I've bisected the deadlock when many small appends are done on jffs2 down to
this commit:
commit 6fe6900e1e
Author: Nick Piggin <npiggin@suse.de>
Date: Sun May 6 14:49:04 2007 -0700
mm: make read_cache_page synchronous
Ensure pages are uptodate after returning from read_cache_page, which allows
us to cut out most of the filesystem-internal PageUptodate calls.
I didn't have a great look down the call chains, but this appears to fixes 7
possible use-before uptodate in hfs, 2 in hfsplus, 1 in jfs, a few in
ecryptfs, 1 in jffs2, and a possible cleared data overwritten with readpage in
block2mtd. All depending on whether the filler is async and/or can return
with a !uptodate page.
It introduced a wait to read_cache_page, as well as a
read_cache_page_async function equivalent to the old read_cache_page
without any callers.
Switching jffs2_gc_fetch_page to read_cache_page_async for the old
behavior makes the deadlocks go away, but maybe reintroduces the
use-before-uptodate problem? I don't understand the mm/fs interaction
well enough to say.
[It's fine. dwmw2.]
Signed-off-by: Jason Lunz <lunz@falooley.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Ryusuke Konishi says:
The recent truncate_complete_page() clears the dirty flag from a page
before calling a_ops->invalidatepage(),
^^^^^^
static void
truncate_complete_page(struct address_space *mapping, struct page *page)
{
...
cancel_dirty_page(page, PAGE_CACHE_SIZE); <--- Inserted here at
kernel 2.6.20
if (PagePrivate(page))
do_invalidatepage(page, 0); ---> will call
a_ops->invalidatepage()
...
}
and this is disturbing nfs_wb_page_priority() from calling
nfs_writepage_locked() that is expected to handle the pending
request (=nfs_page) associated with the page.
int nfs_wb_page_priority(struct inode *inode, struct page *page, int how)
{
...
if (clear_page_dirty_for_io(page)) {
ret = nfs_writepage_locked(page, &wbc);
if (ret < 0)
goto out;
}
...
}
Since truncate_complete_page() will get rid of the page after
a_ops->invalidatepage() returns, the request (=nfs_page) associated
with the page becomes a garbage in nfs_inode->nfs_page_tree.
------------------------
Fix this by ensuring that nfs_wb_page_priority() recognises that it may
also need to clear out non-dirty pages that have an nfs_page associated
with them.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
According to the mount(2) man page, the proper error return code for the
mount(2) system call when the special device name or the mounted-on
directory name is too long is ENAMETOOLONG.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The hostname was getting truncated in the new text-based NFS mount API.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Don't filter the return code from the in-kernel rpcbind or NFS mount
clients. Return the real error code so that callers of the new NFS
text-based mount API can apply a useful retry strategy.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The new text-based NFS mount option parsing logic doesn't recognize any
valid transport protocols due to a silly mistake in the protocol token
matching logic. This prevents basic mount requests such as:
mount.nfs server:/export /mnt -o proto=tcp
from working with the new text-based NFS mount API.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Doh! We can't use cancel_delayed_work_sync because we may have been called
from an unmount that was being performed by nfs_automount_task.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This avoids the recent NFS mount regression (returning EBUSY when
mounting the same filesystem twice with different parameters).
The best I can do given the constraints appears to be to have the kernel
first look for a superblock that matches both the fsid and the
user-specified mount options, and then spawn off a new superblock if
that search fails.
Note that this is not the same as specifying nosharecache everywhere
since nosharecache will never attempt to match an existing superblock.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Tested-by: Hua Zhong <hzhong@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For hugepage mappings, the file offset, like the address and size, needs to
be aligned to the size of a hugepage.
In commit 68589bc353, the check for this was
moved into prepare_hugepage_range() along with the address and size checks.
But since BenH's rework of the get_unmapped_area() paths leading up to
commit 4b1d89290b, prepare_hugepage_range()
is only called for MAP_FIXED mappings, not for other mappings. This means
we're no longer ever checking for an aligned offset - I've confirmed that
mmap() will (apparently) succeed with a misaligned offset on both powerpc
and i386 at least.
This patch restores the check, removing it from prepare_hugepage_range()
and putting it back into hugetlbfs_file_mmap(). I'm putting it there,
rather than in the get_unmapped_area() path so it only needs to go in one
place, than separately in the half-dozen or so arch-specific
implementations of hugetlb_get_unmapped_area().
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Cc: Adam Litke <agl@us.ibm.com>
Cc: Andi Kleen <ak@suse.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This will avoid a possible fault in ecryptfs_sync_page().
In the function, eCryptfs calls sync_page() method of a lower filesystem
without checking its existence. However, there are many filesystems that
don't have this method including network filesystems such as NFS, AFS, and
so forth. They may fail when an eCryptfs page is waiting for lock.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Acked-by: Michael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix possible NULL pointer dereference when freeing blocks in case table of
free space is used. Also fix handling of the case when we need to move
extent from one block to another one to make space for indirect extent.
BTW: Nobody seem to have ever used this code.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If UDF superblock is incorrect, we can fail to find a table of free /
allocated space and consequently Oops. Handle this situation more
gracefully by ignoring the broken UDF partition.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
cifs reconnect could end up happening incorrectly due to
the small initial tcp recvmsg response. When the socket
was within three bytes of being full and the recvmsg
returned only 1 to 3 bytes of the initial 4 byte
read of the RFC1001 length field. Fortunately this
seems to be less common on more current kernels, but
this fixes it so cifs tries to retrieve all 4 bytes
of the initial tcp read.
Signed-off-by: Shirish Pargoankar <shirishp@us.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Modified form of original patch from Christoph Hellwig to make btrfs
mount into the default subvolume by default.
mount /dev/somedevice:subvolumename to get other subvolumes or
mount /dev/somedevice:. to get the root
Signed-off-by: Chris Mason <chris.mason@oracle.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs:
9p: fix bad error path in conversion routines
9p: remove deprecated v9fs_fid_lookup_remove()
9p: update maintainers and documentation
9p: fix use after free
* master.kernel.org:/pub/scm/linux/kernel/git/gregkh/driver-2.6:
sysfs: don't warn on removal of a nonexistent binary file
HOWTO: latest lxr url address changed
HOWTO: korean translation of Documentation/HOWTO
Fix Off-by-one in /sys/module/*/refcnt
sysfs: fix locking in sysfs_lookup() and sysfs_rename_dir()
On a mount without posix extensions enabled, when an unlock request is
made, the client can release more than is intended. To reproduce, on a
CIFS mount without posix extensions enabled:
1) open file
2) do fcntl lock: start=0 len=1
3) do fcntl lock: start=2 len=1
4) do fcntl unlock: start=0 len=1
...on the unlock call the client sends an unlock request to the server
for both locks. The problem is a bad test in cifs_lock.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
This patch removes the v9fs_fid_lookup_remove which is no longer used.
Based on original patch from Adrian Bunk <bunk@stusta.de> which
used #if 0 to isolate the code.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Fix the accounting regression for CONFIG_VIRT_CPU_ACCOUNTING. It
reverts parts of commit b27f03d4bd by
converting fs/proc/array.c back to cputime_t. The new functions
task_utime and task_stime now return cputime_t instead of clock_t. If
CONFIG_VIRT_CPU_ACCOUTING is set, task->utime and task->stime are
returned directly instead of using sum_exec_runtime.
Patch is tested on s390x with and without VIRT_CPU_ACCOUTING as well as
on i386.
[ mingo@elte.hu: cleanups, comments. ]
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
de_thread:
if (atomic_read(&oldsighand->count) <= 1)
BUG_ON(atomic_read(&sig->count) != 1);
This is not safe without the rmb() in between. The results of two
correctly ordered __exit_signal()->atomic_dec_and_test()'s could be seen
out of order on our CPU.
The same is true for the "thread_group_empty()" case, __unhash_process()'s
changes could be seen before atomic_dec_and_test(&sig->count).
On some platforms (including i386) atomic_read() doesn't provide even the
compiler barrier, in that case these checks are simply racy.
Remove these BUG_ON()'s. Alternatively, we can do something like
BUG_ON( ({ smp_rmb(); atomic_read(&sig->count) != 1; }) );
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Due to inconsistent locking in the VFS between calls to lookup and
revalidate deadlock can occur in the automounter.
The inconsistency is that the directory inode mutex is held for both lookup
and revalidate calls when called via lookup_hash whereas it is held only
for lookup during a path walk. Consequently, if the mutex is held during a
call to revalidate autofs4 can't release the mutex to callback the daemon
as it can't know whether it owns the mutex.
This situation happens when a process tries to create a directory within an
automount and a second process also tries to create the same directory
between the lookup and the mkdir. Since the first process has dropped the
mutex for the daemon callback, the second process takes it during
revalidate leading to deadlock between the autofs daemon and the second
process when the daemon tries to create the mount point directory.
After spending quite a bit of time trying to resolve this on more than one
occassion, using rather complex and ulgy approaches, it turns out that just
delaying the hashing of the dentry until the create operation works fine.
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With this patch any thread can dequeue its own private signals via signalfd,
even if it was created by another sub-thread.
To do so, we pass "current" to dequeue_signal() if the caller is from the same
thread group. This also fixes the scheduling of posix timers broken by the
previous patch.
If the caller doesn't belong to this thread group, we can't handle __SI_TIMER
case properly anyway. Perhaps we should forbid the cross-process signalfd usage
and convert ctx->tsk to ctx->sighand.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Davide Libenzi <davidel@xmailserver.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Michael Kerrisk <mtk-manpages@gmx.net>
Cc: Roland McGrath <roland@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When ecryptfs_lookup() is called against special files, eCryptfs generates
the following errors because it tries to treat them like regular eCryptfs
files.
Error opening lower file for lower_dentry [0xffff810233a6f150], lower_mnt [0xffff810235bb4c80], and flags [0x8000]
Error opening lower_file to read header region
Error attempting to read the [user.ecryptfs] xattr from the lower file; return value = [-95]
Valid metadata not found in header region or xattr region; treating file as unencrypted
For instance, the problem can be reproduced by the steps below.
# mkdir /root/crypt /mnt/crypt
# mount -t ecryptfs /root/crypt /mnt/crypt
# mknod /mnt/crypt/c0 c 0 0
# umount /mnt/crypt
# mount -t ecryptfs /root/crypt /mnt/crypt
# ls -l /mnt/crypt
This patch fixes it by adding a check similar to directories and
symlinks.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Acked-by: Michael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
vmtruncate had added the same fix to handle the case of private pages
being Copy on writed while truncate_inode_pages is going on
Signed-off-by: Steve French <sfrench@us.ibm.com>
This patch (as960) removes the error message and stack dump logged by
sysfs_remove_bin_file() when someone tries to remove a nonexistent
file. The warning doesn't seem to be needed, since none of the other
file-, symlink-, or directory-removal routines in sysfs complain in a
comparable way.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Tejun Heo <htejun@gmail.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
sd children list walking in sysfs_lookup() and sd renaming in
sysfs_rename_dir() were left out during i_mutex -> sysfs_mutex
conversion. Fix them.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
fs/jffs2/erase.c: In function 'jffs2_block_check_erase':
fs/jffs2/erase.c:355: warning: format '%08x' expects type 'unsigned int', but argument 3 has type 'long unsigned int'
and
fs/jffs2/erase.c: In function 'jffs2_erase_pending_blocks':
fs/jffs2/erase.c:404: warning: 'bad_offset' may be used uninitialized in this function
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
