Attempts to read() from the non-existent dmesg buffer will return zero and
userspace tends to get stuck in a busyloop.
So just remove /dev/kmsg altogether if CONFIG_PRINTK=n.
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
In journal=ordered or journal=data mode retry in ext4_prepare_write()
breaks the requirements of journaling of data with respect to metadata.
The fix is to call commit_write to commit allocated zero blocks before
retry.
Signed-off-by: Kirill Korotaev <dev@openvz.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Ken Chen <kenneth.w.chen@intel.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
In journal=ordered or journal=data mode retry in ext3_prepare_write()
breaks the requirements of journaling of data with respect to metadata.
The fix is to call commit_write to commit allocated zero blocks before
retry.
Signed-off-by: Kirill Korotaev <dev@openvz.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Ken Chen <kenneth.w.chen@intel.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Port commit a090d9132c into ext2:
All modifications of ->i_flags in inodes that might be visible to somebody
else must be under ->i_mutex. That patch fixes ext2 ioctl() setting S_APPEND.
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The Coverity checker noted that this was dead code, since in all places
above in this function, "err" is immediately checked.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Steve Grubb's fzfuzzer tool (http://people.redhat.com/sgrubb/files/
fsfuzzer-0.6.tar.gz) generates corrupt Cramfs filesystems which cause
Cramfs to kernel oops in cramfs_uncompress_block(). The cause of the oops
is an unchecked corrupted block length field read by cramfs_readpage().
This patch adds a sanity check to cramfs_readpage() which checks that the
block length field is sensible. The (PAGE_CACHE_SIZE << 1) size check is
intentional, even though the uncompressed data is not going to be larger
than PAGE_CACHE_SIZE, gzip sometimes generates compressed data larger than
the original source data. Mkcramfs checks that the compressed size is
always less than or equal to PAGE_CACHE_SIZE << 1. Of course Cramfs could
use the original uncompressed data in this case, but it doesn't.
Signed-off-by: Phillip Lougher <phillip@lougher.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
As Mikulas points out, (1 << anything) won't be evaluating to zero. This code
is long-dead.
Cc: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fix hpfs printk warnings:
fs/hpfs/dir.c:87: warning: format '%08x' expects type 'unsigned int', but argument 3 has type 'long unsigned int'
fs/hpfs/dir.c:147: warning: format '%08x' expects type 'unsigned int', but argument 3 has type 'long int'
fs/hpfs/dir.c:148: warning: format '%08x' expects type 'unsigned int', but argument 3 has type 'long int'
fs/hpfs/dnode.c:537: warning: format '%08x' expects type 'unsigned int', but argument 5 has type 'long unsigned int'
fs/hpfs/dnode.c:854: warning: format '%08x' expects type 'unsigned int', but argument 3 has type 'loff_t'
fs/hpfs/ea.c:247: warning: format '%08x' expects type 'unsigned int', but argument 3 has type 'long unsigned int'
fs/hpfs/inode.c:254: warning: format '%08x' expects type 'unsigned int', but argument 3 has type 'long unsigned int'
fs/hpfs/map.c:129: warning: format '%08x' expects type 'unsigned int', but argument 3 has type 'ino_t'
fs/hpfs/map.c:135: warning: format '%08x' expects type 'unsigned int', but argument 3 has type 'ino_t'
fs/hpfs/map.c:140: warning: format '%08x' expects type 'unsigned int', but argument 3 has type 'ino_t'
fs/hpfs/map.c:147: warning: format '%08x' expects type 'unsigned int', but argument 3 has type 'ino_t'
fs/hpfs/map.c:154: warning: format '%08x' expects type 'unsigned int', but argument 3 has type 'ino_t'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
- switch to error message buffer in .bss
- missing va_end() (htf it worked before?)
- use vsnprintf()
- rename variables to understandable "fmt", "args".
- "const char *fmt", yes.
- add __attribute__((format ...
Still, put that coffee down before reading more.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
It would very lame to get buffer overflow via one of the following.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Dave Kleikamp <shaggy@austin.ibm.com>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Function v9fs_get_idpool returns int, not u32. Actually it returns -1 on
errors, and these two callers check if the value is smaller than 0, which
was caught by gcc with extra warning flags. Compile tested only but should
be OK, as the value computed in v9fs_get_idpool() is also int.
Signed-of-by: Mika Kukkonen <mikukkon@iki.fi>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@lanl.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
I've been using Steve Grubb's purely evil "fsfuzzer" tool, at
http://people.redhat.com/sgrubb/files/fsfuzzer-0.4.tar.gz
Basically it makes a filesystem, splats some random bits over it, then
tries to mount it and do some simple filesystem actions.
At best, the filesystem catches the corruption gracefully. At worst,
things spin out of control.
As you might guess, we found a couple places in ext4 where things spin out
of control :)
First, we had a corrupted directory that was never checked for
consistency... it was corrupt, and pointed to another bad "entry" of
length 0. The for() loop looped forever, since the length of
ext4_next_entry(de) was 0, and we kept looking at the same pointer over and
over and over and over... I modeled this check and subsequent action on
what is done for other directory types in ext4_readdir...
(adding this check adds some computational expense; I am testing a followup
patch to reduce the number of times we check and re-check these directory
entries, in all cases. Thanks for the idea, Andreas).
Next we had a root directory inode which had a corrupted size, claimed to
be > 200M on a 4M filesystem. There was only really 1 block in the
directory, but because the size was so large, readdir kept coming back for
more, spewing thousands of printk's along the way.
Per Andreas' suggestion, if we're in this read error condition and we're
trying to read an offset which is greater than i_blocks worth of bytes,
stop trying, and break out of the loop.
With these two changes fsfuzz test survives quite well on ext4.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
I've been using Steve Grubb's purely evil "fsfuzzer" tool, at
http://people.redhat.com/sgrubb/files/fsfuzzer-0.4.tar.gz
Basically it makes a filesystem, splats some random bits over it, then
tries to mount it and do some simple filesystem actions.
At best, the filesystem catches the corruption gracefully. At worst,
things spin out of control.
As you might guess, we found a couple places in ext3 where things spin out
of control :)
First, we had a corrupted directory that was never checked for
consistency... it was corrupt, and pointed to another bad "entry" of
length 0. The for() loop looped forever, since the length of
ext3_next_entry(de) was 0, and we kept looking at the same pointer over and
over and over and over... I modeled this check and subsequent action on
what is done for other directory types in ext3_readdir...
(adding this check adds some computational expense; I am testing a followup
patch to reduce the number of times we check and re-check these directory
entries, in all cases. Thanks for the idea, Andreas).
Next we had a root directory inode which had a corrupted size, claimed to
be > 200M on a 4M filesystem. There was only really 1 block in the
directory, but because the size was so large, readdir kept coming back for
more, spewing thousands of printk's along the way.
Per Andreas' suggestion, if we're in this read error condition and we're
trying to read an offset which is greater than i_blocks worth of bytes,
stop trying, and break out of the loop.
With these two changes fsfuzz test survives quite well on ext3.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Randomizes -pie compiled binaries from 64k (0x10000) up to ELF_ET_DYN_BASE.
0 -> 64k is excluded to allow NULL ptr accesses to fail.
Signed-off-by: Marcus Meissner <meissner@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
lock_super() is unnecessary for setting super-block feature flags. Use the
provided *_SET_COMPAT_FEATURE() macros as well.
Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
One of our test team hit a reiserfs_panic while running fsstress tests on
2.6.19-rc1. The message looks like :
REISERFS: panic(device Null superblock):
reiserfs[5676]: assertion !(p->path_length != 1 ) failed at
fs/reiserfs/stree.c:397:reiserfs_check_path: path not properly relsed.
The backtrace looked :
kernel BUG in reiserfs_panic at fs/reiserfs/prints.c:361!
.reiserfs_check_path+0x58/0x74
.reiserfs_get_block+0x1444/0x1508
.__block_prepare_write+0x1c8/0x558
.block_prepare_write+0x34/0x64
.reiserfs_prepare_write+0x118/0x1d0
.generic_file_buffered_write+0x314/0x82c
.__generic_file_aio_write_nolock+0x350/0x3e0
.__generic_file_write_nolock+0x78/0xb0
.generic_file_write+0x60/0xf0
.reiserfs_file_write+0x198/0x2038
.vfs_write+0xd0/0x1b4
.sys_write+0x4c/0x8c
syscall_exit+0x0/0x4
Upon debugging I found that the restart_transaction was not releasing
the path if the th->refcount was > 1.
/*static*/
int restart_transaction(struct reiserfs_transaction_handle *th,
struct inode *inode, struct path *path)
{
[...]
/* we cannot restart while nested */
if (th->t_refcount > 1) { <<- Path is not released in this case!
return 0;
}
pathrelse(path); <<- Path released here.
[...]
This could happen in such a situation :
In reiserfs/inode.c: reiserfs_get_block() ::
if (repeat == NO_DISK_SPACE || repeat == QUOTA_EXCEEDED) {
/* restart the transaction to give the journal a chance to free
** some blocks. releases the path, so we have to go back to
** research if we succeed on the second try
*/
SB_JOURNAL(inode->i_sb)->j_next_async_flush = 1;
-->> retval = restart_transaction(th, inode, &path); <<--
We are supposed to release the path, no matter we succeed or fail. But
if the th->refcount is > 1, the path is still valid. And,
if (retval)
goto failure;
repeat =
_allocate_block(th, block, inode,
&allocated_block_nr, NULL, create);
If the above allocate_block fails with NO_DISK_SPACE or QUOTA_EXCEEDED,
we would have path which is not released.
if (repeat != NO_DISK_SPACE && repeat != QUOTA_EXCEEDED) {
goto research;
}
if (repeat == QUOTA_EXCEEDED)
retval = -EDQUOT;
else
retval = -ENOSPC;
goto failure;
[...]
failure:
[...]
reiserfs_check_path(&path); << Panics here !
Attached here is a patch which could fix the issue.
fix reiserfs/inode.c : restart_transaction() to release the path in all
cases.
The restart_transaction() doesn't release the path when the the journal
handle has a refcount > 1. This would trigger a reiserfs_panic() if we
encounter an -ENOSPC / -EDQUOT in reiserfs_get_block().
Signed-off-by: Suzuki K P <suzuki@in.ibm.com>
Cc: "Vladimir V. Saveliev" <vs@namesys.com>
Cc: <reiserfs-dev@namesys.com>
Cc: Jeff Mahoney <jeffm@suse.com>
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
free_fdtable_rc() schedules timer to reschedule fddef->wq if
schedule_work() on it returns 0. However, schedule_work() guarantees that
the target work is executed at least once after the scheduling regardless
of its return value. 0 return simply means that the work was already
pending and thus no further action was required.
Another problem is that it used contant '5' as @expires argument to
mod_timer().
Kill unnecessary fddef->timer.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Randy Dunlap wote:
> Should FUSE depend on BLOCK? Without that and with BLOCK=n, I get:
>
> inode.c:(.text+0x3acc5): undefined reference to `sb_set_blocksize'
> inode.c:(.text+0x3a393): undefined reference to `get_sb_bdev'
> fs/built-in.o:(.data+0xd718): undefined reference to `kill_block_super
Most fuse filesystems work fine without block device support, so I
think a better solution is to disable the 'fuseblk' filesystem type if
BLOCK=n.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add a DESTROY operation for block device based filesystems. With the help of
this operation, such a filesystem can flush dirty data to the device
synchronously before the umount returns.
This is needed in situations where the filesystem is assumed to be clean
immediately after unmount (e.g. ejecting removable media).
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add support for the BMAP operation for block device based filesystems. This
is needed to support swap-files and lilo.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add 'blksize' option for block device based filesystems. During
initialization this is used to set the block size on the device and the super
block. The default block size is 512bytes.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
I never intended this, but people started using fuse to implement block device
based "real" filesystems (ntfs-3g, zfs).
The following four patches add better support for these kinds of filesystems.
Unlike "normal" fuse filesystems, using this feature should require superuser
privileges (enforced by the fusermount utility).
Thanks to Szabolcs Szakacsits for the input and testing.
This patch adds a 'fuseblk' filesystem type, which is only different from the
'fuse' filesystem type in how the 'dev_name' mount argument is interpreted.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Remove unneeded code from fuse_dentry_revalidate(). This made some sense
while the validity time could wrap around, but now it's a very obvious no-op.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Update ext4_statfs to return an FSID that is a 64 bit XOR of the 128 bit
filesystem UUID as suggested by Andreas Dilger. See the following Bugzilla
entry for details:
http://bugzilla.kernel.org/show_bug.cgi?id=136
Cc: Andreas Dilger <adilger@clusterfs.com>
Cc: Stephen Tweedie <sct@redhat.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Update ext3_statfs to return an FSID that is a 64 bit XOR of the 128 bit
filesystem UUID as suggested by Andreas Dilger. See the following Bugzilla
entry for details:
http://bugzilla.kernel.org/show_bug.cgi?id=136
Cc: Andreas Dilger <adilger@clusterfs.com>
Cc: Stephen Tweedie <sct@redhat.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Update ext2_statfs to return an FSID that is a 64 bit XOR of the 128 bit
filesystem UUID as suggested by Andreas Dilger. See the following Bugzilla
entry for details:
http://bugzilla.kernel.org/show_bug.cgi?id=136
Cc: Andreas Dilger <adilger@clusterfs.com>
Cc: Stephen Tweedie <sct@redhat.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Make access(X_OK) take the "noexec" mount option into account.
Signed-off-by: Stas Sergeev <stsp@aknet.ru>
Cc: Jakub Jelinek <jakub@redhat.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Ulrich Drepper <drepper@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
check_partition() stops its probe once it hits an I/O error from the
partition checkers. This would prevent the actual partition checker
getting a chance to verify the partition.
So this patch lets check_partition() continue probing untill it hits a
success while recording the I/O error which might have been reported by the
checking routines.
Also, it does some cleanup of the partition methods for ibm, atari and
amiga to return -1 upon hitting an I/O error.
Signed-off-by: Suzuki K P <suzuki@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The current rescan_partition implementation ignores the errors that comes from
the lower layer. It reports success for unknown partitions as well as I/O
error cases while reading the partition information.
The unknown partition is not (and will not be) considered as an error in the
kernel, since there are legal users of it (e.g, members of a RAID5 MD Device
or a new disk which is not partitioned at all ). Changing this behaviour
would scare the user about a serious problem with their disk and is not
recommended. Thus for both "unknown partitions" to the Linux (eg., DEC
VMS,Novell Netware) and the legal users of NULL partition, would still be
reported as "SUCCESS".
The patch attached here, scares the user about something which he does need to
worry about. i.e, returning -EIO on disk I/O errors while reading the
partition information.
Signed-off-by: Suzuki K P <suzuki@in.ibm.com>
Cc: Erik Mouw <erik@harddisk-recovery.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Make the workqueues used by XFS freezeable, so their worker threads don't
submit any I/O after the suspend image has been created.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: Nigel Cunningham <nigel@suspend2.net>
Cc: David Chinner <dgc@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Move process freezing functions from include/linux/sched.h to freezer.h, so
that modifications to the freezer or the kernel configuration don't require
recompiling just about everything.
[akpm@osdl.org: fix ueagle driver]
Signed-off-by: Nigel Cunningham <nigel@suspend2.net>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Replace all uses of kmem_cache_t with struct kmem_cache.
The patch was generated using the following script:
#!/bin/sh
#
# Replace one string by another in all the kernel sources.
#
set -e
for file in `find * -name "*.c" -o -name "*.h"|xargs grep -l $1`; do
quilt add $file
sed -e "1,\$s/$1/$2/g" $file >/tmp/$$
mv /tmp/$$ $file
quilt refresh
done
The script was run like this
sh replace kmem_cache_t "struct kmem_cache"
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
SLAB_KERNEL is an alias of GFP_KERNEL.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
SLAB_USER is an alias of GFP_USER
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
SLAB_NOFS is an alias of GFP_NOFS.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Currently a user process cannot rise its own oom_adj value (i.e.
unprotecting itself from the OOM killer). As this value is stored in the
task structure it gets inherited and the unprivileged childs will be unable
to rise it.
The EPERM will be handled by the generic proc fs layer, as only processes
with the proper caps or the owner of the process will be able to write to
the file. So we allow only the processes with CAP_SYS_RESOURCE to lower
the value, otherwise it will get an EACCES which seems more appropriate
than EPERM.
Signed-off-by: Guillem Jover <guillem.jover@nokia.com>
Acked-by: Andrea Arcangeli <andrea@novell.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
OpenVZ Linux kernel team has found a problem with mounting in compat mode.
Simple command "mount -t smbfs ..." on Fedora Core 5 distro in 32-bit mode
leads to oops:
Unable to handle kernel NULL pointer dereference at 0000000000000000 RIP: compat_sys_mount+0xd6/0x290
Process mount (pid: 14656, veid=300, threadinfo ffff810034d30000, task ffff810034c86bc0)
Call Trace: ia32_sysret+0x0/0xa
The problem is that data_page pointer can be NULL, so we should skip data
conversion in this case.
Signed-off-by: Andrey Mirkin <amirkin@openvz.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This fixes up most of the things pointed out by akpm and Pavel Machek
with comments below indicating why some things have been left:
Andrew Morton wrote:
>
>> +static struct nodeinfo *nodeid2nodeinfo(int nodeid, gfp_t alloc)
>> +{
>> + struct nodeinfo *ni;
>> + int r;
>> + int n;
>> +
>> + down_read(&nodeinfo_lock);
>
> Given that this function can sleep, I wonder if `alloc' is useful.
>
> I see lots of callers passing in a literal "0" for `alloc'. That's in fact
> a secret (GFP_ATOMIC & ~__GFP_HIGH). I doubt if that's what you really
> meant. Particularly as the code could at least have used __GFP_WAIT (aka
> GFP_NOIO) which is much, much more reliable than "0". In fact "0" is the
> least reliable mode possible.
>
> IOW, this is all bollixed up.
When 0 is passed into nodeid2nodeinfo the function does not try to allocate a
new structure at all. it's an indication that the caller only wants the nodeinfo
struct for that nodeid if there actually is one in existance.
I've tidied the function itself so it's more obvious, (and tidier!)
>> +/* Data received from remote end */
>> +static int receive_from_sock(void)
>> +{
>> + int ret = 0;
>> + struct msghdr msg;
>> + struct kvec iov[2];
>> + unsigned len;
>> + int r;
>> + struct sctp_sndrcvinfo *sinfo;
>> + struct cmsghdr *cmsg;
>> + struct nodeinfo *ni;
>> +
>> + /* These two are marginally too big for stack allocation, but this
>> + * function is (currently) only called by dlm_recvd so static should be
>> + * OK.
>> + */
>> + static struct sockaddr_storage msgname;
>> + static char incmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
>
> whoa. This is globally singly-threaded code??
Yes. it is only ever run in the context of dlm_recvd.
>>
>> +static void initiate_association(int nodeid)
>> +{
>> + struct sockaddr_storage rem_addr;
>> + static char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
>
> Another static buffer to worry about. Globally singly-threaded code?
Yes. Only ever called by dlm_sendd.
>> +
>> +/* Send a message */
>> +static int send_to_sock(struct nodeinfo *ni)
>> +{
>> + int ret = 0;
>> + struct writequeue_entry *e;
>> + int len, offset;
>> + struct msghdr outmsg;
>> + static char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
>
> Singly-threaded?
Yep.
>>
>> +static void dealloc_nodeinfo(void)
>> +{
>> + int i;
>> +
>> + for (i=1; i<=max_nodeid; i++) {
>> + struct nodeinfo *ni = nodeid2nodeinfo(i, 0);
>> + if (ni) {
>> + idr_remove(&nodeinfo_idr, i);
>
> Didn't that need locking?
Not. it's only ever called at DLM shutdown after all the other threads
have been stopped.
>>
>> +static int write_list_empty(void)
>> +{
>> + int status;
>> +
>> + spin_lock_bh(&write_nodes_lock);
>> + status = list_empty(&write_nodes);
>> + spin_unlock_bh(&write_nodes_lock);
>> +
>> + return status;
>> +}
>
> This function's return value is meaningless. As soon as the lock gets
> dropped, the return value can get out of sync with reality.
>
> Looking at the caller, this _might_ happen to be OK, but it's a nasty and
> dangerous thing. Really the locking should be moved into the caller.
It's just an optimisation to allow the caller to schedule if there is no work
to do. if something arrives immediately afterwards then it will get picked up
when the process re-awakes (and it will be woken by that arrival).
The 'accepting' atomic has gone completely. as Andrew pointed out it didn't
really achieve much anyway. I suspect it was a plaster over some other
startup or shutdown bug to be honest.
Signed-off-by: Patrick Caulfield <pcaulfie@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Andrew Morton <akpm@osdl.org>
Cc: Pavel Machek <pavel@ucw.cz>
This is a bit better than the previous version of gfs2_fsync()
although it would be better still if we were able to call a
function which only wrote the inode & metadata. Its no big deal
though that this will potentially write the data as well since
the VFS has already done that before calling gfs2_fsync(). I've
also added a comment to explain whats going on here.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Andrew Morton <akpm@osdl.org>
JFS_NOINTEGRITY and JFS_USRQUOTA are defined to be the same value.
Change JFS_NOINTEGRITY to 0x40 and re-order the flags in the header
file to avoid repeating this problem.
Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>
The tk_pid field is an unsigned short. The proper print format specifier for
that type is %5u, not %4d.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We're really accounting for the same page twice now: once in
generic_writepages(), and once in nfs_scan_dirty().
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
There is now no reason to account for the dirty pages in the NFS code,
since the VM code will now do it for us via __set_page_dirty_nobuffers(),
and set_page_writeback().
We still need to keep the accounting of stable writes, though.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Mike Galbraith