Skip to content

K
Kernel

openeuler / Kernel
1 年多 前同步成功

通知 8
Star 0
Fork 0
K
Kernel
切换分支/标签
  1. 05 3月, 2016 1 次提交
  3. 23 1月, 2016 1 次提交
    • A
      wrappers for ->i_mutex access · 5955102c
      由 Al Viro 提交于 
      parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
inode_foo(inode) being mutex_foo(&inode->i_mutex).

Please, use those for access to ->i_mutex; over the coming cycle
->i_mutex will become rwsem, with ->lookup() done with it held
only shared.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      5955102c
  5. 15 1月, 2016 1 次提交
  7. 09 1月, 2016 1 次提交
    • N
      nfsd: don't hold i_mutex over userspace upcalls · bbddca8e
      由 NeilBrown 提交于 
      We need information about exports when crossing mountpoints during
lookup or NFSv4 readdir.  If we don't already have that information
cached, we may have to ask (and wait for) rpc.mountd.

In both cases we currently hold the i_mutex on the parent of the
directory we're asking rpc.mountd about.  We've seen situations where
rpc.mountd performs some operation on that directory that tries to take
the i_mutex again, resulting in deadlock.

With some care, we may be able to avoid that in rpc.mountd.  But it
seems better just to avoid holding a mutex while waiting on userspace.

It appears that lookup_one_len is pretty much the only operation that
needs the i_mutex.  So we could just drop the i_mutex elsewhere and do
something like

	mutex_lock()
	lookup_one_len()
	mutex_unlock()

In many cases though the lookup would have been cached and not required
the i_mutex, so it's more efficient to create a lookup_one_len() variant
that only takes the i_mutex when necessary.
Signed-off-by: NNeilBrown <neilb@suse.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      bbddca8e
  9. 08 12月, 2015 1 次提交
  11. 13 10月, 2015 1 次提交
  13. 01 9月, 2015 1 次提交
  15. 23 6月, 2015 1 次提交
    • C
      nfsd: take struct file setup fully into nfs4_preprocess_stateid_op · af90f707
      由 Christoph Hellwig 提交于 
      This patch changes nfs4_preprocess_stateid_op so it always returns
a valid struct file if it has been asked for that.  For that we
now allocate a temporary struct file for special stateids, and check
permissions if we got the file structure from the stateid.  This
ensures that all callers will get their handling of special stateids
right, and avoids code duplication.

There is a little wart in here because the read code needs to know
if we allocated a file structure so that it can copy around the
read-ahead parameters.  In the long run we should probably aim to
cache full file structures used with special stateids instead.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>
      af90f707
  17. 20 6月, 2015 1 次提交
  19. 29 5月, 2015 1 次提交
  21. 05 5月, 2015 1 次提交
  23. 16 4月, 2015 1 次提交
  25. 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
  27. 10 12月, 2014 2 次提交
  29. 20 11月, 2014 1 次提交
  31. 08 11月, 2014 1 次提交
  33. 01 11月, 2014 1 次提交
  35. 24 10月, 2014 1 次提交
    • Z
      nfsd: fix inclusive vfs_fsync_range() end · e77a7b4f
      由 Zach Brown 提交于 
      The vfs_fsync_range() call during write processing got the end of the
range off by one.  The range is inclusive, not exclusive.  The error has
nfsd sync more data than requested -- it's correct but unnecessary
overhead.

The call during commit processing is correct so I copied that pattern in
write processing.  Maybe a helper would be nice but I kept it trivial.

This is untested.  I found it while reviewing code for something else
entirely.
Signed-off-by: NZach Brown <zab@zabbo.net>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>
      e77a7b4f
  37. 11 9月, 2014 1 次提交
  39. 09 9月, 2014 1 次提交
  41. 04 9月, 2014 1 次提交
  43. 10 7月, 2014 1 次提交
  45. 09 7月, 2014 3 次提交
  47. 23 6月, 2014 3 次提交
  49. 31 5月, 2014 3 次提交
  51. 23 5月, 2014 1 次提交
    • N
      nfsd: Only set PF_LESS_THROTTLE when really needed. · 8658452e
      由 NeilBrown 提交于 
      PF_LESS_THROTTLE has a very specific use case: to avoid deadlocks
and live-locks while writing to the page cache in a loop-back
NFS mount situation.

It therefore makes sense to *only* set PF_LESS_THROTTLE in this
situation.
We now know when a request came from the local-host so it could be a
loop-back mount.  We already know when we are handling write requests,
and when we are doing anything else.

So combine those two to allow nfsd to still be throttled (like any
other process) in every situation except when it is known to be
problematic.
Signed-off-by: NNeilBrown <neilb@suse.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>
      8658452e
  53. 22 5月, 2014 1 次提交
    • K
      NFSD: Don't clear SUID/SGID after root writing data · 368fe39b
      由 Kinglong Mee 提交于 
      We're clearing the SUID/SGID bits on write by hand in nfsd_vfs_write,
even though the subsequent vfs_writev() call will end up doing this for
us (through file system write methods eventually calling
file_remove_suid(), e.g., from __generic_file_aio_write).

So, remove the redundant nfsd code.

The only change in behavior is when the write is by root, in which case
we previously cleared SUID/SGID, but will now leave it alone.  The new
behavior is the behavior of every filesystem we've checked.

It seems better to be consistent with local filesystem behavior.  And
the security advantage seems limited as root could always restore these
bits by hand if it wanted.

SUID/SGID is not cleared after writing data with (root, local ext4),
   File: ‘test’
   Size: 0               Blocks: 0          IO Block: 4096   regular
empty file
Device: 803h/2051d      Inode: 1200137     Links: 1
Access: (4777/-rwsrwxrwx)  Uid: (    0/    root)   Gid: (    0/    root)
Context: unconfined_u:object_r:admin_home_t:s0
Access: 2014-04-18 21:36:31.016029014 +0800
Modify: 2014-04-18 21:36:31.016029014 +0800
Change: 2014-04-18 21:36:31.026030285 +0800
  Birth: -
   File: ‘test’
   Size: 5               Blocks: 8          IO Block: 4096   regular file
Device: 803h/2051d      Inode: 1200137     Links: 1
Access: (4777/-rwsrwxrwx)  Uid: (    0/    root)   Gid: (    0/    root)
Context: unconfined_u:object_r:admin_home_t:s0
Access: 2014-04-18 21:36:31.016029014 +0800
Modify: 2014-04-18 21:36:31.040032065 +0800
Change: 2014-04-18 21:36:31.040032065 +0800
  Birth: -

With no_root_squash, (root, remote ext4), SUID/SGID are cleared,
   File: ‘test’
   Size: 0               Blocks: 0          IO Block: 262144 regular
empty file
Device: 24h/36d Inode: 786439      Links: 1
Access: (4777/-rwsrwxrwx)  Uid: ( 1000/    test)   Gid: ( 1000/    test)
Context: system_u:object_r:nfs_t:s0
Access: 2014-04-18 21:45:32.155805097 +0800
Modify: 2014-04-18 21:45:32.155805097 +0800
Change: 2014-04-18 21:45:32.168806749 +0800
  Birth: -
   File: ‘test’
   Size: 5               Blocks: 8          IO Block: 262144 regular file
Device: 24h/36d Inode: 786439      Links: 1
Access: (0777/-rwxrwxrwx)  Uid: ( 1000/    test)   Gid: ( 1000/    test)
Context: system_u:object_r:nfs_t:s0
Access: 2014-04-18 21:45:32.155805097 +0800
Modify: 2014-04-18 21:45:32.184808783 +0800
Change: 2014-04-18 21:45:32.184808783 +0800
  Birth: -
Signed-off-by: NKinglong Mee <kinglongmee@gmail.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>
      368fe39b
  55. 01 4月, 2014 1 次提交
  57. 29 3月, 2014 1 次提交
  59. 28 3月, 2014 1 次提交
  61. 19 2月, 2014 1 次提交
  63. 28 1月, 2014 1 次提交
    • J
      nfsd4: fix delegation-unlink/rename race · 4335723e
      由 J. Bruce Fields 提交于 
      If a file is unlinked or renamed between the time when we do the local
open and the time when we get the delegation, then we will return to the
client indicating that it holds a delegation even though the file no
longer exists under the name it was open under.

But a client performing an open-by-name, when it is returned a
delegation, must be able to assume that the file is still linked at the
name it was opened under.

So, hold the parent i_mutex for longer to prevent concurrent renames or
unlinks.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>
      4335723e
  65. 26 1月, 2014 1 次提交