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  1. 23 6月, 2008 7 次提交
    • J
      [patch 2/4] fs: make struct file arg to d_path const · 20d4fdc1
      由 Jan Engelhardt 提交于 
      Signed-off-by: NJan Engelhardt <jengelh@medozas.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      20d4fdc1
    • J
      [patch 1/4] vfs: path_{get,put}() cleanups · c8e7f449
      由 Jan Blunck 提交于 
      Here are some more places where path_{get,put}() can be used instead of
dput()/mntput() pair.
Signed-off-by: NJan Blunck <jblunck@suse.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      c8e7f449
    • M
      [patch for 2.6.26 4/4] vfs: utimensat(): fix write access check for futimens() · c70f8441
      由 Michael Kerrisk 提交于 
      The POSIX.1 draft spec for futimens()/utimensat() says:

        Only a process with the effective user ID equal to the
        user ID of the file, *or with write access to the file*,
        or with appropriate privileges may use futimens() or
        utimensat() with a null pointer as the times argument
        or with both tv_nsec fields set to the special value
        UTIME_NOW.

The important piece here is "with write access to the file", and
this matters for futimens(), which deals with an argument that
is a file descriptor referring to the file whose timestamps are
being updated,  The standard is saying that the "writability"
check is based on the file permissions, not the access mode with
which the file is opened.  (This behavior is consistent with the
semantics of FreeBSD's futimes().)  However, Linux is currently
doing the latter -- futimens(fd, times) is a library
function implemented as

       utimensat(fd, NULL, times, 0)

and within the utimensat() implementation we have the code:

                f = fget(dfd);  // dfd is 'fd'
                ...
                if (f) {
                        if (!(f->f_mode & FMODE_WRITE))
                                goto mnt_drop_write_and_out;

The check should instead be based on the file permissions.

Thanks to Miklos for pointing out how to do this check.
Miklos also pointed out a simplification that could be
made to my first version of this patch, since the checks
for the pathname and file descriptor cases can now be
conflated.
Acked-by: NMiklos Szeredi <miklos@szeredi.hu>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: NMichael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      c70f8441
    • M
      [patch for 2.6.26 3/4] vfs: utimensat(): fix error checking for {UTIME_NOW,UTIME_OMIT} case · 4cca9226
      由 Michael Kerrisk 提交于 
      The POSIX.1 draft spec for utimensat() says:

    Only a process with the effective user ID equal to the
    user ID of the file or with appropriate privileges may use
    futimens() or utimensat() with a non-null times argument
    that does not have both tv_nsec fields set to UTIME_NOW
    and does not have both tv_nsec fields set to UTIME_OMIT.

If this condition is violated, then the error EPERM should result.
However, the current implementation does not generate EPERM if
one tv_nsec field is UTIME_NOW while the other is UTIME_OMIT.
It should give this error for that case.

This patch:

a) Repairs that problem.
b) Removes the now unneeded nsec_special() helper function.
c) Adds some comments to explain the checks that are being
   performed.

Thanks to Miklos, who provided comments on the previous iteration
of this patch.  As a result, this version is a little simpler and
and its logic is better structured.

Miklos suggested an alternative idea, migrating the
is_owner_or_cap() checks into fs/attr.c:inode_change_ok() via
the use of an ATTR_OWNER_CHECK flag.  Maybe we could do that
later, but for now I've gone with this version, which is
IMO simpler, and can be more easily read as being correct.
Acked-by: NMiklos Szeredi <miklos@szeredi.hu>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: NMichael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      4cca9226
    • M
      [patch for 2.6.26 1/4] vfs: utimensat(): ignore tv_sec if tv_nsec == UTIME_OMIT or UTIME_NOW · 94c70b9b
      由 Michael Kerrisk 提交于 
      The POSIX.1 draft spec for utimensat() says that if a times[n].tv_nsec
field is UTIME_OMIT or UTIME_NOW, then the value in the corresponding
tv_sec field is ignored.  See the last sentence of this para, from
the spec:

    If the tv_nsec field of a timespec structure has
    the special value UTIME_NOW, the file's relevant
    timestamp shall be set to the greatest value
    supported by the file system that is not greater than
    the current time. If the tv_nsec field has the
    special value UTIME_OMIT, the file's relevant
    timestamp shall not be changed. In either case,
    the tv_sec field shall be ignored.

However the current Linux implementation requires the tv_sec value to be
zero (or the EINVAL error results). This requirement should be removed.
Acked-by: NMiklos Szeredi <miklos@szeredi.hu>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: NMichael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      94c70b9b
    • M
      [patch for 2.6.26 2/4] vfs: utimensat(): be consistent with utime() for... · 12fd0d30
      由 Michael Kerrisk 提交于 
      [patch for 2.6.26 2/4] vfs: utimensat(): be consistent with utime() for immutable and append-only files

This patch fixes utimensat() to make its behavior consistent
with that of utime()/utimes() when dealing with files marked
immutable and append-only.

The current utimensat() implementation also returns EPERM if
'times' is non-NULL and the tv_nsec fields are both UTIME_NOW.
For consistency, the

(times != NULL && times[0].tv_nsec == UTIME_NOW &&
                  times[1].tv_nsec == UTIME_NOW)

case should be treated like the traditional utimes() case where
'times' is NULL.  That is, the call should succeed for a file
marked append-only and should give the error EACCES if the file
is marked as immutable.

The simple way to do this is to set 'times' to NULL
if (times[0].tv_nsec == UTIME_NOW && times[1].tv_nsec == UTIME_NOW).

This is also the natural approach, since POSIX.1 semantics consider the
times == {{x, UTIME_NOW}, {y, UTIME_NOW}}
to be exactly equivalent to the case for
times == NULL.

(Thanks to Miklos for pointing this out.)

Patch 3 in this series relies on the simplification provided
by this patch.
Acked-by: NMiklos Szeredi <miklos@szeredi.hu>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: NMichael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      12fd0d30
    • A
      [PATCH] fix cgroup-inflicted breakage in block_dev.c · fe6e9c1f
      由 Al Viro 提交于 
      devcgroup_inode_permission() expects MAY_FOO, not FMODE_FOO; kindly
keep your misdesign consistent if you positively have to inflict it
on the kernel.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      fe6e9c1f
  3. 22 6月, 2008 4 次提交
  5. 21 6月, 2008 29 次提交