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path: root/fs/block_dev.c
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2017-02-21block: Revalidate i_bdev reference in bd_aquire()Jan Kara1-1/+10
When a device gets removed, block device inode unhashed so that it is not used anymore (bdget() will not find it anymore). Later when a new device gets created with the same device number, we create new block device inode. However there may be file system device inodes whose i_bdev still points to the original block device inode and thus we get two active block device inodes for the same device. They will share the same gendisk so the only visible differences will be that page caches will not be coherent and BDIs will be different (the old block device inode still points to unregistered BDI). Fix the problem by checking in bd_acquire() whether i_bdev still points to active block device inode and re-lookup the block device if not. That way any open of a block device happening after the old device has been removed will get correct block device inode. Tested-by: Lekshmi Pillai <lekshmicpillai@in.ibm.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-02-18Merge branch 'for-4.11/next' into for-4.11/linus-mergeJens Axboe1-0/+22
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-02-02block: Make blk_get_backing_dev_info() safe without open bdevJan Kara1-0/+7
Currenly blk_get_backing_dev_info() is not safe to be called when the block device is not open as bdev->bd_disk is NULL in that case. However inode_to_bdi() uses this function and may be call called from flusher worker or other writeback related functions without bdev being open which leads to crashes such as: [113031.075540] Unable to handle kernel paging request for data at address 0x00000000 [113031.075614] Faulting instruction address: 0xc0000000003692e0 0:mon> t [c0000000fb65f900] c00000000036cb6c writeback_sb_inodes+0x30c/0x590 [c0000000fb65fa10] c00000000036ced4 __writeback_inodes_wb+0xe4/0x150 [c0000000fb65fa70] c00000000036d33c wb_writeback+0x30c/0x450 [c0000000fb65fb40] c00000000036e198 wb_workfn+0x268/0x580 [c0000000fb65fc50] c0000000000f3470 process_one_work+0x1e0/0x590 [c0000000fb65fce0] c0000000000f38c8 worker_thread+0xa8/0x660 [c0000000fb65fd80] c0000000000fc4b0 kthread+0x110/0x130 [c0000000fb65fe30] c0000000000098f0 ret_from_kernel_thread+0x5c/0x6c Signed-off-by: Jens Axboe <axboe@fb.com>
2017-02-02block: Unhash block device inodes on gendisk destructionJan Kara1-0/+15
Currently, block device inodes stay around after corresponding gendisk hash died until memory reclaim finds them and frees them. Since we will make block device inode pin the bdi, we want to free the block device inode as soon as the device goes away so that bdi does not stay around unnecessarily. Furthermore we need to avoid issues when new device with the same major,minor pair gets created since reusing the bdi structure would be rather difficult in this case. Unhashing block device inode on gendisk destruction nicely deals with these problems. Once last block device inode reference is dropped (which may be directly in del_gendisk()), the inode gets evicted. Furthermore if the major,minor pair gets reallocated, we are guaranteed to get new block device inode even if old block device inode is not yet evicted and thus we avoid issues with possible reuse of bdi. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-24block: fix use after free in __blkdev_direct_IOChristoph Hellwig1-3/+3
We can't dereference the dio structure after submitting the last bio for this request, as I/O completion might have happened before the code is run. Introduce a local is_sync variable instead. Fixes: 542ff7bf ("block: new direct I/O implementation") Signed-off-by: Christoph Hellwig <hch@lst.de> Reported-by: Matias Bjørling <m@bjorling.me> Tested-by: Matias Bjørling <m@bjorling.me> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-04Merge branch 'for-linus' of git://git.kernel.dk/linux-blockLinus Torvalds1-0/+3
Pull block layer fixes from Jens Axboe: "A set of fixes for the current series, one fixing a regression with block size < page cache size in the alias series from Jan. Outside of that, two small cleanups for wbt from Bart, a nvme pull request from Christoph, and a few small fixes of documentation updates" * 'for-linus' of git://git.kernel.dk/linux-block: block: fix up io_poll documentation block: Avoid that sparse complains about context imbalance in __wbt_wait() block: Make wbt_wait() definition consistent with declaration clean_bdev_aliases: Prevent cleaning blocks that are not in block range genhd: remove dead and duplicated scsi code block: add back plugging in __blkdev_direct_IO nvmet/fcloop: remove some logically dead code performing redundant ret checks nvmet: fix KATO offset in Set Features nvme/fc: simplify error handling of nvme_fc_create_hw_io_queues nvme/fc: correct some printk information nvme/scsi: Remove START STOP emulation nvme/pci: Delete misleading queue-wrap comment nvme/pci: Fix whitespace problem nvme: simplify stripe quirk nvme: update maintainers information
2016-12-24Replace <asm/uaccess.h> with <linux/uaccess.h> globallyLinus Torvalds1-1/+1
This was entirely automated, using the script by Al: PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>' sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \ $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h) to do the replacement at the end of the merge window. Requested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-22block: add back plugging in __blkdev_direct_IOChristoph Hellwig1-0/+3
This allows sending larger than 1 MB requests to devices that support large I/O sizes. Signed-off-by: Christoph Hellwig <hch@lst.de> Reported-by: Laurence Oberman <loberman@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-12-14block_dev: don't update file access position for sync direct IOShaohua Li1-4/+1
For sync direct IO, generic_file_direct_write/generic_file_read_iter will update file access position. Don't duplicate the update in .direct_IO. This cause my raid array can't assemble. Cc: Christoph Hellwig <hch@lst.de> Cc: Jens Axboe <axboe@fb.com> Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-12-14block_dev: don't test bdev->bd_contains when it is not stableNeilBrown1-1/+1
bdev->bd_contains is not stable before calling __blkdev_get(). When __blkdev_get() is called on a parition with ->bd_openers == 0 it sets bdev->bd_contains = bdev; which is not correct for a partition. After a call to __blkdev_get() succeeds, ->bd_openers will be > 0 and then ->bd_contains is stable. When FMODE_EXCL is used, blkdev_get() calls bd_start_claiming() -> bd_prepare_to_claim() -> bd_may_claim() This call happens before __blkdev_get() is called, so ->bd_contains is not stable. So bd_may_claim() cannot safely use ->bd_contains. It currently tries to use it, and this can lead to a BUG_ON(). This happens when a whole device is already open with a bd_holder (in use by dm in my particular example) and two threads race to open a partition of that device for the first time, one opening with O_EXCL and one without. The thread that doesn't use O_EXCL gets through blkdev_get() to __blkdev_get(), gains the ->bd_mutex, and sets bdev->bd_contains = bdev; Immediately thereafter the other thread, using FMODE_EXCL, calls bd_start_claiming() from blkdev_get(). This should fail because the whole device has a holder, but because bdev->bd_contains == bdev bd_may_claim() incorrectly reports success. This thread continues and blocks on bd_mutex. The first thread then sets bdev->bd_contains correctly and drops the mutex. The thread using FMODE_EXCL then continues and when it calls bd_may_claim() again in: BUG_ON(!bd_may_claim(bdev, whole, holder)); The BUG_ON fires. Fix this by removing the dependency on ->bd_contains in bd_may_claim(). As bd_may_claim() has direct access to the whole device, it can simply test if the target bdev is the whole device. Fixes: 6b4517a7913a ("block: implement bd_claiming and claiming block") Cc: stable@vger.kernel.org (v2.6.35+) Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-12-01block: protect iterate_bdevs() against concurrent closeRabin Vincent1-1/+6
If a block device is closed while iterate_bdevs() is handling it, the following NULL pointer dereference occurs because bdev->b_disk is NULL in bdev_get_queue(), which is called from blk_get_backing_dev_info() (in turn called by the mapping_cap_writeback_dirty() call in __filemap_fdatawrite_range()): BUG: unable to handle kernel NULL pointer dereference at 0000000000000508 IP: [<ffffffff81314790>] blk_get_backing_dev_info+0x10/0x20 PGD 9e62067 PUD 9ee8067 PMD 0 Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC Modules linked in: CPU: 1 PID: 2422 Comm: sync Not tainted 4.5.0-rc7+ #400 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) task: ffff880009f4d700 ti: ffff880009f5c000 task.ti: ffff880009f5c000 RIP: 0010:[<ffffffff81314790>] [<ffffffff81314790>] blk_get_backing_dev_info+0x10/0x20 RSP: 0018:ffff880009f5fe68 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff88000ec17a38 RCX: ffffffff81a4e940 RDX: 7fffffffffffffff RSI: 0000000000000000 RDI: ffff88000ec176c0 RBP: ffff880009f5fe68 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffff88000ec17860 R13: ffffffff811b25c0 R14: ffff88000ec178e0 R15: ffff88000ec17a38 FS: 00007faee505d700(0000) GS:ffff88000fb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000508 CR3: 0000000009e8a000 CR4: 00000000000006e0 Stack: ffff880009f5feb8 ffffffff8112e7f5 0000000000000000 7fffffffffffffff 0000000000000000 0000000000000000 7fffffffffffffff 0000000000000001 ffff88000ec178e0 ffff88000ec17860 ffff880009f5fec8 ffffffff8112e81f Call Trace: [<ffffffff8112e7f5>] __filemap_fdatawrite_range+0x85/0x90 [<ffffffff8112e81f>] filemap_fdatawrite+0x1f/0x30 [<ffffffff811b25d6>] fdatawrite_one_bdev+0x16/0x20 [<ffffffff811bc402>] iterate_bdevs+0xf2/0x130 [<ffffffff811b2763>] sys_sync+0x63/0x90 [<ffffffff815d4272>] entry_SYSCALL_64_fastpath+0x12/0x76 Code: 0f 1f 44 00 00 48 8b 87 f0 00 00 00 55 48 89 e5 <48> 8b 80 08 05 00 00 5d RIP [<ffffffff81314790>] blk_get_backing_dev_info+0x10/0x20 RSP <ffff880009f5fe68> CR2: 0000000000000508 ---[ end trace 2487336ceb3de62d ]--- The crash is easily reproducible by running the following command, if an msleep(100) is inserted before the call to func() in iterate_devs(): while :; do head -c1 /dev/nullb0; done > /dev/null & while :; do sync; done Fix it by holding the bd_mutex across the func() call and only calling func() if the bdev is opened. Cc: stable@vger.kernel.org Fixes: 5c0d6b60a0ba ("vfs: Create function for iterating over block devices") Reported-and-tested-by: Wei Fang <fangwei1@huawei.com> Signed-off-by: Rabin Vincent <rabinv@axis.com> Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-22block: bio: pass bvec table to bio_init()Ming Lei1-3/+1
Some drivers often use external bvec table, so introduce this helper for this case. It is always safe to access the bio->bi_io_vec in this way for this case. After converting to this usage, it will becomes a bit easier to evaluate the remaining direct access to bio->bi_io_vec, so it can help to prepare for the following multipage bvec support. Signed-off-by: Ming Lei <tom.leiming@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Fixed up the new O_DIRECT cases. Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-22block_dev: get rid of blksize bits calculationJens Axboe1-4/+4
We store the bits in the bdev sector size locally, but we don't use the calculation anymore. All we do with it is shift it back up to the bdev sector size. So let's just use that directly and kill the variable and bits calculation. Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-22block_dev: Fixed direct I/O bio sector calculationDamien Le Moal1-2/+2
A direct I/O alignment must be always checked against the device blocks size, but the I/O offset (bio->bi_iter.bi_sector must always use 512B sector unit, and not the actual logical block size. Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-17block: new direct I/O implementationChristoph Hellwig1-4/+162
Similar to the simple fast path, but we now need a dio structure to track multiple-bio completions. It's basically a cut-down version of the new iomap-based direct I/O code for filesystems, but without all the logic to call into the filesystem for extent lookup or allocation, and without the complex I/O completion workqueue handler for AIO - instead we just use the FUA bit on the bios to ensure data is flushed to stable storage. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-17block: make __blkdev_direct_IO_sync() support O_SYNC/DSYNCJens Axboe1-2/+12
Split the op setting code into a helper, use it in both places. Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-17block: support a full bio worth of IO for simplified bdev direct-ioJens Axboe1-4/+15
Just alloc the bio_vec array if we exceed the inline limit. Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-17block: fast-path for small and simple direct I/O requestsChristoph Hellwig1-0/+80
This patch adds a small and simple fast patch for small direct I/O requests on block devices that don't use AIO. Between the neat bio_iov_iter_get_pages helper that avoids allocating a page array for get_user_pages and the on-stack bio and biovec this avoid memory allocations and atomic operations entirely in the direct I/O code (lower levels might still do memory allocations and will usually have at least some atomic operations, though). Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com> Tested-By: Stephen Bates <sbates@raithlin.com> Reviewed-By: Stephen Bates <sbates@raithlin.com>
2016-10-12block: implement (some of) fallocate for block devicesDarrick J. Wong1-0/+77
After much discussion, it seems that the fallocate feature flag FALLOC_FL_ZERO_RANGE maps nicely to SCSI WRITE SAME; and the feature FALLOC_FL_PUNCH_HOLE maps nicely to the devices that have been whitelisted for zeroing SCSI UNMAP. Punch still requires that FALLOC_FL_KEEP_SIZE is set. A length that goes past the end of the device will be clamped to the device size if KEEP_SIZE is set; or will return -EINVAL if not. Both start and length must be aligned to the device's logical block size. Since the semantics of fallocate are fairly well established already, wire up the two pieces. The other fallocate variants (collapse range, insert range, and allocate blocks) are not supported. Link: http://lkml.kernel.org/r/147518379992.22791.8849838163218235007.stgit@birch.djwong.org Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Martin K. Petersen <martin.petersen@oracle.com> Cc: Mike Snitzer <snitzer@redhat.com> # tweaked header Cc: Brian Foster <bfoster@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Hannes Reinecke <hare@suse.de> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-05fs/block_dev.c: return the right error in thaw_bdev()Pierre Morel1-5/+2
When triggering thaw-filesystems via magic sysrq, the system enters a loop in do_thaw_one(), as thaw_bdev() still returns success if bd_fsfreeze_count == 0. To fix this, let thaw_bdev() always return error (and simplify the code a bit at the same time). Reviewed-by: Eric Farman <farman@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Pierre Morel <pmorel@linux.vnet.ibm.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-09-14block_dev: remove DAX leftoversChristoph Hellwig1-10/+1
DAX support for block devices was removed in commits 03cdad ("block: disable block device DAX by default") and 99a01cd ("block: remove BLK_DEV_DAX config option"), but we still kept a call to dax_do_io and some uneeded i_flags manipulations introduced in commit bbab37 ("block: Add support for DAX reads/writes to block devices"). Remove those leftovers. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Acked-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-25fs/block_dev: fix potential NULL ptr deref in freeze_bdev()Andrey Ryabinin1-1/+2
Calling freeze_bdev() twice on the same block device without mounted filesystem get_super() will return NULL, which will lead to NULL-ptr dereference later in drop_super(). Check get_super() result to fix that. Note, that this is a purely theoretical issue. We have only 3 freeze_bdev() callers. 2 of them are in filesystem code and used on a device with mounted fs. The third one in lock_fs() has protection in upper-layer code against freezing block device the second time without thawing it first. Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-22bdev: fix NULL pointer dereferenceVegard Nossum1-1/+1
I got this: kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) CPU: 0 PID: 5505 Comm: syz-executor Not tainted 4.8.0-rc2+ #161 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2014 task: ffff880113415940 task.stack: ffff880118350000 RIP: 0010:[<ffffffff8172cb32>] [<ffffffff8172cb32>] bd_mount+0x52/0xa0 RSP: 0018:ffff880118357ca0 EFLAGS: 00010207 RAX: dffffc0000000000 RBX: ffffffffffffffff RCX: ffffc90000bb6000 RDX: 0000000000000018 RSI: ffffffff846d6b20 RDI: 00000000000000c7 RBP: ffff880118357cb0 R08: ffff880115967c68 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801188211e8 R13: ffffffff847baa20 R14: ffff8801139cb000 R15: 0000000000000080 FS: 00007fa3ff6c0700(0000) GS:ffff88011aa00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc1d8cc7e78 CR3: 0000000109f20000 CR4: 00000000000006f0 DR0: 000000000000001e DR1: 000000000000001e DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Stack: ffff880112cfd6c0 ffff8801188211e8 ffff880118357cf0 ffffffff8167f207 ffffffff816d7a1e ffff880112a413c0 ffffffff847baa20 ffff8801188211e8 0000000000000080 ffff880112cfd6c0 ffff880118357d38 ffffffff816dce0a Call Trace: [<ffffffff8167f207>] mount_fs+0x97/0x2e0 [<ffffffff816d7a1e>] ? alloc_vfsmnt+0x55e/0x760 [<ffffffff816dce0a>] vfs_kern_mount+0x7a/0x300 [<ffffffff83c3247c>] ? _raw_read_unlock+0x2c/0x50 [<ffffffff816dfc87>] do_mount+0x3d7/0x2730 [<ffffffff81235fd4>] ? trace_do_page_fault+0x1f4/0x3a0 [<ffffffff816df8b0>] ? copy_mount_string+0x40/0x40 [<ffffffff8161ea81>] ? memset+0x31/0x40 [<ffffffff816df73e>] ? copy_mount_options+0x1ee/0x320 [<ffffffff816e2a02>] SyS_mount+0xb2/0x120 [<ffffffff816e2950>] ? copy_mnt_ns+0x970/0x970 [<ffffffff81005524>] do_syscall_64+0x1c4/0x4e0 [<ffffffff83c3282a>] entry_SYSCALL64_slow_path+0x25/0x25 Code: 83 e8 63 1b fc ff 48 85 c0 48 89 c3 74 4c e8 56 35 d1 ff 48 8d bb c8 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 75 36 4c 8b a3 c8 00 00 00 48 b8 00 00 00 00 00 fc RIP [<ffffffff8172cb32>] bd_mount+0x52/0xa0 RSP <ffff880118357ca0> ---[ end trace 13690ad962168b98 ]--- mount_pseudo() returns ERR_PTR(), not NULL, on error. Fixes: 3684aa7099e0 ("block-dev: enable writeback cgroup support") Cc: Shaohua Li <shli@fb.com> Cc: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@fb.com> Cc: stable@vger.kernel.org Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-07block/mm: make bdev_ops->rw_page() take a bool for read/writeJens Axboe1-4/+2
Commit abf545484d31 changed it from an 'rw' flags type to the newer ops based interface, but now we're effectively leaking some bdev internals to the rest of the kernel. Since we only care about whether it's a read or a write at that level, just pass in a bool 'is_write' parameter instead. Then we can also move op_is_write() and friends back under CONFIG_BLOCK protection. Reviewed-by: Mike Christie <mchristi@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-04mm/block: convert rw_page users to bio op useMike Christie1-3/+4
The rw_page users were not converted to use bio/req ops. As a result bdev_write_page is not passing down REQ_OP_WRITE and the IOs will be sent down as reads. Signed-off-by: Mike Christie <mchristi@redhat.com> Fixes: 4e1b2d52a80d ("block, fs, drivers: remove REQ_OP compat defs and related code") Modified by me to: 1) Drop op_flags passing into ->rw_page(), as we don't use it. 2) Make op_is_write() and friends safe to use for !CONFIG_BLOCK Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-04block: remove BLK_DEV_DAX config optionRoss Zwisler1-5/+1
The functionality for block device DAX was already removed with commit acc93d30d7d4 ("Revert "block: enable dax for raw block devices"") However, we still had a config option hanging around that was always disabled because it depended on CONFIG_BROKEN. This config option was introduced in commit 03cdadb04077 ("block: disable block device DAX by default") This change reverts that commit, removing the dead config option. Link: http://lkml.kernel.org/r/20160729182314.6368-1-ross.zwisler@linux.intel.com Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Dan Williams <dan.j.williams@intel.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-30Merge branch 'for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull userns vfs updates from Eric Biederman: "This tree contains some very long awaited work on generalizing the user namespace support for mounting filesystems to include filesystems with a backing store. The real world target is fuse but the goal is to update the vfs to allow any filesystem to be supported. This patchset is based on a lot of code review and testing to approach that goal. While looking at what is needed to support the fuse filesystem it became clear that there were things like xattrs for security modules that needed special treatment. That the resolution of those concerns would not be fuse specific. That sorting out these general issues made most sense at the generic level, where the right people could be drawn into the conversation, and the issues could be solved for everyone. At a high level what this patchset does a couple of simple things: - Add a user namespace owner (s_user_ns) to struct super_block. - Teach the vfs to handle filesystem uids and gids not mapping into to kuids and kgids and being reported as INVALID_UID and INVALID_GID in vfs data structures. By assigning a user namespace owner filesystems that are mounted with only user namespace privilege can be detected. This allows security modules and the like to know which mounts may not be trusted. This also allows the set of uids and gids that are communicated to the filesystem to be capped at the set of kuids and kgids that are in the owning user namespace of the filesystem. One of the crazier corner casees this handles is the case of inodes whose i_uid or i_gid are not mapped into the vfs. Most of the code simply doesn't care but it is easy to confuse the inode writeback path so no operation that could cause an inode write-back is permitted for such inodes (aka only reads are allowed). This set of changes starts out by cleaning up the code paths involved in user namespace permirted mounts. Then when things are clean enough adds code that cleanly sets s_user_ns. Then additional restrictions are added that are possible now that the filesystem superblock contains owner information. These changes should not affect anyone in practice, but there are some parts of these restrictions that are changes in behavior. - Andy's restriction on suid executables that does not honor the suid bit when the path is from another mount namespace (think /proc/[pid]/fd/) or when the filesystem was mounted by a less privileged user. - The replacement of the user namespace implicit setting of MNT_NODEV with implicitly setting SB_I_NODEV on the filesystem superblock instead. Using SB_I_NODEV is a stronger form that happens to make this state user invisible. The user visibility can be managed but it caused problems when it was introduced from applications reasonably expecting mount flags to be what they were set to. There is a little bit of work remaining before it is safe to support mounting filesystems with backing store in user namespaces, beyond what is in this set of changes. - Verifying the mounter has permission to read/write the block device during mount. - Teaching the integrity modules IMA and EVM to handle filesystems mounted with only user namespace root and to reduce trust in their security xattrs accordingly. - Capturing the mounters credentials and using that for permission checks in d_automount and the like. (Given that overlayfs already does this, and we need the work in d_automount it make sense to generalize this case). Furthermore there are a few changes that are on the wishlist: - Get all filesystems supporting posix acls using the generic posix acls so that posix_acl_fix_xattr_from_user and posix_acl_fix_xattr_to_user may be removed. [Maintainability] - Reducing the permission checks in places such as remount to allow the superblock owner to perform them. - Allowing the superblock owner to chown files with unmapped uids and gids to something that is mapped so the files may be treated normally. I am not considering even obvious relaxations of permission checks until it is clear there are no more corner cases that need to be locked down and handled generically. Many thanks to Seth Forshee who kept this code alive, and putting up with me rewriting substantial portions of what he did to handle more corner cases, and for his diligent testing and reviewing of my changes" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (30 commits) fs: Call d_automount with the filesystems creds fs: Update i_[ug]id_(read|write) to translate relative to s_user_ns evm: Translate user/group ids relative to s_user_ns when computing HMAC dquot: For now explicitly don't support filesystems outside of init_user_ns quota: Handle quota data stored in s_user_ns in quota_setxquota quota: Ensure qids map to the filesystem vfs: Don't create inodes with a uid or gid unknown to the vfs vfs: Don't modify inodes with a uid or gid unknown to the vfs cred: Reject inodes with invalid ids in set_create_file_as() fs: Check for invalid i_uid in may_follow_link() vfs: Verify acls are valid within superblock's s_user_ns. userns: Handle -1 in k[ug]id_has_mapping when !CONFIG_USER_NS fs: Refuse uid/gid changes which don't map into s_user_ns selinux: Add support for unprivileged mounts from user namespaces Smack: Handle labels consistently in untrusted mounts Smack: Add support for unprivileged mounts from user namespaces fs: Treat foreign mounts as nosuid fs: Limit file caps to the user namespace of the super block userns: Remove the now unnecessary FS_USERNS_DEV_MOUNT flag userns: Remove implicit MNT_NODEV fragility. ...
2016-07-28Merge branch 'work.misc' of ↵Linus Torvalds1-14/+2
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs updates from Al Viro: "Assorted cleanups and fixes. Probably the most interesting part long-term is ->d_init() - that will have a bunch of followups in (at least) ceph and lustre, but we'll need to sort the barrier-related rules before it can get used for really non-trivial stuff. Another fun thing is the merge of ->d_iput() callers (dentry_iput() and dentry_unlink_inode()) and a bunch of ->d_compare() ones (all except the one in __d_lookup_lru())" * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (26 commits) fs/dcache.c: avoid soft-lockup in dput() vfs: new d_init method vfs: Update lookup_dcache() comment bdev: get rid of ->bd_inodes Remove last traces of ->sync_page new helper: d_same_name() dentry_cmp(): use lockless_dereference() instead of smp_read_barrier_depends() vfs: clean up documentation vfs: document ->d_real() vfs: merge .d_select_inode() into .d_real() unify dentry_iput() and dentry_unlink_inode() binfmt_misc: ->s_root is not going anywhere drop redundant ->owner initializations ufs: get rid of redundant checks orangefs: constify inode_operations missed comment updates from ->direct_IO() prototype change file_inode(f)->i_mapping is f->f_mapping trim fsnotify hooks a bit 9p: new helper - v9fs_parent_fid() debugfs: ->d_parent is never NULL or negative ...
2016-07-21block: add QUEUE_FLAG_DAX for devices to advertise their DAX supportToshi Kani1-2/+3
Currently, presence of direct_access() in block_device_operations indicates support of DAX on its block device. Because block_device_operations is instantiated with 'const', this DAX capablity may not be enabled conditinally. In preparation for supporting DAX to device-mapper devices, add QUEUE_FLAG_DAX to request_queue flags to advertise their DAX support. This will allow to set the DAX capability based on how mapped device is composed. Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Acked-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: <linux-s390@vger.kernel.org> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-07-19bdev: get rid of ->bd_inodesAl Viro1-14/+2
Since 2006 we have ->i_bdev pinning bdev in question, so there's no way to get to bdev ->evict_inode() while there's an aliasing inode anywhere. In other words, the only place walking the list of aliases is guaranteed to do it only when the list is empty... Remove the detritus; it should've been done in "[PATCH] Fix a race condition between ->i_mapping and iput()", but nobody had noticed it back then. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-06-23vfs: Generalize filesystem nodev handling.Eric W. Biederman1-1/+1
Introduce a function may_open_dev that tests MNT_NODEV and a new superblock flab SB_I_NODEV. Use this new function in all of the places where MNT_NODEV was previously tested. Add the new SB_I_NODEV s_iflag to proc, sysfs, and mqueuefs as those filesystems should never support device nodes, and a simple superblock flags makes that very hard to get wrong. With SB_I_NODEV set if any device nodes somehow manage to show up on on a filesystem those device nodes will be unopenable. Acked-by: Seth Forshee <seth.forshee@canonical.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2016-05-27Merge tag 'dax-misc-for-4.7' of ↵Linus Torvalds1-30/+84
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull misc DAX updates from Vishal Verma: "DAX error handling for 4.7 - Until now, dax has been disabled if media errors were found on any device. This enables the use of DAX in the presence of these errors by making all sector-aligned zeroing go through the driver. - The driver (already) has the ability to clear errors on writes that are sent through the block layer using 'DSMs' defined in ACPI 6.1. Other misc changes: - When mounting DAX filesystems, check to make sure the partition is page aligned. This is a requirement for DAX, and previously, we allowed such unaligned mounts to succeed, but subsequent reads/writes would fail. - Misc/cleanup fixes from Jan that remove unused code from DAX related to zeroing, writeback, and some size checks" * tag 'dax-misc-for-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: dax: fix a comment in dax_zero_page_range and dax_truncate_page dax: for truncate/hole-punch, do zeroing through the driver if possible dax: export a low-level __dax_zero_page_range helper dax: use sb_issue_zerout instead of calling dax_clear_sectors dax: enable dax in the presence of known media errors (badblocks) dax: fallback from pmd to pte on error block: Update blkdev_dax_capable() for consistency xfs: Add alignment check for DAX mount ext2: Add alignment check for DAX mount ext4: Add alignment check for DAX mount block: Add bdev_dax_supported() for dax mount checks block: Add vfs_msg() interface dax: Remove redundant inode size checks dax: Remove pointless writeback from dax_do_io() dax: Remove zeroing from dax_io() dax: Remove dead zeroing code from fault handlers ext2: Avoid DAX zeroing to corrupt data ext2: Fix block zeroing in ext2_get_blocks() for DAX dax: Remove complete_unwritten argument DAX: move RADIX_DAX_ definitions to dax.c
2016-05-23Merge tag 'libnvdimm-for-4.7' of ↵Linus Torvalds1-67/+29
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm updates from Dan Williams: "The bulk of this update was stabilized before the merge window and appeared in -next. The "device dax" implementation was revised this week in response to review feedback, and to address failures detected by the recently expanded ndctl unit test suite. Not included in this pull request are two dax topic branches (dax error handling, and dax radix-tree locking). These topics were deferred to get a few more days of -next integration testing, and to coordinate a branch baseline with Ted and the ext4 tree. Vishal and Ross will send the error handling and locking topics respectively in the next few days. This branch has received a positive build result from the kbuild robot across 226 configs. Summary: - Device DAX for persistent memory: Device DAX is the device-centric analogue of Filesystem DAX (CONFIG_FS_DAX). It allows memory ranges to be allocated and mapped without need of an intervening file system. Device DAX is strict, precise and predictable. Specifically this interface: a) Guarantees fault granularity with respect to a given page size (pte, pmd, or pud) set at configuration time. b) Enforces deterministic behavior by being strict about what fault scenarios are supported. Persistent memory is the first target, but the mechanism is also targeted for exclusive allocations of performance/feature differentiated memory ranges. - Support for the HPE DSM (device specific method) command formats. This enables management of these first generation devices until a unified DSM specification materializes. - Further ACPI 6.1 compliance with support for the common dimm identifier format. - Various fixes and cleanups across the subsystem" * tag 'libnvdimm-for-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (40 commits) libnvdimm, dax: fix deletion libnvdimm, dax: fix alignment validation libnvdimm, dax: autodetect support libnvdimm: release ida resources Revert "block: enable dax for raw block devices" /dev/dax, core: file operations and dax-mmap /dev/dax, pmem: direct access to persistent memory libnvdimm: stop requiring a driver ->remove() method libnvdimm, dax: record the specified alignment of a dax-device instance libnvdimm, dax: reserve space to store labels for device-dax libnvdimm, dax: introduce device-dax infrastructure nfit: add sysfs dimm 'family' and 'dsm_mask' attributes tools/testing/nvdimm: ND_CMD_CALL support nfit: disable vendor specific commands nfit: export subsystem ids as attributes nfit: fix format interface code byte order per ACPI6.1 nfit, libnvdimm: limited/whitelisted dimm command marshaling mechanism nfit, libnvdimm: clarify "commands" vs "_DSMs" libnvdimm: increase max envelope size for ioctl acpi/nfit: Add sysfs "id" for NVDIMM ID ...
2016-05-21Revert "block: enable dax for raw block devices"Dan Williams1-67/+29
This reverts commit 5a023cdba50c5f5f2bc351783b3131699deb3937. The functionality is superseded by the new "Device DAX" facility. Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <david@fromorbit.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Jan Kara <jack@suse.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-05-18dax: enable dax in the presence of known media errors (badblocks)Dan Williams1-12/+1
1/ If a mapping overlaps a bad sector fail the request. 2/ Do not opportunistically report more dax-capable capacity than is requested when errors present. Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com> [vishal: fix a conflict with system RAM collision patches] [vishal: add a 'size' parameter to ->direct_access] [vishal: fix a conflict with DAX alignment check patches] Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
2016-05-17block: Update blkdev_dax_capable() for consistencyToshi Kani1-2/+37
blkdev_dax_capable() is similar to bdev_dax_supported(), but needs to remain as a separate interface for checking dax capability of a raw block device. Rename and relocate blkdev_dax_capable() to keep them maintained consistently, and call bdev_direct_access() for the dax capability check. There is no change in the behavior. Link: https://lkml.org/lkml/2016/5/9/950 Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Jens Axboe <axboe@fb.com> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Jan Kara <jack@suse.cz> Cc: Dave Chinner <david@fromorbit.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Boaz Harrosh <boaz@plexistor.com> Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
2016-05-17block: Add bdev_dax_supported() for dax mount checksToshi Kani1-0/+45
DAX imposes additional requirements to a device. Add bdev_dax_supported() which performs all the precondition checks necessary for filesystem to mount the device with dax option. Also add a new check to verify if a partition is aligned by 4KB. When a partition is unaligned, any dax read/write access fails, except for metadata update. Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Jens Axboe <axboe@fb.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Jan Kara <jack@suse.cz> Cc: Dave Chinner <david@fromorbit.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Boaz Harrosh <boaz@plexistor.com> Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
2016-05-17block: Add vfs_msg() interfaceToshi Kani1-0/+12
In preparation of moving DAX capability checks to the block layer from filesystem code, add a VFS message interface that aligns with filesystem's message format. For instance, a vfs_msg() message followed by XFS messages in case of a dax mount error may look like: VFS (pmem0p1): error: unaligned partition for dax XFS (pmem0p1): DAX unsupported by block device. Turning off DAX. XFS (pmem0p1): Mounting V5 Filesystem : vfs_msg() is largely based on ext4_msg(). Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Jens Axboe <axboe@fb.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Jan Kara <jack@suse.cz> Cc: Dave Chinner <david@fromorbit.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Boaz Harrosh <boaz@plexistor.com> Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
2016-05-17dax: Remove complete_unwritten argumentJan Kara1-2/+2
Fault handlers currently take complete_unwritten argument to convert unwritten extents after PTEs are updated. However no filesystem uses this anymore as the code is racy. Remove the unused argument. Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
2016-05-02fs: simplify the generic_write_sync prototypeChristoph Hellwig1-6/+2
The kiocb already has the new position, so use that. The only interesting case is AIO, where we currently don't bother updating ki_pos. We're about to free the kiocb after we're done, so we might as well update it to make everyone's life simpler. While we're at it also return the bytes written argument passed in if we were successful so that the boilerplate error switch code in the callers can go away. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-02fs: add IOCB_SYNC and IOCB_DSYNCChristoph Hellwig1-1/+1
This will allow us to do per-I/O sync file writes, as required by a lot of fileservers or storage targets. XXX: Will need a few additional audits for O_DSYNC Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-02direct-io: eliminate the offset argument to ->direct_IOChristoph Hellwig1-3/+3
Including blkdev_direct_IO and dax_do_io. It has to be ki_pos to actually work, so eliminate the superflous argument. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-04-04mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macrosKirill A. Shutemov1-2/+2
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago with promise that one day it will be possible to implement page cache with bigger chunks than PAGE_SIZE. This promise never materialized. And unlikely will. We have many places where PAGE_CACHE_SIZE assumed to be equal to PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_* or PAGE_* constant should be used in a particular case, especially on the border between fs and mm. Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much breakage to be doable. Let's stop pretending that pages in page cache are special. They are not. The changes are pretty straight-forward: - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN}; - page_cache_get() -> get_page(); - page_cache_release() -> put_page(); This patch contains automated changes generated with coccinelle using script below. For some reason, coccinelle doesn't patch header files. I've called spatch for them manually. The only adjustment after coccinelle is revert of changes to PAGE_CAHCE_ALIGN definition: we are going to drop it later. There are few places in the code where coccinelle didn't reach. I'll fix them manually in a separate patch. Comments and documentation also will be addressed with the separate patch. virtual patch @@ expression E; @@ - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ expression E; @@ - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ @@ - PAGE_CACHE_SHIFT + PAGE_SHIFT @@ @@ - PAGE_CACHE_SIZE + PAGE_SIZE @@ @@ - PAGE_CACHE_MASK + PAGE_MASK @@ expression E; @@ - PAGE_CACHE_ALIGN(E) + PAGE_ALIGN(E) @@ expression E; @@ - page_cache_get(E) + get_page(E) @@ expression E; @@ - page_cache_release(E) + put_page(E) Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-19Merge branch 'for-4.6/core' of git://git.kernel.dk/linux-blockLinus Torvalds1-1/+5
Pull core block updates from Jens Axboe: "Here are the core block changes for this merge window. Not a lot of exciting stuff going on in this round, most of the changes have been on the driver side of things. That pull request is coming next. This pull request contains: - A set of fixes for chained bio handling from Christoph. - A tag bounds check for blk-mq from Hannes, ensuring that we don't do something stupid if a device reports an invalid tag value. - A set of fixes/updates for the CFQ IO scheduler from Jan Kara. - A set of blk-mq fixes from Keith, adding support for dynamic hardware queues, and fixing init of max_dev_sectors for stacking devices. - A fix for the dynamic hw context from Ming. - Enabling of cgroup writeback support on a block device, from Shaohua" * 'for-4.6/core' of git://git.kernel.dk/linux-block: blk-mq: add bounds check on tag-to-rq conversion block: bio_remaining_done() isn't unlikely block: cleanup bio_endio block: factor out chained bio completion block: don't unecessarily clobber bi_error for chained bios block-dev: enable writeback cgroup support blk-mq: Fix NULL pointer updating nr_requests blk-mq: mark request queue as mq asap block: Initialize max_dev_sectors to 0 blk-mq: dynamic h/w context count cfq-iosched: Allow parent cgroup to preempt its child cfq-iosched: Allow sync noidle workloads to preempt each other cfq-iosched: Reorder checks in cfq_should_preempt() cfq-iosched: Don't group_idle if cfqq has big thinktime
2016-03-04block-dev: enable writeback cgroup supportShaohua Li1-1/+5
block_dev's .writepages/.writepage already handles wbc_init_bio/wbc_account_io. We only set the SB_I_CGROUPWB bit to suppport writeback cgroup support. Signed-off-by: Shaohua Li <shli@fb.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-02-27dax: move writeback calls into the filesystemsRoss Zwisler1-1/+12
Previously calls to dax_writeback_mapping_range() for all DAX filesystems (ext2, ext4 & xfs) were centralized in filemap_write_and_wait_range(). dax_writeback_mapping_range() needs a struct block_device, and it used to get that from inode->i_sb->s_bdev. This is correct for normal inodes mounted on ext2, ext4 and XFS filesystems, but is incorrect for DAX raw block devices and for XFS real-time files. Instead, call dax_writeback_mapping_range() directly from the filesystem ->writepages function so that it can supply us with a valid block device. This also fixes DAX code to properly flush caches in response to sync(2). Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Jan Kara <jack@suse.cz> Cc: Al Viro <viro@ftp.linux.org.uk> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Jens Axboe <axboe@fb.com> Cc: Matthew Wilcox <matthew.r.wilcox@intel.com> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-27block: disable block device DAX by defaultDan Williams1-1/+5
The recent *sync enabling discovered that we are inserting into the block_device pagecache counter to the expectations of the dirty data tracking for dax mappings. This can lead to data corruption. We want to support DAX for block devices eventually, but it requires wider changes to properly manage the pagecache. dump_stack+0x85/0xc2 dax_writeback_mapping_range+0x60/0xe0 blkdev_writepages+0x3f/0x50 do_writepages+0x21/0x30 __filemap_fdatawrite_range+0xc6/0x100 filemap_write_and_wait+0x4a/0xa0 set_blocksize+0x70/0xd0 sb_set_blocksize+0x1d/0x50 ext4_fill_super+0x75b/0x3360 mount_bdev+0x180/0x1b0 ext4_mount+0x15/0x20 mount_fs+0x38/0x170 Mark the support broken so its disabled by default, but otherwise still available for testing. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reported-by: Ross Zwisler <ross.zwisler@linux.intel.com> Suggested-by: Dave Chinner <david@fromorbit.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@fb.com> Cc: Matthew Wilcox <matthew.r.wilcox@intel.com> Cc: Al Viro <viro@ftp.linux.org.uk> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-06block: fix pfn_mkwrite() DAX fault handlerRoss Zwisler1-1/+7
Previously the pfn_mkwrite() fault handler for raw block devices called bldev_dax_fault() -> __dax_fault() to do a full DAX page fault. Really what the pfn_mkwrite() fault handler needs to do is call dax_pfn_mkwrite() to make sure that the radix tree entry for the given PTE is marked as dirty so that a follow-up fsync or msync call will flush it durably to media. Fixes: 5a023cdba50c ("block: enable dax for raw block devices") Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Chinner <david@fromorbit.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-31block: revert runtime dax control of the raw block deviceDan Williams1-28/+0
Dynamically enabling DAX requires that the page cache first be flushed and invalidated. This must occur atomically with the change of DAX mode otherwise we confuse the fsync/msync tracking and violate data durability guarantees. Eliminate the possibilty of DAX-disabled to DAX-enabled transitions for now and revisit this for the next cycle. Cc: Jan Kara <jack@suse.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <david@fromorbit.com> Cc: Matthew Wilcox <willy@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-01-23Merge branch 'for-linus' of ↵Linus Torvalds1-10/+10
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull final vfs updates from Al Viro: - The ->i_mutex wrappers (with small prereq in lustre) - a fix for too early freeing of symlink bodies on shmem (they need to be RCU-delayed) (-stable fodder) - followup to dedupe stuff merged this cycle * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: vfs: abort dedupe loop if fatal signals are pending make sure that freeing shmem fast symlinks is RCU-delayed wrappers for ->i_mutex access lustre: remove unused declaration
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