_page+0x6c read_cache_page+0x14 f2fs_quota_read+0xa4 read_blk+0x54 find_tree_dqentry+0xe4 find_tree_dqentry+0xb8 find_tree_dqentry+0xb8 find_tree_dqentry+0xb8 qtree_read_dquot+0x68 v2_read_dquot+0x24 dquot_acquire+0x5c // mutex_lock(&dqopt->dqio_mutex); dqget+0x238 __dquot_initialize+0xd4 dquot_initialize+0x10 dquot_file_open+0x34 f2fs_file_open+0x6c do_dentry_open+0x1e4 vfs_open+0x6c path_openat+0xa20 do_filp_open+0x4c do_sys_open+0x178 Signed-off-by: Ritesh Harjani Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim --- fs/f2fs/super.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index 98b2c7f..0c1fe9b 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -1572,7 +1572,7 @@ static ssize_t f2fs_quota_read(struct super_block *sb, int type, char *data, while (toread > 0) { tocopy = min_t(unsigned long, sb->s_blocksize - offset, toread); repeat: - page = read_mapping_page(mapping, blkidx, NULL); + page = read_cache_page_gfp(mapping, blkidx, GFP_NOFS); if (IS_ERR(page)) { if (PTR_ERR(page) == -ENOMEM) { congestion_wait(BLK_RW_ASYNC, HZ/50); -- 2.7.4