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| author |   Bart Van Assche <bart.vanassche@sandisk.com> | 2017-04-21 12:00:40 -0600 |
|---|---|---|
| committer |   Jens Axboe <axboe@fb.com> | 2017-04-21 12:00:40 -0600 |
| commit | abc25a693091e61537e40dfe24e8ee5deaf08208 (patch) | |
| tree | 556f1ef5612c57fa8ff6370c28011fd3a11b0f19 /block | |
| parent | Merge branch 'nvme-4.12' of git://git.infradead.org/nvme into for-4.12/block (diff) | |
| download | linux-dev-abc25a693091e61537e40dfe24e8ee5deaf08208.tar.xz linux-dev-abc25a693091e61537e40dfe24e8ee5deaf08208.zip | |
blk-mq: Fix preempt count imbalance
Avoid that the following kernel bug gets triggered:
BUG: sleeping function called from invalid context at ./include/linux/buffer_head.h:349
in_atomic(): 1, irqs_disabled(): 0, pid: 8019, name: find
CPU: 10 PID: 8019 Comm: find Tainted: G W I 4.11.0-rc4-dbg+ #2
Call Trace:
dump_stack+0x68/0x93
___might_sleep+0x16e/0x230
__might_sleep+0x4a/0x80
__ext4_get_inode_loc+0x1e0/0x4e0
ext4_iget+0x70/0xbc0
ext4_iget_normal+0x2f/0x40
ext4_lookup+0xb6/0x1f0
lookup_slow+0x104/0x1e0
walk_component+0x19a/0x330
path_lookupat+0x4b/0x100
filename_lookup+0x9a/0x110
user_path_at_empty+0x36/0x40
vfs_statx+0x67/0xc0
SYSC_newfstatat+0x20/0x40
SyS_newfstatat+0xe/0x10
entry_SYSCALL_64_fastpath+0x18/0xad
This happens since the big if/else in blk_mq_make_request() doesn't
have final else section that also drops the ctx. Add that.
Fixes: b00c53e8f411 ("blk-mq: fix schedule-while-atomic with scheduler attached")
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Omar Sandoval <osandov@fb.com>
Added a bit more to the commit log.
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'block')
| -rw-r--r-- | block/blk-mq.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c index 0b2f60407748..e6aad49c1686 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1639,7 +1639,8 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio) } else if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) { blk_mq_put_ctx(data.ctx); blk_mq_run_hw_queue(data.hctx, true); - } + } else + blk_mq_put_ctx(data.ctx); return cookie; } |