Commit Graph

124 Commits

Author SHA1 Message Date
Al Viro af04fadcaa Revert "fs: fold open_check_o_direct into do_dentry_open"
This reverts commit cab64df194.

Having vfs_open() in some cases drop the reference to
struct file combined with

	error = vfs_open(path, f, cred);
	if (error) {
		put_filp(f);
		return ERR_PTR(error);
	}
	return f;

is flat-out wrong.  It used to be

		error = vfs_open(path, f, cred);
		if (!error) {
			/* from now on we need fput() to dispose of f */
			error = open_check_o_direct(f);
			if (error) {
				fput(f);
				f = ERR_PTR(error);
			}
		} else {
			put_filp(f);
			f = ERR_PTR(error);
		}

and sure, having that open_check_o_direct() boilerplate gotten rid of is
nice, but not that way...

Worse, another call chain (via finish_open()) is FUBAR now wrt
FILE_OPENED handling - in that case we get error returned, with file
already hit by fput() *AND* FILE_OPENED not set.  Guess what happens in
path_openat(), when it hits

	if (!(opened & FILE_OPENED)) {
		BUG_ON(!error);
		put_filp(file);
	}

The root cause of all that crap is that the callers of do_dentry_open()
have no way to tell which way did it fail; while that could be fixed up
(by passing something like int *opened to do_dentry_open() and have it
marked if we'd called ->open()), it's probably much too late in the
cycle to do so right now.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-03 10:58:23 -07:00
Linus Torvalds 9022ca6b11 Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull misc vfs updates from Al Viro:
 "Assorted stuff, including Christoph's I_DIRTY patches"

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fs: move I_DIRTY_INODE to fs.h
  ubifs: fix bogus __mark_inode_dirty(I_DIRTY_SYNC | I_DIRTY_DATASYNC) call
  ntfs: fix bogus __mark_inode_dirty(I_DIRTY_SYNC | I_DIRTY_DATASYNC) call
  gfs2: fix bogus __mark_inode_dirty(I_DIRTY_SYNC | I_DIRTY_DATASYNC) calls
  fs: fold open_check_o_direct into do_dentry_open
  vfs: Replace stray non-ASCII homoglyph characters with their ASCII equivalents
  vfs: make sure struct filename->iname is word-aligned
  get rid of pointless includes of fs_struct.h
  [poll] annotate SAA6588_CMD_POLL users
2018-04-06 11:07:08 -07:00
Dominik Brodowski 411d9475cf fs: add ksys_ftruncate() wrapper; remove in-kernel calls to sys_ftruncate()
Using the ksys_ftruncate() wrapper allows us to get rid of in-kernel
calls to the sys_ftruncate() syscall. The ksys_ prefix denotes that this
function is meant as a drop-in replacement for the syscall. In
particular, it uses the same calling convention as sys_ftruncate().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-04-02 20:16:00 +02:00
Dominik Brodowski 55731b3cda fs: add do_fchownat(), ksys_fchown() helpers and ksys_{,l}chown() wrappers
Using the fs-interal do_fchownat() wrapper allows us to get rid of
fs-internal calls to the sys_fchownat() syscall.

Introducing the ksys_fchown() helper and the ksys_{,}chown() wrappers
allows us to avoid the in-kernel calls to the sys_{,l,f}chown() syscalls.
The ksys_ prefix denotes that these functions are meant as a drop-in
replacement for the syscalls. In particular, they use the same calling
convention as sys_{,l,f}chown().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-04-02 20:15:59 +02:00
Dominik Brodowski cbfe20f565 fs: add do_faccessat() helper and ksys_access() wrapper; remove in-kernel calls to syscall
Using the fs-internal do_faccessat() helper allows us to get rid of
fs-internal calls to the sys_faccessat() syscall.

Introducing the ksys_access() wrapper allows us to avoid the in-kernel
calls to the sys_access() syscall. The ksys_ prefix denotes that this
function is meant as a drop-in replacement for the syscall. In
particular, it uses the same calling convention as sys_access().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-04-02 20:15:58 +02:00
Dominik Brodowski 03450e271a fs: add ksys_fchmod() and do_fchmodat() helpers and ksys_chmod() wrapper; remove in-kernel calls to syscall
Using the fs-internal do_fchmodat() helper allows us to get rid of
fs-internal calls to the sys_fchmodat() syscall.

Introducing the ksys_fchmod() helper and the ksys_chmod() wrapper allows
us to avoid the in-kernel calls to the sys_fchmod() and sys_chmod()
syscalls. The ksys_ prefix denotes that these functions are meant as a
drop-in replacement for the syscalls. In particular, they use the same
calling convention as sys_fchmod() and sys_chmod().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-04-02 20:15:57 +02:00
Dominik Brodowski 46ea89eb65 fs: add do_linkat() helper and ksys_link() wrapper; remove in-kernel calls to syscall
Using the fs-internal do_linkat() helper allows us to get rid of
fs-internal calls to the sys_linkat() syscall.

Introducing the ksys_link() wrapper allows us to avoid the in-kernel
calls to sys_link() syscall. The ksys_ prefix denotes that this function
is meant as a drop-in replacement for the syscall. In particular, it uses
the same calling convention as sys_link().

In the near future, the only fs-external user of ksys_link() should be
converted to use vfs_link() instead.

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-04-02 20:15:57 +02:00
Dominik Brodowski 87c4e19262 fs: add do_mknodat() helper and ksys_mknod() wrapper; remove in-kernel calls to syscall
Using the fs-internal do_mknodat() helper allows us to get rid of
fs-internal calls to the sys_mknodat() syscall.

Introducing the ksys_mknod() wrapper allows us to avoid the in-kernel
calls to sys_mknod() syscall. The ksys_ prefix denotes that this function
is meant as a drop-in replacement for the syscall. In particular, it uses
the same calling convention as sys_mknod().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-04-02 20:15:56 +02:00
Dominik Brodowski b724e846b4 fs: add do_symlinkat() helper and ksys_symlink() wrapper; remove in-kernel calls to syscall
Using the fs-internal do_symlinkat() helper allows us to get rid of
fs-internal calls to the sys_symlinkat() syscall.

Introducing the ksys_symlink() wrapper allows us to avoid the in-kernel
calls to the sys_symlink() syscall. The ksys_ prefix denotes that this
function is meant as a drop-in replacement for the syscall. In particular,
it uses the same calling convention as sys_symlink().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-04-02 20:15:55 +02:00
Dominik Brodowski 0101db7a30 fs: add do_mkdirat() helper and ksys_mkdir() wrapper; remove in-kernel calls to syscall
Using the fs-internal do_mkdirat() helper allows us to get rid of
fs-internal calls to the sys_mkdirat() syscall.

Introducing the ksys_mkdir() wrapper allows us to avoid the in-kernel calls
to the sys_mkdir() syscall. The ksys_ prefix denotes that this function is
meant as a drop-in replacement for the syscall. In particular, it uses the
same calling convention as sys_mkdir().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-04-02 20:15:54 +02:00
Dominik Brodowski f459dffae1 fs: add ksys_rmdir() wrapper; remove in-kernel calls to sys_rmdir()
Using this wrapper allows us to avoid the in-kernel calls to the
sys_rmdir() syscall. The ksys_ prefix denotes that this function is meant
as a drop-in replacement for the syscall. In particular, it uses the same
calling convention as sys_rmdir().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-04-02 20:15:54 +02:00
Christoph Hellwig cab64df194 fs: fold open_check_o_direct into do_dentry_open
do_dentry_open is where we do the actual open of the file, so this is
where we should do our O_DIRECT sanity check to cover all potential
callers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-03-28 01:39:01 -04:00
Christoph Hellwig da2f1362c8 fs: expose do_unlinkat for built-in callers
And make it take a struct filename instead of a user pointer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-11-10 08:48:46 -05:00
Linus Torvalds c353f88f3d Merge branch 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs
Pull overlayfs updates from Miklos Szeredi:
 "This fixes d_ino correctness in readdir, which brings overlayfs on par
  with normal filesystems regarding inode number semantics, as long as
  all layers are on the same filesystem.

  There are also some bug fixes, one in particular (random ioctl's
  shouldn't be able to modify lower layers) that touches some vfs code,
  but of course no-op for non-overlay fs"

* 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
  ovl: fix false positive ESTALE on lookup
  ovl: don't allow writing ioctl on lower layer
  ovl: fix relatime for directories
  vfs: add flags to d_real()
  ovl: cleanup d_real for negative
  ovl: constant d_ino for non-merge dirs
  ovl: constant d_ino across copy up
  ovl: fix readdir error value
  ovl: check snprintf return
2017-09-13 09:11:44 -07:00
Miklos Szeredi 7c6893e3c9 ovl: don't allow writing ioctl on lower layer
Problem with ioctl() is that it's a file operation, yet often used as an
inode operation (i.e. modify the inode despite the file being opened for
read-only).

mnt_want_write_file() is used by filesystems in such cases to get write
access on an arbitrary open file.

Since overlayfs lets filesystems do all file operations, including ioctl,
this can lead to mnt_want_write_file() returning OK for a lower file and
modification of that lower file.

This patch prevents modification by checking if the file is from an
overlayfs lower layer and returning EPERM in that case.

Need to introduce a mnt_want_write_file_path() variant that still does the
old thing for inode operations that can do the copy up + modification
correctly in such cases (fchown, fsetxattr, fremovexattr).

This does not address the correctness of such ioctls on overlayfs (the
correct way would be to copy up and attempt to perform ioctl on upper
file).

In theory this could be a regression.  We very much hope that nobody is
relying on such a hack in any sane setup.

While this patch meddles in VFS code, it has no effect on non-overlayfs
filesystems.

Reported-by: "zhangyi (F)" <yi.zhang@huawei.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-09-05 12:53:12 +02:00
Darrick J. Wong 799ea9e9c5 xfs: evict all inodes involved with log redo item
When we introduced the bmap redo log items, we set MS_ACTIVE on the
mountpoint and XFS_IRECOVERY on the inode to prevent unlinked inodes
from being truncated prematurely during log recovery.  This also had the
effect of putting linked inodes on the lru instead of evicting them.

Unfortunately, we neglected to find all those unreferenced lru inodes
and evict them after finishing log recovery, which means that we leak
them if anything goes wrong in the rest of xfs_mountfs, because the lru
is only cleaned out on unmount.

Therefore, evict unreferenced inodes in the lru list immediately
after clearing MS_ACTIVE.

Fixes: 17c12bcd30 ("xfs: when replaying bmap operations, don't let unlinked inodes get reaped")
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Cc: viro@ZenIV.linux.org.uk
Reviewed-by: Brian Foster <bfoster@redhat.com>
2017-09-01 10:55:30 -07:00
Linus Torvalds 11fbf53d66 Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull misc vfs updates from Al Viro:
 "Assorted bits and pieces from various people. No common topic in this
  pile, sorry"

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fs/affs: add rename exchange
  fs/affs: add rename2 to prepare multiple methods
  Make stat/lstat/fstatat pass AT_NO_AUTOMOUNT to vfs_statx()
  fs: don't set *REFERENCED on single use objects
  fs: compat: Remove warning from COMPATIBLE_IOCTL
  remove pointless extern of atime_need_update_rcu()
  fs: completely ignore unknown open flags
  fs: add a VALID_OPEN_FLAGS
  fs: remove _submit_bh()
  fs: constify tree_descr arrays passed to simple_fill_super()
  fs: drop duplicate header percpu-rwsem.h
  fs/affs: bugfix: Write files greater than page size on OFS
  fs/affs: bugfix: enable writes on OFS disks
  fs/affs: remove node generation check
  fs/affs: import amigaffs.h
  fs/affs: bugfix: make symbolic links work again
2017-05-09 09:12:53 -07:00
Al Viro 0b33540f9d remove pointless extern of atime_need_update_rcu()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-04-29 17:42:25 -04:00
Al Viro 2b8910264a fhandle: move compat syscalls from compat.c
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-04-17 12:52:26 -04:00
Christoph Hellwig 8ff6daa17b iomap: constify struct iomap_ops
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-01-30 16:32:25 -08:00
Linus Torvalds 0110c350c8 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull more vfs updates from Al Viro:
 "In this pile:

   - autofs-namespace series
   - dedupe stuff
   - more struct path constification"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (40 commits)
  ocfs2: implement the VFS clone_range, copy_range, and dedupe_range features
  ocfs2: charge quota for reflinked blocks
  ocfs2: fix bad pointer cast
  ocfs2: always unlock when completing dio writes
  ocfs2: don't eat io errors during _dio_end_io_write
  ocfs2: budget for extent tree splits when adding refcount flag
  ocfs2: prohibit refcounted swapfiles
  ocfs2: add newlines to some error messages
  ocfs2: convert inode refcount test to a helper
  simple_write_end(): don't zero in short copy into uptodate
  exofs: don't mess with simple_write_{begin,end}
  9p: saner ->write_end() on failing copy into non-uptodate page
  fix gfs2_stuffed_write_end() on short copies
  fix ceph_write_end()
  nfs_write_end(): fix handling of short copies
  vfs: refactor clone/dedupe_file_range common functions
  fs: try to clone files first in vfs_copy_file_range
  vfs: misc struct path constification
  namespace.c: constify struct path passed to a bunch of primitives
  quota: constify struct path in quota_on
  ...
2016-12-17 18:44:00 -08:00
Al Viro ca71cf71ee namespace.c: constify struct path passed to a bunch of primitives
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-12-05 19:03:12 -05:00
Christoph Hellwig ec1b826097 fs: make sb_init_dio_done_wq available outside of direct-io.c
We want to use the per-sb completion workqueue from the new iomap
direct I/O code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-11-30 14:33:53 +11:00
Linus Torvalds abb5a14fa2 Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull misc vfs updates from Al Viro:
 "Assorted misc bits and pieces.

  There are several single-topic branches left after this (rename2
  series from Miklos, current_time series from Deepa Dinamani, xattr
  series from Andreas, uaccess stuff from from me) and I'd prefer to
  send those separately"

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (39 commits)
  proc: switch auxv to use of __mem_open()
  hpfs: support FIEMAP
  cifs: get rid of unused arguments of CIFSSMBWrite()
  posix_acl: uapi header split
  posix_acl: xattr representation cleanups
  fs/aio.c: eliminate redundant loads in put_aio_ring_file
  fs/internal.h: add const to ns_dentry_operations declaration
  compat: remove compat_printk()
  fs/buffer.c: make __getblk_slow() static
  proc: unsigned file descriptors
  fs/file: more unsigned file descriptors
  fs: compat: remove redundant check of nr_segs
  cachefiles: Fix attempt to read i_blocks after deleting file [ver #2]
  cifs: don't use memcpy() to copy struct iov_iter
  get rid of separate multipage fault-in primitives
  fs: Avoid premature clearing of capabilities
  fs: Give dentry to inode_change_ok() instead of inode
  fuse: Propagate dentry down to inode_change_ok()
  ceph: Propagate dentry down to inode_change_ok()
  xfs: Propagate dentry down to inode_change_ok()
  ...
2016-10-10 13:04:49 -07:00
Al Viro f334bcd94b Merge remote-tracking branch 'ovl/misc' into work.misc 2016-10-08 11:00:01 -04:00
Rasmus Villemoes be218aa2e3 fs/internal.h: add const to ns_dentry_operations declaration
The actual definition in fs/nsfs.c is already const.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-09-27 21:45:46 -04:00
Christoph Hellwig befb503ca6 iomap: expose iomap_apply outside iomap.c
This allows the DAX code to use it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-09-19 11:24:49 +10:00
Miklos Szeredi 598e3c8f72 vfs: update ovl inode before relatime check
On overlayfs relatime_need_update() needs inode times to be correct on
overlay inode.  But i_mtime and i_ctime are updated by filesystem code on
underlying inode only, so they will be out-of-date on the overlay inode.

This patch copies the times from the underlying inode if needed.  This
can't be done if called from RCU lookup (link following) but link m/ctime
are not updated by fs, so this is all right.

This patch doesn't change functionality for anything but overlayfs.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-09-16 12:44:20 +02:00
Linus Torvalds e9d488c311 binfmt_misc for-linus on 20160727
First off, the intention of this pull is to declare that I'll be the
 binfmt_misc maintainer (mainly on the grounds of you touched it last,
 it's yours).  There's no MAINTAINERS entry, but get_maintainers.pl
 will now finger me.
 
 The update itself is to allow architecture emulation containers to
 function such that the emulation binary can be housed outside the
 container itself.  The container and fs parts both have acks from
 relevant experts.
 
 The change is user visible. To use the new feature you have to add an
 F option to your binfmt_misc configuration.  However, the existing
 tools, like systemd-binfmt work with this without modification.
 
 Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
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Merge tag 'binfmt-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/binfmt_misc

Pull binfmt_misc update from James Bottomley:
 "This update is to allow architecture emulation containers to function
  such that the emulation binary can be housed outside the container
  itself.  The container and fs parts both have acks from relevant
  experts.

  To use the new feature you have to add an F option to your binfmt_misc
  configuration"

From the docs:
 "The usual behaviour of binfmt_misc is to spawn the binary lazily when
  the misc format file is invoked.  However, this doesn't work very well
  in the face of mount namespaces and changeroots, so the F mode opens
  the binary as soon as the emulation is installed and uses the opened
  image to spawn the emulator, meaning it is always available once
  installed, regardless of how the environment changes"

* tag 'binfmt-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/binfmt_misc:
  binfmt_misc: add F option description to documentation
  binfmt_misc: add persistent opened binary handler for containers
  fs: add filp_clone_open API
2016-08-07 10:13:14 -04:00
Al Viro 8ecfb75216 Merge branch 'for-viro' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs into for-linus 2016-08-03 13:31:51 -04:00
Miklos Szeredi f0fce87c36 vfs: make dentry_needs_remove_privs() internal
Only used by the vfs.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-08-03 13:57:57 +02:00
Linus Torvalds 0e6acf0204 xfs: update for 4.8-rc1
Changes in this update:
 o generic iomap based IO path infrastructure
 o generic iomap based fiemap implementation
 o xfs iomap based Io path implementation
 o buffer error handling fixes
 o tracking of in flight buffer IO for unmount serialisation
 o direct IO and DAX io path separation and simplification
 o shortform directory format definition changes for wider platform compatibility
 o various buffer cache fixes
 o cleanups in preparation for rmap merge
 o error injection cleanups and fixes
 o log item format buffer memory allocation restructuring to prevent rare OOM
   reclaim deadlocks
 o sparse inode chunks are now fully supported.
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Merge tag 'xfs-for-linus-4.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs

Pull xfs updates from Dave Chinner:
 "The major addition is the new iomap based block mapping
  infrastructure.  We've been kicking this about locally for years, but
  there are other filesystems want to use it too (e.g. gfs2).  Now it
  is fully working, reviewed and ready for merge and be used by other
  filesystems.

  There are a lot of other fixes and cleanups in the tree, but those are
  XFS internal things and none are of the scale or visibility of the
  iomap changes.  See below for details.

  I am likely to send another pull request next week - we're just about
  ready to merge some new functionality (on disk block->owner reverse
  mapping infrastructure), but that's a huge chunk of code (74 files
  changed, 7283 insertions(+), 1114 deletions(-)) so I'm keeping that
  separate to all the "normal" pull request changes so they don't get
  lost in the noise.

  Summary of changes in this update:
   - generic iomap based IO path infrastructure
   - generic iomap based fiemap implementation
   - xfs iomap based Io path implementation
   - buffer error handling fixes
   - tracking of in flight buffer IO for unmount serialisation
   - direct IO and DAX io path separation and simplification
   - shortform directory format definition changes for wider platform
     compatibility
   - various buffer cache fixes
   - cleanups in preparation for rmap merge
   - error injection cleanups and fixes
   - log item format buffer memory allocation restructuring to prevent
     rare OOM reclaim deadlocks
   - sparse inode chunks are now fully supported"

* tag 'xfs-for-linus-4.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs: (53 commits)
  xfs: remove EXPERIMENTAL tag from sparse inode feature
  xfs: bufferhead chains are invalid after end_page_writeback
  xfs: allocate log vector buffers outside CIL context lock
  libxfs: directory node splitting does not have an extra block
  xfs: remove dax code from object file when disabled
  xfs: skip dirty pages in ->releasepage()
  xfs: remove __arch_pack
  xfs: kill xfs_dir2_inou_t
  xfs: kill xfs_dir2_sf_off_t
  xfs: split direct I/O and DAX path
  xfs: direct calls in the direct I/O path
  xfs: stop using generic_file_read_iter for direct I/O
  xfs: split xfs_file_read_iter into buffered and direct I/O helpers
  xfs: remove s_maxbytes enforcement in xfs_file_read_iter
  xfs: kill ioflags
  xfs: don't pass ioflags around in the ioctl path
  xfs: track and serialize in-flight async buffers against unmount
  xfs: exclude never-released buffers from buftarg I/O accounting
  xfs: don't reset b_retries to 0 on every failure
  xfs: remove extraneous buffer flag changes
  ...
2016-07-27 09:53:35 -07:00
Christoph Hellwig ae259a9c85 fs: introduce iomap infrastructure
Add infrastructure for multipage buffered writes.  This is implemented
using an main iterator that applies an actor function to a range that
can be written.

This infrastucture is used to implement a buffered write helper, one
to zero file ranges and one to implement the ->page_mkwrite VM
operations.  All of them borrow a fair amount of code from fs/buffers.
for now by using an internal version of __block_write_begin that
gets passed an iomap and builds the corresponding buffer head.

The file system is gets a set of paired ->iomap_begin and ->iomap_end
calls which allow it to map/reserve a range and get a notification
once the write code is finished with it.

Based on earlier code from Dave Chinner.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-06-21 09:23:11 +10:00
Al Viro ba65dc5ef1 much milder d_walk() race
d_walk() relies upon the tree not getting rearranged under it without
rename_lock being touched.  And we do grab rename_lock around the
places that change the tree topology.  Unfortunately, branch reordering
is just as bad from d_walk() POV and we have two places that do it
without touching rename_lock - one in handling of cursors (for ramfs-style
directories) and another in autofs.  autofs one is a separate story; this
commit deals with the cursors.
	* mark cursor dentries explicitly at allocation time
	* make __dentry_kill() leave ->d_child.next pointing to the next
non-cursor sibling, making sure that it won't be moved around unnoticed
before the parent is relocked on ascend-to-parent path in d_walk().
	* make d_walk() skip cursors explicitly; strictly speaking it's
not necessary (all callbacks we pass to d_walk() are no-ops on cursors),
but it makes analysis easier.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-06-10 11:32:47 -04:00
James Bottomley 9a08c352d0 fs: add filp_clone_open API
I need an API that allows me to obtain a clone of the current file
pointer to pass in to an exec handler.  I've labelled this as an
internal API because I can't see how it would be useful outside of the
fs subsystem.  The use case will be a persistent binfmt_misc handler.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Acked-by: Jan Kara <jack@suse.cz>
2016-03-30 14:12:22 -07:00
Al Viro 6108209c4a Merge branch 'for-linus' into work.misc 2016-01-08 21:20:11 -05:00
Al Viro 66cf191f3e compat_ioctl: don't pass fd around when not needed
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-01-08 21:16:50 -05:00
Al Viro b40ef8696f saner calling conventions for copy_mount_options()
let it just return NULL, pointer to kernel copy or ERR_PTR().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-01-04 10:28:32 -05:00
Dave Chinner c7f5408493 inode: rename i_wb_list to i_io_list
There's a small consistency problem between the inode and writeback
naming. Writeback calls the "for IO" inode queues b_io and
b_more_io, but the inode calls these the "writeback list" or
i_wb_list. This makes it hard to an new "under writeback" list to
the inode, or call it an "under IO" list on the bdi because either
way we'll have writeback on IO and IO on writeback and it'll just be
confusing. I'm getting confused just writing this!

So, rename the inode "for IO" list variable to i_io_list so we can
add a new "writeback list" in a subsequent patch.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Dave Chinner <dchinner@redhat.com>
2015-08-17 23:38:10 -04:00
Dave Chinner 74278da9f7 inode: convert inode_sb_list_lock to per-sb
The process of reducing contention on per-superblock inode lists
starts with moving the locking to match the per-superblock inode
list. This takes the global lock out of the picture and reduces the
contention problems to within a single filesystem. This doesn't get
rid of contention as the locks still have global CPU scope, but it
does isolate operations on different superblocks form each other.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Dave Chinner <dchinner@redhat.com>
2015-08-17 18:39:46 -04:00
David Howells 4bacc9c923 overlayfs: Make f_path always point to the overlay and f_inode to the underlay
Make file->f_path always point to the overlay dentry so that the path in
/proc/pid/fd is correct and to ensure that label-based LSMs have access to the
overlay as well as the underlay (path-based LSMs probably don't need it).

Using my union testsuite to set things up, before the patch I see:

	[root@andromeda union-testsuite]# bash 5</mnt/a/foo107
	[root@andromeda union-testsuite]# ls -l /proc/$$/fd/
	...
	lr-x------. 1 root root 64 Jun  5 14:38 5 -> /a/foo107
	[root@andromeda union-testsuite]# stat /mnt/a/foo107
	...
	Device: 23h/35d Inode: 13381       Links: 1
	...
	[root@andromeda union-testsuite]# stat -L /proc/$$/fd/5
	...
	Device: 23h/35d Inode: 13381       Links: 1
	...

After the patch:

	[root@andromeda union-testsuite]# bash 5</mnt/a/foo107
	[root@andromeda union-testsuite]# ls -l /proc/$$/fd/
	...
	lr-x------. 1 root root 64 Jun  5 14:22 5 -> /mnt/a/foo107
	[root@andromeda union-testsuite]# stat /mnt/a/foo107
	...
	Device: 23h/35d Inode: 40346       Links: 1
	...
	[root@andromeda union-testsuite]# stat -L /proc/$$/fd/5
	...
	Device: 23h/35d Inode: 40346       Links: 1
	...

Note the change in where /proc/$$/fd/5 points to in the ls command.  It was
pointing to /a/foo107 (which doesn't exist) and now points to /mnt/a/foo107
(which is correct).

The inode accessed, however, is the lower layer.  The union layer is on device
25h/37d and the upper layer on 24h/36d.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-06-19 03:19:32 -04:00
Konstantin Khlebnikov eb6ef3df4f trylock_super(): replacement for grab_super_passive()
I've noticed significant locking contention in memory reclaimer around
sb_lock inside grab_super_passive(). Grab_super_passive() is called from
two places: in icache/dcache shrinkers (function super_cache_scan) and
from writeback (function __writeback_inodes_wb). Both are required for
progress in memory allocator.

Grab_super_passive() acquires sb_lock to increment sb->s_count and check
sb->s_instances. It seems sb->s_umount locked for read is enough here:
super-block deactivation always runs under sb->s_umount locked for write.
Protecting super-block itself isn't a problem: in super_cache_scan() sb
is protected by shrinker_rwsem: it cannot be freed if its slab shrinkers
are still active. Inside writeback super-block comes from inode from bdi
writeback list under wb->list_lock.

This patch removes locking sb_lock and checks s_instances under s_umount:
generic_shutdown_super() unlinks it under sb->s_umount locked for write.
New variant is called trylock_super() and since it only locks semaphore,
callers must call up_read(&sb->s_umount) instead of drop_super(sb) when
they're done.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-02-22 11:38:42 -05:00
Linus Torvalds 50652963ea Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull misc VFS updates from Al Viro:
 "This cycle a lot of stuff sits on topical branches, so I'll be sending
  more or less one pull request per branch.

  This is the first pile; more to follow in a few.  In this one are
  several misc commits from early in the cycle (before I went for
  separate branches), plus the rework of mntput/dput ordering on umount,
  switching to use of fs_pin instead of convoluted games in
  namespace_unlock()"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  switch the IO-triggering parts of umount to fs_pin
  new fs_pin killing logics
  allow attaching fs_pin to a group not associated with some superblock
  get rid of the second argument of acct_kill()
  take count and rcu_head out of fs_pin
  dcache: let the dentry count go down to zero without taking d_lock
  pull bumping refcount into ->kill()
  kill pin_put()
  mode_t whack-a-mole: chelsio
  file->f_path.dentry is pinned down for as long as the file is open...
  get rid of lustre_dump_dentry()
  gut proc_register() a bit
  kill d_validate()
  ncpfs: get rid of d_validate() nonsense
  selinuxfs: don't open-code d_genocide()
2015-02-17 14:56:45 -08:00
Vladimir Davydov 503c358cf1 list_lru: introduce list_lru_shrink_{count,walk}
Kmem accounting of memcg is unusable now, because it lacks slab shrinker
support.  That means when we hit the limit we will get ENOMEM w/o any
chance to recover.  What we should do then is to call shrink_slab, which
would reclaim old inode/dentry caches from this cgroup.  This is what
this patch set is intended to do.

Basically, it does two things.  First, it introduces the notion of
per-memcg slab shrinker.  A shrinker that wants to reclaim objects per
cgroup should mark itself as SHRINKER_MEMCG_AWARE.  Then it will be
passed the memory cgroup to scan from in shrink_control->memcg.  For
such shrinkers shrink_slab iterates over the whole cgroup subtree under
the target cgroup and calls the shrinker for each kmem-active memory
cgroup.

Secondly, this patch set makes the list_lru structure per-memcg.  It's
done transparently to list_lru users - everything they have to do is to
tell list_lru_init that they want memcg-aware list_lru.  Then the
list_lru will automatically distribute objects among per-memcg lists
basing on which cgroup the object is accounted to.  This way to make FS
shrinkers (icache, dcache) memcg-aware we only need to make them use
memcg-aware list_lru, and this is what this patch set does.

As before, this patch set only enables per-memcg kmem reclaim when the
pressure goes from memory.limit, not from memory.kmem.limit.  Handling
memory.kmem.limit is going to be tricky due to GFP_NOFS allocations, and
it is still unclear whether we will have this knob in the unified
hierarchy.

This patch (of 9):

NUMA aware slab shrinkers use the list_lru structure to distribute
objects coming from different NUMA nodes to different lists.  Whenever
such a shrinker needs to count or scan objects from a particular node,
it issues commands like this:

        count = list_lru_count_node(lru, sc->nid);
        freed = list_lru_walk_node(lru, sc->nid, isolate_func,
                                   isolate_arg, &sc->nr_to_scan);

where sc is an instance of the shrink_control structure passed to it
from vmscan.

To simplify this, let's add special list_lru functions to be used by
shrinkers, list_lru_shrink_count() and list_lru_shrink_walk(), which
consolidate the nid and nr_to_scan arguments in the shrink_control
structure.

This will also allow us to avoid patching shrinkers that use list_lru
when we make shrink_slab() per-memcg - all we will have to do is extend
the shrink_control structure to include the target memcg and make
list_lru_shrink_{count,walk} handle this appropriately.

Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Suggested-by: Dave Chinner <david@fromorbit.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Greg Thelen <gthelen@google.com>
Cc: Glauber Costa <glommer@gmail.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-12 18:54:08 -08:00
Al Viro fdab684d72 allow attaching fs_pin to a group not associated with some superblock
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-01-25 23:17:28 -05:00
Al Viro e149ed2b80 take the targets of /proc/*/ns/* symlinks to separate fs
New pseudo-filesystem: nsfs.  Targets of /proc/*/ns/* live there now.
It's not mountable (not even registered, so it's not in /proc/filesystems,
etc.).  Files on it *are* bindable - we explicitly permit that in do_loopback().

This stuff lives in fs/nsfs.c now; proc_ns_fget() moved there as well.
get_proc_ns() is a macro now (it's simply returning ->i_private; would
have been an inline, if not for header ordering headache).
proc_ns_inode() is an ex-parrot.  The interface used in procfs is
ns_get_path(path, task, ops) and ns_get_name(buf, size, task, ops).

Dentries and inodes are never hashed; a non-counting reference to dentry
is stashed in ns_common (removed by ->d_prune()) and reused by ns_get_path()
if present.  See ns_get_path()/ns_prune_dentry/nsfs_evict() for details
of that mechanism.

As the result, proc_ns_follow_link() has stopped poking in nd->path.mnt;
it does nd_jump_link() on a consistent <vfsmount,dentry> pair it gets
from ns_get_path().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-12-10 21:30:20 -05:00
Miklos Szeredi bd5d08569c vfs: export __inode_permission() to modules
We need to be able to check inode permissions (but not filesystem implied
permissions) for stackable filesystems.  Expose this interface for overlayfs.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-10-24 00:14:35 +02:00
Miklos Szeredi 1c118596a7 vfs: export do_splice_direct() to modules
Export do_splice_direct() to modules.  Needed by overlay filesystem.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-10-24 00:14:35 +02:00
Linus Torvalds 77c688ac87 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs updates from Al Viro:
 "The big thing in this pile is Eric's unmount-on-rmdir series; we
  finally have everything we need for that.  The final piece of prereqs
  is delayed mntput() - now filesystem shutdown always happens on
  shallow stack.

  Other than that, we have several new primitives for iov_iter (Matt
  Wilcox, culled from his XIP-related series) pushing the conversion to
  ->read_iter()/ ->write_iter() a bit more, a bunch of fs/dcache.c
  cleanups and fixes (including the external name refcounting, which
  gives consistent behaviour of d_move() wrt procfs symlinks for long
  and short names alike) and assorted cleanups and fixes all over the
  place.

  This is just the first pile; there's a lot of stuff from various
  people that ought to go in this window.  Starting with
  unionmount/overlayfs mess...  ;-/"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (60 commits)
  fs/file_table.c: Update alloc_file() comment
  vfs: Deduplicate code shared by xattr system calls operating on paths
  reiserfs: remove pointless forward declaration of struct nameidata
  don't need that forward declaration of struct nameidata in dcache.h anymore
  take dname_external() into fs/dcache.c
  let path_init() failures treated the same way as subsequent link_path_walk()
  fix misuses of f_count() in ppp and netlink
  ncpfs: use list_for_each_entry() for d_subdirs walk
  vfs: move getname() from callers to do_mount()
  gfs2_atomic_open(): skip lookups on hashed dentry
  [infiniband] remove pointless assignments
  gadgetfs: saner API for gadgetfs_create_file()
  f_fs: saner API for ffs_sb_create_file()
  jfs: don't hash direct inode
  [s390] remove pointless assignment of ->f_op in vmlogrdr ->open()
  ecryptfs: ->f_op is never NULL
  android: ->f_op is never NULL
  nouveau: __iomem misannotations
  missing annotation in fs/file.c
  fs: namespace: suppress 'may be used uninitialized' warnings
  ...
2014-10-13 11:28:42 +02:00
Akinobu Mita 4db96b71e3 vfs: guard end of device for mpage interface
Add guard_bio_eod() check for mpage code in order to allow us to do IO
even on the odd last sectors of a device, even if the block size is some
multiple of the physical sector size.

Using mpage_readpages() for block device requires this guard check.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:53 -04:00