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  1. 13 8月, 2015 1 次提交
  3. 01 7月, 2015 1 次提交
    • E
      fs: Add helper functions for permanently empty directories. · fbabfd0f
      由 Eric W. Biederman 提交于 
      To ensure it is safe to mount proc and sysfs I need to check if
filesystems that are mounted on top of them are mounted on truly empty
directories.  Given that some directories can gain entries over time,
knowing that a directory is empty right now is insufficient.

Therefore add supporting infrastructure for permantently empty
directories that proc and sysfs can use when they create mount points
for filesystems and fs_fully_visible can use to test for permanently
empty directories to ensure that nothing will be gained by mounting a
fresh copy of proc or sysfs.

Cc: stable@vger.kernel.org
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
      fbabfd0f
  5. 24 6月, 2015 1 次提交
  7. 11 5月, 2015 5 次提交
  9. 16 4月, 2015 1 次提交
  11. 23 2月, 2015 1 次提交
    • D
      VFS: (Scripted) Convert S_ISLNK/DIR/REG(dentry->d_inode) to d_is_*(dentry) · e36cb0b8
      由 David Howells 提交于 
      Convert the following where appropriate:

 (1) S_ISLNK(dentry->d_inode) to d_is_symlink(dentry).

 (2) S_ISREG(dentry->d_inode) to d_is_reg(dentry).

 (3) S_ISDIR(dentry->d_inode) to d_is_dir(dentry).  This is actually more
     complicated than it appears as some calls should be converted to
     d_can_lookup() instead.  The difference is whether the directory in
     question is a real dir with a ->lookup op or whether it's a fake dir with
     a ->d_automount op.

In some circumstances, we can subsume checks for dentry->d_inode not being
NULL into this, provided we the code isn't in a filesystem that expects
d_inode to be NULL if the dirent really *is* negative (ie. if we're going to
use d_inode() rather than d_backing_inode() to get the inode pointer).

Note that the dentry type field may be set to something other than
DCACHE_MISS_TYPE when d_inode is NULL in the case of unionmount, where the VFS
manages the fall-through from a negative dentry to a lower layer.  In such a
case, the dentry type of the negative union dentry is set to the same as the
type of the lower dentry.

However, if you know d_inode is not NULL at the call site, then you can use
the d_is_xxx() functions even in a filesystem.

There is one further complication: a 0,0 chardev dentry may be labelled
DCACHE_WHITEOUT_TYPE rather than DCACHE_SPECIAL_TYPE.  Strictly, this was
intended for special directory entry types that don't have attached inodes.

The following perl+coccinelle script was used:

use strict;

my @callers;
open($fd, 'git grep -l \'S_IS[A-Z].*->d_inode\' |') ||
    die "Can't grep for S_ISDIR and co. callers";
@callers = <$fd>;
close($fd);
unless (@callers) {
    print "No matches\n";
    exit(0);
}

my @cocci = (
    '@@',
    'expression E;',
    '@@',
    '',
    '- S_ISLNK(E->d_inode->i_mode)',
    '+ d_is_symlink(E)',
    '',
    '@@',
    'expression E;',
    '@@',
    '',
    '- S_ISDIR(E->d_inode->i_mode)',
    '+ d_is_dir(E)',
    '',
    '@@',
    'expression E;',
    '@@',
    '',
    '- S_ISREG(E->d_inode->i_mode)',
    '+ d_is_reg(E)' );

my $coccifile = "tmp.sp.cocci";
open($fd, ">$coccifile") || die $coccifile;
print($fd "$_\n") || die $coccifile foreach (@cocci);
close($fd);

foreach my $file (@callers) {
    chomp $file;
    print "Processing ", $file, "\n";
    system("spatch", "--sp-file", $coccifile, $file, "--in-place", "--no-show-diff") == 0 ||
	die "spatch failed";
}

[AV: overlayfs parts skipped]
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      e36cb0b8
  13. 05 2月, 2015 1 次提交
    • T
      vfs: add support for a lazytime mount option · 0ae45f63
      由 Theodore Ts'o 提交于 
      Add a new mount option which enables a new "lazytime" mode.  This mode
causes atime, mtime, and ctime updates to only be made to the
in-memory version of the inode.  The on-disk times will only get
updated when (a) if the inode needs to be updated for some non-time
related change, (b) if userspace calls fsync(), syncfs() or sync(), or
(c) just before an undeleted inode is evicted from memory.

This is OK according to POSIX because there are no guarantees after a
crash unless userspace explicitly requests via a fsync(2) call.

For workloads which feature a large number of random write to a
preallocated file, the lazytime mount option significantly reduces
writes to the inode table.  The repeated 4k writes to a single block
will result in undesirable stress on flash devices and SMR disk
drives.  Even on conventional HDD's, the repeated writes to the inode
table block will trigger Adjacent Track Interference (ATI) remediation
latencies, which very negatively impact long tail latencies --- which
is a very big deal for web serving tiers (for example).

Google-Bug-Id: 18297052
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      0ae45f63
  15. 04 11月, 2014 1 次提交
  17. 08 10月, 2014 1 次提交
    • J
      locks: plumb a "priv" pointer into the setlease routines · e6f5c789
      由 Jeff Layton 提交于 
      In later patches, we're going to add a new lock_manager_operation to
finish setting up the lease while still holding the i_lock.  To do
this, we'll need to pass a little bit of info in the fcntl setlease
case (primarily an fasync structure). Plumb the extra pointer into
there in advance of that.

We declare this pointer as a void ** to make it clear that this is
private info, and that the caller isn't required to set this unless
the lm_setup specifically requires it.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
      e6f5c789
  19. 10 9月, 2014 1 次提交
  21. 05 6月, 2014 1 次提交
  23. 16 11月, 2013 1 次提交
  25. 09 11月, 2013 1 次提交
  27. 25 10月, 2013 2 次提交
  29. 14 7月, 2013 1 次提交
  31. 29 6月, 2013 1 次提交
  33. 21 12月, 2012 1 次提交
  35. 18 12月, 2012 1 次提交
  37. 05 9月, 2012 1 次提交
  39. 14 7月, 2012 2 次提交
  41. 11 5月, 2012 1 次提交
    • L
      vfs: make it possible to access the dentry hash/len as one 64-bit entry · 26fe5750
      由 Linus Torvalds 提交于 
      This allows comparing hash and len in one operation on 64-bit
architectures.  Right now only __d_lookup_rcu() takes advantage of this,
since that is the case we care most about.

The use of anonymous struct/unions hides the alternate 64-bit approach
from most users, the exception being a few cases where we initialize a
'struct qstr' with a static initializer.  This makes the problematic
cases use a new QSTR_INIT() helper function for that (but initializing
just the name pointer with a "{ .name = xyzzy }" initializer remains
valid, as does just copying another qstr structure).
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      26fe5750
  43. 09 4月, 2012 1 次提交
    • A
      dentry leak in simple_fill_super() failure exit · 640946f2
      由 Al Viro 提交于 
      d_genocide() does _not_ evict dentries; it just removes extra ref
pinning each of those.  Normally it's followed by shrinking the
tree (it's done just before generic_shutdown_super() by kill_litter_super()),
but in case of simple_fill_super() nothing of that kind will follow.
Just do shrink_dcache_parent() manually.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      640946f2
  45. 06 4月, 2012 1 次提交
  47. 21 3月, 2012 2 次提交
  49. 29 2月, 2012 1 次提交
  51. 04 1月, 2012 1 次提交
  53. 02 11月, 2011 2 次提交
  55. 23 7月, 2011 1 次提交
  57. 21 7月, 2011 1 次提交
    • J
      fs: push i_mutex and filemap_write_and_wait down into ->fsync() handlers · 02c24a82
      由 Josef Bacik 提交于 
      Btrfs needs to be able to control how filemap_write_and_wait_range() is called
in fsync to make it less of a painful operation, so push down taking i_mutex and
the calling of filemap_write_and_wait() down into the ->fsync() handlers.  Some
file systems can drop taking the i_mutex altogether it seems, like ext3 and
ocfs2.  For correctness sake I just pushed everything down in all cases to make
sure that we keep the current behavior the same for everybody, and then each
individual fs maintainer can make up their mind about what to do from there.
Thanks,
Acked-by: NJan Kara <jack@suse.cz>
Signed-off-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      02c24a82
  59. 20 7月, 2011 2 次提交
    • A
      Make ->d_sb assign-once and always non-NULL · a4464dbc
      由 Al Viro 提交于 
      New helper (non-exported, fs/internal.h-only): __d_alloc(sb, name).
Allocates dentry, sets its ->d_sb to given superblock and sets
->d_op accordingly.  Old d_alloc(NULL, name) callers are converted
to that (all of them know what superblock they want).  d_alloc()
itself is left only for parent != NULl case; uses __d_alloc(),
inserts result into the list of parent's children.

Note that now ->d_sb is assign-once and never NULL *and*
->d_parent is never NULL either.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      a4464dbc
    • A
      fs/libfs.c: fix simple_attr_write() on 32bit machines · f7b88631
      由 Akinobu Mita 提交于 
      Assume that /sys/kernel/debug/dummy64 is debugfs file created by
debugfs_create_x64().

	# cd /sys/kernel/debug
	# echo 0x1234567812345678 > dummy64
	# cat dummy64
	0x0000000012345678

	# echo 0x80000000 > dummy64
	# cat dummy64
	0xffffffff80000000

A value larger than INT_MAX cannot be written to the debugfs file created
by debugfs_create_u64 or debugfs_create_x64 on 32bit machine.  Because
simple_attr_write() uses simple_strtol() for the conversion.

To fix this, use simple_strtoll() instead.
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      f7b88631
  61. 26 5月, 2011 1 次提交