There was another FAT BKL conversion deadlock reported by Bart
Trojanowski due to the BKL being used as a recursive lock by FAT, which
was missed because it only triggers with 'sync' (or 'dirsync') mounts.
The recursion worked for the BKL, but after the conversion to lock_super
(which uses a mutex), it just deadlocks.
Thanks to Bart for debugging this and testing the fix. The lock
debugging information from the original report:
=============================================
[ INFO: possible recursive locking detected ]
2.6.27-rc3-bisect-00448-ga7f5aaf #16
---------------------------------------------
mv/4020 is trying to acquire lock:
(&type->s_lock_key#9){--..}, at: [<c01a90fe>] lock_super+0x1e/0x20
but task is already holding lock:
(&type->s_lock_key#9){--..}, at: [<c01a90fe>] lock_super+0x1e/0x20
other info that might help us debug this:
3 locks held by mv/4020:
#0: (&sb->s_type->i_mutex_key#9/1){--..}, at: [<c01b2336>] do_unlinkat+0x66/0x140
#1: (&sb->s_type->i_mutex_key#9){--..}, at: [<c01b0954>] vfs_unlink+0x84/0x110
#2: (&type->s_lock_key#9){--..}, at: [<c01a90fe>] lock_super+0x1e/0x20
stack backtrace:
Pid: 4020, comm: mv Not tainted 2.6.27-rc3-bisect-00448-ga7f5aaf #16
[<c014e694>] validate_chain+0x984/0xea0
[<c0108d70>] ? native_sched_clock+0x0/0xf0
[<c014ee9c>] __lock_acquire+0x2ec/0x9b0
[<c014f5cf>] lock_acquire+0x6f/0x90
[<c01a90fe>] ? lock_super+0x1e/0x20
[<c044e5fd>] mutex_lock_nested+0xad/0x300
[<c01a90fe>] ? lock_super+0x1e/0x20
[<c01a90fe>] ? lock_super+0x1e/0x20
[<c01a90fe>] lock_super+0x1e/0x20
[<f8b3a700>] fat_write_inode+0x60/0x2b0 [fat]
[<c0450878>] ? _spin_unlock_irqrestore+0x48/0x80
[<f8b3a953>] ? fat_sync_inode+0x3/0x20 [fat]
[<f8b3a962>] fat_sync_inode+0x12/0x20 [fat]
[<f8b37c7e>] fat_remove_entries+0xbe/0x120 [fat]
[<f8b422ef>] vfat_unlink+0x5f/0x90 [vfat]
[<f8b42290>] ? vfat_unlink+0x0/0x90 [vfat]
[<c01b0968>] vfs_unlink+0x98/0x110
[<c01b2400>] do_unlinkat+0x130/0x140
[<c016a8f5>] ? audit_syscall_entry+0x105/0x150
[<c01b253b>] sys_unlinkat+0x3b/0x40
[<c01040d3>] sysenter_do_call+0x12/0x3f
=======================
where the deadlock is due to the nesting of lock_super from vfat_unlink
to fat_write_inode:
- do_unlinkat
- vfs_unlink
- vfat_unlink
* lock_super
- fat_remove_entries
- fat_sync_inode
- fat_write_inode
* lock_super
and the fix is to simply remove the use of lock_super() in fat_write_inode.
The lock_super() there had been just an automatic conversion of the
kernel lock to the superblock lock, but no locking was actually needed
there, since the code in fat_write_inode already protected all relevant
accesses with a spinlock (sbi->inode_hash_lock to be exact). The only
code inside the BKL (and thus the superblock lock) was accesses tp local
variables or calls to functions that have long been SMP-safe (i.e.
sb_bread, mark_buffe_dirty and brlese).
Bart reports:
"Looks good. I ran 10 parallel processes creating 1M files truncating
them, writing to them again and then deleting them. This patch fixes
the issue I ran into.
Signed-off-by: Bart Trojanowski <bart@jukie.net>"
Reported-and-tested-by: Bart Trojanowski <bart@jukie.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
FAT has to handle the newly introduced ATTR_TIMES_SET for allow_utime
option.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The FAT_IOCTL_SET_ATTRIBUTES ioctl() calls notify_change() to change
the file mode before changing the inode attributes. Replace with
explicit calls to security_inode_setattr(), fat_setattr() and
fsnotify_change().
This is equivalent to the original. The reason it is needed, is that
later in the series we move the immutable check into notify_change().
That would break the FAT_IOCTL_SET_ATTRIBUTES ioctl, as it needs to
perform the mode change regardless of the immutability of the file.
[Fix error if fat is built as a module. Thanks to OGAWA Hirofumi for
noticing.]
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Kmem cache passed to constructor is only needed for constructors that are
themselves multiplexeres. Nobody uses this "feature", nor does anybody uses
passed kmem cache in non-trivial way, so pass only pointer to object.
Non-trivial places are:
arch/powerpc/mm/init_64.c
arch/powerpc/mm/hugetlbpage.c
This is flag day, yes.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Jon Tollefson <kniht@linux.vnet.ibm.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Matt Mackall <mpm@selenic.com>
[akpm@linux-foundation.org: fix arch/powerpc/mm/hugetlbpage.c]
[akpm@linux-foundation.org: fix mm/slab.c]
[akpm@linux-foundation.org: fix ubifs]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Provide a new mount option ("tz=UTC") for DOS (vfat/msdos) filesystems,
allowing timestamps to be in coordinated universal time (UTC) rather than
local time in applications where doing this is advantageous.
In particular, portable devices that use fat/vfat (such as digital
cameras) can benefit from using UTC in their internal clocks, thus
avoiding daylight saving time errors and general time ambiguity issues.
The user of the device does not have to worry about changing the time when
moving from place or when daylight saving changes.
The new mount option, when set, disables the counter-adjustment that Linux
currently makes to FAT timestamp info in anticipation of the normal
userspace time zone correction. When used in this new mode, all daylight
saving time and time zone handling is done in userspace as is normal for
many other filesystems (like ext3). The default mode, which remains
unchanged, is still appropriate when mounting volumes written in Windows
(because of its use of local time).
I originally based this patch on one submitted last year by Paul Collins,
but I updated it to work with current source and changed variable/option
naming. Ogawa Hirofumi (who maintains these filesystems) and I discussed
this patch at length on lkml, and he suggested using the option name in
the attached version of the patch. Barry Bouwsma pointed out a good
addition to the patch as well.
Signed-off-by: Joe Peterson <joe@skyrush.com>
Signed-off-by: Paul Collins <paul@ondioline.org>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Barry Bouwsma <free_beer_for_all@yahoo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This removes unnecessary parsing for directory entries.
If short_only, we don't need to parse longname. And if !both and it found
the longname, we don't need shortname.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This uses uses stack for shortname, and uses __getname() for longname in
fat_search_long() and __fat_readdir(). By this, it removes unneeded
__getname() for shortname.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is no logic changes, just cleans fs/fat/dir.c up.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
struct __fat_dirent is what was formerly the kernel struct dirent (that
was different from the userspace struct dirent).
Converting all fat users to struct __fat_dirent will allow us to get rid
of the conflicting struct dirent definition.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Current parse_options() exits too early. We need to run the code of
bottom in this function even if users doesn't specify options.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The FAT BKL removal patch can cause deadlocks. It turns out that the new
lock_super() calls are unneeded, remove them (as directed by Linus).
Reported-by: "Tony Luck" <tony.luck@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
This replaces the use of the BKL in the FAT family of filesystems with the
existing superblock lock instead.
The code already appears to do mostly proper locking with its own private
spinlocks (and mutexes), but while the BKL could possibly have been
dropped entirely, converting it to use the superblock lock (which is just
a regular mutex) is the conservative thing to do.
As a per-filesystem mutex, it not only won't have any of the possible
latency issues related to the BKL, but the lock is obviously private to
the particular filesystem instance and will thus not cause problems for
entirely unrelated users like the BKL can.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
New chmod() allows only acceptable permission, and if not acceptable, it
returns -EPERM. Old one allows even if it can't store permission to on
disk inode. But it seems too strict for users.
E.g. https://bugzilla.redhat.com/show_bug.cgi?id=449080: With new one,
rsync couldn't create the temporary file.
So, this patch allows like old one, but now it doesn't change the
permission if it can't store, and it returns 0.
Also, this patch fixes missing check.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
__FUNCTION__ is gcc-specific, use __func__
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Annoying gcc warning:
fs/fat/inode.c: In function 'fat_fill_super':
fs/fat/inode.c:1222: warning: comparison is always false due to limited range of data type
Change it to compare with 4K instead of PAGE_CACHE_SIZE, as suggested
by OGAWA-san.
[FAT spec says: logical_sector_size should be 512, 1024, 2048 4096]
So, at least for now, we limit it to 4096.
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The on-disk media specification field in FAT is only 8-bits, so testing for
<=0xff is pointless, and can generate a "comparison is always true due to
limited range of data type" warning.
While we're there, convert FAT_VALID_MEDIA() into a C function - the present
implementation is buggy: it generates either one or two references to its
argument.
Cc: Frank Seidel <fseidel@suse.de>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
__getname() is faster than __get_free_page(). Use it.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch fix the problem that the buffer allocated for convert of unicode to
utf8 in fat/dir.c is too small.
And cannot handle filename with 255 asian characters when mounted with utf8
options.
Also it fix the filename length limitation checking in vfat/namei.c that the
filename length should be checked against the number of converted unicode
characters.
Not the length before NLS/UTF8 converted.
Signed-off-by: Keith Mok <ek9852@gmail.com>
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, free_clusters is not updated until it is trusted, because
Windows doesn't update it correctly.
But if user is using FAT driver of Linux, it updates free_clusters
correctly. Instead, this updates it even if it's untrusted, so if
free_clustes is correct, now keep correct value.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Normally utime(2) checks current process is owner of the file, or it
has CAP_FOWNER capability. But FAT filesystem doesn't have uid/gid as
on disk info, so normal check is too unflexible.
With this option you can relax it.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix fat_setattr() on the case of showexec option. If user specified
showexec option, inode->i_mode may not have S_IXUGO. This just use
inode->i_mode to fix it.
And with this patch, we don't allow chmod() on memory inode, it's just
bad behaviour. IOW, we allow changing S_IWUGO only which can be stored
to disk.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
FAT doesn't need to check bad inode anymore.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Some ioctl()s can cause writes to the filesystem. Take these, and make them
use mnt_want/drop_write() instead.
[AV: updated]
Acked-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Stop the FAT filesystem from using iget() and read_inode(). Replace the call
to iget() with a call to ilookup().
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This makes sure printk format strings contain no more than a single line.
Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
[the message was tweaked.]
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Prohibit mode changes in non-quiet mode that cannot be stored reliably with
the on-disk format.
Suppose a vfat filesystem is mounted with umask=0 and [not-quiet]. Then
all files will have mode 0777. Trying to change the owner will fail,
because fat does not know about owners or groups. chmod 0770, on the other
hand, will succeed, even though fat does not know about the permission
triplet [user/group/other].
So this patch changes fat's not-quiet behavior so that only UNIX modes are
accepted that can be mapped lossless between the fat disk format and the
local system. There is only one attribute, and that is the readonly
attribute, which is mapped to the UNIX write permission bit(s). chmod 0555
is therefore valid (taking away the +w bits <=> setting the readonly
attribute). Since chmod 0775 and chmod 0755 is an ambiguous case as to
whether to set or clear the readonly bit, these modes are also denied.
In quiet mode, chmod and chown will continue to "succeed" as they did
before, meaning that a subsequent stat() will temporarily return the new
mode as long as the inode is not reread from disk, and chown will silently
do nothing, not even return the new uid/gid in stat().
Signed-off-by: Jan Engelhardt <jengelh@computergmbh.de>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
On large partition, scanning the free clusters is very slow if users
doesn't use "usefree" option.
For optimizing it, this patch uses sb_breadahead() to read of FAT
sectors. On some user's 15GB partition, this patch improved it very
much (1min => 600ms).
The following is the result of 2GB partition on my machine.
without patch:
root@devron (/)# time df -h > /dev/null
real 0m1.202s
user 0m0.000s
sys 0m0.440s
with patch:
root@devron (/)# time df -h > /dev/null
real 0m0.378s
user 0m0.012s
sys 0m0.168s
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now that nfsd has stopped writing to the find_exported_dentry member we an
mark the export_operations const
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Neil Brown <neilb@suse.de>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: <linux-ext4@vger.kernel.org>
Cc: Dave Kleikamp <shaggy@austin.ibm.com>
Cc: Anton Altaparmakov <aia21@cantab.net>
Cc: David Chinner <dgc@sgi.com>
Cc: Timothy Shimmin <tes@sgi.com>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Chris Mason <mason@suse.com>
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: "Vladimir V. Saveliev" <vs@namesys.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Very little changes here, fat had a mostly no op decode_fh before and does not
store any parent information.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Neil Brown <neilb@suse.de>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Slab constructors currently have a flags parameter that is never used. And
the order of the arguments is opposite to other slab functions. The object
pointer is placed before the kmem_cache pointer.
Convert
ctor(void *object, struct kmem_cache *s, unsigned long flags)
to
ctor(struct kmem_cache *s, void *object)
throughout the kernel
[akpm@linux-foundation.org: coupla fixes]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Slab destructors were no longer supported after Christoph's
c59def9f22 change. They've been
BUGs for both slab and slub, and slob never supported them
either.
This rips out support for the dtor pointer from kmem_cache_create()
completely and fixes up every single callsite in the kernel (there were
about 224, not including the slab allocator definitions themselves,
or the documentation references).
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
currently the export_operation structure and helpers related to it are in
fs.h. fs.h is already far too large and there are very few places needing the
export bits, so split them off into a separate header.
[akpm@linux-foundation.org: fix cifs build]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Neil Brown <neilb@suse.de>
Cc: Steven French <sfrench@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
FAT12 entry is 12bits, so it needs 2 phase to update the value. And
writer and reader access it without any lock, so reader can get the
half updated value.
This fixes the long standing race condition by adding a global
spinlock to only FAT12 for avoiding any impact against FAT16/32.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch fixes the following warnings.
fs/fat/dir.c: In function 'fat_parse_long':
include/linux/msdos_fs.h:294: warning: array subscript is above array bounds
include/linux/msdos_fs.h:295: warning: array subscript is above array bounds
include/linux/msdos_fs.h:295: warning: array subscript is above array bounds
The ->name is defined as "name[8], ext[3]", but fat_checksum() uses
those as name[11]. There is no actual problem, but it's not a good manner.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
They can use generic_file_splice_read() instead. Since sys_sendfile() now
prefers that, there should be no change in behaviour.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
SLAB_CTOR_CONSTRUCTOR is always specified. No point in checking it.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Steven French <sfrench@us.ibm.com>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Dave Kleikamp <shaggy@austin.ibm.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Anton Altaparmakov <aia21@cantab.net>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jan Kara <jack@ucw.cz>
Cc: David Chinner <dgc@sgi.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If you compile and run the below test case in an msdos or vfat directory on
an x86-64 system with -m32 you'll get garbage in the kernel_dirent struct
followed by a SIGSEGV.
The patch fixes this.
Reported and initial fix by Bart Oldeman
#include <sys/types.h>
#include <sys/ioctl.h>
#include <dirent.h>
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
struct kernel_dirent {
long d_ino;
long d_off;
unsigned short d_reclen;
char d_name[256]; /* We must not include limits.h! */
};
#define VFAT_IOCTL_READDIR_BOTH _IOR('r', 1, struct kernel_dirent [2])
#define VFAT_IOCTL_READDIR_SHORT _IOR('r', 2, struct kernel_dirent [2])
int main(void)
{
int fd = open(".", O_RDONLY);
struct kernel_dirent de[2];
while (1) {
int i = ioctl(fd, VFAT_IOCTL_READDIR_BOTH, (long)de);
if (i == -1) break;
if (de[0].d_reclen == 0) break;
printf("SFN: reclen=%2d off=%d ino=%d, %-12s",
de[0].d_reclen, de[0].d_off, de[0].d_ino, de[0].d_name);
if (de[1].d_reclen)
printf("\tLFN: reclen=%2d off=%d ino=%d, %s",
de[1].d_reclen, de[1].d_off, de[1].d_ino, de[1].d_name);
printf("\n");
}
return 0;
}
Signed-off-by: Bart Oldeman <bartoldeman@users.sourceforge.net>
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It seems that the recent Windows changed specification, and it's
undocumented. Windows doesn't update ->free_clusters correctly.
This patch doesn't use ->free_clusters by default. (instead, add "usefree"
for forcing to use it)
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Juergen Beisert <juergen127@kreuzholzen.de>
Cc: Andreas Schwab <schwab@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Replacing (n & (n-1)) in the context of power of 2 checks with
is_power_of_2
Signed-off-by: vignesh babu <vignesh.babu@wipro.com>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I have never seen a use of SLAB_DEBUG_INITIAL. It is only supported by
SLAB.
I think its purpose was to have a callback after an object has been freed
to verify that the state is the constructor state again? The callback is
performed before each freeing of an object.
I would think that it is much easier to check the object state manually
before the free. That also places the check near the code object
manipulation of the object.
Also the SLAB_DEBUG_INITIAL callback is only performed if the kernel was
compiled with SLAB debugging on. If there would be code in a constructor
handling SLAB_DEBUG_INITIAL then it would have to be conditional on
SLAB_DEBUG otherwise it would just be dead code. But there is no such code
in the kernel. I think SLUB_DEBUG_INITIAL is too problematic to make real
use of, difficult to understand and there are easier ways to accomplish the
same effect (i.e. add debug code before kfree).
There is a related flag SLAB_CTOR_VERIFY that is frequently checked to be
clear in fs inode caches. Remove the pointless checks (they would even be
pointless without removeal of SLAB_DEBUG_INITIAL) from the fs constructors.
This is the last slab flag that SLUB did not support. Remove the check for
unimplemented flags from SLUB.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If the DIO write on FAT is expanding the size, it will be fail by -EINVAL,
because FAT can't handle it now.
This patch fallback it to the normal buffered-write and would return
success.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch is inspired by Arjan's "Patch series to mark struct
file_operations and struct inode_operations const".
Compile tested with gcc & sparse.
Signed-off-by: Josef 'Jeff' Sipek <jsipek@cs.sunysb.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Many struct inode_operations in the kernel can be "const". Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data. In addition it'll catch accidental writes at compile time to
these shared resources.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
