nothing blocking there, since all instances of sysctl
->permissions() method are non-blocking - both of them,
that is.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
... and never did, what with its ->permission() being what we do by default
when ->permission is NULL...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
return -EIO; is *not* a blocking operation, thank you very much.
Nick, what the hell have you been smoking?
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
d251ed271d "ubifs: fix sget races" left out the goto from this
error path so the static checkers complain that we're dereferencing
"sb" when it's an ERR_PTR.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
AFS: Use i_generation not i_version for the vnode uniquifier
AFS: Set s_id in the superblock to the volume name
vfs: Fix data corruption after failed write in __block_write_begin()
afs: afs_fill_page reads too much, or wrong data
VFS: Fix vfsmount overput on simultaneous automount
fix wrong iput on d_inode introduced by e6bc45d65d
Delay struct net freeing while there's a sysfs instance refering to it
afs: fix sget() races, close leak on umount
ubifs: fix sget races
ubifs: split allocation of ubifs_info into a separate function
fix leak in proc_set_super()
Store the AFS vnode uniquifier in the i_generation field, not the i_version
field of the inode struct. i_version can then be given the AFS data version
number.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Set s_id in the superblock to the name of the AFS volume that this superblock
corresponds to.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
I've got a report of a file corruption from fsxlinux on ext3. The important
operations to the page were:
mapwrite to a hole
partial write to the page
read - found the page zeroed from the end of the normal write
The culprit seems to be that if get_block() fails in __block_write_begin()
(e.g. transient ENOSPC in ext3), the function does ClearPageUptodate(page).
Thus when we retry the write, the logic in __block_write_begin() thinks zeroing
of the page is needed and overwrites old data. In fact, I don't see why we
should ever need to zero the uptodate bit here - either the page was uptodate
when we entered __block_write_begin() and it should stay so when we leave it,
or it was not uptodate and noone had right to set it uptodate during
__block_write_begin() so it remains !uptodate when we leave as well. So just
remove clearing of the bit.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
afs_fill_page should read the page that is about to be written but
the current implementation has a number of issues. If we aren't
extending the file we always read PAGE_CACHE_SIZE at offset 0. If we
are extending the file we try to read the entire file.
Change afs_fill_page to read PAGE_CACHE_SIZE at the right offset,
clamped to i_size.
While here, avoid calling afs_fill_page when we are doing a
PAGE_CACHE_SIZE write.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[Kudos to dhowells for tracking that crap down]
If two processes attempt to cause automounting on the same mountpoint at the
same time, the vfsmount holding the mountpoint will be left with one too few
references on it, causing a BUG when the kernel tries to clean up.
The problem is that lock_mount() drops the caller's reference to the
mountpoint's vfsmount in the case where it finds something already mounted on
the mountpoint as it transits to the mounted filesystem and replaces path->mnt
with the new mountpoint vfsmount.
During a pathwalk, however, we don't take a reference on the vfsmount if it is
the same as the one in the nameidata struct, but do_add_mount() doesn't know
this.
The fix is to make sure we have a ref on the vfsmount of the mountpoint before
calling do_add_mount(). However, if lock_mount() doesn't transit, we're then
left with an extra ref on the mountpoint vfsmount which needs releasing.
We can handle that in follow_managed() by not making assumptions about what
we can and what we cannot get from lookup_mnt() as the current code does.
The callers of follow_managed() expect that reference to path->mnt will be
grabbed iff path->mnt has been changed. follow_managed() and follow_automount()
keep track of whether such reference has been grabbed and assume that it'll
happen in those and only those cases that'll have us return with changed
path->mnt. That assumption is almost correct - it breaks in case of
racing automounts and in even harder to hit race between following a mountpoint
and a couple of mount --move. The thing is, we don't need to make that
assumption at all - after the end of loop in follow_manage() we can check
if path->mnt has ended up unchanged and do mntput() if needed.
The BUG can be reproduced with the following test program:
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <sys/wait.h>
int main(int argc, char **argv)
{
int pid, ws;
struct stat buf;
pid = fork();
stat(argv[1], &buf);
if (pid > 0) wait(&ws);
return 0;
}
and the following procedure:
(1) Mount an NFS volume that on the server has something else mounted on a
subdirectory. For instance, I can mount / from my server:
mount warthog:/ /mnt -t nfs4 -r
On the server /data has another filesystem mounted on it, so NFS will see
a change in FSID as it walks down the path, and will mark /mnt/data as
being a mountpoint. This will cause the automount code to be triggered.
!!! Do not look inside the mounted fs at this point !!!
(2) Run the above program on a file within the submount to generate two
simultaneous automount requests:
/tmp/forkstat /mnt/data/testfile
(3) Unmount the automounted submount:
umount /mnt/data
(4) Unmount the original mount:
umount /mnt
At this point the kernel should throw a BUG with something like the
following:
BUG: Dentry ffff880032e3c5c0{i=2,n=} still in use (1) [unmount of nfs4 0:12]
Note that the bug appears on the root dentry of the original mount, not the
mountpoint and not the submount because sys_umount() hasn't got to its final
mntput_no_expire() yet, but this isn't so obvious from the call trace:
[<ffffffff8117cd82>] shrink_dcache_for_umount+0x69/0x82
[<ffffffff8116160e>] generic_shutdown_super+0x37/0x15b
[<ffffffffa00fae56>] ? nfs_super_return_all_delegations+0x2e/0x1b1 [nfs]
[<ffffffff811617f3>] kill_anon_super+0x1d/0x7e
[<ffffffffa00d0be1>] nfs4_kill_super+0x60/0xb6 [nfs]
[<ffffffff81161c17>] deactivate_locked_super+0x34/0x83
[<ffffffff811629ff>] deactivate_super+0x6f/0x7b
[<ffffffff81186261>] mntput_no_expire+0x18d/0x199
[<ffffffff811862a8>] mntput+0x3b/0x44
[<ffffffff81186d87>] release_mounts+0xa2/0xbf
[<ffffffff811876af>] sys_umount+0x47a/0x4ba
[<ffffffff8109e1ca>] ? trace_hardirqs_on_caller+0x1fd/0x22f
[<ffffffff816ea86b>] system_call_fastpath+0x16/0x1b
as do_umount() is inlined. However, you can see release_mounts() in there.
Note also that it may be necessary to have multiple CPU cores to be able to
trigger this bug.
Tested-by: Jeff Layton <jlayton@redhat.com>
Tested-by: Ian Kent <raven@themaw.net>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Git bisection shows that commit e6bc45d65d causes
BUG_ONs under high I/O load:
kernel BUG at fs/inode.c:1368!
[ 2862.501007] Call Trace:
[ 2862.501007] [<ffffffff811691d8>] d_kill+0xf8/0x140
[ 2862.501007] [<ffffffff81169c19>] dput+0xc9/0x190
[ 2862.501007] [<ffffffff8115577f>] fput+0x15f/0x210
[ 2862.501007] [<ffffffff81152171>] filp_close+0x61/0x90
[ 2862.501007] [<ffffffff81152251>] sys_close+0xb1/0x110
[ 2862.501007] [<ffffffff814c14fb>] system_call_fastpath+0x16/0x1b
A reliable way to reproduce this bug is:
Login to KDE, run 'rsnapshot sync', and apt-get install openjdk-6-jdk,
and apt-get remove openjdk-6-jdk.
The buggy part of the patch is this:
struct inode *inode = NULL;
.....
- if (nd.last.name[nd.last.len])
- goto slashes;
inode = dentry->d_inode;
- if (inode)
- ihold(inode);
+ if (nd.last.name[nd.last.len] || !inode)
+ goto slashes;
+ ihold(inode)
...
if (inode)
iput(inode); /* truncate the inode here */
If nd.last.name[nd.last.len] is nonzero (and thus goto slashes branch is taken),
and dentry->d_inode is non-NULL, then this code now does an additional iput on
the inode, which is wrong.
Fix this by only setting the inode variable if nd.last.name[nd.last.len] is 0.
Reference: https://lkml.org/lkml/2011/6/15/50
Reported-by: Norbert Preining <preining@logic.at>
Reported-by: Török Edwin <edwintorok@gmail.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Török Edwin <edwintorok@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This reverts commit 7f81c8890c.
It turns out that it's not actually a build-time check on x86-64 UML,
which does some seriously crazy stuff with VM_STACK_FLAGS.
The VM_STACK_FLAGS define depends on the arch-supplied
VM_STACK_DEFAULT_FLAGS value, and on x86-64 UML we have
arch/um/sys-x86_64/shared/sysdep/vm-flags.h:
#define VM_STACK_DEFAULT_FLAGS \
(test_thread_flag(TIF_IA32) ? vm_stack_flags32 : vm_stack_flags)
#define VM_STACK_DEFAULT_FLAGS vm_stack_flags
(yes, seriously: two different #define's for that thing, with the first
one being inside an "#ifdef TIF_IA32")
It's possible that it is UML that should just be fixed in this area, but
for now let's just undo the (very small) optimization.
Reported-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Richard Weinberger <richard@nod.at>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit a8bef8ff6e ("mm: migration: avoid race between shift_arg_pages()
and rmap_walk() during migration by not migrating temporary stacks")
introduced a BUG_ON() to ensure that VM_STACK_FLAGS and
VM_STACK_INCOMPLETE_SETUP do not overlap. The check is a compile time
one, so BUILD_BUG_ON is more appropriate.
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Don't call iput with the inode half setup to be a namespace filedescriptor.
Instead rearrange the code so that we don't initialize ei->ns_ops until
after I ns_ops->get succeeds, preventing us from invoking ns_ops->put
when ns_ops->get failed.
Reported-by: Ingo Saitz <Ingo.Saitz@stud.uni-hannover.de>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Long ago (in commit 00e485b0), I added some code to handle share-level
passwords in CIFSTCon. That code ignored the fact that it's legit to
pass in a NULL tcon pointer when connecting to the IPC$ share on the
server.
This wasn't really a problem until recently as we only called CIFSTCon
this way when the server returned -EREMOTE. With the introduction of
commit c1508ca2 however, it gets called this way on every mount, causing
an oops when share-level security is in effect.
Fix this by simply treating a NULL tcon pointer as if user-level
security were in effect. I'm not aware of any servers that protect the
IPC$ share with a specific password anyway. Also, add a comment to the
top of CIFSTCon to ensure that we don't make the same mistake again.
Cc: <stable@kernel.org>
Reported-by: Martijn Uffing <mp3project@sarijopen.student.utwente.nl>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
It's possible for the following set of events to happen:
cifsd calls cifs_reconnect which reconnects the socket. A userspace
process then calls cifs_negotiate_protocol to handle the NEGOTIATE and
gets a reply. But, while processing the reply, cifsd calls
cifs_reconnect again. Eventually the GlobalMid_Lock is dropped and the
reply from the earlier NEGOTIATE completes and the tcpStatus is set to
CifsGood. cifs_reconnect then goes through and closes the socket and sets the
pointer to zero, but because the status is now CifsGood, the new socket
is not created and cifs_reconnect exits with the socket pointer set to
NULL.
Fix this by only setting the tcpStatus to CifsGood if the tcpStatus is
CifsNeedNegotiate, and by making sure that generic_ip_connect is always
called at least once in cifs_reconnect.
Note that this is not a perfect fix for this issue. It's still possible
that the NEGOTIATE reply is handled after the socket has been closed and
reconnected. In that case, the socket state will look correct but it no
NEGOTIATE was performed on it be for the wrong socket. In that situation
though the server should just shut down the socket on the next attempted
send, rather than causing the oops that occurs today.
Cc: <stable@kernel.org> # .38.x: fd88ce9: [CIFS] cifs: clarify the meaning of tcpStatus == CifsGood
Reported-and-Tested-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
cifs_sb_master_tlink was declared as inline, but without a definition.
Remove the declaration and move the definition up.
Signed-off-by: Pavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
ceph: unwind canceled flock state
ceph: fix ENOENT logic in striped_read
ceph: fix short sync reads from the OSD
ceph: fix sync vs canceled write
ceph: use ihold when we already have an inode ref
* new refcount in struct net, controlling actual freeing of the memory
* new method in kobj_ns_type_operations (->drop_ns())
* ->current_ns() semantics change - it's supposed to be followed by
corresponding ->drop_ns(). For struct net in case of CONFIG_NET_NS it bumps
the new refcount; net_drop_ns() decrements it and calls net_free() if the
last reference has been dropped. Method renamed to ->grab_current_ns().
* old net_free() callers call net_drop_ns() instead.
* sysfs_exit_ns() is gone, along with a large part of callchain
leading to it; now that the references stored in ->ns[...] stay valid we
do not need to hunt them down and replace them with NULL. That fixes
problems in sysfs_lookup() and sysfs_readdir(), along with getting rid
of sb->s_instances abuse.
Note that struct net *shutdown* logics has not changed - net_cleanup()
is called exactly when it used to be called. The only thing postponed by
having a sysfs instance refering to that struct net is actual freeing of
memory occupied by struct net.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* set ->s_fs_info in set() callback passed to sget()
* allocate the thing and set it up enough for afs_test_super() before
making it visible
* have it freed in ->kill_sb() (current tree simply leaks it)
* have ->put_super() leave ->s_fs_info->volume alone; it's too early for
dropping it; do that from ->kill_sb() after having called kill_anon_super().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* allocate ubifs_info in ->mount(), fill it enough for sb_test() and
set ->s_fs_info to it in set() callback passed to sget().
* do *not* free it in ->put_super(); do that in ->kill_sb() after we'd
done kill_anon_super().
* don't free it in ubifs_fill_super() either - deactivate_locked_super()
done by caller when ubifs_fill_super() returns an error will take care
of that sucker.
* get rid of kludge with passing ubi to ubifs_fill_super() in ->s_fs_info;
we only need it in alloc_ubifs_info(), so ubifs_fill_super() will need
only ubifs_info. Which it will find in ->s_fs_info just fine, no need to
reassign anything...
As the result, sb_test() becomes safe to apply to all superblocks that
can be found by sget() (and a kludge with temporary use of ->s_fs_info
to store a pointer to very different structure goes away).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
Btrfs: use join_transaction in btrfs_evict_inode()
Btrfs - use %pU to print fsid
Btrfs: fix extent state leak on failed nodatasum reads
btrfs: fix unlocked access of delalloc_inodes
Btrfs: avoid stack bloat in btrfs_ioctl_fs_info()
btrfs: remove 64bit alignment padding to allow extent_buffer to fit into one fewer cacheline
Btrfs: clear current->journal_info on async transaction commit
Btrfs: make sure to recheck for bitmaps in clusters
btrfs: remove unneeded includes from scrub.c
btrfs: reinitialize scrub workers
btrfs: scrub: errors in tree enumeration
Btrfs: don't map extent buffer if path->skip_locking is set
Btrfs: unlock the trans lock properly
Btrfs: don't map extent buffer if path->skip_locking is set
Btrfs: fix duplicate checking logic
Btrfs: fix the allocator loop logic
Btrfs: fix bitmap regression
Btrfs: don't commit the transaction if we dont have enough pinned bytes
Btrfs: noinline the cluster searching functions
Btrfs: cache bitmaps when searching for a cluster
The WARN_ON() in start_transaction() was triggered while balancing.
The cause is btrfs_relocate_chunk() started a transaction and
then called iput() on the inode that stores free space cache,
and iput() called btrfs_start_transaction() again.
Reported-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Reviewed-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Checkpoint generation interval of nilfs goes wrong after user has
changed the interval parameter with nilfs-tune tool.
segctord starting. Construction interval = 5 seconds,
CP frequency < 30 seconds
segctord starting. Construction interval = 0 seconds,
CP frequency < 30 seconds
This turned out to be caused by a trivial bug in initialization code
of log writer. This will fix it.
Reported-by: Andrea Gelmini <andrea.gelmini@gmail.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
nilfs_btree_delete function does not terminate part of virtual block
addresses when shrinking the last remaining child node into the root
node. The missing address termination causes that dead btree node
blocks persist and chip away free disk space.
This fixes the leak bug on the btree node deletion.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
nilfs_btree_delete function wrongly terminates virtual block address
of the btree node held by its parent at index 0. When concatenating
the index-0 node with its right sibling node, nilfs_btree_delete
terminates the block address of index-0 node instead of the right
sibling node which should be deleted.
This bug not only wears disk space in the long run, but also causes
file system corruption. This will fix it.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Get rid of FIXME comment. Uuids from dmesg are now the same as uuids
given by btrfs-progs.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
When encountering an EIO while reading from a nodatasum extent, we
insert an error record into the inode's failure tree.
btrfs_readpage_end_io_hook returns early for nodatasum inodes. We'd
better clear the failure tree in that case, otherwise the kernel
complains about
BUG extent_state: Objects remaining on kmem_cache_close()
on rmmod.
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
list_splice_init will make delalloc_inodes empty, but without a spinlock
around, this may produce corrupted list head, accessed in many placess,
The race window is very tight and nobody seems to have hit it so far.
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
The size of struct btrfs_ioctl_fs_info_args is as big as 1KB, so
don't declare the variable on stack.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Reviewed-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Reorder extent_buffer to remove 8 bytes of alignment padding on 64 bit
builds. This shrinks its size to 128 bytes allowing it to fit into one
fewer cache lines and allows more objects per slab in its kmem_cache.
slabinfo extent_buffer reports :-
before:-
Sizes (bytes) Slabs
----------------------------------
Object : 136 Total : 123
SlabObj: 136 Full : 121
SlabSiz: 4096 Partial: 0
Loss : 0 CpuSlab: 2
Align : 8 Objects: 30
after :-
Object : 128 Total : 4
SlabObj: 128 Full : 2
SlabSiz: 4096 Partial: 0
Loss : 0 CpuSlab: 2
Align : 8 Objects: 32
Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Normally current->jouranl_info is cleared by commit_transaction. For an
async snap or subvol creation, though, it runs in a work queue. Clear
it in btrfs_commit_transaction_async() to avoid leaking a non-NULL
journal_info when we return to userspace. When the actual commit runs in
the other thread it won't care that it's current->journal_info is already
NULL.
Signed-off-by: Sage Weil <sage@newdream.net>
Tested-by: Jim Schutt <jaschut@sandia.gov>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Josef recently changed the free extent cache to look in
the block group cluster for any bitmaps before trying to
add a new bitmap for the same offset. This avoids BUG_ON()s due
covering duplicate ranges.
But it didn't go quite far enough. A given free range might span
between one or more bitmaps or free space entries. The code has
looping to cover this, but it doesn't check for clustered bitmaps
every time.
This shuffles our gotos to check for a bitmap in the cluster
for every new bitmap entry we try to add.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
