Commit Graph

310 Commits

Author SHA1 Message Date
Martin Brandenburg
7a3bc1f019 orangefs: make orangefs_client_debug_init static
Signed-off-by: Martin Brandenburg <martin@omnibond.com>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2018-02-06 16:38:12 -05:00
Martin Brandenburg
6793f1c450 orangefs: fix deadlock; do not write i_size in read_iter
After do_readv_writev, the inode cache is invalidated anyway, so i_size
will never be read.  It will be fetched from the server which will also
know about updates from other machines.

Fixes deadlock on 32-bit SMP.

See https://marc.info/?l=linux-fsdevel&m=151268557427760&w=2

Signed-off-by: Martin Brandenburg <martin@omnibond.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Mike Marshall <hubcap@omnibond.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-01-25 17:26:24 -08:00
Martin Brandenburg
a0ec1ded22 orangefs: initialize op on loop restart in orangefs_devreq_read
In orangefs_devreq_read, there is a loop which picks an op off the list
of pending ops.  If the loop fails to find an op, there is nothing to
read, and it returns EAGAIN.  If the op has been given up on, the loop
is restarted via a goto.  The bug is that the variable which the found
op is written to is not reinitialized, so if there are no more eligible
ops on the list, the code runs again on the already handled op.

This is triggered by interrupting a process while the op is being copied
to the client-core.  It's a fairly small window, but it's there.

Signed-off-by: Martin Brandenburg <martin@omnibond.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-01-22 13:51:14 -08:00
Martin Brandenburg
0afc0decf2 orangefs: use list_for_each_entry_safe in purge_waiting_ops
set_op_state_purged can delete the op.

Signed-off-by: Martin Brandenburg <martin@omnibond.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-01-22 13:51:14 -08:00
Linus Torvalds
1751e8a6cb Rename superblock flags (MS_xyz -> SB_xyz)
This is a pure automated search-and-replace of the internal kernel
superblock flags.

The s_flags are now called SB_*, with the names and the values for the
moment mirroring the MS_* flags that they're equivalent to.

Note how the MS_xyz flags are the ones passed to the mount system call,
while the SB_xyz flags are what we then use in sb->s_flags.

The script to do this was:

    # places to look in; re security/*: it generally should *not* be
    # touched (that stuff parses mount(2) arguments directly), but
    # there are two places where we really deal with superblock flags.
    FILES="drivers/mtd drivers/staging/lustre fs ipc mm \
            include/linux/fs.h include/uapi/linux/bfs_fs.h \
            security/apparmor/apparmorfs.c security/apparmor/include/lib.h"
    # the list of MS_... constants
    SYMS="RDONLY NOSUID NODEV NOEXEC SYNCHRONOUS REMOUNT MANDLOCK \
          DIRSYNC NOATIME NODIRATIME BIND MOVE REC VERBOSE SILENT \
          POSIXACL UNBINDABLE PRIVATE SLAVE SHARED RELATIME KERNMOUNT \
          I_VERSION STRICTATIME LAZYTIME SUBMOUNT NOREMOTELOCK NOSEC BORN \
          ACTIVE NOUSER"

    SED_PROG=
    for i in $SYMS; do SED_PROG="$SED_PROG -e s/MS_$i/SB_$i/g"; done

    # we want files that contain at least one of MS_...,
    # with fs/namespace.c and fs/pnode.c excluded.
    L=$(for i in $SYMS; do git grep -w -l MS_$i $FILES; done| sort|uniq|grep -v '^fs/namespace.c'|grep -v '^fs/pnode.c')

    for f in $L; do sed -i $f $SED_PROG; done

Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-27 13:05:09 -08:00
Linus Torvalds
b620fd2df2 3 Cleanups: remove initialization of i_version - Jeff Layton
use ARRAY_SIZE - Jérémy Lefaure
             call op_release sooner when creating inodes - Martin Brandenburg
 
 1 Patch: stop setting atime on inode dirty - Martin Brandenburg
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Merge tag 'for-linus-4.15-ofs1' of git://git.kernel.org/pub/scm/linux/kernel/git/hubcap/linux

Pull orangefs updates from Mike Marshall:
 "Fix:

   - stop setting atime on inode dirty (Martin Brandenburg)

  Cleanups:

   - remove initialization of i_version (Jeff Layton)

   - use ARRAY_SIZE (Jérémy Lefaure)

   - call op_release sooner when creating inodes (Mike MarshallMartin
     Brandenburg)"

* tag 'for-linus-4.15-ofs1' of git://git.kernel.org/pub/scm/linux/kernel/git/hubcap/linux:
  orangefs: call op_release sooner when creating inodes
  orangefs: stop setting atime on inode dirty
  orangefs: use ARRAY_SIZE
  orangefs: remove initialization of i_version
2017-11-21 05:40:48 -10:00
Linus Torvalds
16382e17c0 Merge branch 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull iov_iter updates from Al Viro:

 - bio_{map,copy}_user_iov() series; those are cleanups - fixes from the
   same pile went into mainline (and stable) in late September.

 - fs/iomap.c iov_iter-related fixes

 - new primitive - iov_iter_for_each_range(), which applies a function
   to kernel-mapped segments of an iov_iter.

   Usable for kvec and bvec ones, the latter does kmap()/kunmap() around
   the callback. _Not_ usable for iovec- or pipe-backed iov_iter; the
   latter is not hard to fix if the need ever appears, the former is by
   design.

   Another related primitive will have to wait for the next cycle - it
   passes page + offset + size instead of pointer + size, and that one
   will be usable for everything _except_ kvec. Unfortunately, that one
   didn't get exposure in -next yet, so...

 - a bit more lustre iov_iter work, including a use case for
   iov_iter_for_each_range() (checksum calculation)

 - vhost/scsi leak fix in failure exit

 - misc cleanups and detritectomy...

* 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (21 commits)
  iomap_dio_actor(): fix iov_iter bugs
  switch ksocknal_lib_recv_...() to use of iov_iter_for_each_range()
  lustre: switch struct ksock_conn to iov_iter
  vhost/scsi: switch to iov_iter_get_pages()
  fix a page leak in vhost_scsi_iov_to_sgl() error recovery
  new primitive: iov_iter_for_each_range()
  lnet_return_rx_credits_locked: don't abuse list_entry
  xen: don't open-code iov_iter_kvec()
  orangefs: remove detritus from struct orangefs_kiocb_s
  kill iov_shorten()
  bio_alloc_map_data(): do bmd->iter setup right there
  bio_copy_user_iov(): saner bio size calculation
  bio_map_user_iov(): get rid of copying iov_iter
  bio_copy_from_iter(): get rid of copying iov_iter
  move more stuff down into bio_copy_user_iov()
  blk_rq_map_user_iov(): move iov_iter_advance() down
  bio_map_user_iov(): get rid of the iov_for_each()
  bio_map_user_iov(): move alignment check into the main loop
  don't rely upon subsequent bio_add_pc_page() calls failing
  ... and with iov_iter_get_pages_alloc() it becomes even simpler
  ...
2017-11-17 12:08:18 -08:00
Martin Brandenburg
db0267e7af orangefs: call op_release sooner when creating inodes
Prevents holding an unnecessary op while the kernel processes another op
and yields the CPU.

Signed-off-by: Martin Brandenburg <martin@omnibond.com>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2017-11-13 15:10:18 -05:00
Martin Brandenburg
a55f2d8615 orangefs: stop setting atime on inode dirty
The previous code path was to mark the inode dirty, let
orangefs_inode_dirty set a flag in our private inode, then later during
inode release call orangefs_flush_inode which notices the flag and
writes the atime out.

The code path worked almost identically for mtime, ctime, and mode
except that those flags are set explicitly and not as side effects of
dirty.

Now orangefs_flush_inode is removed.  Marking an inode dirty does not
imply an atime update.  Any place where flags were set before is now
an explicit call to orangefs_inode_setattr.  Since OrangeFS does not
utilize inode writeback, the attribute change should be written out
immediately.

Fixes generic/120.

In namei.c, there are several places where the directory mtime and ctime
are set, but only the mtime is sent to the server.  These don't seem
right, but I've left them as is for now.

Signed-off-by: Martin Brandenburg <martin@omnibond.com>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2017-11-13 15:10:11 -05:00
Jérémy Lefaure
296200d3bb orangefs: use ARRAY_SIZE
Using the ARRAY_SIZE macro improves the readability of the code.

Found with Coccinelle with the following semantic patch:
@r depends on (org || report)@
type T;
T[] E;
position p;
@@
(
 (sizeof(E)@p /sizeof(*E))
|
 (sizeof(E)@p /sizeof(E[...]))
|
 (sizeof(E)@p /sizeof(T))
)

Signed-off-by: Jérémy Lefaure <jeremy.lefaure@lse.epita.fr>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2017-11-13 15:09:58 -05:00
Jeff Layton
933f7ac1a1 orangefs: remove initialization of i_version
...as it's completely unused.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2017-11-13 15:09:33 -05:00
Greg Kroah-Hartman
b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00
Al Viro
6570f0dd60 orangefs: remove detritus from struct orangefs_kiocb_s
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-10-11 17:23:44 -04:00
Markus Elfring
0b08273c8a orangefs: Adjust three checks for null pointers
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The script “checkpatch.pl” pointed information out like the following.

Comparison to NULL could be written !…

Thus fix affected source code places.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2017-09-14 14:58:31 -04:00
Markus Elfring
5e273a0e06 orangefs: Use kcalloc() in orangefs_prepare_cdm_array()
* A multiplication for the size determination of a memory allocation
  indicated that an array data structure should be processed.
  Thus use the corresponding function "kcalloc".

  This issue was detected by using the Coccinelle software.

* Replace the specification of a data structure by a pointer dereference
  to make the corresponding size determination a bit safer according to
  the Linux coding style convention.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2017-09-14 14:58:30 -04:00
Markus Elfring
07a258531c orangefs: Delete error messages for a failed memory allocation in five functions
Omit an extra message for a memory allocation failure in these functions.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2017-09-14 14:58:29 -04:00
Julia Lawall
1217444405 orangefs: constify xattr_handler structure
The xattr_handler structure is only stored in an array of const
structures.  Thus the xattr_handler structure itself can be
const.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2017-09-14 14:58:29 -04:00
Jeff Layton
49e5571324 orangefs: don't call filemap_write_and_wait from fsync
Orangefs doesn't do buffered writes yet, so there's no point in
initiating and waiting for writeback.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2017-09-14 14:58:28 -04:00
Dan Carpenter
5f13e58767 orangefs: off by ones in xattr size checks
A previous patch which claimed to remove off by ones actually introduced
them.

strlen() returns the length of the string not including the NUL
character.  We are using strcpy() to copy "name" into a buffer which is
ORANGEFS_MAX_XATTR_NAMELEN characters long.  We should make sure to
leave space for the NUL, otherwise we're writing one character beyond
the end of the buffer.

Fixes: e675c5ec51 ("orangefs: clean up oversize xattr validation")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2017-09-14 14:58:27 -04:00
Mike Marshall
4bef69000d orangefs: react properly to posix_acl_update_mode's aftermath.
posix_acl_update_mode checks to see if the permissions
described by the ACL can be encoded into the
object's mode. If so, it sets "acl" to NULL
and "mode" to the new desired value. Prior to this patch
we failed to actually propagate the new mode back to the
server.

Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2017-09-14 14:54:38 -04:00
Jan Kara
b5accbb0df orangefs: Don't clear SGID when inheriting ACLs
When new directory 'DIR1' is created in a directory 'DIR0' with SGID bit
set, DIR1 is expected to have SGID bit set (and owning group equal to
the owning group of 'DIR0'). However when 'DIR0' also has some default
ACLs that 'DIR1' inherits, setting these ACLs will result in SGID bit on
'DIR1' to get cleared if user is not member of the owning group.

Fix the problem by creating __orangefs_set_acl() function that does not
call posix_acl_update_mode() and use it when inheriting ACLs. That
prevents SGID bit clearing and the mode has been properly set by
posix_acl_create() anyway.

Fixes: 073931017b
CC: stable@vger.kernel.org
CC: Mike Marshall <hubcap@omnibond.com>
CC: pvfs2-developers@beowulf-underground.org
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2017-09-14 14:54:37 -04:00
Linus Torvalds
78dcf73421 Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull ->s_options removal from Al Viro:
 "Preparations for fsmount/fsopen stuff (coming next cycle). Everything
  gets moved to explicit ->show_options(), killing ->s_options off +
  some cosmetic bits around fs/namespace.c and friends. Basically, the
  stuff needed to work with fsmount series with minimum of conflicts
  with other work.

  It's not strictly required for this merge window, but it would reduce
  the PITA during the coming cycle, so it would be nice to have those
  bits and pieces out of the way"

* 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  isofs: Fix isofs_show_options()
  VFS: Kill off s_options and helpers
  orangefs: Implement show_options
  9p: Implement show_options
  isofs: Implement show_options
  afs: Implement show_options
  affs: Implement show_options
  befs: Implement show_options
  spufs: Implement show_options
  bpf: Implement show_options
  ramfs: Implement show_options
  pstore: Implement show_options
  omfs: Implement show_options
  hugetlbfs: Implement show_options
  VFS: Don't use save/replace_mount_options if not using generic_show_options
  VFS: Provide empty name qstr
  VFS: Make get_filesystem() return the affected filesystem
  VFS: Clean up whitespace in fs/namespace.c and fs/super.c
  Provide a function to create a NUL-terminated string from unterminated data
2017-07-15 12:00:42 -07:00
David Howells
4dfdb71307 orangefs: Implement show_options
Implement the show_options superblock op for orangefs as part of a bid to
rid of s_options and generic_show_options() to make it easier to implement
a context-based mount where the mount options can be passed individually
over a file descriptor.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Mike Marshall <hubcap@omnibond.com>
cc: pvfs2-developers@beowulf-underground.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-07-11 06:09:21 -04:00
Ingo Molnar
2055da9738 sched/wait: Disambiguate wq_entry->task_list and wq_head->task_list naming
So I've noticed a number of instances where it was not obvious from the
code whether ->task_list was for a wait-queue head or a wait-queue entry.

Furthermore, there's a number of wait-queue users where the lists are
not for 'tasks' but other entities (poll tables, etc.), in which case
the 'task_list' name is actively confusing.

To clear this all up, name the wait-queue head and entry list structure
fields unambiguously:

	struct wait_queue_head::task_list	=> ::head
	struct wait_queue_entry::task_list	=> ::entry

For example, this code:

	rqw->wait.task_list.next != &wait->task_list

... is was pretty unclear (to me) what it's doing, while now it's written this way:

	rqw->wait.head.next != &wait->entry

... which makes it pretty clear that we are iterating a list until we see the head.

Other examples are:

	list_for_each_entry_safe(pos, next, &x->task_list, task_list) {
	list_for_each_entry(wq, &fence->wait.task_list, task_list) {

... where it's unclear (to me) what we are iterating, and during review it's
hard to tell whether it's trying to walk a wait-queue entry (which would be
a bug), while now it's written as:

	list_for_each_entry_safe(pos, next, &x->head, entry) {
	list_for_each_entry(wq, &fence->wait.head, entry) {

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-20 12:19:14 +02:00
Ingo Molnar
ac6424b981 sched/wait: Rename wait_queue_t => wait_queue_entry_t
Rename:

	wait_queue_t		=>	wait_queue_entry_t

'wait_queue_t' was always a slight misnomer: its name implies that it's a "queue",
but in reality it's a queue *entry*. The 'real' queue is the wait queue head,
which had to carry the name.

Start sorting this out by renaming it to 'wait_queue_entry_t'.

This also allows the real structure name 'struct __wait_queue' to
lose its double underscore and become 'struct wait_queue_entry',
which is the more canonical nomenclature for such data types.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-20 12:18:27 +02:00
Linus Torvalds
aeced66196 Some cleanups:
remove unused get_fsid_from_ino
   fix bounds check for listxattr
   clean up oversize xattr validation
   do not set getattr_time on orangefs_lookup
   return from orangefs_devreq_read quickly if possible
   do not wait for timeout if umounting
   handle zero size write in debugfs
 
 Bug fixes:
 
   do not check possibly stale size on truncate
   ensure the userspace component is unmounted if mount fails
   total reimplementation of dir.c
 
 New feature:
 
   implement statx
 
 The new implementation of dir.c is kind of a big deal, all new
 code. It has been posted to fs-devel during the previous rc period,
 we didn't get much review or feedback from there, but it has been reviewed
 very heavily here, so much so that we have two entire versions of the
 reimplementation. Not only does the new implementation fix some
 xfstests, but it passes all the new tests we made here that involve
 seeking and rewinding and giant directories and long file names.
 The new dir code has three patches itself:
 
   skip forward to the next directory entry if seek is short
   invalidate stored directory on seek
   count directory pieces correctly
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Merge tag 'for-linus-4.12-ofs-1' of git://git.kernel.org/pub/scm/linux/kernel/git/hubcap/linux

Pull orangefs updates from Mike Marshall:
 "Orangefs cleanups, fixes and statx support.

  Some cleanups:

   - remove unused get_fsid_from_ino
   - fix bounds check for listxattr
   - clean up oversize xattr validation
   - do not set getattr_time on orangefs_lookup
   - return from orangefs_devreq_read quickly if possible
   - do not wait for timeout if umounting
   - handle zero size write in debugfs

  Bug fixes:

   - do not check possibly stale size on truncate
   - ensure the userspace component is unmounted if mount fails
   - total reimplementation of dir.c

  New feature:

   - implement statx

  The new implementation of dir.c is kind of a big deal, all new code.
  It has been posted to fs-devel during the previous rc period, we
  didn't get much review or feedback from there, but it has been
  reviewed very heavily here, so much so that we have two entire
  versions of the reimplementation.

  Not only does the new implementation fix some xfstests, but it passes
  all the new tests we made here that involve seeking and rewinding and
  giant directories and long file names. The new dir code has three
  patches itself:

   - skip forward to the next directory entry if seek is short
   - invalidate stored directory on seek
   - count directory pieces correctly"

* tag 'for-linus-4.12-ofs-1' of git://git.kernel.org/pub/scm/linux/kernel/git/hubcap/linux:
  orangefs: count directory pieces correctly
  orangefs: invalidate stored directory on seek
  orangefs: skip forward to the next directory entry if seek is short
  orangefs: handle zero size write in debugfs
  orangefs: do not wait for timeout if umounting
  orangefs: return from orangefs_devreq_read quickly if possible
  orangefs: ensure the userspace component is unmounted if mount fails
  orangefs: do not check possibly stale size on truncate
  orangefs: implement statx
  orangefs: remove ORANGEFS_READDIR macros
  orangefs: support very large directories
  orangefs: support llseek on directories
  orangefs: rewrite readdir to fix several bugs
  orangefs: do not set getattr_time on orangefs_lookup
  orangefs: clean up oversize xattr validation
  orangefs: fix bounds check for listxattr
  orangefs: remove unused get_fsid_from_ino
2017-05-05 13:36:10 -07:00
Martin Brandenburg
2f713b5c7d orangefs: count directory pieces correctly
A large directory full of differently sized file names triggered this.
Most directories, even very large directories with shorter names, would
be lucky enough to fit in one server response.

Signed-off-by: Martin Brandenburg <martin@omnibond.com>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2017-05-04 14:38:24 -04:00
Martin Brandenburg
942835d68f orangefs: invalidate stored directory on seek
If an application seeks to a position before the point which has been
read, it must want updates which have been made to the directory.  So
delete the copy stored in the kernel so it will be fetched again.

Signed-off-by: Martin Brandenburg <martin@omnibond.com>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2017-05-04 14:38:15 -04:00
Martin Brandenburg
bf15ba7c1f orangefs: skip forward to the next directory entry if seek is short
If userspace seeks to a position in the stream which is not correct, it
would have returned EIO because the data in the buffer at that offset
would be incorrect.  This and the userspace daemon returning a corrupt
directory are indistinguishable.

Now if the data does not look right, skip forward to the next chunk and
try again.  The motivation is that if the directory changes, an
application may seek to a position that was valid and no longer is valid.

It is not yet possible for a directory to change.

Signed-off-by: Martin Brandenburg <martin@omnibond.com>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2017-05-04 14:38:10 -04:00
Dan Carpenter
907bfcd8d8 orangefs: handle zero size write in debugfs
If we write zero bytes to this debugfs file, then it will cause an
underflow when we do copy_from_user(buf, ubuf, count - 1).  Debugfs can
normally only be written to by root so the impact of this is low.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2017-04-26 14:33:01 -04:00
Martin Brandenburg
b5a9d61eeb orangefs: do not wait for timeout if umounting
When the computer is turned off, all the processes are killed and then
all the filesystems are umounted.  OrangeFS should not wait for the
userspace daemon to come back in that case.

This only works for plain umount(2).  To actually take advantage of this
interactively, `umount -f' is needed; otherwise umount will issue a
statfs first, which will wait for the userspace daemon to come back.

Signed-off-by: Martin Brandenburg <martin@omnibond.com>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2017-04-26 14:33:01 -04:00
Martin Brandenburg
b7a57ccab8 orangefs: return from orangefs_devreq_read quickly if possible
It is not necessary to take the lock and search through the request list
if the list is empty.

Signed-off-by: Martin Brandenburg <martin@omnibond.com>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2017-04-26 14:33:00 -04:00
Martin Brandenburg
9d286b0d82 orangefs: ensure the userspace component is unmounted if mount fails
If the mount is aborted after userspace has been asked to mount,
userspace must be told to unmount.

Ordinarily orangefs_kill_sb does the unmount.  However it cannot be
called if the superblock has not been set up.  This is a very narrow
window.

The NULL fs_id is not unmounted.

Signed-off-by: Martin Brandenburg <martin@omnibond.com>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2017-04-26 14:33:00 -04:00
Martin Brandenburg
53950ef541 orangefs: do not check possibly stale size on truncate
Let the server figure this out because our size might be out of date or
not present.

The bug was that

	xfs_io -f -t -c "pread -v 0 100" /mnt/foo
	echo "Test" > /mnt/foo
	xfs_io -f -t -c "pread -v 0 100" /mnt/foo

fails because the second truncate did not happen if nothing had
requested the size after the write in echo.  Thus i_size was zero (not
present) and the orangefs_setattr though i_size was zero and there was
nothing to do.

Signed-off-by: Martin Brandenburg <martin@omnibond.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2017-04-26 14:33:00 -04:00
Martin Brandenburg
68a24a6cc4 orangefs: implement statx
Fortunately OrangeFS has had a getattr request mask for a long time.

The server basically has two difficulty levels for attributes.  Fetching
any attribute except size requires communicating with the metadata
server for that handle.  Since all the attributes are right there, it
makes sense to return them all.  Fetching the size requires
communicating with every I/O server (that the file is distributed
across).  Therefore if asked for anything except size, get everything
except size, and if asked for size, get everything.

Signed-off-by: Martin Brandenburg <martin@omnibond.com>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2017-04-26 14:33:00 -04:00
Martin Brandenburg
7b796ae370 orangefs: remove ORANGEFS_READDIR macros
They are clones of the ORANGEFS_ITERATE macros in use elsewhere.  Delete
ORANGEFS_ITERATE_NEXT which is a hack previously used by readdir.

Signed-off-by: Martin Brandenburg <martin@omnibond.com>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2017-04-26 14:33:00 -04:00
Martin Brandenburg
480e3e532e orangefs: support very large directories
This works by maintaining a linked list of pages which the directory
has been read into rather than one giant fixed-size buffer.

This replaces code which limits the total directory size to the total
amount that could be returned in one server request.  Since filenames
are usually considerably shorter than the maximum, the old code could
usually handle several server requests before running out of space.

Signed-off-by: Martin Brandenburg <martin@omnibond.com>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2017-04-26 14:33:00 -04:00
Martin Brandenburg
72f66b8329 orangefs: support llseek on directories
This and the previous commit fix xfstests generic/257.

Signed-off-by: Martin Brandenburg <martin@omnibond.com>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2017-04-26 14:33:00 -04:00
Martin Brandenburg
382f4581e6 orangefs: rewrite readdir to fix several bugs
In the past, readdir assumed that the user buffer will be large enough
that all entries from the server will fit.  If this was not true,
entries would be skipped.

Since it works now, request 512 entries rather than 96 per server
operation.

Signed-off-by: Martin Brandenburg <martin@omnibond.com>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2017-04-26 14:33:00 -04:00
Martin Brandenburg
17930b252c orangefs: do not set getattr_time on orangefs_lookup
Since orangefs_lookup calls orangefs_iget which calls
orangefs_inode_getattr, getattr_time will get set.

Signed-off-by: Martin Brandenburg <martin@omnibond.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2017-04-26 14:33:00 -04:00
Martin Brandenburg
e675c5ec51 orangefs: clean up oversize xattr validation
Also don't check flags as this has been validated by the VFS already.

Fix an off-by-one error in the max size checking.

Stop logging just because userspace wants to write attributes which do
not fit.

This and the previous commit fix xfstests generic/020.

Signed-off-by: Martin Brandenburg <martin@omnibond.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2017-04-26 14:33:00 -04:00
Martin Brandenburg
a956af337b orangefs: fix bounds check for listxattr
Signed-off-by: Martin Brandenburg <martin@omnibond.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2017-04-26 14:33:00 -04:00
Martin Brandenburg
418ce3eb66 orangefs: remove unused get_fsid_from_ino
Signed-off-by: Martin Brandenburg <martin@omnibond.com>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2017-04-26 14:33:00 -04:00
Al Viro
c63ed807d1 orangefs: use iov_iter_revert()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-04-21 13:57:32 -04:00
Al Viro
890559e34e orangefs_bufmap_copy_from_iovec(): fix EFAULT handling
short copy here should mean instant EFAULT, not "move to the
next page and hope it fails there, this time with nothing
copied"

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-04-17 14:23:20 -04:00
Martin Brandenburg
1ec1688c53 orangefs: free superblock when mount fails
Otherwise lockdep says:

[ 1337.483798] ================================================
[ 1337.483999] [ BUG: lock held when returning to user space! ]
[ 1337.484252] 4.11.0-rc6 #19 Not tainted
[ 1337.484423] ------------------------------------------------
[ 1337.484626] mount/14766 is leaving the kernel with locks still held!
[ 1337.484841] 1 lock held by mount/14766:
[ 1337.485017]  #0:  (&type->s_umount_key#33/1){+.+.+.}, at: [<ffffffff8124171f>] sget_userns+0x2af/0x520

Caught by xfstests generic/413 which tried to mount with the unsupported
mount option dax.  Then xfstests generic/422 ran sync which deadlocks.

Signed-off-by: Martin Brandenburg <martin@omnibond.com>
Acked-by: Mike Marshall <hubcap@omnibond.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-04-15 09:39:31 -07:00
Martin Brandenburg
cefdc26e86 orangefs: move features validation to fix filesystem hang
Without this fix (and another to the userspace component itself
described later), the kernel will be unable to process any OrangeFS
requests after the userspace component is restarted (due to a crash or
at the administrator's behest).

The bug here is that inside orangefs_remount, the orangefs_request_mutex
is locked.  When the userspace component restarts while the filesystem
is mounted, it sends a ORANGEFS_DEV_REMOUNT_ALL ioctl to the device,
which causes the kernel to send it a few requests aimed at synchronizing
the state between the two.  While this is happening the
orangefs_request_mutex is locked to prevent any other requests going
through.

This is only half of the bugfix.  The other half is in the userspace
component which outright ignores(!) requests made before it considers
the filesystem remounted, which is after the ioctl returns.  Of course
the ioctl doesn't return until after the userspace component responds to
the request it ignores.  The userspace component has been changed to
allow ORANGEFS_VFS_OP_FEATURES regardless of the mount status.

Mike Marshall says:
 "I've tested this patch against the fixed userspace part. This patch is
  real important, I hope it can make it into 4.11...

  Here's what happens when the userspace daemon is restarted, without
  the patch:

    =============================================
    [ INFO: possible recursive locking detected ]
    [   4.10.0-00007-ge98bdb3 #1 Not tainted    ]
    ---------------------------------------------
    pvfs2-client-co/29032 is trying to acquire lock:
     (orangefs_request_mutex){+.+.+.}, at: service_operation+0x3c7/0x7b0 [orangefs]
                  but task is already holding lock:
     (orangefs_request_mutex){+.+.+.}, at: dispatch_ioctl_command+0x1bf/0x330 [orangefs]

    CPU: 0 PID: 29032 Comm: pvfs2-client-co Not tainted 4.10.0-00007-ge98bdb3 #1
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.3-1.fc25 04/01/2014
    Call Trace:
     __lock_acquire+0x7eb/0x1290
     lock_acquire+0xe8/0x1d0
     mutex_lock_killable_nested+0x6f/0x6e0
     service_operation+0x3c7/0x7b0 [orangefs]
     orangefs_remount+0xea/0x150 [orangefs]
     dispatch_ioctl_command+0x227/0x330 [orangefs]
     orangefs_devreq_ioctl+0x29/0x70 [orangefs]
     do_vfs_ioctl+0xa3/0x6e0
     SyS_ioctl+0x79/0x90"

Signed-off-by: Martin Brandenburg <martin@omnibond.com>
Acked-by: Mike Marshall <hubcap@omnibond.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-04-07 13:41:22 -07:00
Linus Torvalds
590dce2d49 Merge branch 'rebased-statx' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs 'statx()' update from Al Viro.

This adds the new extended stat() interface that internally subsumes our
previous stat interfaces, and allows user mode to specify in more detail
what kind of information it wants.

It also allows for some explicit synchronization information to be
passed to the filesystem, which can be relevant for network filesystems:
is the cached value ok, or do you need open/close consistency, or what?

From David Howells.

Andreas Dilger points out that the first version of the extended statx
interface was posted June 29, 2010:

    https://www.spinics.net/lists/linux-fsdevel/msg33831.html

* 'rebased-statx' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  statx: Add a system call to make enhanced file info available
2017-03-03 11:38:56 -08:00
Linus Torvalds
1827adb11a Merge branch 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull sched.h split-up from Ingo Molnar:
 "The point of these changes is to significantly reduce the
  <linux/sched.h> header footprint, to speed up the kernel build and to
  have a cleaner header structure.

  After these changes the new <linux/sched.h>'s typical preprocessed
  size goes down from a previous ~0.68 MB (~22K lines) to ~0.45 MB (~15K
  lines), which is around 40% faster to build on typical configs.

  Not much changed from the last version (-v2) posted three weeks ago: I
  eliminated quirks, backmerged fixes plus I rebased it to an upstream
  SHA1 from yesterday that includes most changes queued up in -next plus
  all sched.h changes that were pending from Andrew.

  I've re-tested the series both on x86 and on cross-arch defconfigs,
  and did a bisectability test at a number of random points.

  I tried to test as many build configurations as possible, but some
  build breakage is probably still left - but it should be mostly
  limited to architectures that have no cross-compiler binaries
  available on kernel.org, and non-default configurations"

* 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (146 commits)
  sched/headers: Clean up <linux/sched.h>
  sched/headers: Remove #ifdefs from <linux/sched.h>
  sched/headers: Remove the <linux/topology.h> include from <linux/sched.h>
  sched/headers, hrtimer: Remove the <linux/wait.h> include from <linux/hrtimer.h>
  sched/headers, x86/apic: Remove the <linux/pm.h> header inclusion from <asm/apic.h>
  sched/headers, timers: Remove the <linux/sysctl.h> include from <linux/timer.h>
  sched/headers: Remove <linux/magic.h> from <linux/sched/task_stack.h>
  sched/headers: Remove <linux/sched.h> from <linux/sched/init.h>
  sched/core: Remove unused prefetch_stack()
  sched/headers: Remove <linux/rculist.h> from <linux/sched.h>
  sched/headers: Remove the 'init_pid_ns' prototype from <linux/sched.h>
  sched/headers: Remove <linux/signal.h> from <linux/sched.h>
  sched/headers: Remove <linux/rwsem.h> from <linux/sched.h>
  sched/headers: Remove the runqueue_is_locked() prototype
  sched/headers: Remove <linux/sched.h> from <linux/sched/hotplug.h>
  sched/headers: Remove <linux/sched.h> from <linux/sched/debug.h>
  sched/headers: Remove <linux/sched.h> from <linux/sched/nohz.h>
  sched/headers: Remove <linux/sched.h> from <linux/sched/stat.h>
  sched/headers: Remove the <linux/gfp.h> include from <linux/sched.h>
  sched/headers: Remove <linux/rtmutex.h> from <linux/sched.h>
  ...
2017-03-03 10:16:38 -08:00
David Howells
a528d35e8b statx: Add a system call to make enhanced file info available
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: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-03-02 20:51:15 -05:00