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path: root/drivers/block/loop.c
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2013-06-29move linux/loop.h to drivers/blockAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-05-07block_device_operations->release() should return voidAl Viro
The value passed is 0 in all but "it can never happen" cases (and those only in a couple of drivers) *and* it would've been lost on the way out anyway, even if something tried to pass something meaningful. Just don't bother. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-05-02Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull VFS updates from Al Viro, Misc cleanups all over the place, mainly wrt /proc interfaces (switch create_proc_entry to proc_create(), get rid of the deprecated create_proc_read_entry() in favor of using proc_create_data() and seq_file etc). 7kloc removed. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (204 commits) don't bother with deferred freeing of fdtables proc: Move non-public stuff from linux/proc_fs.h to fs/proc/internal.h proc: Make the PROC_I() and PDE() macros internal to procfs proc: Supply a function to remove a proc entry by PDE take cgroup_open() and cpuset_open() to fs/proc/base.c ppc: Clean up scanlog ppc: Clean up rtas_flash driver somewhat hostap: proc: Use remove_proc_subtree() drm: proc: Use remove_proc_subtree() drm: proc: Use minor->index to label things, not PDE->name drm: Constify drm_proc_list[] zoran: Don't print proc_dir_entry data in debug reiserfs: Don't access the proc_dir_entry in r_open(), r_start() r_show() proc: Supply an accessor for getting the data from a PDE's parent airo: Use remove_proc_subtree() rtl8192u: Don't need to save device proc dir PDE rtl8187se: Use a dir under /proc/net/r8180/ proc: Add proc_mkdir_data() proc: Move some bits from linux/proc_fs.h to linux/{of.h,signal.h,tty.h} proc: Move PDE_NET() to fs/proc/proc_net.c ...
2013-04-09Merge tag 'for-linus-20130409' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block fixes from Jens Axboe: "I've got a few smaller fixes queued up for 3.9 that should go in. The major one is the loop regression, the others are nice fixes on their own though. It contains: - Fix for unitialized var in the block sysfs code, courtesy of Arnd and gcc-4.8. - Two fixes for mtip32xx, fixing probe and command timeout. Also a debug measure that could have waited for 3.10, but it's driver only, so I let it slip in. - Revert the loop partition cleanup fix, it could cause a deadlock on auto-teardown as part of umount. The fix is clear, but at this point we just want to revert it and get a real fix in for 3.10." * tag 'for-linus-20130409' of git://git.kernel.dk/linux-block: Revert "loop: cleanup partitions when detaching loop device" mtip32xx: fix two smatch warnings mtip32xx: Add debugfs entry device_status mtip32xx: return 0 from pci probe in case of rebuild mtip32xx: recovery from command timeout block: avoid using uninitialized value in from queue_var_store
2013-04-09lift sb_start_write() out of ->write()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-04-08Revert "loop: cleanup partitions when detaching loop device"Jens Axboe
This reverts commit 8761a3dc1f07b163414e2215a2cadbb4cfe2a107. There are situations where the destruction path is called with the bdev->bd_mutex already held, which then deadlocks in loop_clr_fd(). The normal partition cleanup does a trylock() on the mutex, but it'd be nice to have a more bullet proof method in loop. So punt this more involved fix to the next merge window, and just back out this buggy fix for now. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-04-01loop: prevent bdev freeing while device in useAnatol Pomozov
struct block_device lifecycle is defined by its inode (see fs/block_dev.c) - block_device allocated first time we access /dev/loopXX and deallocated on bdev_destroy_inode. When we create the device "losetup /dev/loopXX afile" we want that block_device stay alive until we destroy the loop device with "losetup -d". But because we do not hold /dev/loopXX inode its counter goes 0, and inode/bdev can be destroyed at any moment. Usually it happens at memory pressure or when user drops inode cache (like in the test below). When later in loop_clr_fd() we want to use bdev we have use-after-free error with following stack: BUG: unable to handle kernel NULL pointer dereference at 0000000000000280 bd_set_size+0x10/0xa0 loop_clr_fd+0x1f8/0x420 [loop] lo_ioctl+0x200/0x7e0 [loop] lo_compat_ioctl+0x47/0xe0 [loop] compat_blkdev_ioctl+0x341/0x1290 do_filp_open+0x42/0xa0 compat_sys_ioctl+0xc1/0xf20 do_sys_open+0x16e/0x1d0 sysenter_dispatch+0x7/0x1a To prevent use-after-free we need to grab the device in loop_set_fd() and put it later in loop_clr_fd(). The issue is reprodusible on current Linus head and v3.3. Here is the test: dd if=/dev/zero of=loop.file bs=1M count=1 while [ true ]; do losetup /dev/loop0 loop.file echo 2 > /proc/sys/vm/drop_caches losetup -d /dev/loop0 done [ Doing bdgrab/bput in loop_set_fd/loop_clr_fd is safe, because every time we call loop_set_fd() we check that loop_device->lo_state is Lo_unbound and set it to Lo_bound If somebody will try to set_fd again it will get EBUSY. And if we try to loop_clr_fd() on unbound loop device we'll get ENXIO. loop_set_fd/loop_clr_fd (and any other loop ioctl) is called under loop_device->lo_ctl_mutex. ] Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-03-22loop: cleanup partitions when detaching loop devicePhillip Susi
Any partitions added by user space to the loop device were being left in place after detaching the loop device. This was because the detach path issued a BLKRRPART to clean up partitions if LO_FLAGS_PARTSCAN was set, meaning that the partitions were auto scanned on attach. Replace this BLKRRPART with code that unconditionally cleans up partitions on detach instead. Signed-off-by: Phillip Susi <psusi@ubuntu.com> Modified by Jens to export delete_partition(). Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-03-22loop: fix error return code in loop_add()Wei Yongjun
Fix to return a negative error code from the error handling case, as returned elsewhere in this function. Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-02-28Merge branch 'for-3.9/drivers' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block driver bits from Jens Axboe: "After the block IO core bits are in, please grab the driver updates from below as well. It contains: - Fix ancient regression in dac960. Nobody must be using that anymore... - Some good fixes from Guo Ghao for loop, fixing both potential oopses and deadlocks. - Improve mtip32xx for NUMA systems, by being a bit more clever in distributing work. - Add IBM RamSan 70/80 driver. A second round of fixes for that is pending, that will come in through for-linus during the 3.9 cycle as per usual. - A few xen-blk{back,front} fixes from Konrad and Roger. - Other minor fixes and improvements." * 'for-3.9/drivers' of git://git.kernel.dk/linux-block: loopdev: ignore negative offset when calculate loop device size loopdev: remove an user triggerable oops loopdev: move common code into loop_figure_size() loopdev: update block device size in loop_set_status() loopdev: fix a deadlock xen-blkback: use balloon pages for persistent grants xen-blkfront: drop the use of llist_for_each_entry_safe xen/blkback: Don't trust the handle from the frontend. xen-blkback: do not leak mode property block: IBM RamSan 70/80 driver fixes rsxx: add slab.h include to dma.c drivers/block/mtip32xx: add missing GENERIC_HARDIRQS dependency block: remove new __devinit/exit annotations on ramsam driver block: IBM RamSan 70/80 device driver drivers/block/mtip32xx/mtip32xx.c:1726:5: sparse: symbol 'mtip_send_trim' was not declared. Should it be static? drivers/block/mtip32xx/mtip32xx.c:4029:1: sparse: symbol 'mtip_workq_sdbf0' was not declared. Should it be static? dac960: return success instead of -ENOTTY mtip32xx: add trim support mtip32xx: Add workqueue and NUMA support block: delete super ancient PC-XT driver for 1980's hardware
2013-02-28block/loop: convert to idr_alloc()Tejun Heo
Convert to the much saner new idr interface. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-28block/loop: don't use idr_remove_all()Tejun Heo
idr_destroy() can destroy idr by itself and idr_remove_all() is being deprecated. Drop its usage. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-26switch vfs_getattr() to struct pathAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-22loopdev: ignore negative offset when calculate loop device sizeGuo Chao
Negative offset may cause loop device size larger than backing file size. $ fallocate -l 1M a $ losetup --offset 0xffffffffffff0000 /dev/loop0 a $ blockdev --getsize64 /dev/loop0 1114112 $ ls -l a -rw-r--r-- 1 root root 1048576 Jan 23 12:46 a $ cat /dev/loop0 cat: /dev/loop0: Input/output error It makes no sense to do that. Only apply offset when it's positive. Fix a typo in the comment by the way. Signed-off-by: Guo Chao <yan@linux.vnet.ibm.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Guo Chao <yan@linux.vnet.ibm.com> Cc: M. Hindess <hindessm@uk.ibm.com> Cc: Nikanth Karthikesan <knikanth@suse.de> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-02-22loopdev: remove an user triggerable oopsGuo Chao
When loopdev is built as module and we pass an invalid parameter, loop_init() will return directly without deregister misc device, which will cause an oops when insert loop module next time because we left some garbage in the misc device list. Test case: sudo modprobe loop max_part=1024 (failed due to invalid parameter) sudo modprobe loop (oops) Clean up nicely to avoid such oops. Signed-off-by: Guo Chao <yan@linux.vnet.ibm.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Guo Chao <yan@linux.vnet.ibm.com> Cc: M. Hindess <hindessm@uk.ibm.com> Cc: Nikanth Karthikesan <knikanth@suse.de> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-02-22loopdev: move common code into loop_figure_size()Guo Chao
Update block device size in accord with gendisk size and let userspace know the change in loop_figure_size(). This is a clean up to remove common code of loop_figure_size()'s two callers. Signed-off-by: Guo Chao <yan@linux.vnet.ibm.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Guo Chao <yan@linux.vnet.ibm.com> Cc: M. Hindess <hindessm@uk.ibm.com> Cc: Nikanth Karthikesan <knikanth@suse.de> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-02-22loopdev: update block device size in loop_set_status()Guo Chao
Loop device driver sometimes fails to impose the size limit on the device. Keep issuing following two commands: losetup --offset 7517244416 --sizelimit 3224971264 /dev/loop0 backed_file blockdev --getsize64 /dev/loop0 blockdev reports file size instead of sizelimit several out of 100 times. The problems are: - losetup set up the device in two ioctl: LOOP_SET_FD and LOOP_SET_STATUS64. - LOOP_SET_STATUS64 only update size of gendisk. Block device size will be updated lazily when device comes to use. If udev rushes in between the two ioctl, it will bring in a block device whose size is backing file size. If the device is not released after LOOP_SET_STATUS64 ioctl, blockdev will not see the updated size. Update block size in LOOP_SET_STATUS64 ioctl. Signed-off-by: Guo Chao <yan@linux.vnet.ibm.com> Reported-by: M. Hindess <hindessm@uk.ibm.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Guo Chao <yan@linux.vnet.ibm.com> Cc: Nikanth Karthikesan <knikanth@suse.de> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-02-22loopdev: fix a deadlockGuo Chao
bd_mutex and lo_ctl_mutex can be held in different order. Path #1: blkdev_open blkdev_get __blkdev_get (hold bd_mutex) lo_open (hold lo_ctl_mutex) Path #2: blkdev_ioctl lo_ioctl (hold lo_ctl_mutex) lo_set_capacity (hold bd_mutex) Lockdep does not report it, because path #2 actually holds a subclass of lo_ctl_mutex. This subclass seems creep into the code by mistake. The patch author actually just mentioned it in the changelog, see commit f028f3b2 ("loop: fix circular locking in loop_clr_fd()"), also see: http://marc.info/?l=linux-kernel&m=123806169129727&w=2 Path #2 hold bd_mutex to call bd_set_size(), I've protected it with i_mutex in a previous patch, so drop bd_mutex at this site. Signed-off-by: Guo Chao <yan@linux.vnet.ibm.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Guo Chao <yan@linux.vnet.ibm.com> Cc: M. Hindess <hindessm@uk.ibm.com> Cc: Nikanth Karthikesan <knikanth@suse.de> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-12-17Merge branch 'for-3.8/drivers' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block driver update from Jens Axboe: "Now that the core bits are in, here are the driver bits for 3.8. The branch contains: - A huge pile of drbd bits that were dumped from the 3.7 merge window. Following that, it was both made perfectly clear that there is going to be no more over-the-wall pulls and how the situation on individual pulls can be improved. - A few cleanups from Akinobu Mita for drbd and cciss. - Queue improvement for loop from Lukas. This grew into adding a generic interface for waiting/checking an even with a specific lock, allowing this to be pulled out of md and now loop and drbd is also using it. - A few fixes for xen back/front block driver from Roger Pau Monne. - Partition improvements from Stephen Warren, allowing partiion UUID to be used as an identifier." * 'for-3.8/drivers' of git://git.kernel.dk/linux-block: (609 commits) drbd: update Kconfig to match current dependencies drbd: Fix drbdsetup wait-connect, wait-sync etc... commands drbd: close race between drbd_set_role and drbd_connect drbd: respect no-md-barriers setting also when changed online via disk-options drbd: Remove obsolete check drbd: fixup after wait_even_lock_irq() addition to generic code loop: Limit the number of requests in the bio list wait: add wait_event_lock_irq() interface xen-blkfront: free allocated page xen-blkback: move free persistent grants code block: partition: msdos: provide UUIDs for partitions init: reduce PARTUUID min length to 1 from 36 block: store partition_meta_info.uuid as a string cciss: use check_signature() cciss: cleanup bitops usage drbd: use copy_highpage drbd: if the replication link breaks during handshake, keep retrying drbd: check return of kmalloc in receive_uuids drbd: Broadcast sync progress no more often than once per second drbd: don't try to clear bits once the disk has failed ...
2012-11-30loop: Limit the number of requests in the bio listLukas Czerner
Currently there is not limitation of number of requests in the loop bio list. This can lead into some nasty situations when the caller spawns tons of bio requests taking huge amount of memory. This is even more obvious with discard where blkdev_issue_discard() will submit all bios for the range and wait for them to finish afterwards. On really big loop devices and slow backing file system this can lead to OOM situation as reported by Dave Chinner. With this patch we will wait in loop_make_request() if the number of bios in the loop bio list would exceed 'nr_congestion_on'. We'll wake up the process as we process the bios form the list. Some threshold hysteresis is in place to avoid high frequency oscillation. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Reported-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-10-30loop: Make explicit loop device destruction lazyDave Chinner
xfstests has always had random failures of tests due to loop devices failing to be torn down and hence leaving filesytems that cannot be unmounted. This causes test runs to immediately stop. Over the past 6 or 7 years we've added hacks like explicit unmount -d commands for loop mounts, losetup -d after unmount -d fails, etc, but still the problems persist. Recently, the frequency of loop related failures increased again to the point that xfstests 259 will reliably fail with a stray loop device that was not torn down. That is despite the fact the test is above as simple as it gets - loop 5 or 6 times running mkfs.xfs with different paramters: lofile=$(losetup -f) losetup $lofile "$testfile" "$MKFS_XFS_PROG" -b size=512 $lofile >/dev/null || echo "mkfs failed!" sync losetup -d $lofile And losteup -d $lofile is failing with EBUSY on 1-3 of these loops every time the test is run. Turns out that blkid is running simultaneously with losetup -d, and so it sees an elevated reference count and returns EBUSY. But why is blkid running? It's obvious, isn't it? udev has decided to try and find out what is on the block device as a result of a creation notification. And it is racing with mkfs, so might still be scanning the device when mkfs finishes and we try to tear it down. So, make losetup -d force autoremove behaviour. That is, when the last reference goes away, tear down the device. xfstests wants it *gone*, not causing random teardown failures when we know that all the operations the tests have specifically run on the device have completed and are no longer referencing the loop device. Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-09-21userns: Convert loop to use kuid_t instead of uid_tEric W. Biederman
Cc: Jens Axboe <jaxboe@fusionio.com> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-07-14blk: fix wrong idr_pre_get() error check in loop.cSilva Paulo
The idr_pre_get() function never returns a value < 0. It returns 0 (no memory) or 1 (OK). Reported-by: Silva Paulo <psdasilva@yahoo.com> [ Rewrote Silva's patch, but attributing it to Silva anyway - Linus ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-20block: remove the second argument of k[un]map_atomic()Cong Wang
Signed-off-by: Cong Wang <amwang@redhat.com>
2012-02-08loop: zero fill bio instead of return -EIO for partial readDave Young
commit 8268f5a741 ("deny partial write for loop dev fd") tried to fix the loop device partial read information leak problem. But it changed the semantics of read behavior. When we read beyond the end of the device we should get 0 bytes, which is normal behavior, we should not just return -EIO Instead of returning -EIO, zero out the bio to avoid information leak in case of partail read. Signed-off-by: Dave Young <dyoung@redhat.com> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Tested-by: Jeff Moyer <jmoyer@redhat.com> Cc: Dmitry Monakhov <dmonakhov@sw.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-01-04fs: move code out of buffer.cAl Viro
Move invalidate_bdev, block_sync_page into fs/block_dev.c. Export kill_bdev as well, so brd doesn't have to open code it. Reduce buffer_head.h requirement accordingly. Removed a rather large comment from invalidate_bdev, as it looked a bit obsolete to bother moving. The small comment replacing it says enough. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-12-02loop: Fix discard_alignment default settingLukas Czerner
discard_alignment is not relevant to the loop driver since it is supposed to be set as a workaround for the old sector 63 alignments. So set it to zero rather than block size. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Reported-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2011-11-25loop: fix loop block driver discard and encryption commentDave Young
The loop driver does not support discard if encryption is enabled, fix the comment. Signed-off-by: Dave Young <dyoung@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2011-11-16loop: cleanup set_status interfaceDmitry Monakhov
1) Anyone who has read access to loopdev has permission to call set_status and may change important parameters such as lo_offset, lo_sizelimit and so on, which contradicts to read access pattern and definitely equals to write access pattern. 2) Add lo_offset over i_size check to prevent blkdev_size overflow. ##Testcase_bagin #dd if=/dev/zero of=./file bs=1k count=1 #losetup /dev/loop0 ./file /* userspace_application */ struct loop_info64 loinf; fd = open("/dev/loop0", O_RDONLY); ioctl(fd, LOOP_GET_STATUS64, &loinf); /* Set offset to any value which is bigger than i_size, and sizelimit * to nonzero value*/ loinf.lo_offset = 4096*1024; loinf.lo_sizelimit = 1024; ioctl(fd, LOOP_SET_STATUS64, &loinf); /* After this loop device will have size similar to 0x7fffffffffxxxx */ #blockdev --getsz /dev/loop0 ##OUTPUT: 36028797018955968 ##Testcase_end [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2011-11-16loop: prevent information leak after failed readDmitry Monakhov
If read was not fully successful we have to fail whole bio to prevent information leak of old pages ##Testcase_begin dd if=/dev/zero of=./file bs=1M count=1 losetup /dev/loop0 ./file -o 4096 truncate -s 0 ./file # OOps loop offset is now beyond i_size, so read will silently fail. # So bio's pages would not be cleared, may which result in information leak. hexdump -C /dev/loop0 ##testcase_end Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2011-11-05Merge branch 'for-3.2/drivers' of git://git.kernel.dk/linux-blockLinus Torvalds
* 'for-3.2/drivers' of git://git.kernel.dk/linux-block: (30 commits) virtio-blk: use ida to allocate disk index hpsa: add small delay when using PCI Power Management to reset for kump cciss: add small delay when using PCI Power Management to reset for kump xen/blkback: Fix two races in the handling of barrier requests. xen/blkback: Check for proper operation. xen/blkback: Fix the inhibition to map pages when discarding sector ranges. xen/blkback: Report VBD_WSECT (wr_sect) properly. xen/blkback: Support 'feature-barrier' aka old-style BARRIER requests. xen-blkfront: plug device number leak in xlblk_init() error path xen-blkfront: If no barrier or flush is supported, use invalid operation. xen-blkback: use kzalloc() in favor of kmalloc()+memset() xen-blkback: fixed indentation and comments xen-blkfront: fix a deadlock while handling discard response xen-blkfront: Handle discard requests. xen-blkback: Implement discard requests ('feature-discard') xen-blkfront: add BLKIF_OP_DISCARD and discard request struct drivers/block/loop.c: remove unnecessary bdev argument from loop_clr_fd() drivers/block/loop.c: emit uevent on auto release drivers/block/cpqarray.c: use pci_dev->revision loop: always allow userspace partitions and optionally support automatic scanning ... Fic up trivial header file includsion conflict in drivers/block/loop.c
2011-10-24Merge branch 'for-linus' into for-3.2/coreJens Axboe
2011-10-19Merge branch 'v3.1-rc10' into for-3.2/coreJens Axboe
Conflicts: block/blk-core.c include/linux/blkdev.h Signed-off-by: Jens Axboe <axboe@kernel.dk>
2011-10-17loop: remove the incorrect write_begin/write_end shortcutChristoph Hellwig
Currently the loop device tries to call directly into write_begin/write_end instead of going through ->write if it can. This is a fairly nasty shortcut as write_begin and write_end are only callbacks for the generic write code and expect to be called with filesystem specific locks held. This code currently causes various issues for clustered filesystems as it doesn't take the required cluster locks, and it also causes issues for XFS as it doesn't properly lock against the swapext ioctl as called by the defragmentation tools. This in case causes data corruption if defragmentation hits a busy loop device in the wrong time window, as reported by RH QA. The reason why we have this shortcut is that it saves a data copy when doing a transformation on the loop device, which is the technical term for using cryptoloop (or an XOR transformation). Given that cryptoloop has been deprecated in favour of dm-crypt my opinion is that we should simply drop this shortcut instead of finding complicated ways to to introduce a formal interface for this shortcut. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2011-09-21drivers/block/loop.c: remove unnecessary bdev argument from loop_clr_fd()Ayan George
If the loop device is associated (lo->lo_state == Lo_bound), it will have a valid bdev pointed to by lo->lo_device. There is no reason to ever pass an additional block_device pointer. Signed-off-by: Ayan George <ayan.george@canonical.com> Cc: Phillip Susi <psusi@cfl.rr.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@google.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2011-09-21drivers/block/loop.c: emit uevent on auto releasePhillip Susi
The loopback driver failed to emit the change uevent when auto releasing the device. Fixed lo_release() to pass the bdev to loop_clr_fd() so it can emit the event. Signed-off-by: Phillip Susi <psusi@cfl.rr.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Ayan George <ayan@ayan.net> Signed-off-by: Andrew Morton <akpm@google.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2011-09-12block: remove support for bio remapping from ->make_requestChristoph Hellwig
There is very little benefit in allowing to let a ->make_request instance update the bios device and sector and loop around it in __generic_make_request when we can archive the same through calling generic_make_request from the driver and letting the loop in generic_make_request handle it. Note that various drivers got the return value from ->make_request and returned non-zero values for errors. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: NeilBrown <neilb@suse.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-08-23loop: always allow userspace partitions and optionally support automatic ↵Kay Sievers
scanning Automatic partition scanning can be requested individually per loop device during its setup by setting LO_FLAGS_PARTSCAN. By default, no partition tables are scanned. Userspace can now always add and remove partitions from all loop devices, regardless if the in-kernel partition scanner is enabled or not. The needed partition minor numbers are allocated from the extended minors space, the main loop device numbers will continue to match the loop minors, regardless of the number of partitions used. # grep . /sys/class/block/loop1/loop/* /sys/block/loop1/loop/autoclear:0 /sys/block/loop1/loop/backing_file:/home/kay/data/stuff/part.img /sys/block/loop1/loop/offset:0 /sys/block/loop1/loop/partscan:1 /sys/block/loop1/loop/sizelimit:0 # ls -l /dev/loop* brw-rw---- 1 root disk 7, 0 Aug 14 20:22 /dev/loop0 brw-rw---- 1 root disk 7, 1 Aug 14 20:23 /dev/loop1 brw-rw---- 1 root disk 259, 0 Aug 14 20:23 /dev/loop1p1 brw-rw---- 1 root disk 259, 1 Aug 14 20:23 /dev/loop1p2 brw-rw---- 1 root disk 7, 99 Aug 14 20:23 /dev/loop99 brw-rw---- 1 root disk 259, 2 Aug 14 20:23 /dev/loop99p1 brw-rw---- 1 root disk 259, 3 Aug 14 20:23 /dev/loop99p2 crw------T 1 root root 10, 237 Aug 14 20:22 /dev/loop-control Cc: Karel Zak <kzak@redhat.com> Cc: Davidlohr Bueso <dave@gnu.org> Acked-By: Tejun Heo <tj@kernel.org> Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-08-19loop: add discard support for loop devicesLukas Czerner
This commit adds discard support for loop devices. Discard is usually supported by SSD and thinly provisioned devices as a method for reclaiming unused space. This is no different than trying to reclaim back space which is not used by the file system on the image, but it still occupies space on the host file system. We can do the reclamation on file system which does support hole punching. So when discard request gets to the loop driver we can translate that to punch a hole to the underlying file, hence reclaim the free space. This is very useful for trimming down the size of the image to only what is really used by the file system on that image. Fstrim may be used for that purpose. It has been tested on ext4, xfs and btrfs with the image file systems ext4, ext3, xfs and btrfs. ext4, or ext6 image on ext4 file system has some problems but it seems that ext4 punch hole implementation is somewhat flawed and it is unrelated to this commit. Also this is a very good method of validating file systems punch hole implementation. Note that when encryption is used, discard support is disabled, because using it might leak some information useful for possible attacker. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-07-31loop: fix deadlock when sysfs and LOOP_CLR_FD race against each otherKay Sievers
LOOP_CLR_FD takes lo->lo_ctl_mutex and tries to remove the loop sysfs files. Sysfs calls show() and waits for lo->lo_ctl_mutex. LOOP_CLR_FD waits for show() to finish to remove the sysfs file. cat /sys/class/block/loop0/loop/backing_file mutex_lock_nested+0x176/0x350 ? loop_attr_do_show_backing_file+0x2f/0xd0 [loop] ? loop_attr_do_show_backing_file+0x2f/0xd0 [loop] loop_attr_do_show_backing_file+0x2f/0xd0 [loop] dev_attr_show+0x1b/0x60 ? sysfs_read_file+0x86/0x1a0 ? __get_free_pages+0x12/0x50 sysfs_read_file+0xaf/0x1a0 ioctl(LOOP_CLR_FD): wait_for_common+0x12c/0x180 ? try_to_wake_up+0x2a0/0x2a0 wait_for_completion+0x18/0x20 sysfs_deactivate+0x178/0x180 ? sysfs_addrm_finish+0x43/0x70 ? sysfs_addrm_start+0x1d/0x20 sysfs_addrm_finish+0x43/0x70 sysfs_hash_and_remove+0x85/0xa0 sysfs_remove_group+0x59/0x100 loop_clr_fd+0x1dc/0x3f0 [loop] lo_ioctl+0x223/0x7a0 [loop] Instead of taking the lo_ctl_mutex from sysfs code, take the inner lo->lo_lock, to protect the access to the backing_file data. Thanks to Tejun for help debugging and finding a solution. Cc: Milan Broz <mbroz@redhat.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Cc: stable@kernel.org Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-07-31loop: add BLK_DEV_LOOP_MIN_COUNT=%i to allow distros 0 pre-allocated loop ↵Kay Sievers
devices Instead of unconditionally creating a fixed number of dead loop devices which need to be investigated by storage handling services, even when they are never used, we allow distros start with 0 loop devices and have losetup(8) and similar switch to the dynamic /dev/loop-control interface instead of searching /dev/loop%i for free devices. Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-07-31loop: add management interface for on-demand device allocationKay Sievers
Loop devices today have a fixed pre-allocated number of usually 8. The number can only be changed at module init time. To find a free device to use, /dev/loop%i needs to be scanned, and all devices need to be opened until a free one is possibly found. This adds a new /dev/loop-control device node, that allows to dynamically find or allocate a free device, and to add and remove loop devices from the running system: LOOP_CTL_ADD adds a specific device. Arg is the number of the device. It returns the device i or a negative error code. LOOP_CTL_REMOVE removes a specific device, Arg is the number the device. It returns the device i or a negative error code. LOOP_CTL_GET_FREE finds the next unbound device or allocates a new one. No arg is given. It returns the device i or a negative error code. The loop kernel module gets automatically loaded when /dev/loop-control is accessed the first time. The alias specified in the module, instructs udev to create this 'dead' device node, even when the module is not loaded. Example: cfd = open("/dev/loop-control", O_RDWR); # add a new specific loop device err = ioctl(cfd, LOOP_CTL_ADD, devnr); # remove a specific loop device err = ioctl(cfd, LOOP_CTL_REMOVE, devnr); # find or allocate a free loop device to use devnr = ioctl(cfd, LOOP_CTL_GET_FREE); sprintf(loopname, "/dev/loop%i", devnr); ffd = open("backing-file", O_RDWR); lfd = open(loopname, O_RDWR); err = ioctl(lfd, LOOP_SET_FD, ffd); Cc: Tejun Heo <tj@kernel.org> Cc: Karel Zak <kzak@redhat.com> Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-07-31loop: replace linked list of allocated devices with an idr indexKay Sievers
Replace the linked list, that keeps track of allocated devices, with an idr index to allow a more efficient lookup of devices. Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-05-27loop: export module parametersNamhyung Kim
Export 'max_loop' and 'max_part' parameters to sysfs so user can know that how many devices are allowed and how many partitions are supported. If 'max_loop' is 0, there is no restriction on the number of loop devices. User can create/use the devices as many as minor numbers available. If 'max_part' is 0, it means simply the device doesn't support partitioning. Also note that 'max_part' can be adjusted to power of 2 minus 1 form if needed. User should check this value after the module loading if he/she want to use that number correctly (i.e. fdisk, mknod, etc.). Signed-off-by: Namhyung Kim <namhyung@gmail.com> Cc: Laurent Vivier <Laurent.Vivier@bull.net> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-05-24loop: handle on-demand devices correctlyNamhyung Kim
When finding or allocating a loop device, loop_probe() did not take partition numbers into account so that it can result to a different device. Consider following example: $ sudo modprobe loop max_part=15 $ ls -l /dev/loop* brw-rw---- 1 root disk 7, 0 2011-05-24 22:16 /dev/loop0 brw-rw---- 1 root disk 7, 16 2011-05-24 22:16 /dev/loop1 brw-rw---- 1 root disk 7, 32 2011-05-24 22:16 /dev/loop2 brw-rw---- 1 root disk 7, 48 2011-05-24 22:16 /dev/loop3 brw-rw---- 1 root disk 7, 64 2011-05-24 22:16 /dev/loop4 brw-rw---- 1 root disk 7, 80 2011-05-24 22:16 /dev/loop5 brw-rw---- 1 root disk 7, 96 2011-05-24 22:16 /dev/loop6 brw-rw---- 1 root disk 7, 112 2011-05-24 22:16 /dev/loop7 $ sudo mknod /dev/loop8 b 7 128 $ sudo losetup /dev/loop8 ~/temp/disk-with-3-parts.img $ sudo losetup -a /dev/loop128: [0805]:278201 (/home/namhyung/temp/disk-with-3-parts.img) $ ls -l /dev/loop* brw-rw---- 1 root disk 7, 0 2011-05-24 22:16 /dev/loop0 brw-rw---- 1 root disk 7, 16 2011-05-24 22:16 /dev/loop1 brw-rw---- 1 root disk 7, 2048 2011-05-24 22:18 /dev/loop128 brw-rw---- 1 root disk 7, 2049 2011-05-24 22:18 /dev/loop128p1 brw-rw---- 1 root disk 7, 2050 2011-05-24 22:18 /dev/loop128p2 brw-rw---- 1 root disk 7, 2051 2011-05-24 22:18 /dev/loop128p3 brw-rw---- 1 root disk 7, 32 2011-05-24 22:16 /dev/loop2 brw-rw---- 1 root disk 7, 48 2011-05-24 22:16 /dev/loop3 brw-rw---- 1 root disk 7, 64 2011-05-24 22:16 /dev/loop4 brw-rw---- 1 root disk 7, 80 2011-05-24 22:16 /dev/loop5 brw-rw---- 1 root disk 7, 96 2011-05-24 22:16 /dev/loop6 brw-rw---- 1 root disk 7, 112 2011-05-24 22:16 /dev/loop7 brw-r--r-- 1 root root 7, 128 2011-05-24 22:17 /dev/loop8 After this patch, /dev/loop8 - instead of /dev/loop128 - was accessed correctly. In addition, 'range' passed to blk_register_region() should include all range of dev_t that LOOP_MAJOR can address. It does not need to be limited by partition numbers unless 'max_loop' param was specified. Signed-off-by: Namhyung Kim <namhyung@gmail.com> Cc: Laurent Vivier <Laurent.Vivier@bull.net> Cc: stable@kernel.org Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-05-24loop: limit 'max_part' module param to DISK_MAX_PARTSNamhyung Kim
The 'max_part' parameter controls the number of maximum partition a loop block device can have. However if a user specifies very large value it would exceed the limitation of device minor number and can cause a kernel panic (or, at least, produce invalid device nodes in some cases). On my desktop system, following command kills the kernel. On qemu, it triggers similar oops but the kernel was alive: $ sudo modprobe loop max_part0000 ------------[ cut here ]------------ kernel BUG at /media/Linux_Data/project/linux/fs/sysfs/group.c:65! invalid opcode: 0000 [#1] SMP last sysfs file: CPU 0 Modules linked in: loop(+) Pid: 43, comm: insmod Tainted: G W 2.6.39-qemu+ #155 Bochs Bochs RIP: 0010:[<ffffffff8113ce61>] [<ffffffff8113ce61>] internal_create_group= +0x2a/0x170 RSP: 0018:ffff880007b3fde8 EFLAGS: 00000246 RAX: 00000000ffffffef RBX: ffff880007b3d878 RCX: 00000000000007b4 RDX: ffffffff8152da50 RSI: 0000000000000000 RDI: ffff880007b3d878 RBP: ffff880007b3fe38 R08: ffff880007b3fde8 R09: 0000000000000000 R10: ffff88000783b4a8 R11: ffff880007b3d878 R12: ffffffff8152da50 R13: ffff880007b3d868 R14: 0000000000000000 R15: ffff880007b3d800 FS: 0000000002137880(0063) GS:ffff880007c00000(0000) knlGS:00000000000000= 00 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000422680 CR3: 0000000007b50000 CR4: 00000000000006b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 0000000000000000 DR7: 0000000000000000 Process insmod (pid: 43, threadinfo ffff880007b3e000, task ffff880007afb9c= 0) Stack: ffff880007b3fe58 ffffffff811e66dd ffff880007b3fe58 ffffffff811e570b 0000000000000010 ffff880007b3d800 ffff880007a7b390 ffff880007b3d868 0000000000400920 ffff880007b3d800 ffff880007b3fe48 ffffffff8113cfc8 Call Trace: [<ffffffff811e66dd>] ? device_add+0x4bc/0x5af [<ffffffff811e570b>] ? dev_set_name+0x3c/0x3e [<ffffffff8113cfc8>] sysfs_create_group+0xe/0x12 [<ffffffff810b420e>] blk_trace_init_sysfs+0x14/0x16 [<ffffffff8116a090>] blk_register_queue+0x47/0xf7 [<ffffffff8116f527>] add_disk+0xdf/0x290 [<ffffffffa00060eb>] loop_init+0xeb/0x1b8 [loop] [<ffffffffa0006000>] ? 0xffffffffa0005fff [<ffffffff8100020a>] do_one_initcall+0x7a/0x12e [<ffffffff81096804>] sys_init_module+0x9c/0x1e0 [<ffffffff813329bb>] system_call_fastpath+0x16/0x1b Code: c3 55 48 89 e5 41 57 41 56 41 89 f6 41 55 41 54 49 89 d4 53 48 89 fb= 48 83 ec 28 48 85 ff 74 0b 85 f6 75 0b 48 83 7f 30 00 75 14 <0f> 0b eb fe = 48 83 7f 30 00 b9 ea ff ff ff 0f 84 18 01 00 00 49 RIP [<ffffffff8113ce61>] internal_create_group+0x2a/0x170 RSP <ffff880007b3fde8> ---[ end trace a123eb592043acad ]--- Signed-off-by: Namhyung Kim <namhyung@gmail.com> Cc: Laurent Vivier <Laurent.Vivier@bull.net> Cc: stable@kernel.org Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-03-10Merge branch 'for-2.6.39/stack-plug' into for-2.6.39/coreJens Axboe
Conflicts: block/blk-core.c block/blk-flush.c drivers/md/raid1.c drivers/md/raid10.c drivers/md/raid5.c fs/nilfs2/btnode.c fs/nilfs2/mdt.c Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-03-10block: remove per-queue pluggingJens Axboe
Code has been converted over to the new explicit on-stack plugging, and delay users have been converted to use the new API for that. So lets kill off the old plugging along with aops->sync_page(). Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-03-04Merge branch 'for-linus' of ../linux-2.6-block into block-for-2.6.39/coreTejun Heo
This merge creates two set of conflicts. One is simple context conflicts caused by removal of throtl_scheduled_delayed_work() in for-linus and removal of throtl_shutdown_timer_wq() in for-2.6.39/core. The other is caused by commit 255bb490c8 (block: blk-flush shouldn't call directly into q->request_fn() __blk_run_queue()) in for-linus crashing with FLUSH reimplementation in for-2.6.39/core. The conflict isn't trivial but the resolution is straight-forward. * __blk_run_queue() calls in flush_end_io() and flush_data_end_io() should be called with @force_kblockd set to %true. * elv_insert() in blk_kick_flush() should use %ELEVATOR_INSERT_REQUEUE. Both changes are to avoid invoking ->request_fn() directly from request completion path and closely match the changes in the commit 255bb490c8. Signed-off-by: Tejun Heo <tj@kernel.org>
2011-03-03block: kill loop_mutexPetr Uzel
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: [<c102ec04>] irq_exit+0x36/0x59 [<c101502c>] smp_apic_timer_interrupt+0x6b/0x75 [<c127f639>] apic_timer_interrupt+0x31/0x38 [<c101df88>] mutex_spin_on_owner+0x54/0x5b [<fe2250e9>] lo_release+0x12/0x67 [loop] [<c10c4eae>] __blkdev_put+0x7c/0x10c [<c10a4da5>] fput+0xd5/0x1aa [<fe2250cf>] loop_clr_fd+0x1a9/0x1b1 [loop] [<fe225110>] lo_release+0x39/0x67 [loop] [<c10c4eae>] __blkdev_put+0x7c/0x10c [<c10a59d9>] deactivate_locked_super+0x17/0x36 [<c10b6f37>] sys_umount+0x27e/0x2a5 [<c10b6f69>] sys_oldumount+0xb/0xe [<c1002897>] sysenter_do_call+0x12/0x26 [<ffffffff>] 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 <petr.uzel@suse.cz> Cc: stable@kernel.org Reviewed-by: Nikanth Karthikesan <knikanth@suse.de> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>