Before patch(sysfs: prepare path write for unified regular / bin
file handling), when size of bin file is zero, writting still can
continue, but this patch changes the behaviour.
The worse thing is that firmware loader is broken by this patch,
and user space application can't write to firmware bin file any more
because both firmware loader and drivers can't know at advance how
large the firmware file is and have to set its initialized size as
zero.
This patch fixes the problem and keeps behaviour of writting to bin
as before.
Reported-by: Lothar Waßmann <LW@karo-electronics.de>
Tested-by: Lothar Waßmann <LW@karo-electronics.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull btrfs fix from Chris Mason:
"Sage hit a deadlock with ceph on btrfs, and Josef tracked it down to a
regression in our initial rc1 pull. When doing nocow writes we were
sometimes starting a transaction with locks held"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: release path before starting transaction in can_nocow_extent
We can't be holding tree locks while we try to start a transaction, we will
deadlock. Thanks,
Reported-by: Sage Weil <sage@inktank.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Pull CIFS fixes from Steve French:
"Five small cifs fixes (includes fixes for: unmount hang, 2 security
related, symlink, large file writes)"
* 'for-linus' of git://git.samba.org/sfrench/cifs-2.6:
cifs: ntstatus_to_dos_map[] is not terminated
cifs: Allow LANMAN auth method for servers supporting unencapsulated authentication methods
cifs: Fix inability to write files >2GB to SMB2/3 shares
cifs: Avoid umount hangs with smb2 when server is unresponsive
do not treat non-symlink reparse points as valid symlinks
Merge misc fixes from Andrew Morton.
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (21 commits)
mm: revert mremap pud_free anti-fix
mm: fix BUG in __split_huge_page_pmd
swap: fix set_blocksize race during swapon/swapoff
procfs: call default get_unmapped_area on MMU-present architectures
procfs: fix unintended truncation of returned mapped address
writeback: fix negative bdi max pause
percpu_refcount: export symbols
fs: buffer: move allocation failure loop into the allocator
mm: memcg: handle non-error OOM situations more gracefully
tools/testing/selftests: fix uninitialized variable
block/partitions/efi.c: treat size mismatch as a warning, not an error
mm: hugetlb: initialize PG_reserved for tail pages of gigantic compound pages
mm/zswap: bugfix: memory leak when re-swapon
mm: /proc/pid/pagemap: inspect _PAGE_SOFT_DIRTY only on present pages
mm: migration: do not lose soft dirty bit if page is in migration state
gcov: MAINTAINERS: Add an entry for gcov
mm/hugetlb.c: correct missing private flag clearing
mm/vmscan.c: don't forget to free shrinker->nr_deferred
ipc/sem.c: synchronize semop and semctl with IPC_RMID
ipc: update locking scheme comments
...
Commit c4fe244857 ("sparc: fix PCI device proc file mmap(2)") added
proc_reg_get_unmapped_area in proc_reg_file_ops and
proc_reg_file_ops_no_compat, by which now mmap always returns EIO if
get_unmapped_area method is not defined for the target procfs file,
which causes regression of mmap on /proc/vmcore.
To address this issue, like get_unmapped_area(), call default
current->mm->get_unmapped_area on MMU-present architectures if
pde->proc_fops->get_unmapped_area, i.e. the one in actual file
operation in the procfs file, is not defined.
Reported-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Tested-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, proc_reg_get_unmapped_area truncates upper 32-bit of the
mapped virtual address returned from get_unmapped_area method in
pde->proc_fops due to the variable rv of signed integer on x86_64. This
is too small to have vitual address of unsigned long on x86_64 since on
x86_64, signed integer is of 4 bytes while unsigned long is of 8 bytes.
To fix this issue, use unsigned long instead.
Fixes a regression added in commit c4fe244857 ("sparc: fix PCI device
proc file mmap(2)").
Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Tested-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Buffer allocation has a very crude indefinite loop around waking the
flusher threads and performing global NOFS direct reclaim because it can
not handle allocation failures.
The most immediate problem with this is that the allocation may fail due
to a memory cgroup limit, where flushers + direct reclaim might not make
any progress towards resolving the situation at all. Because unlike the
global case, a memory cgroup may not have any cache at all, only
anonymous pages but no swap. This situation will lead to a reclaim
livelock with insane IO from waking the flushers and thrashing unrelated
filesystem cache in a tight loop.
Use __GFP_NOFAIL allocations for buffers for now. This makes sure that
any looping happens in the page allocator, which knows how to
orchestrate kswapd, direct reclaim, and the flushers sensibly. It also
allows memory cgroups to detect allocations that can't handle failure
and will allow them to ultimately bypass the limit if reclaim can not
make progress.
Reported-by: azurIt <azurit@pobox.sk>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If a page we are inspecting is in swap we may occasionally report it as
having soft dirty bit (even if it is clean). The pte_soft_dirty helper
should be called on present pte only.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull tmpfile fix from Al Viro:
"A fix for double iput() in ->tmpfile() on ext3 and ext4; I'd fucked it
up, Miklos has caught it"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
ext[34]: fix double put in tmpfile
Functions that walk the ntstatus_to_dos_map[] array could
run off the end. For example, ntstatus_to_dos() loops
while ntstatus_to_dos_map[].ntstatus is not 0. Granted,
this is mostly theoretical, but could be used as a DOS attack
if the error code in the SMB header is bogus.
[Might consider adding to stable, as this patch is low risk - Steve]
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Steve French <smfrench@gmail.com>
While looking at the code, I noticed that bin_attribute read() and write()
ops copy the inode size into an int for futher comparisons.
Some bin_attributes can be fairly large. For example, pci creates some for
BARs set to the BAR size and giant BARs are around the corner, so this is
going to break something somewhere eventually.
Let's use the right type.
[adjust for seqfile conversions, only needed for bin_read() - gkh]
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
375b611e60 ("sysfs: remove sysfs_buffer->ops") introduced
sysfs_file_ops() which determines the associated file operation of a
given sysfs_dirent. As file ops access should be protected by an
active reference, the new function includes a lockdep assertion on the
sysfs_dirent; unfortunately, I forgot to take attr->ignore_lockdep
flag into account and the lockdep assertion trips spuriously for files
which opt out from active reference lockdep checking.
# cat /sys/devices/pci0000:00/0000:00:01.2/usb1/authorized
------------[ cut here ]------------
WARNING: CPU: 1 PID: 540 at /work/os/work/fs/sysfs/file.c:79 sysfs_file_ops+0x4e/0x60()
Modules linked in:
CPU: 1 PID: 540 Comm: cat Not tainted 3.11.0-work+ #3
Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
0000000000000009 ffff880016205c08 ffffffff81ca0131 0000000000000000
ffff880016205c40 ffffffff81096d0d ffff8800166cb898 ffff8800166f6f60
ffffffff8125a220 ffff880011ab1ec0 ffff88000aff0c78 ffff880016205c50
Call Trace:
[<ffffffff81ca0131>] dump_stack+0x4e/0x82
[<ffffffff81096d0d>] warn_slowpath_common+0x7d/0xa0
[<ffffffff81096dea>] warn_slowpath_null+0x1a/0x20
[<ffffffff8125994e>] sysfs_file_ops+0x4e/0x60
[<ffffffff8125a274>] sysfs_open_file+0x54/0x300
[<ffffffff811df612>] do_dentry_open.isra.17+0x182/0x280
[<ffffffff811df820>] finish_open+0x30/0x40
[<ffffffff811f0623>] do_last+0x503/0xd90
[<ffffffff811f0f6b>] path_openat+0xbb/0x6d0
[<ffffffff811f23ba>] do_filp_open+0x3a/0x90
[<ffffffff811e09a9>] do_sys_open+0x129/0x220
[<ffffffff811e0abe>] SyS_open+0x1e/0x20
[<ffffffff81caf3c2>] system_call_fastpath+0x16/0x1b
---[ end trace aa48096b111dafdb ]---
Rename fs/sysfs/dir.c::ignore_lockdep() to sysfs_ignore_lockdep() and
move it to fs/sysfs/sysfs.h and make sysfs_file_ops() skip lockdep
assertion if sysfs_ignore_lockdep() is true.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Olga reported that file descriptors opened with O_PATH do not work with
fstatfs(), found during further development of ksh93's thread support.
There is no reason to not allow O_PATH file descriptors here (fstatfs is
very much a path operation), so use "fdget_raw()". See commit
55815f7014 ("vfs: make O_PATH file descriptors usable for 'fstat()'")
for a very similar issue reported for fstat() by the same team.
Reported-and-tested-by: ольга крыжановская <olga.kryzhanovska@gmail.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: stable@kernel.org # O_PATH introduced in 3.0+
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull btrfs fixes from Chris Mason:
"We've got more bug fixes in my for-linus branch:
One of these fixes another corner of the compression oops from last
time. Miao nailed down some problems with concurrent snapshot
deletion and drive balancing.
I kept out one of his patches for more testing, but these are all
stable"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: fix oops caused by the space balance and dead roots
Btrfs: insert orphan roots into fs radix tree
Btrfs: limit delalloc pages outside of find_delalloc_range
Btrfs: use right root when checking for hash collision
If we take the 2nd retry path in ext4_expand_extra_isize_ea, we
potentionally return from the function without having freed these
allocations. If we don't do the return, we over-write the previous
allocation pointers, so we leak either way.
Spotted with Coverity.
[ Fixed by tytso to set is and bs to NULL after freeing these
pointers, in case in the retry loop we later end up triggering an
error causing a jump to cleanup, at which point we could have a double
free bug. -- Ted ]
Signed-off-by: Dave Jones <davej@fedoraproject.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Cc: stable@vger.kernel.org
When doing space balance and subvolume destroy at the same time, we met
the following oops:
kernel BUG at fs/btrfs/relocation.c:2247!
RIP: 0010: [<ffffffffa04cec16>] prepare_to_merge+0x154/0x1f0 [btrfs]
Call Trace:
[<ffffffffa04b5ab7>] relocate_block_group+0x466/0x4e6 [btrfs]
[<ffffffffa04b5c7a>] btrfs_relocate_block_group+0x143/0x275 [btrfs]
[<ffffffffa0495c56>] btrfs_relocate_chunk.isra.27+0x5c/0x5a2 [btrfs]
[<ffffffffa0459871>] ? btrfs_item_key_to_cpu+0x15/0x31 [btrfs]
[<ffffffffa048b46a>] ? btrfs_get_token_64+0x7e/0xcd [btrfs]
[<ffffffffa04a3467>] ? btrfs_tree_read_unlock_blocking+0xb2/0xb7 [btrfs]
[<ffffffffa049907d>] btrfs_balance+0x9c7/0xb6f [btrfs]
[<ffffffffa049ef84>] btrfs_ioctl_balance+0x234/0x2ac [btrfs]
[<ffffffffa04a1e8e>] btrfs_ioctl+0xd87/0x1ef9 [btrfs]
[<ffffffff81122f53>] ? path_openat+0x234/0x4db
[<ffffffff813c3b78>] ? __do_page_fault+0x31d/0x391
[<ffffffff810f8ab6>] ? vma_link+0x74/0x94
[<ffffffff811250f5>] vfs_ioctl+0x1d/0x39
[<ffffffff811258c8>] do_vfs_ioctl+0x32d/0x3e2
[<ffffffff811259d4>] SyS_ioctl+0x57/0x83
[<ffffffff813c3bfa>] ? do_page_fault+0xe/0x10
[<ffffffff813c73c2>] system_call_fastpath+0x16/0x1b
It is because we returned the error number if the reference of the root was 0
when doing space relocation. It was not right here, because though the root
was dead(refs == 0), but the space it held still need be relocated, or we
could not remove the block group. So in this case, we should return the root
no matter it is dead or not.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Now we don't drop all the deleted snapshots/subvolumes before the space
balance. It means we have to relocate the space which is held by the dead
snapshots/subvolumes. So we must into them into fs radix tree, or we would
forget to commit the change of them when doing transaction commit, and it
would corrupt the metadata.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Liu fixed part of this problem and unfortunately I steered him in slightly the
wrong direction and so didn't completely fix the problem. The problem is we
limit the size of the delalloc range we are looking for to max bytes and then we
try to lock that range. If we fail to lock the pages in that range we will
shrink the max bytes to a single page and re loop. However if our first page is
inside of the delalloc range then we will end up limiting the end of the range
to a period before our first page. This is illustrated below
[0 -------- delalloc range --------- 256mb]
[page]
So find_delalloc_range will return with delalloc_start as 0 and end as 128mb,
and then we will notice that delalloc_start < *start and adjust it up, but not
adjust delalloc_end up, so things go sideways. To fix this we need to not limit
the max bytes in find_delalloc_range, but in find_lock_delalloc_range and that
way we don't end up with this confusion. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
btrfs_rename was using the root of the old dir instead of the root of the new
dir when checking for a hash collision, so if you tried to move a file into a
subvol it would freak out because it would see the file you are trying to move
in its current root. This fixes the bug where this would fail
btrfs subvol create test1
btrfs subvol create test2
mv test1 test2.
Thanks to Chris Murphy for catching this,
Cc: stable@vger.kernel.org
Reported-by: Chris Murphy <lists@colorremedies.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
This allows users to use LANMAN authentication on servers which support
unencapsulated authentication.
The patch fixes a regression where users using plaintext authentication
were no longer able to do so because of changed bought in by patch
3f618223dchttps://bugzilla.redhat.com/show_bug.cgi?id=1011621
Reported-by: Panos Kavalagios <Panagiotis.Kavalagios@eurodyn.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
When connecting to SMB2/3 shares, maximum file size is set to non-LFS maximum in superblock. This is due to cap_large_files bit being different for SMB1 and SMB2/3 (where it is just an internal flag that is not negotiated and the SMB1 one corresponds to multichannel capability, so maybe LFS works correctly if server sends 0x08 flag) while capabilities are checked always for the SMB1 bit in cifs_read_super().
The patch fixes this by checking for the correct bit according to the protocol version.
CC: Stable <stable@kernel.org>
Signed-off-by: Jan Klos <honza.klos@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Do not send SMB2 Logoff command when reconnecting, the way smb1
code base works.
Also, no need to wait for a credit for an echo command when one is already
in flight.
Without these changes, umount command hangs if the server is unresponsive
e.g. hibernating.
Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@us.ibm.com>
Windows 8 and later can create NFS symlinks (within reparse points)
which we were assuming were normal NTFS symlinks and thus reporting
corrupt paths for. Add check for reparse points to make sure that
they really are normal symlinks before we try to parse the pathname.
We also should not be parsing other types of reparse points (DFS
junctions etc) as if they were a symlink so return EOPNOTSUPP
on those. Also fix endian errors (we were not parsing symlink
lengths as little endian).
This fixes commit d244bf2dfb
which implemented follow link for non-Unix CIFS mounts
CC: Stable <stable@kernel.org>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
With the previous changes, sysfs regular file code is ready to handle
bin files too. This patch makes bin files share the regular file
path.
* sysfs_create/remove_bin_file() are moved to fs/sysfs/file.c.
* sysfs_init_inode() is updated to use the new sysfs_bin_operations
instead of bin_fops for bin files.
* fs/sysfs/bin.c and the related pieces are removed.
This patch shouldn't introduce any behavior difference to bin file
accesses.
Overall, this unification reduces the amount of duplicate logic, makes
behaviors more consistent and paves the road for building simpler and
more versatile interface which will allow other subsystems to make use
of sysfs for their pseudo filesystems.
v2: Stale fs/sysfs/bin.c reference dropped from
Documentation/DocBook/filesystems.tmpl. Reported by kbuild test
robot.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Kay Sievers <kay@vrfy.org>
Cc: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sysfs bin file handling will be merged into the regular file support.
This patch prepares the open path.
This patch updates sysfs_open_file() such that it can handle both
regular and bin files.
This is a preparation and the new bin file path isn't used yet.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sysfs bin file handling will be merged into the regular file support.
This patch copies mmap support from bin so that fs/sysfs/file.c can
handle mmapping bin files.
The code is copied mostly verbatim with the following updates.
* ->mmapped and ->vm_ops are added to sysfs_open_file and bin_buffer
references are replaced with sysfs_open_file ones.
* Symbols are prefixed with sysfs_.
* sysfs_unmap_bin_file() grabs sysfs_open_dirent and traverses
->files. Invocation of this function is added to
sysfs_addrm_finish().
* sysfs_bin_mmap() is added to sysfs_bin_operations.
This is a preparation and the new mmap path isn't used yet.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sysfs bin file handling will be merged into the regular file support.
This patch prepares the read path.
Copy fs/sysfs/bin.c::read() to fs/sysfs/file.c and make it use
sysfs_open_file instead of bin_buffer. The function is identical copy
except for the use of sysfs_open_file.
The new function is added to sysfs_bin_operations. This isn't used
yet but will eventually replace fs/sysfs/bin.c.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sysfs bin file handling will be merged into the regular file support.
This patch prepares the write path.
bin file write is almost identical to regular file write except that
the write length is capped by the inode size and @off is passed to the
write method. This patch adds bin file handling to sysfs_write_file()
so that it can handle both regular and bin files.
A new file_operations struct sysfs_bin_operations is added, which
currently only hosts sysfs_write_file() and generic_file_llseek().
This isn't used yet but will eventually replace fs/sysfs/bin.c.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
read() is simple enough and fill_read() being in a separate function
doesn't add anything. Let's collapse it into read(). This will make
merging bin file handling with regular file.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
After b31ca3f5df ("sysfs: fix deadlock"), bin read() first writes
data to bb->buffer and bounces it to a transient kernel buffer which
is then copied out to userland. The double bouncing doesn't add
anything. Let's just use the transient buffer directly.
While at it, rename @temp to @buf for clarity.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sysfs read path implements its own buffering scheme between userland
and kernel callbacks, which essentially is a degenerate duplicate of
seq_file. This patch replaces the custom read buffering
implementation in sysfs with seq_file.
While the amount of code reduction is small, this reduces low level
hairiness and enables future development of a new versatile API based
on seq_file so that sysfs features can be shared with other
subsystems.
As write path was already converted to not use sysfs_open_file->page,
this patch makes ->page and ->count unused and removes them.
Userland behavior remains the same except for some extreme corner
cases - e.g. sysfs will now regenerate the content each time a file is
read after a non-contiguous seek whereas the original code would keep
using the same content. While this is a userland visible behavior
change, it is extremely unlikely to be noticeable and brings sysfs
behavior closer to that of procfs.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Kay Sievers <kay@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There isn't much to be gained by keeping around kernel buffer while a
file is open especially as the read path planned to be converted to
use seq_file and won't use the buffer. This patch makes
sysfs_write_file() use per-write transient buffer instead of
sysfs_open_file->page.
This simplifies the write path, enables removing sysfs_open_file->page
once read path is updated and will help merging bin file write path
which already requires the use of a transient buffer due to a locking
order issue.
As the function comments of flush_write_buffer() and
sysfs_write_buffer() are being updated anyway, reformat them so that
they're more conventional.
v2: Use min_t() instead of min() in sysfs_write_file() to avoid build
warning on arm. Reported by build test robot.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sysfs will be converted to use seq_file for read path, which will make
it difficult to pass around multiple pointers directly. This patch
adds sysfs_open_file->sd and ->file so that we can reach all the
necessary data structures from sysfs_open_file.
flush_write_buffer() is updated to drop @dentry which was used to
discover the sysfs_dirent as it's now available through
sysfs_open_file->sd.
This patch doesn't cause any behavior difference.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sysfs read path will be converted to use seq_file which will handle
buffering making sysfs_buffer a misnomer. Rename sysfs_buffer to
sysfs_open_file, and sysfs_open_dirent->buffers to ->files.
This path is pure rename.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add a separate mutex to protect sysfs_open_dirent->buffers list. This
will allow performing sleepable operations while traversing
sysfs_buffers, which will be renamed to sysfs_open_file.
Note that currently sysfs_open_dirent->buffers list isn't being used
for anything and this patch doesn't make any functional difference.
It will be used to merge regular and bin file supports.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently, sysfs_ops is fetched during sysfs_open_file() and cached in
sysfs_buffer->ops to be used while the file is open. This patch
removes the caching and makes each operation directly fetch sysfs_ops.
This patch doesn't introduce any behavior difference and is to prepare
for merging regular and bin file supports.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull btrfs fixes from Chris Mason:
"This is a small collection of fixes, including a regression fix from
Liu Bo that solves rare crashes with compression on.
I've merged my for-linus up to 3.12-rc3 because the top commit is only
meant for 3.12. The rest of the fixes are also available in my master
branch on top of my last 3.11 based pull"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
btrfs: Fix crash due to not allocating integrity data for a bioset
Btrfs: fix a use-after-free bug in btrfs_dev_replace_finishing
Btrfs: eliminate races in worker stopping code
Btrfs: fix crash of compressed writes
Btrfs: fix transid verify errors when recovering log tree
->needs_read_fill is used to implement the following behaviors.
1. Ensure buffer filling on the first read.
2. Force buffer filling after a write.
3. Force buffer filling after a successful poll.
However, #2 and #3 don't really work as sysfs doesn't reset file
position. While the read buffer would be refilled, the next read
would continue from the position after the last read or write,
requiring an explicit seek to the start for it to be useful, which
makes ->needs_read_fill superflous as read buffer is always refilled
if f_pos == 0.
Update sysfs_read_file() to test buffer->page for #1 instead and
remove ->needs_read_fill. While this changes behavior in extreme
corner cases - e.g. re-reading a sysfs file after seeking to non-zero
position after a write or poll, it's highly unlikely to lead to actual
breakage. This change is to prepare for using seq_file in the read
path.
While at it, reformat a comment in fill_write_buffer().
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Kay Sievers <kay@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull CIFS fixes from Steve French:
"Small set of cifs fixes. Most important is Jeff's fix that works
around disconnection problems which can be caused by simultaneous use
of user space tools (starting a long running smbclient backup then
doing a cifs kernel mount) or multiple cifs mounts through a NAT, and
Jim's fix to deal with reexport of cifs share.
I expect to send two more cifs fixes next week (being tested now) -
fixes to address an SMB2 unmount hang when server dies and a fix for
cifs symlink handling of Windows "NFS" symlinks"
* 'for-linus' of git://git.samba.org/sfrench/cifs-2.6:
[CIFS] update cifs.ko version
[CIFS] Remove ext2 flags that have been moved to fs.h
[CIFS] Provide sane values for nlink
cifs: stop trying to use virtual circuits
CIFS: FS-Cache: Uncache unread pages in cifs_readpages() before freeing them
- lockdep fix for project quotas
- fix for dirent dtype support on v4 filesystems
- fix for a memory leak in recovery
- fix for build failure due to the recovery fix
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Merge tag 'xfs-for-linus-v3.12-rc4' of git://oss.sgi.com/xfs/xfs
Pull xfs bugfixes from Ben Myers:
"There are lockdep annotations for project quotas, a fix for dirent
dtype support on v4 filesystems, a fix for a memory leak in recovery,
and a fix for the build error that resulted from it. D'oh"
* tag 'xfs-for-linus-v3.12-rc4' of git://oss.sgi.com/xfs/xfs:
xfs: Use kmem_free() instead of free()
xfs: fix memory leak in xlog_recover_add_to_trans
xfs: dirent dtype presence is dependent on directory magic numbers
xfs: lockdep needs to know about 3 dquot-deep nesting
free_device rcu callback, scheduled from btrfs_rm_dev_replace_srcdev,
can be processed before btrfs_scratch_superblock is called, which would
result in a use-after-free on btrfs_device contents. Fix this by
zeroing the superblock before the rcu callback is registered.
Cc: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
The current implementation of worker threads in Btrfs has races in
worker stopping code, which cause all kinds of panics and lockups when
running btrfs/011 xfstest in a loop. The problem is that
btrfs_stop_workers is unsynchronized with respect to check_idle_worker,
check_busy_worker and __btrfs_start_workers.
E.g., check_idle_worker race flow:
btrfs_stop_workers(): check_idle_worker(aworker):
- grabs the lock
- splices the idle list into the
working list
- removes the first worker from the
working list
- releases the lock to wait for
its kthread's completion
- grabs the lock
- if aworker is on the working list,
moves aworker from the working list
to the idle list
- releases the lock
- grabs the lock
- puts the worker
- removes the second worker from the
working list
......
btrfs_stop_workers returns, aworker is on the idle list
FS is umounted, memory is freed
......
aworker is waken up, fireworks ensue
With this applied, I wasn't able to trigger the problem in 48 hours,
whereas previously I could reliably reproduce at least one of these
races within an hour.
Reported-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
The crash[1] is found by xfstests/generic/208 with "-o compress",
it's not reproduced everytime, but it does panic.
The bug is quite interesting, it's actually introduced by a recent commit
(573aecafca,
Btrfs: actually limit the size of delalloc range).
Btrfs implements delay allocation, so during writeback, we
(1) get a page A and lock it
(2) search the state tree for delalloc bytes and lock all pages within the range
(3) process the delalloc range, including find disk space and create
ordered extent and so on.
(4) submit the page A.
It runs well in normal cases, but if we're in a racy case, eg.
buffered compressed writes and aio-dio writes,
sometimes we may fail to lock all pages in the 'delalloc' range,
in which case, we need to fall back to search the state tree again with
a smaller range limit(max_bytes = PAGE_CACHE_SIZE - offset).
The mentioned commit has a side effect, that is, in the fallback case,
we can find delalloc bytes before the index of the page we already have locked,
so we're in the case of (delalloc_end <= *start) and return with (found > 0).
This ends with not locking delalloc pages but making ->writepage still
process them, and the crash happens.
This fixes it by just thinking that we find nothing and returning to caller
as the caller knows how to deal with it properly.
[1]:
------------[ cut here ]------------
kernel BUG at mm/page-writeback.c:2170!
[...]
CPU: 2 PID: 11755 Comm: btrfs-delalloc- Tainted: G O 3.11.0+ #8
[...]
RIP: 0010:[<ffffffff810f5093>] [<ffffffff810f5093>] clear_page_dirty_for_io+0x1e/0x83
[...]
[ 4934.248731] Stack:
[ 4934.248731] ffff8801477e5dc8 ffffea00049b9f00 ffff8801869f9ce8 ffffffffa02b841a
[ 4934.248731] 0000000000000000 0000000000000000 0000000000000fff 0000000000000620
[ 4934.248731] ffff88018db59c78 ffffea0005da8d40 ffffffffa02ff860 00000001810016c0
[ 4934.248731] Call Trace:
[ 4934.248731] [<ffffffffa02b841a>] extent_range_clear_dirty_for_io+0xcf/0xf5 [btrfs]
[ 4934.248731] [<ffffffffa02a8889>] compress_file_range+0x1dc/0x4cb [btrfs]
[ 4934.248731] [<ffffffff8104f7af>] ? detach_if_pending+0x22/0x4b
[ 4934.248731] [<ffffffffa02a8bad>] async_cow_start+0x35/0x53 [btrfs]
[ 4934.248731] [<ffffffffa02c694b>] worker_loop+0x14b/0x48c [btrfs]
[ 4934.248731] [<ffffffffa02c6800>] ? btrfs_queue_worker+0x25c/0x25c [btrfs]
[ 4934.248731] [<ffffffff810608f5>] kthread+0x8d/0x95
[ 4934.248731] [<ffffffff81060868>] ? kthread_freezable_should_stop+0x43/0x43
[ 4934.248731] [<ffffffff814fe09c>] ret_from_fork+0x7c/0xb0
[ 4934.248731] [<ffffffff81060868>] ? kthread_freezable_should_stop+0x43/0x43
[ 4934.248731] Code: ff 85 c0 0f 94 c0 0f b6 c0 59 5b 5d c3 0f 1f 44 00 00 55 48 89 e5 41 54 53 48 89 fb e8 2c de 00 00 49 89 c4 48 8b 03 a8 01 75 02 <0f> 0b 4d 85 e4 74 52 49 8b 84 24 80 00 00 00 f6 40 20 01 75 44
[ 4934.248731] RIP [<ffffffff810f5093>] clear_page_dirty_for_io+0x1e/0x83
[ 4934.248731] RSP <ffff8801869f9c48>
[ 4934.280307] ---[ end trace 36f06d3f8750236a ]---
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
