linux-stable.git/block/bio.c, branch linux-5.6.y

fs: move guard_bio_eod() after bio_set_op_attrs

2020-01-09T15:16:12+00:00

Commit 85a8ce62c2ea ("block: add bio_truncate to fix guard_bio_eod")
adds bio_truncate() for handling bio EOD. However, bio_truncate()
doesn't use the passed 'op' parameter from guard_bio_eod's callers.

So bio_trunacate() may retrieve wrong 'op', and zering pages may
not be done for READ bio.

Fixes this issue by moving guard_bio_eod() after bio_set_op_attrs()
in submit_bh_wbc() so that bio_truncate() can always retrieve correct
op info.

Meantime remove the 'op' parameter from guard_bio_eod() because it isn't
used any more.

Cc: Carlos Maiolino 
Cc: linux-fsdevel@vger.kernel.org
Fixes: 85a8ce62c2ea ("block: add bio_truncate to fix guard_bio_eod")
Signed-off-by: Ming Lei 

Fold in kerneldoc and bio_op() change.

Signed-off-by: Jens Axboe

block: add bio_truncate to fix guard_bio_eod

2019-12-28T16:44:56+00:00

Some filesystem, such as vfat, may send bio which crosses device boundary,
and the worse thing is that the IO request starting within device boundaries
can contain more than one segment past EOD.

Commit dce30ca9e3b6 ("fs: fix guard_bio_eod to check for real EOD errors")
tries to fix this issue by returning -EIO for this situation. However,
this way lets fs user code lose chance to handle -EIO, then sync_inodes_sb()
may hang for ever.

Also the current truncating on last segment is dangerous by updating the
last bvec, given bvec table becomes not immutable any more, and fs bio
users may not retrieve the truncated pages via bio_for_each_segment_all() in
its .end_io callback.

Fixes this issue by supporting multi-segment truncating. And the
approach is simpler:

- just update bio size since block layer can make correct bvec with
the updated bio size. Then bvec table becomes really immutable.

- zero all truncated segments for read bio

Cc: Carlos Maiolino 
Cc: linux-fsdevel@vger.kernel.org
Fixed-by: dce30ca9e3b6 ("fs: fix guard_bio_eod to check for real EOD errors")
Reported-by: syzbot+2b9e54155c8c25d8d165@syzkaller.appspotmail.com
Signed-off-by: Ming Lei 
Signed-off-by: Jens Axboe

block: fix "check bi_size overflow before merge"

2019-12-10T05:04:35+00:00

This partially reverts commit e3a5d8e386c3fb973fa75f2403622a8f3640ec06.

Commit e3a5d8e386c3 ("check bi_size overflow before merge") adds a bio_full
check to __bio_try_merge_page.  This will cause __bio_try_merge_page to fail
when the last bi_io_vec has been reached.  Instead, what we want here is only
the bi_size overflow check.

Fixes: e3a5d8e386c3 ("block: check bi_size overflow before merge")
Cc: stable@vger.kernel.org # v5.4+
Reviewed-by: Ming Lei 
Signed-off-by: Andreas Gruenbacher 
Signed-off-by: Jens Axboe

block: fix memleak of bio integrity data

2019-12-05T18:38:36+00:00

7c20f11680a4 ("bio-integrity: stop abusing bi_end_io") moves
bio_integrity_free from bio_uninit() to bio_integrity_verify_fn()
and bio_endio(). This way looks wrong because bio may be freed
without calling bio_endio(), for example, blk_rq_unprep_clone() is
called from dm_mq_queue_rq() when the underlying queue of dm-mpath
is busy.

So memory leak of bio integrity data is caused by commit 7c20f11680a4.

Fixes this issue by re-adding bio_integrity_free() to bio_uninit().

Fixes: 7c20f11680a4 ("bio-integrity: stop abusing bi_end_io")
Reviewed-by: Christoph Hellwig 
Signed-off-by Justin Tee 

Add commit log, and simplify/fix the original patch wroten by Justin.

Signed-off-by: Ming Lei 
Signed-off-by: Jens Axboe

block: check bi_size overflow before merge

2019-11-12T14:26:27+00:00

__bio_try_merge_page() may merge a page to bio without bio_full() check
and cause bi_size overflow.

The overflow typically ends up with sd_init_command() warning on zero
segment request with call trace like this:

    ------------[ cut here ]------------
    WARNING: CPU: 2 PID: 1986 at drivers/scsi/scsi_lib.c:1025 scsi_init_io+0x156/0x180
    CPU: 2 PID: 1986 Comm: kworker/2:1H Kdump: loaded Not tainted 5.4.0-rc7 #1
    Workqueue: kblockd blk_mq_run_work_fn
    RIP: 0010:scsi_init_io+0x156/0x180
    RSP: 0018:ffffa11487663bf0 EFLAGS: 00010246
    RAX: 00000000002be0a0 RBX: ffff8e6e9ff30118 RCX: 0000000000000000
    RDX: 00000000ffffffe1 RSI: 0000000000000000 RDI: ffff8e6e9ff30118
    RBP: ffffa11487663c18 R08: ffffa11487663d28 R09: ffff8e6e9ff30150
    R10: 0000000000000001 R11: 0000000000000000 R12: ffff8e6e9ff30000
    R13: 0000000000000001 R14: ffff8e74a1cf1800 R15: ffff8e6e9ff30000
    FS:  0000000000000000(0000) GS:ffff8e6ea7680000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: 00007fff18cf0fe8 CR3: 0000000659f0a001 CR4: 00000000001606e0
    Call Trace:
     sd_init_command+0x326/0xb40 [sd_mod]
     scsi_queue_rq+0x502/0xaa0
     ? blk_mq_get_driver_tag+0xe7/0x120
     blk_mq_dispatch_rq_list+0x256/0x5a0
     ? elv_rb_del+0x24/0x30
     ? deadline_remove_request+0x7b/0xc0
     blk_mq_do_dispatch_sched+0xa3/0x140
     blk_mq_sched_dispatch_requests+0xfb/0x170
     __blk_mq_run_hw_queue+0x81/0x130
     blk_mq_run_work_fn+0x1b/0x20
     process_one_work+0x179/0x390
     worker_thread+0x4f/0x3e0
     kthread+0x105/0x140
     ? max_active_store+0x80/0x80
     ? kthread_bind+0x20/0x20
     ret_from_fork+0x35/0x40
    ---[ end trace f9036abf5af4a4d3 ]---
    blk_update_request: I/O error, dev sdd, sector 2875552 op 0x1:(WRITE) flags 0x0 phys_seg 0 prio class 0
    XFS (sdd1): writeback error on sector 2875552

__bio_try_merge_page() should check the overflow before actually doing
merge.

Fixes: 07173c3ec276c ("block: enable multipage bvecs")
Reviewed-by: Christoph Hellwig 
Reviewed-by: Ming Lei 
Reviewed-by: Hannes Reinecke 
Signed-off-by: Jun'ichi Nomura 
Signed-off-by: Jens Axboe

block: move same page handling from __bio_add_pc_page to the callers

2019-08-22T13:14:39+00:00

Hiding page refcount manipulation inside a low-level bio helper is
somewhat awkward.  Instead return the same page information to the
callers, where it fits in much better.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

block: create a bio_try_merge_pc_page helper

2019-08-22T13:14:38+00:00

Passsthrough bio handling should be the same as normal bio handling,
except that we need to take hardware limitations into account.  Thus
use the common try_merge implementation after checking the hardware
limits.  This changes behavior in that we now also check segment
and dma boundary settings for same page merges, which is a little
more work but has no effect as those need to be larger than the
page size.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

block: improve the gap check in __bio_add_pc_page

2019-08-22T13:14:36+00:00

If we can add more data into an existing segment we do not create a gap
per definition, so move the check for a gap after the attempt to merge
into the segment.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Johannes Thumshirn 
Signed-off-by: Jens Axboe

block: annotate refault stalls from IO submission

2019-08-14T14:50:01+00:00

psi tracks the time tasks wait for refaulting pages to become
uptodate, but it does not track the time spent submitting the IO. The
submission part can be significant if backing storage is contended or
when cgroup throttling (io.latency) is in effect - a lot of time is
spent in submit_bio(). In that case, we underreport memory pressure.

Annotate submit_bio() to account submission time as memory stall when
the bio is reading userspace workingset pages.

Tested-by: Suren Baghdasaryan 
Signed-off-by: Johannes Weiner 
Signed-off-by: Jens Axboe

block: stop exporting bio_map_kern

2019-08-06T14:20:10+00:00

Now that there no module users left of bio_map_kern, stop exporting the
symbol.

Reviewed-by: Javier González 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Hans Holmberg 
Signed-off-by: Jens Axboe