linux/drivers/block/loop.c, branch v2.6.38

block: kill loop_mutex

2011-03-03T16:53:25Z

Following steps lead to deadlock in kernel: dd if=/dev/zero of=img bs=512 count=1000 losetup -f img mkfs.ext2 /dev/loop0 mount -t ext2 -o loop /dev/loop0 mnt umount mnt/ Stacktrace: [] irq_exit+0x36/0x59 [] smp_apic_timer_interrupt+0x6b/0x75 [] apic_timer_interrupt+0x31/0x38 [] mutex_spin_on_owner+0x54/0x5b [] lo_release+0x12/0x67 [loop] [] __blkdev_put+0x7c/0x10c [] fput+0xd5/0x1aa [] loop_clr_fd+0x1a9/0x1b1 [loop] [] lo_release+0x39/0x67 [loop] [] __blkdev_put+0x7c/0x10c [] deactivate_locked_super+0x17/0x36 [] sys_umount+0x27e/0x2a5 [] sys_oldumount+0xb/0xe [] sysenter_do_call+0x12/0x26 [] 0xffffffff Regression since 2a48fc0ab24241755dc9, which introduced the private loop_mutex as part of the BKL removal process. As per [1], the mutex can be safely removed. [1] http://www.gossamer-threads.com/lists/linux/kernel/1341930 Addresses: https://bugzilla.novell.com/show_bug.cgi?id=669394 Addresses: https://bugzilla.kernel.org/show_bug.cgi?id=29172 Signed-off-by: Petr Uzel Cc: stable@kernel.org Reviewed-by: Nikanth Karthikesan Acked-by: Arnd Bergmann Signed-off-by: Jens Axboe

loop: queue_lock NULL pointer derefence in blk_throtl_exit

2011-01-19T15:25:02Z

Performing $ sudo mount -o loop -o umask=0 /dev/sdb1 /mnt/ mount: wrong fs type, bad option, bad superblock on /dev/loop0, missing codepage or helper program, or other error In some cases useful info is found in syslog - try dmesg | tail or so $ sudo modprobe -r loop results in oops: BUG: unable to handle kernel NULL pointer dereference at 0000000000000004 IP: [] do_raw_spin_lock+0x14/0x122 Process modprobe (pid: 6189, threadinfo ffff88009a898000, task ffff880154a88000) Call Trace: [] _raw_spin_lock_irq+0x4a/0x51 [] ? blk_throtl_exit+0x3b/0xa0 [] ? cancel_delayed_work_sync+0xd/0xf [] blk_throtl_exit+0x3b/0xa0 [] blk_release_queue+0x21/0x65 [] kobject_release+0x51/0x66 [] ? kobject_release+0x0/0x66 [] kref_put+0x43/0x4d [] kobject_put+0x47/0x4b [] blk_cleanup_queue+0x56/0x5b [] loop_exit+0x68/0x844 [loop] [] sys_delete_module+0x1e8/0x25b [] ? trace_hardirqs_on_thunk+0x3a/0x3f [] system_call_fastpath+0x16/0x1b because of an attempt to acquire NULL queue_lock. I added the same lines as in blk_queue_make_request - index 44e18c0..49e6a54 100644`fall back to embedded per-queue lock'. Signed-off-by: Sergey Senozhatsky Signed-off-by: Andrew Morton Signed-off-by: Jens Axboe

Fix compile warnings due to missing removal of a 'ret' variable

2010-12-20T08:15:19Z

Commit a8adbe3 forgot to remove the return variable, kill it. drivers/block/loop.c: In function 'lo_splice_actor': drivers/block/loop.c:398: warning: unused variable 'ret' [...] fs/nfsd/vfs.c: In function 'nfsd_splice_actor': fs/nfsd/vfs.c:848: warning: unused variable 'ret' Reported-by: Stephen Rothwell Signed-off-by: Jens Axboe

fs/splice: Pull buf->ops->confirm() from splice_from_pipe actors

2010-12-17T07:56:44Z

This patch pulls calls to buf->ops->confirm() from all actors passed (also indirectly) to splice_from_pipe_feed(). Is avoiding the call to buf->ops->confirm() while splice()ing to /dev/null is an intentional optimization? No other user does that and this will remove this special case. Against current linux.git 6313e3c21743cc88bb5bd8aa72948ee1e83937b6. Signed-off-by: Michał Mirosław Signed-off-by: Jens Axboe

block: remove REQ_HARDBARRIER

2010-11-10T13:54:09Z

REQ_HARDBARRIER is dead now, so remove the leftovers. What's left at this point is: - various checks inside the block layer. - sanity checks in bio based drivers. - now unused bio_empty_barrier helper. - Xen blockfront use of BLKIF_OP_WRITE_BARRIER - it's dead for a while, but Xen really needs to sort out it's barrier situaton. - setting of ordered tags in uas - dead code copied from old scsi drivers. - scsi different retry for barriers - it's dead and should have been removed when flushes were converted to FS requests. - blktrace handling of barriers - removed. Someone who knows blktrace better should add support for REQ_FLUSH and REQ_FUA, though. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe

loop: Properly clear sysfs in autoclear mode

2010-10-28T01:51:30Z

In autoclear mode bdev is NULL but the sysfs entry should be destroyed otherwise this warning appears: WARNING: at fs/sysfs/dir.c:451 sysfs_add_one+0x82/0x95() sysfs: cannot create duplicate filename '/devices/virtual/block/loop0/loop' Fixes commit ee86273062cbb310665fe49e1f1937d2cf85b0b9 Signed-off-by: Milan Broz Signed-off-by: Jens Axboe

mm: strictly nested kmap_atomic()

2010-10-26T23:52:08Z

Ensure kmap_atomic() usage is strictly nested Signed-off-by: Peter Zijlstra Reviewed-by: Rik van Riel Acked-by: Chris Metcalf Cc: David Howells Cc: Hugh Dickins Cc: Ingo Molnar Cc: Thomas Gleixner Cc: "H. Peter Anvin" Cc: Steven Rostedt Cc: Russell King Cc: Ralf Baechle Cc: David Miller Cc: Paul Mackerras Cc: Benjamin Herrenschmidt Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'for-2.6.37/barrier' of git://git.kernel.dk/linux-2.6-block

2010-10-23T00:07:18Z

* 'for-2.6.37/barrier' of git://git.kernel.dk/linux-2.6-block: (46 commits) xen-blkfront: disable barrier/flush write support Added blk-lib.c and blk-barrier.c was renamed to blk-flush.c block: remove BLKDEV_IFL_WAIT aic7xxx_old: removed unused 'req' variable block: remove the BH_Eopnotsupp flag block: remove the BLKDEV_IFL_BARRIER flag block: remove the WRITE_BARRIER flag swap: do not send discards as barriers fat: do not send discards as barriers ext4: do not send discards as barriers jbd2: replace barriers with explicit flush / FUA usage jbd2: Modify ASYNC_COMMIT code to not rely on queue draining on barrier jbd: replace barriers with explicit flush / FUA usage nilfs2: replace barriers with explicit flush / FUA usage reiserfs: replace barriers with explicit flush / FUA usage gfs2: replace barriers with explicit flush / FUA usage btrfs: replace barriers with explicit flush / FUA usage xfs: replace barriers with explicit flush / FUA usage block: pass gfp_mask and flags to sb_issue_discard dm: convey that all flushes are processed as empty ...

Merge branch 'for-2.6.37/drivers' of git://git.kernel.dk/linux-2.6-block

2010-10-23T00:03:12Z

* 'for-2.6.37/drivers' of git://git.kernel.dk/linux-2.6-block: (95 commits) cciss: fix PCI IDs for new Smart Array controllers drbd: add race-breaker to drbd_go_diskless drbd: use dynamic_dev_dbg to optionally log uuid changes dynamic_debug.h: Fix dynamic_dev_dbg() macro if CONFIG_DYNAMIC_DEBUG not set drbd: cleanup: change "<= 0" to "== 0" drbd: relax the grace period of the md_sync timer again drbd: add some more explicit drbd_md_sync drbd: drop wrong debug asserts, fix recently introduced race drbd: cleanup useless leftover warn/error printk's drbd: add explicit drbd_md_sync to drbd_resync_finished drbd: Do not log an ASSERT for P_OV_REQUEST packets while C_CONNECTED drbd: fix for possible deadlock on IO error during resync drbd: fix unlikely access after free and list corruption drbd: fix for spurious fullsync (uuids rotated too fast) drbd: allow for explicit resync-finished notifications drbd: preparation commit, using full state in receive_state() drbd: drbd_send_ack_dp must not rely on header information drbd: Fix regression in recv_bm_rle_bits (compressed bitmap) drbd: Fixed a stupid copy and paste error drbd: Allow larger values for c-fill-target. ... Fix up trivial conflict in drivers/block/ataflop.c due to BKL removal

block: autoconvert trivial BKL users to private mutex

2010-10-05T13:01:10Z

The block device drivers have all gained new lock_kernel calls from a recent pushdown, and some of the drivers were already using the BKL before. This turns the BKL into a set of per-driver mutexes. Still need to check whether this is safe to do. file=$1 name=$2 if grep -q lock_kernel ${file} ; then if grep -q 'include.*linux.mutex.h' ${file} ; then sed -i '/include.*/d' ${file} else sed -i 's/include.*.*$/include /g' ${file} fi sed -i ${file} \ -e "/^#include.*linux.mutex.h/,$ { 1,/^$static\|int\|long$/ { /^$static\|int\|long$/istatic DEFINE_MUTEX(${name}_mutex); } }" \ -e "s/$un$*lock_kernel\>[ ]*()/mutex_\1lock(\&${name}_mutex)/g" \ -e '/[ ]*cycle_kernel_lock();/d' else sed -i -e '/include.*\/d' ${file} \ -e '/cycle_kernel_lock()/d' fi Signed-off-by: Arnd Bergmann