1. 17 Jul, 2017 1 commit
    • David Howells's avatar
      VFS: Convert sb->s_flags & MS_RDONLY to sb_rdonly(sb) · bc98a42c
      David Howells authored
      Firstly by applying the following with coccinelle's spatch:
      	@@ expression SB; @@
      	-SB->s_flags & MS_RDONLY
      to effect the conversion to sb_rdonly(sb), then by applying:
      	@@ expression A, SB; @@
      	-(!sb_rdonly(SB)) && A
      	+!sb_rdonly(SB) && A
      	-A != (sb_rdonly(SB))
      	+A != sb_rdonly(SB)
      	-A == (sb_rdonly(SB))
      	+A == sb_rdonly(SB)
      	-A && (sb_rdonly(SB))
      	+A && sb_rdonly(SB)
      	-A || (sb_rdonly(SB))
      	+A || sb_rdonly(SB)
      	-(sb_rdonly(SB)) != A
      	+sb_rdonly(SB) != A
      	-(sb_rdonly(SB)) == A
      	+sb_rdonly(SB) == A
      	-(sb_rdonly(SB)) && A
      	+sb_rdonly(SB) && A
      	-(sb_rdonly(SB)) || A
      	+sb_rdonly(SB) || A
      	@@ expression A, B, SB; @@
      	-(sb_rdonly(SB)) ? 1 : 0
      	-(sb_rdonly(SB)) ? A : B
      	+sb_rdonly(SB) ? A : B
      to remove left over excess bracketage and finally by applying:
      	@@ expression A, SB; @@
      	-(A & MS_RDONLY) != sb_rdonly(SB)
      	+(bool)(A & MS_RDONLY) != sb_rdonly(SB)
      	-(A & MS_RDONLY) == sb_rdonly(SB)
      	+(bool)(A & MS_RDONLY) == sb_rdonly(SB)
      to make comparisons against the result of sb_rdonly() (which is a bool)
      work correctly.
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
  2. 07 Jul, 2017 1 commit
  3. 06 Jul, 2017 2 commits
    • Jeff Layton's avatar
      buffer: set errors in mapping at the time that the error occurs · 87354e5d
      Jeff Layton authored
      I noticed on xfs that I could still sometimes get back an error on fsync
      on a fd that was opened after the error condition had been cleared.
      The problem is that the buffer code sets the write_io_error flag and
      then later checks that flag to set the error in the mapping. That flag
      perisists for quite a while however. If the file is later opened with
      O_TRUNC, the buffers will then be invalidated and the mapping's error
      set such that a subsequent fsync will return error. I think this is
      incorrect, as there was no writeback between the open and fsync.
      Add a new mark_buffer_write_io_error operation that sets the flag and
      the error in the mapping at the same time. Replace all calls to
      set_buffer_write_io_error with mark_buffer_write_io_error, and remove
      the places that check this flag in order to set the error in the
      This sets the error in the mapping earlier, at the time that it's first
      Signed-off-by: default avatarJeff Layton <jlayton@redhat.com>
      Reviewed-by: default avatarJan Kara <jack@suse.cz>
      Reviewed-by: Carlos Maiolino's avatarCarlos Maiolino <cmaiolino@redhat.com>
    • David Howells's avatar
      VFS: Provide empty name qstr · cdf01226
      David Howells authored
      Provide an empty name (ie. "") qstr for general use.
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
  4. 05 Jul, 2017 5 commits
  5. 20 Jun, 2017 1 commit
  6. 12 Jun, 2017 2 commits
  7. 09 Jun, 2017 2 commits
  8. 05 Jun, 2017 1 commit
  9. 24 May, 2017 1 commit
    • Jan Kara's avatar
      gfs2: Make flush bios explicitely sync · 0f0b9b63
      Jan Kara authored
      Commit b685d3d6 "block: treat REQ_FUA and REQ_PREFLUSH as
      synchronous" removed REQ_SYNC flag from WRITE_{FUA|PREFLUSH|...}
      definitions.  generic_make_request_checks() however strips REQ_FUA and
      REQ_PREFLUSH flags from a bio when the storage doesn't report volatile
      write cache and thus write effectively becomes asynchronous which can
      lead to performance regressions
      Fix the problem by making sure all bios which are synchronous are
      properly marked with REQ_SYNC.
      Fixes: b685d3d6
      CC: Steven Whitehouse <swhiteho@redhat.com>
      CC: cluster-devel@redhat.com
      CC: stable@vger.kernel.org
      Acked-by: default avatarBob Peterson <rpeterso@redhat.com>
      Signed-off-by: default avatarJan Kara <jack@suse.cz>
  10. 09 May, 2017 1 commit
  11. 05 May, 2017 1 commit
    • Bob Peterson's avatar
      GFS2: Allow glocks to be unlocked after withdraw · ed17545d
      Bob Peterson authored
      This bug fixes a regression introduced by patch 0d1c7ae9.
      The intent of the patch was to stop promoting glocks after a
      file system is withdrawn due to a variety of errors, because doing
      so results in a BUG(). (You should be able to unmount after a
      withdraw rather than having the kernel panic.)
      Unfortunately, it also stopped demotions, so glocks could not be
      unlocked after withdraw, which means the unmount would hang.
      This patch allows function do_xmote to demote locks to an
      unlocked state after a withdraw, but not promote them.
      Signed-off-by: default avatarBob Peterson <rpeterso@redhat.com>
  12. 20 Apr, 2017 2 commits
  13. 19 Apr, 2017 1 commit
    • Bob Peterson's avatar
      GFS2: Non-recursive delete · d552a2b9
      Bob Peterson authored
      Implement truncate/delete as a non-recursive algorithm. The older
      algorithm was implemented with recursion to strip off each layer
      at a time (going by height, starting with the maximum height.
      This version tries to do the same thing but without recursion,
      and without needing to allocate new structures or lists in memory.
      For example, say you want to truncate a very large file to 1 byte,
      and its end-of-file metapath is: 0.505.463.428. The starting
      metapath would be Since it's a truncate to non-zero, it
      needs to preserve that byte, and all metadata pointing to it.
      So it would start at, look up all its metadata buffers,
      then free all data blocks pointed to at the highest level.
      After that buffer is "swept", it moves on to, then, etc., reading in buffers and sweeping them clean.
      When it gets to the end of the 0.0.0 metadata buffer (for 4K
      blocks the last valid one is, it backs up to the
      previous height and starts working on, then,
      and so forth. After it reaches the end and sweeps,
      it continues with, and so on. When that height is
      exhausted, and it reaches 0.0.508.508 it backs up another level,
      to, then, through So it has to keep
      marching backwards and forwards through the metadata until it's
      all swept clean. Once it has all the data blocks freed, it
      lowers the strip height, and begins the process all over again,
      but with one less height. This time it sweeps 0.0.0 through
      0.505.463. When that's clean, it lowers the strip height again
      and works to free 0.505. Eventually it strips the lowest height, 0.
      For a delete or truncate to 0, all metadata for all heights of would be freed. For a truncate to 1 byte, would
      be preserved.
      This isn't much different from normal integer incrementing,
      where an integer gets incremented from 0000 ( to 3021
      ( So 0000 gets increments to 0001, 0002, up to 0009,
      then on to 0010, 0011 up to 0099, then 0100 and so forth. It's
      just that each "digit" goes from 0 to 508 (for a total of 509
      pointers) rather than from 0 to 9.
      Note that the dinode will only have 483 pointers due to the
      dinode structure itself.
      Also note: this is just an example. These numbers (509 and 483)
      are based on a standard 4K block size. Smaller block sizes will
      yield smaller numbers of indirect pointers accordingly.
      The truncation process is accomplished with the help of two
      major functions and a few helper functions.
      Functions do_strip and recursive_scan are obsolete, so removed.
      New function sweep_bh_for_rgrps cleans a buffer_head pointed to
      by the given metapath and height. By cleaning, I mean it frees
      all blocks starting at the offset passed in metapath. It starts
      at the first block in the buffer pointed to by the metapath and
      identifies its resource group (rgrp). From there it frees all
      subsequent block pointers that lie within that rgrp. If it's
      already inside a transaction, it stays within it as long as it
      can. In other words, it doesn't close a transaction until it knows
      it's freed what it can from the resource group. In this way,
      multiple buffers may be cleaned in a single transaction, as long
      as those blocks in the buffer all lie within the same rgrp.
      If it's not in a transaction, it starts one. If the buffer_head
      has references to blocks within multiple rgrps, it frees all the
      blocks inside the first rgrp it finds, then closes the
      transaction. Then it repeats the cycle: identifies the next
      unfreed block, uses it to find its rgrp, then starts a new
      transaction for that set. It repeats this process repeatedly
      until the buffer_head contains no more references to any blocks
      past the given metapath.
      Function trunc_dealloc has been reworked into a finite state
      automaton. It has basically 3 active states:
      The DEALLOC_MP_FULL state implies the metapath has a full set
      of buffers out to the "shrink height", and therefore, it can
      call function sweep_bh_for_rgrps to free the blocks within the
      highest height of the metapath. If it's just swept the lowest
      level (or an error has occurred) the state machine is ended.
      Otherwise it proceeds to the DEALLOC_MP_LOWER state.
      The DEALLOC_MP_LOWER state implies we are finished with a given
      buffer_head, which may now be released, and therefore we are
      then missing some buffer information from the metapath. So we
      need to find more buffers to read in. In most cases, this is
      just a matter of releasing the buffer_head and moving to the
      next pointer from the previous height, so it may be read in and
      swept as well. If it can't find another non-null pointer to
      process, it checks whether it's reached the end of a height
      and needs to lower the strip height, or whether it still needs
      move forward through the previous height's metadata. In this
      state, all zero-pointers are skipped. From this state, it can
      only loop around (once more backing up another height) or,
      once a valid metapath is found (one that has non-zero
      pointers), proceed to state DEALLOC_FILL_MP.
      The DEALLOC_FILL_MP state implies that we have a metapath
      but not all its buffers are read in. So we must proceed to read
      in buffer_heads until the metapath has a valid buffer for every
      height. If the previous state backed us up 3 heights, we may
      need to read in a buffer, increment the height, then repeat the
      process until buffers have been read in for all required heights.
      If it's successful reading a buffer, and it's at the highest
      height we need, it proceeds back to the DEALLOC_MP_FULL state.
      If it's unable to fill in a buffer, (encounters a hole, etc.)
      it tries to find another non-zero block pointer. If they're all
      zero, it lowers the height and returns to the DEALLOC_MP_LOWER
      state. If it finds a good non-null pointer, it loops around and
      reads it in, while keeping the metapath in lock-step with the
      pointers it examines.
      The state machine runs until the truncation request is
      satisfied. Then any transactions are ended, the quota and
      statfs data are updated, and the function is complete.
      Helper function metaptr1 was introduced to be an easy way to
      determine the start of a buffer_head's indirect pointers.
      Helper function lookup_mp_height was introduced to find a
      metapath index and read in the buffer that corresponds to it.
      In this way, function lookup_metapath becomes a simple loop to
      call it for every height.
      Helper function fillup_metapath is similar to lookup_metapath
      except it can do partial lookups. If the state machine
      backed up multiple levels (like 2999 wrapping to 3000) it
      needs to find out the next starting point and start issuing
      metadata reads at that point.
      Helper function hptrs is a shortcut to determine how many
      pointers should be expected in a buffer. Height 0 is the dinode
      which has fewer pointers than the others.
      Signed-off-by: default avatarBob Peterson <rpeterso@redhat.com>
  14. 05 Apr, 2017 1 commit
  15. 03 Apr, 2017 2 commits
  16. 16 Mar, 2017 5 commits
  17. 15 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*()
      Functions like vfs_stat() are now inline wrappers around new functions
      vfs_statx() and vfs_statx_fd() to reduce stack usage.
      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
       (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]
      And the following have been left out for future extension:
       (7) Data version number: Could be used by userspace NFS servers [Aneesh
           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.
      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
       (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
      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
      The following structures are defined in which to return the main attribute
      	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
      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:
      [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.
      The following test program can be used to test the statx system call:
      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
      	  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
      	  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>
  19. 02 Mar, 2017 2 commits
  20. 25 Feb, 2017 1 commit
  21. 23 Feb, 2017 1 commit
  22. 17 Feb, 2017 1 commit
  23. 16 Feb, 2017 1 commit
  24. 14 Feb, 2017 1 commit
  25. 03 Feb, 2017 1 commit
  26. 02 Feb, 2017 1 commit