1. 09 Mar, 2018 1 commit
    • Ross Zwisler's avatar
      loop: Fix lost writes caused by missing flag · 1d037577
      Ross Zwisler authored
      The following commit:
      
      commit aa4d8616 ("block: loop: switch to VFS ITER_BVEC")
      
      replaced __do_lo_send_write(), which used ITER_KVEC iterators, with
      lo_write_bvec() which uses ITER_BVEC iterators.  In this change, though,
      the WRITE flag was lost:
      
      -       iov_iter_kvec(&from, ITER_KVEC | WRITE, &kvec, 1, len);
      +       iov_iter_bvec(&i, ITER_BVEC, bvec, 1, bvec->bv_len);
      
      This flag is necessary for the DAX case because we make decisions based on
      whether or not the iterator is a READ or a WRITE in dax_iomap_actor() and
      in dax_iomap_rw().
      
      We end up going through this path in configurations where we combine a PMEM
      device with 4k sectors, a loopback device and DAX.  The consequence of this
      missed flag is that what we intend as a write actually turns into a read in
      the DAX code, so no data is ever written.
      
      The very simplest test case is to create a loopback device and try and
      write a small string to it, then hexdump a few bytes of the device to see
      if the write took.  Without this patch you read back all zeros, with this
      you read back the string you wrote.
      
      For XFS this causes us to fail or panic during the following xfstests:
      
      	xfs/074 xfs/078 xfs/216 xfs/217 xfs/250
      
      For ext4 we have a similar issue where writes never happen, but we don't
      currently have any xfstests that use loopback and show this issue.
      
      Fix this by restoring the WRITE flag argument to iov_iter_bvec().  This
      causes the xfstests to all pass.
      
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: stable@vger.kernel.org
      Fixes: commit aa4d8616 ("block: loop: switch to VFS ITER_BVEC")
      Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
      Reviewed-by: default avatarMing Lei <ming.lei@redhat.com>
      Signed-off-by: default avatarRoss Zwisler <ross.zwisler@linux.intel.com>
      Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
      1d037577
  2. 26 Feb, 2018 1 commit
  3. 06 Jan, 2018 1 commit
  4. 26 Sep, 2017 2 commits
    • Shaohua Li's avatar
      block: fix a build error · 0b508bc9
      Shaohua Li authored
      The code is only for blkcg not for all cgroups
      
      Fixes: d4478e92 ("block/loop: make loop cgroup aware")
      Reported-by: default avatarkbuild test robot <fengguang.wu@intel.com>
      Signed-off-by: default avatarShaohua Li <shli@fb.com>
      Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
      0b508bc9
    • Shaohua Li's avatar
      block/loop: make loop cgroup aware · d4478e92
      Shaohua Li authored
      loop block device handles IO in a separate thread. The actual IO
      dispatched isn't cloned from the IO loop device received, so the
      dispatched IO loses the cgroup context.
      
      I'm ignoring buffer IO case now, which is quite complicated.  Making the
      loop thread aware cgroup context doesn't really help. The loop device
      only writes to a single file. In current writeback cgroup
      implementation, the file can only belong to one cgroup.
      
      For direct IO case, we could workaround the issue in theory. For
      example, say we assign cgroup1 5M/s BW for loop device and cgroup2
      10M/s. We can create a special cgroup for loop thread and assign at
      least 15M/s for the underlayer disk. In this way, we correctly throttle
      the two cgroups. But this is tricky to setup.
      
      This patch tries to address the issue. We record bio's css in loop
      command. When loop thread is handling the command, we then use the API
      provided in patch 1 to set the css for current task. The bio layer will
      use the css for new IO (from patch 3).
      Acked-by: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarShaohua Li <shli@fb.com>
      Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
      d4478e92
  5. 06 Sep, 2017 1 commit
  6. 01 Sep, 2017 3 commits
  7. 31 Aug, 2017 4 commits
  8. 23 Aug, 2017 1 commit
  9. 15 Aug, 2017 1 commit
  10. 29 Jun, 2017 2 commits
  11. 18 Jun, 2017 1 commit
    • NeilBrown's avatar
      loop: Add PF_LESS_THROTTLE to block/loop device thread. · b2ee7d46
      NeilBrown authored
      When a filesystem is mounted from a loop device, writes are
      throttled by balance_dirty_pages() twice: once when writing
      to the filesystem and once when the loop_handle_cmd() writes
      to the backing file.  This double-throttling can trigger
      positive feedback loops that create significant delays.  The
      throttling at the lower level is seen by the upper level as
      a slow device, so it throttles extra hard.
      
      The PF_LESS_THROTTLE flag was created to handle exactly this
      circumstance, though with an NFS filesystem mounted from a
      local NFS server.  It reduces the throttling on the lower
      layer so that it can proceed largely unthrottled.
      
      To demonstrate this, create a filesystem on a loop device
      and write (e.g. with dd) several large files which combine
      to consume significantly more than the limit set by
      /proc/sys/vm/dirty_ratio or dirty_bytes.  Measure the total
      time taken.
      
      When I do this directly on a device (no loop device) the
      total time for several runs (mkfs, mount, write 200 files,
      umount) is fairly stable: 28-35 seconds.
      When I do this over a loop device the times are much worse
      and less stable.  52-460 seconds.  Half below 100seconds,
      half above.
      When I apply this patch, the times become stable again,
      though not as fast as the no-loop-back case: 53-72 seconds.
      
      There may be room for further improvement as the total overhead still
      seems too high, but this is a big improvement.
      Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
      Reviewed-by: default avatarMing Lei <tom.leiming@gmail.com>
      Suggested-by: default avatarMichal Hocko <mhocko@suse.com>
      Acked-by: default avatarMichal Hocko <mhocko@suse.com>
      Signed-off-by: default avatarNeilBrown <neilb@suse.com>
      Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      b2ee7d46
  12. 09 Jun, 2017 3 commits
    • Christoph Hellwig's avatar
      blk-mq: switch ->queue_rq return value to blk_status_t · fc17b653
      Christoph Hellwig authored
      Use the same values for use for request completion errors as the return
      value from ->queue_rq.  BLK_STS_RESOURCE is special cased to cause
      a requeue, and all the others are completed as-is.
      Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
      Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      fc17b653
    • Christoph Hellwig's avatar
      block: introduce new block status code type · 2a842aca
      Christoph Hellwig authored
      Currently we use nornal Linux errno values in the block layer, and while
      we accept any error a few have overloaded magic meanings.  This patch
      instead introduces a new  blk_status_t value that holds block layer specific
      status codes and explicitly explains their meaning.  Helpers to convert from
      and to the previous special meanings are provided for now, but I suspect
      we want to get rid of them in the long run - those drivers that have a
      errno input (e.g. networking) usually get errnos that don't know about
      the special block layer overloads, and similarly returning them to userspace
      will usually return somethings that strictly speaking isn't correct
      for file system operations, but that's left as an exercise for later.
      
      For now the set of errors is a very limited set that closely corresponds
      to the previous overloaded errno values, but there is some low hanging
      fruite to improve it.
      
      blk_status_t (ab)uses the sparse __bitwise annotations to allow for sparse
      typechecking, so that we can easily catch places passing the wrong values.
      Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
      Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      2a842aca
    • Arnd Bergmann's avatar
      loop: fix error handling regression · b040ad9c
      Arnd Bergmann authored
      gcc points out an unusual indentation:
      
      drivers/block/loop.c: In function 'loop_set_status':
      drivers/block/loop.c:1149:3: error: this 'if' clause does not guard... [-Werror=misleading-indentation]
         if (figure_loop_size(lo, info->lo_offset, info->lo_sizelimit,
         ^~
      drivers/block/loop.c:1152:4: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
          goto exit;
      
      This was introduced by a new feature that accidentally moved the opening
      braces from one condition to another. Adding a second pair of braces
      makes it work correctly again and also more readable.
      
      Fixes: f2c6df7d ("loop: support 4k physical blocksize")
      Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
      Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      b040ad9c
  13. 08 Jun, 2017 3 commits
    • Hannes Reinecke's avatar
      loop: support 4k physical blocksize · f2c6df7d
      Hannes Reinecke authored
      When generating bootable VM images certain systems (most notably
      s390x) require devices with 4k blocksize. This patch implements
      a new flag 'LO_FLAGS_BLOCKSIZE' which will set the physical
      blocksize to that of the underlying device, and allow to change
      the logical blocksize for up to the physical blocksize.
      Signed-off-by: default avatarHannes Reinecke <hare@suse.com>
      Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      f2c6df7d
    • Hannes Reinecke's avatar
      51001b7d
    • James Wang's avatar
      Fix loop device flush before configure v3 · 64604957
      James Wang authored
      While installing SLES-12 (based on v4.4), I found that the installer
      will stall for 60+ seconds during LVM disk scan.  The root cause was
      determined to be the removal of a bound device check in loop_flush()
      by commit b5dd2f60 ("block: loop: improve performance via blk-mq").
      
      Restoring this check, examining ->lo_state as set by loop_set_fd()
      eliminates the bad behavior.
      
      Test method:
      modprobe loop max_loop=64
      dd if=/dev/zero of=disk bs=512 count=200K
      for((i=0;i<4;i++))do losetup -f disk; done
      mkfs.ext4 -F /dev/loop0
      for((i=0;i<4;i++))do mkdir t$i; mount /dev/loop$i t$i;done
      for f in `ls /dev/loop[0-9]*|sort`; do \
      	echo $f; dd if=$f of=/dev/null  bs=512 count=1; \
      	done
      
      Test output:  stock          patched
      /dev/loop0    18.1217e-05    8.3842e-05
      /dev/loop1     6.1114e-05    0.000147979
      /dev/loop10    0.414701      0.000116564
      /dev/loop11    0.7474        6.7942e-05
      /dev/loop12    0.747986      8.9082e-05
      /dev/loop13    0.746532      7.4799e-05
      /dev/loop14    0.480041      9.3926e-05
      /dev/loop15    1.26453       7.2522e-05
      
      Note that from loop10 onward, the device is not mounted, yet the
      stock kernel consumes several orders of magnitude more wall time
      than it does for a mounted device.
      (Thanks for Mike Galbraith <efault@gmx.de>, give a changelog review.)
      Reviewed-by: default avatarHannes Reinecke <hare@suse.com>
      Reviewed-by: default avatarMing Lei <ming.lei@redhat.com>
      Signed-off-by: default avatarJames Wang <jnwang@suse.com>
      Fixes: b5dd2f60 ("block: loop: improve performance via blk-mq")
      Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      64604957
  14. 02 May, 2017 1 commit
  15. 20 Apr, 2017 2 commits
  16. 08 Apr, 2017 2 commits
  17. 31 Mar, 2017 1 commit
  18. 03 Mar, 2017 1 commit
    • David Howells's avatar
      statx: Add a system call to make enhanced file info available · a528d35e
      David Howells authored
      Add a system call to make extended file information available, including
      file creation and some attribute flags where available through the
      underlying filesystem.
      
      The getattr inode operation is altered to take two additional arguments: a
      u32 request_mask and an unsigned int flags that indicate the
      synchronisation mode.  This change is propagated to the vfs_getattr*()
      function.
      
      Functions like vfs_stat() are now inline wrappers around new functions
      vfs_statx() and vfs_statx_fd() to reduce stack usage.
      
      ========
      OVERVIEW
      ========
      
      The idea was initially proposed as a set of xattrs that could be retrieved
      with getxattr(), but the general preference proved to be for a new syscall
      with an extended stat structure.
      
      A number of requests were gathered for features to be included.  The
      following have been included:
      
       (1) Make the fields a consistent size on all arches and make them large.
      
       (2) Spare space, request flags and information flags are provided for
           future expansion.
      
       (3) Better support for the y2038 problem [Arnd Bergmann] (tv_sec is an
           __s64).
      
       (4) Creation time: The SMB protocol carries the creation time, which could
           be exported by Samba, which will in turn help CIFS make use of
           FS-Cache as that can be used for coherency data (stx_btime).
      
           This is also specified in NFSv4 as a recommended attribute and could
           be exported by NFSD [Steve French].
      
       (5) Lightweight stat: Ask for just those details of interest, and allow a
           netfs (such as NFS) to approximate anything not of interest, possibly
           without going to the server [Trond Myklebust, Ulrich Drepper, Andreas
           Dilger] (AT_STATX_DONT_SYNC).
      
       (6) Heavyweight stat: Force a netfs to go to the server, even if it thinks
           its cached attributes are up to date [Trond Myklebust]
           (AT_STATX_FORCE_SYNC).
      
      And the following have been left out for future extension:
      
       (7) Data version number: Could be used by userspace NFS servers [Aneesh
           Kumar].
      
           Can also be used to modify fill_post_wcc() in NFSD which retrieves
           i_version directly, but has just called vfs_getattr().  It could get
           it from the kstat struct if it used vfs_xgetattr() instead.
      
           (There's disagreement on the exact semantics of a single field, since
           not all filesystems do this the same way).
      
       (8) BSD stat compatibility: Including more fields from the BSD stat such
           as creation time (st_btime) and inode generation number (st_gen)
           [Jeremy Allison, Bernd Schubert].
      
       (9) Inode generation number: Useful for FUSE and userspace NFS servers
           [Bernd Schubert].
      
           (This was asked for but later deemed unnecessary with the
           open-by-handle capability available and caused disagreement as to
           whether it's a security hole or not).
      
      (10) Extra coherency data may be useful in making backups [Andreas Dilger].
      
           (No particular data were offered, but things like last backup
           timestamp, the data version number and the DOS archive bit would come
           into this category).
      
      (11) Allow the filesystem to indicate what it can/cannot provide: A
           filesystem can now say it doesn't support a standard stat feature if
           that isn't available, so if, for instance, inode numbers or UIDs don't
           exist or are fabricated locally...
      
           (This requires a separate system call - I have an fsinfo() call idea
           for this).
      
      (12) Store a 16-byte volume ID in the superblock that can be returned in
           struct xstat [Steve French].
      
           (Deferred to fsinfo).
      
      (13) Include granularity fields in the time data to indicate the
           granularity of each of the times (NFSv4 time_delta) [Steve French].
      
           (Deferred to fsinfo).
      
      (14) FS_IOC_GETFLAGS value.  These could be translated to BSD's st_flags.
           Note that the Linux IOC flags are a mess and filesystems such as Ext4
           define flags that aren't in linux/fs.h, so translation in the kernel
           may be a necessity (or, possibly, we provide the filesystem type too).
      
           (Some attributes are made available in stx_attributes, but the general
           feeling was that the IOC flags were to ext[234]-specific and shouldn't
           be exposed through statx this way).
      
      (15) Mask of features available on file (eg: ACLs, seclabel) [Brad Boyer,
           Michael Kerrisk].
      
           (Deferred, probably to fsinfo.  Finding out if there's an ACL or
           seclabal might require extra filesystem operations).
      
      (16) Femtosecond-resolution timestamps [Dave Chinner].
      
           (A __reserved field has been left in the statx_timestamp struct for
           this - if there proves to be a need).
      
      (17) A set multiple attributes syscall to go with this.
      
      ===============
      NEW SYSTEM CALL
      ===============
      
      The new system call is:
      
      	int ret = statx(int dfd,
      			const char *filename,
      			unsigned int flags,
      			unsigned int mask,
      			struct statx *buffer);
      
      The dfd, filename and flags parameters indicate the file to query, in a
      similar way to fstatat().  There is no equivalent of lstat() as that can be
      emulated with statx() by passing AT_SYMLINK_NOFOLLOW in flags.  There is
      also no equivalent of fstat() as that can be emulated by passing a NULL
      filename to statx() with the fd of interest in dfd.
      
      Whether or not statx() synchronises the attributes with the backing store
      can be controlled by OR'ing a value into the flags argument (this typically
      only affects network filesystems):
      
       (1) AT_STATX_SYNC_AS_STAT tells statx() to behave as stat() does in this
           respect.
      
       (2) AT_STATX_FORCE_SYNC will require a network filesystem to synchronise
           its attributes with the server - which might require data writeback to
           occur to get the timestamps correct.
      
       (3) AT_STATX_DONT_SYNC will suppress synchronisation with the server in a
           network filesystem.  The resulting values should be considered
           approximate.
      
      mask is a bitmask indicating the fields in struct statx that are of
      interest to the caller.  The user should set this to STATX_BASIC_STATS to
      get the basic set returned by stat().  It should be noted that asking for
      more information may entail extra I/O operations.
      
      buffer points to the destination for the data.  This must be 256 bytes in
      size.
      
      ======================
      MAIN ATTRIBUTES RECORD
      ======================
      
      The following structures are defined in which to return the main attribute
      set:
      
      	struct statx_timestamp {
      		__s64	tv_sec;
      		__s32	tv_nsec;
      		__s32	__reserved;
      	};
      
      	struct statx {
      		__u32	stx_mask;
      		__u32	stx_blksize;
      		__u64	stx_attributes;
      		__u32	stx_nlink;
      		__u32	stx_uid;
      		__u32	stx_gid;
      		__u16	stx_mode;
      		__u16	__spare0[1];
      		__u64	stx_ino;
      		__u64	stx_size;
      		__u64	stx_blocks;
      		__u64	__spare1[1];
      		struct statx_timestamp	stx_atime;
      		struct statx_timestamp	stx_btime;
      		struct statx_timestamp	stx_ctime;
      		struct statx_timestamp	stx_mtime;
      		__u32	stx_rdev_major;
      		__u32	stx_rdev_minor;
      		__u32	stx_dev_major;
      		__u32	stx_dev_minor;
      		__u64	__spare2[14];
      	};
      
      The defined bits in request_mask and stx_mask are:
      
      	STATX_TYPE		Want/got stx_mode & S_IFMT
      	STATX_MODE		Want/got stx_mode & ~S_IFMT
      	STATX_NLINK		Want/got stx_nlink
      	STATX_UID		Want/got stx_uid
      	STATX_GID		Want/got stx_gid
      	STATX_ATIME		Want/got stx_atime{,_ns}
      	STATX_MTIME		Want/got stx_mtime{,_ns}
      	STATX_CTIME		Want/got stx_ctime{,_ns}
      	STATX_INO		Want/got stx_ino
      	STATX_SIZE		Want/got stx_size
      	STATX_BLOCKS		Want/got stx_blocks
      	STATX_BASIC_STATS	[The stuff in the normal stat struct]
      	STATX_BTIME		Want/got stx_btime{,_ns}
      	STATX_ALL		[All currently available stuff]
      
      stx_btime is the file creation time, stx_mask is a bitmask indicating the
      data provided and __spares*[] are where as-yet undefined fields can be
      placed.
      
      Time fields are structures with separate seconds and nanoseconds fields
      plus a reserved field in case we want to add even finer resolution.  Note
      that times will be negative if before 1970; in such a case, the nanosecond
      fields will also be negative if not zero.
      
      The bits defined in the stx_attributes field convey information about a
      file, how it is accessed, where it is and what it does.  The following
      attributes map to FS_*_FL flags and are the same numerical value:
      
      	STATX_ATTR_COMPRESSED		File is compressed by the fs
      	STATX_ATTR_IMMUTABLE		File is marked immutable
      	STATX_ATTR_APPEND		File is append-only
      	STATX_ATTR_NODUMP		File is not to be dumped
      	STATX_ATTR_ENCRYPTED		File requires key to decrypt in fs
      
      Within the kernel, the supported flags are listed by:
      
      	KSTAT_ATTR_FS_IOC_FLAGS
      
      [Are any other IOC flags of sufficient general interest to be exposed
      through this interface?]
      
      New flags include:
      
      	STATX_ATTR_AUTOMOUNT		Object is an automount trigger
      
      These are for the use of GUI tools that might want to mark files specially,
      depending on what they are.
      
      Fields in struct statx come in a number of classes:
      
       (0) stx_dev_*, stx_blksize.
      
           These are local system information and are always available.
      
       (1) stx_mode, stx_nlinks, stx_uid, stx_gid, stx_[amc]time, stx_ino,
           stx_size, stx_blocks.
      
           These will be returned whether the caller asks for them or not.  The
           corresponding bits in stx_mask will be set to indicate whether they
           actually have valid values.
      
           If the caller didn't ask for them, then they may be approximated.  For
           example, NFS won't waste any time updating them from the server,
           unless as a byproduct of updating something requested.
      
           If the values don't actually exist for the underlying object (such as
           UID or GID on a DOS file), then the bit won't be set in the stx_mask,
           even if the caller asked for the value.  In such a case, the returned
           value will be a fabrication.
      
           Note that there are instances where the type might not be valid, for
           instance Windows reparse points.
      
       (2) stx_rdev_*.
      
           This will be set only if stx_mode indicates we're looking at a
           blockdev or a chardev, otherwise will be 0.
      
       (3) stx_btime.
      
           Similar to (1), except this will be set to 0 if it doesn't exist.
      
      =======
      TESTING
      =======
      
      The following test program can be used to test the statx system call:
      
      	samples/statx/test-statx.c
      
      Just compile and run, passing it paths to the files you want to examine.
      The file is built automatically if CONFIG_SAMPLES is enabled.
      
      Here's some example output.  Firstly, an NFS directory that crosses to
      another FSID.  Note that the AUTOMOUNT attribute is set because transiting
      this directory will cause d_automount to be invoked by the VFS.
      
      	[root@andromeda ~]# /tmp/test-statx -A /warthog/data
      	statx(/warthog/data) = 0
      	results=7ff
      	  Size: 4096            Blocks: 8          IO Block: 1048576  directory
      	Device: 00:26           Inode: 1703937     Links: 125
      	Access: (3777/drwxrwxrwx)  Uid:     0   Gid:  4041
      	Access: 2016-11-24 09:02:12.219699527+0000
      	Modify: 2016-11-17 10:44:36.225653653+0000
      	Change: 2016-11-17 10:44:36.225653653+0000
      	Attributes: 0000000000001000 (-------- -------- -------- -------- -------- -------- ---m---- --------)
      
      Secondly, the result of automounting on that directory.
      
      	[root@andromeda ~]# /tmp/test-statx /warthog/data
      	statx(/warthog/data) = 0
      	results=7ff
      	  Size: 4096            Blocks: 8          IO Block: 1048576  directory
      	Device: 00:27           Inode: 2           Links: 125
      	Access: (3777/drwxrwxrwx)  Uid:     0   Gid:  4041
      	Access: 2016-11-24 09:02:12.219699527+0000
      	Modify: 2016-11-17 10:44:36.225653653+0000
      	Change: 2016-11-17 10:44:36.225653653+0000
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      a528d35e
  19. 02 Mar, 2017 1 commit
  20. 28 Feb, 2017 1 commit
  21. 20 Feb, 2017 1 commit
  22. 13 Feb, 2017 1 commit
    • Ming Lei's avatar
      block/loop: fix race between I/O and set_status · ecdd0959
      Ming Lei authored
      Inside set_status, transfer need to setup again, so
      we have to drain IO before the transition, otherwise
      oops may be triggered like the following:
      
      	divide error: 0000 [#1] SMP KASAN
      	CPU: 0 PID: 2935 Comm: loop7 Not tainted 4.10.0-rc7+ #213
      	Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs
      	01/01/2011
      	task: ffff88006ba1e840 task.stack: ffff880067338000
      	RIP: 0010:transfer_xor+0x1d1/0x440 drivers/block/loop.c:110
      	RSP: 0018:ffff88006733f108 EFLAGS: 00010246
      	RAX: 0000000000000000 RBX: ffff8800688d7000 RCX: 0000000000000059
      	RDX: 0000000000000000 RSI: 1ffff1000d743f43 RDI: ffff880068891c08
      	RBP: ffff88006733f160 R08: ffff8800688d7001 R09: 0000000000000000
      	R10: 0000000000000000 R11: 0000000000000000 R12: ffff8800688d7000
      	R13: ffff880067b7d000 R14: dffffc0000000000 R15: 0000000000000000
      	FS:  0000000000000000(0000) GS:ffff88006d000000(0000)
      	knlGS:0000000000000000
      	CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
      	CR2: 00000000006c17e0 CR3: 0000000066e3b000 CR4: 00000000001406f0
      	Call Trace:
      	 lo_do_transfer drivers/block/loop.c:251 [inline]
      	 lo_read_transfer drivers/block/loop.c:392 [inline]
      	 do_req_filebacked drivers/block/loop.c:541 [inline]
      	 loop_handle_cmd drivers/block/loop.c:1677 [inline]
      	 loop_queue_work+0xda0/0x49b0 drivers/block/loop.c:1689
      	 kthread_worker_fn+0x4c3/0xa30 kernel/kthread.c:630
      	 kthread+0x326/0x3f0 kernel/kthread.c:227
      	 ret_from_fork+0x31/0x40 arch/x86/entry/entry_64.S:430
      	Code: 03 83 e2 07 41 29 df 42 0f b6 04 30 4d 8d 44 24 01 38 d0 7f 08
      	84 c0 0f 85 62 02 00 00 44 89 f8 41 0f b6 48 ff 25 ff 01 00 00 99 <f7>
      	7d c8 48 63 d2 48 03 55 d0 48 89 d0 48 89 d7 48 c1 e8 03 83
      	RIP: transfer_xor+0x1d1/0x440 drivers/block/loop.c:110 RSP:
      	ffff88006733f108
      	---[ end trace 0166f7bd3b0c0933 ]---
      Reported-by: default avatarDmitry Vyukov <dvyukov@google.com>
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarMing Lei <tom.leiming@gmail.com>
      Tested-by: default avatarDmitry Vyukov <dvyukov@google.com>
      Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      ecdd0959
  23. 24 Dec, 2016 1 commit
  24. 14 Nov, 2016 1 commit
  25. 11 Oct, 2016 1 commit
    • Petr Mladek's avatar
      kthread: kthread worker API cleanup · 3989144f
      Petr Mladek authored
      A good practice is to prefix the names of functions by the name
      of the subsystem.
      
      The kthread worker API is a mix of classic kthreads and workqueues.  Each
      worker has a dedicated kthread.  It runs a generic function that process
      queued works.  It is implemented as part of the kthread subsystem.
      
      This patch renames the existing kthread worker API to use
      the corresponding name from the workqueues API prefixed by
      kthread_:
      
      __init_kthread_worker()		-> __kthread_init_worker()
      init_kthread_worker()		-> kthread_init_worker()
      init_kthread_work()		-> kthread_init_work()
      insert_kthread_work()		-> kthread_insert_work()
      queue_kthread_work()		-> kthread_queue_work()
      flush_kthread_work()		-> kthread_flush_work()
      flush_kthread_worker()		-> kthread_flush_worker()
      
      Note that the names of DEFINE_KTHREAD_WORK*() macros stay
      as they are. It is common that the "DEFINE_" prefix has
      precedence over the subsystem names.
      
      Note that INIT() macros and init() functions use different
      naming scheme. There is no good solution. There are several
      reasons for this solution:
      
        + "init" in the function names stands for the verb "initialize"
          aka "initialize worker". While "INIT" in the macro names
          stands for the noun "INITIALIZER" aka "worker initializer".
      
        + INIT() macros are used only in DEFINE() macros
      
        + init() functions are used close to the other kthread()
          functions. It looks much better if all the functions
          use the same scheme.
      
        + There will be also kthread_destroy_worker() that will
          be used close to kthread_cancel_work(). It is related
          to the init() function. Again it looks better if all
          functions use the same naming scheme.
      
        + there are several precedents for such init() function
          names, e.g. amd_iommu_init_device(), free_area_init_node(),
          jump_label_init_type(),  regmap_init_mmio_clk(),
      
        + It is not an argument but it was inconsistent even before.
      
      [arnd@arndb.de: fix linux-next merge conflict]
       Link: http://lkml.kernel.org/r/20160908135724.1311726-1-arnd@arndb.de
      Link: http://lkml.kernel.org/r/1470754545-17632-3-git-send-email-pmladek@suse.comSuggested-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarPetr Mladek <pmladek@suse.com>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
      Cc: Josh Triplett <josh@joshtriplett.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Jiri Kosina <jkosina@suse.cz>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Vlastimil Babka <vbabka@suse.cz>
      Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      3989144f
  26. 15 Sep, 2016 1 commit
  27. 04 Aug, 2016 1 commit