From aef4885ae14f1df75b58395c5314d71f613d26d9 Mon Sep 17 00:00:00 2001 From: Dmitry Monakhov Date: Mon, 13 Oct 2014 03:42:12 -0400 Subject: [PATCH] ext4: move error report out of atomic context in ext4_init_block_bitmap() Error report likely result in IO so it is bad idea to do it from atomic context. This patch should fix following issue: BUG: sleeping function called from invalid context at include/linux/buffer_head.h:349 in_atomic(): 1, irqs_disabled(): 0, pid: 137, name: kworker/u128:1 5 locks held by kworker/u128:1/137: #0: ("writeback"){......}, at: [] process_one_work+0x228/0x4d0 #1: ((&(&wb->dwork)->work)){......}, at: [] process_one_work+0x228/0x4d0 #2: (jbd2_handle){......}, at: [] start_this_handle+0x712/0x7b0 #3: (&ei->i_data_sem){......}, at: [] ext4_map_blocks+0x297/0x430 #4: (&(&bgl->locks[i].lock)->rlock){......}, at: [] ext4_read_block_bitmap_nowait+0x5d0/0x630 CPU: 3 PID: 137 Comm: kworker/u128:1 Not tainted 3.17.0-rc2-00184-g82752e4 #165 Hardware name: Intel Corporation W2600CR/W2600CR, BIOS SE5C600.86B.99.99.x028.061320111235 06/13/2011 Workqueue: writeback bdi_writeback_workfn (flush-1:0) 0000000000000411 ffff880813777288 ffffffff815c7fdc ffff880813777288 ffff880813a8bba0 ffff8808137772a8 ffffffff8108fb30 ffff880803e01e38 ffff880803e01e38 ffff8808137772c8 ffffffff811a8d53 ffff88080ecc6000 Call Trace: [] dump_stack+0x51/0x6d [] __might_sleep+0xf0/0x100 [] __sync_dirty_buffer+0x43/0xe0 [] sync_dirty_buffer+0x13/0x20 [] ext4_commit_super+0x1d1/0x230 [] save_error_info+0x23/0x30 [] __ext4_error+0xb6/0xd0 [] ? ext4_group_desc_csum+0x140/0x190 [] ext4_read_block_bitmap_nowait+0x1dc/0x630 [] ext4_mb_init_cache+0x21a/0x8f0 [] ? lru_cache_add+0x55/0x60 [] ? add_to_page_cache_lru+0x6c/0x80 [] ext4_mb_init_group+0x190/0x280 [] ext4_mb_good_group+0xc1/0x190 [] ext4_mb_regular_allocator+0x17a/0x410 [] ? ext4_mb_use_preallocated+0x31/0x380 [] ? ext4_mb_new_blocks+0x205/0x8e0 [] ? kmem_cache_alloc+0xfc/0x180 [] ext4_mb_new_blocks+0x280/0x8e0 [] ? __kmalloc+0x144/0x1c0 [] ? ext4_find_extent+0x97/0x320 [] ext4_ext_map_blocks+0xbc4/0x1050 [] ? ext4_map_blocks+0x297/0x430 [] ext4_map_blocks+0x2bb/0x430 [] ? ext4_init_io_end+0x23/0x50 [] ext4_writepages+0x564/0xaf0 [] ? _raw_spin_unlock+0x2b/0x40 [] ? lock_release_non_nested+0x2fd/0x3c0 [] ? writeback_sb_inodes+0x10e/0x490 [] ? writeback_sb_inodes+0x10e/0x490 [] do_writepages+0x23/0x40 [] __writeback_single_inode+0x9e/0x280 [] writeback_sb_inodes+0x2db/0x490 [] wb_writeback+0x174/0x2d0 [] ? lock_release_holdtime+0x29/0x190 [] wb_do_writeback+0xa3/0x200 [] bdi_writeback_workfn+0x80/0x230 [] ? process_one_work+0x228/0x4d0 [] process_one_work+0x2dd/0x4d0 [] ? process_one_work+0x228/0x4d0 [] worker_thread+0x35d/0x460 [] ? process_one_work+0x4d0/0x4d0 [] ? process_one_work+0x4d0/0x4d0 [] kthread+0xf5/0x100 [] ? local_clock+0x25/0x30 [] ? __init_kthread_worker+0x70/0x70 [] ret_from_fork+0x7c/0xb0 [] ? __init_kthread_work Signed-off-by: Dmitry Monakhov Signed-off-by: Theodore Ts'o Cc: stable@vger.kernel.org --- fs/ext4/balloc.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c index d70f154f6da3..83a6f497c4e0 100644 --- a/fs/ext4/balloc.c +++ b/fs/ext4/balloc.c @@ -176,7 +176,7 @@ static unsigned int num_clusters_in_group(struct super_block *sb, } /* Initializes an uninitialized block bitmap */ -static void ext4_init_block_bitmap(struct super_block *sb, +static int ext4_init_block_bitmap(struct super_block *sb, struct buffer_head *bh, ext4_group_t block_group, struct ext4_group_desc *gdp) @@ -192,7 +192,6 @@ static void ext4_init_block_bitmap(struct super_block *sb, /* If checksum is bad mark all blocks used to prevent allocation * essentially implementing a per-group read-only flag. */ if (!ext4_group_desc_csum_verify(sb, block_group, gdp)) { - ext4_error(sb, "Checksum bad for group %u", block_group); grp = ext4_get_group_info(sb, block_group); if (!EXT4_MB_GRP_BBITMAP_CORRUPT(grp)) percpu_counter_sub(&sbi->s_freeclusters_counter, @@ -205,7 +204,7 @@ static void ext4_init_block_bitmap(struct super_block *sb, count); } set_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &grp->bb_state); - return; + return -EIO; } memset(bh->b_data, 0, sb->s_blocksize); @@ -243,6 +242,7 @@ static void ext4_init_block_bitmap(struct super_block *sb, sb->s_blocksize * 8, bh->b_data); ext4_block_bitmap_csum_set(sb, block_group, gdp, bh); ext4_group_desc_csum_set(sb, block_group, gdp); + return 0; } /* Return the number of free blocks in a block group. It is used when @@ -438,11 +438,15 @@ ext4_read_block_bitmap_nowait(struct super_block *sb, ext4_group_t block_group) } ext4_lock_group(sb, block_group); if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) { - ext4_init_block_bitmap(sb, bh, block_group, desc); + int err; + + err = ext4_init_block_bitmap(sb, bh, block_group, desc); set_bitmap_uptodate(bh); set_buffer_uptodate(bh); ext4_unlock_group(sb, block_group); unlock_buffer(bh); + if (err) + ext4_error(sb, "Checksum bad for grp %u", block_group); return bh; } ext4_unlock_group(sb, block_group);