The intention of commit aae8679b0e
("pagemap: fix bug in add_to_pagemap, require aligned-length reads of
/proc/pid/pagemap") was to force reads of /proc/pid/pagemap to be a
multiple of 8 bytes, but now it allows to read 0 bytes, which actually
puts some data to user's buffer. According to POSIX, if count is zero,
read() should return zero and has no other results.
Signed-off-by: Vitaly Mayatskikh <v.mayatskih@gmail.com>
Cc: Thomas Tuttle <ttuttle@google.com>
Acked-by: Matt Mackall <mpm@selenic.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change page_mkwrite to allow implementations to return with the page
locked, and also change it's callers (in page fault paths) to hold the
lock until the page is marked dirty. This allows the filesystem to have
full control of page dirtying events coming from the VM.
Rather than simply hold the page locked over the page_mkwrite call, we
call page_mkwrite with the page unlocked and allow callers to return with
it locked, so filesystems can avoid LOR conditions with page lock.
The problem with the current scheme is this: a filesystem that wants to
associate some metadata with a page as long as the page is dirty, will
perform this manipulation in its ->page_mkwrite. It currently then must
return with the page unlocked and may not hold any other locks (according
to existing page_mkwrite convention).
In this window, the VM could write out the page, clearing page-dirty. The
filesystem has no good way to detect that a dirty pte is about to be
attached, so it will happily write out the page, at which point, the
filesystem may manipulate the metadata to reflect that the page is no
longer dirty.
It is not always possible to perform the required metadata manipulation in
->set_page_dirty, because that function cannot block or fail. The
filesystem may need to allocate some data structure, for example.
And the VM cannot mark the pte dirty before page_mkwrite, because
page_mkwrite is allowed to fail, so we must not allow any window where the
page could be written to if page_mkwrite does fail.
This solution of holding the page locked over the 3 critical operations
(page_mkwrite, setting the pte dirty, and finally setting the page dirty)
closes out races nicely, preventing page cleaning for writeout being
initiated in that window. This provides the filesystem with a strong
synchronisation against the VM here.
- Sage needs this race closed for ceph filesystem.
- Trond for NFS (http://bugzilla.kernel.org/show_bug.cgi?id=12913).
- I need it for fsblock.
- I suspect other filesystems may need it too (eg. btrfs).
- I have converted buffer.c to the new locking. Even simple block allocation
under dirty pages might be susceptible to i_size changing under partial page
at the end of file (we also have a buffer.c-side problem here, but it cannot
be fixed properly without this patch).
- Other filesystems (eg. NFS, maybe btrfs) will need to change their
page_mkwrite functions themselves.
[ This also moves page_mkwrite another step closer to fault, which should
eventually allow page_mkwrite to be moved into ->fault, and thus avoiding a
filesystem calldown and page lock/unlock cycle in __do_fault. ]
[akpm@linux-foundation.org: fix derefs of NULL ->mapping]
Cc: Sage Weil <sage@newdream.net>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix an obvious incorrect return status in autofs4_mount_busy().
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>
When multiply mounting from the same client to the same server, with
different userids, we create a vcnum which should be unique if
possible (this is not the same as the smb uid, which is the handle
to the security context). We were not endian converting additional
(beyond the first which is zero) vcnum properly.
CC: Stable <stable@kernel.org>
Acked-by: Shirish Pargaonkar <shirishp@us.ibm.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Removes two sparse CHECK_ENDIAN warnings from Jeffs earlier patch,
and removes the dead readlink code (after noting where in
findfirst we will need to add something like that in the future
to handle the newly discovered unexpected error on FindFirst of NTFS symlinks.
Signed-off-by: Steve French <sfrench@us.ibm.com>
The earlier patch to move this code to use the new unicode helpers
assumed that the filename strings would be null terminated. That's not
always the case.
Instead of passing "max_len" to the string converter, pass "min(len,
max_len)", which makes it do the right thing while still keeping the
parser confined to the response. Also fix up the prototypes of this
function and the callers so that max_len is unsigned (like len is).
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
The ocfs2 directory index updates two blocks when we remove an entry -
the dx root and the dx leaf. OCFS2_DELETE_INODE_CREDITS was only
accounting for the dx leaf. This shows up when ocfs2_delete_inode()
runs out of credits in jbd2_journal_dirty_metadata() at
"J_ASSERT_JH(jh, handle->h_buffer_credits > 0);".
The test that caught this was running dirop_file_racer from the
ocfs2-test suite with a 250-character filename PREFIX. Run on a 512B
blocksize, it forces the orphan dir index to grow large enough to
trigger.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
In most cases, cifs_strndup is converting from Unicode (UCS2 / UTF-32) to
the configured local code page for the Linux mount (usually UTF8), so
Jeff suggested that to make it more clear that cifs_strndup is doing
a conversion not just memory allocation and copy, rename the function
to including "from_ucs" (ie Unicode)
Signed-off-by: Steve French <sfrench@us.ibm.com>
Added loop check when mounting DFS tree. mount will fail with
ELOOP if referral walks exceed MAX_NESTED_LINK count.
Signed-off-by: Igor Mammedov <niallain@gmail.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Having remote dfs root support in cifs_mount, we can
afford to pass into it UNC that is remote.
Signed-off-by: Igor Mammedov <niallain@gmail.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Two years ago, when the session setup code in cifs was rewritten and moved
to fs/cifs/sess.c, we were asked to keep the old code for a release or so
(which could be reenabled at runtime) since it was such a large change and
because the asn (SPNEGO) and NTLMSSP code was not rewritten and needed to
be. This was useful to avoid regressions, but is long overdue to be removed.
Now that the Kerberos (asn/spnego) code is working in fs/cifs/sess.c,
and the NTLMSSP code moved (NTLMSSP blob setup be rewritten with the
next patch in this series) quite a bit of dead code from fs/cifs/connect.c
now can be removed.
This old code should have been removed last year, but the earlier krb5
patches did not move/remove the NTLMSSP code which we had asked to
be done first. Since no one else volunteered, I am doing it now.
It is extremely important that we continue to examine the documentation
for this area, to make sure our code continues to be uptodate with
changes since Windows 2003.
Signed-off-by: Steve French <sfrench@us.ibm.com>
...and remove cifs_convertUCSpath. There are no more callers. Also add a
#define for the buffer used in the readdir path so that we don't have so
many magic numbers floating around.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Change CIFSSMBUnixQuerySymLink to use the new unicode helper functions.
Also change the calling conventions so that the allocation of the target
name buffer is done in CIFSSMBUnixQuerySymLink rather than by the caller.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Steve French <sfrench@us.ibm.com>
...and change decode_unicode_ssetup to be a void function. It never
returns an actual error anyway.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Rename cifs_strlcpy_to_host to cifs_strndup since that better describes
what this function really does. Then, convert it to use the new string
conversion and measurement functions that work in units of bytes rather
than wide chars.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Working in units of words means we do a lot of unnecessary conversion back
and forth. Standardize on bytes instead since that's more useful for
allocating buffers and such. Also, remove hostlen_fromUCS since the new
function has a similar purpose.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Add a replacement function for cifs_strtoUCS_le. cifs_from_ucs2
takes args for the source and destination length so that we can ensure
that the function is confined within the intended buffers.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Steve French <sfrench@us.ibm.com>
xfs_getbmap (or rather the formatters called by it) copy out the getbmap
structures under the ilock, which can deadlock against mmap. This has
been reported via bugzilla a while ago (#717) and has recently also
shown up via lockdep.
So allocate a temporary buffer to format the kernel getbmap structures
into and then copy them out after dropping the locks.
A little problem with this is that we limit the number of extents we
can copy out by the maximum allocation size, but I see no real way
around that.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Sandeen <sandeen@sandeen.net>
Reviewed-by: Felix Blyakher <felixb@sgi.com>
Signed-off-by: Felix Blyakher <felixb@sgi.com>
- reshuffle various conditionals for data vs attr fork to make the code
more readable
- do fine-grainded goto-based error handling
- exit early from conditionals instead of keeping a long else branch around
- allow kmem_alloc to fail
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Sandeen <sandeen@sandeen.net>
Reviewed-by: Felix Blyakher <felixb@sgi.com>
Signed-off-by: Felix Blyakher <felixb@sgi.com>
There had been reports where xfs filesystem was randomly
corrupted with fsfuzzer, and xfs failed to handle it
gracefully. This patch fixes couple of reported problem
by providing additional checks in the superblock
validation routine.
Signed-off-by: Olaf Weber <olaf@sgi.com>
Reviewed-by: Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Felix Blyakher <felixb@sgi.com>
We had some systems crash with this stack:
[<a00000010000cb20>] ia64_leave_kernel+0x0/0x280
[<a00000021291ca00>] xfs_bmbt_get_startoff+0x0/0x20 [xfs]
[<a0000002129080b0>] xfs_bmap_last_offset+0x210/0x280 [xfs]
[<a00000021295b010>] xfs_file_last_byte+0x70/0x1a0 [xfs]
[<a00000021295b200>] xfs_itruncate_start+0xc0/0x1a0 [xfs]
[<a0000002129935f0>] xfs_inactive_free_eofblocks+0x290/0x460 [xfs]
[<a000000212998fb0>] xfs_release+0x1b0/0x240 [xfs]
[<a0000002129ad930>] xfs_file_release+0x70/0xa0 [xfs]
[<a000000100162ea0>] __fput+0x1a0/0x420
[<a000000100163160>] fput+0x40/0x60
The problem here is that xfs_file_last_byte() does not acquire the
inode lock and can therefore race with another thread that is modifying
the extext list. While xfs_bmap_last_offset() is trying to lookup
what was the last extent some extents were merged and the extent list
shrunk so the index we lookup is now beyond the end of the extent list
and potentially in a freed buffer.
Signed-off-by: Lachlan McIlroy <lmcilroy@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Felix Blyakher <felixb@sgi.com>
Signed-off-by: Felix Blyakher <felixb@sgi.com>
With indexed dir enabled, now we use ocfs2_dir_lookup_result to
wrap all the bh used for dir. So remove the 2 unused variables.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Destroy bdi on error in fuse_fill_super().
This was an omission from commit 26c3679101
"fuse: destroy bdi on umount", which moved the bdi_destroy() call from
fuse_conn_put() to fuse_put_super().
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
CC: stable@kernel.org
This warning shows up on 64 bit builds:
fs/ecryptfs/inode.c:693: warning: comparison of distinct pointer types
lacks a cast
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
fs/ecryptfs/inode.c:670: warning: format '%d' expects type 'int', but argument 3 has type 'size_t'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Cc: Dustin Kirkland <kirkland@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
st driver uses blk_rq_map_user() in order to just build a request out
of page frames. In this case, map_data->offset is a non zero value and
iov[0].iov_base is NULL. We need to increase nr_pages for that.
Cc: stable@kernel.org
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
Btrfs: look for acls during btrfs_read_locked_inode
Btrfs: fix acl caching
Btrfs: Fix a bunch of printk() warnings.
Btrfs: Fix a trivial warning using max() of u64 vs ULL.
Btrfs: remove unused btrfs_bit_radix slab
Btrfs: ratelimit IO error printks
Btrfs: remove #if 0 code
Btrfs: When shrinking, only update disk size on success
Btrfs: fix deadlocks and stalls on dead root removal
Btrfs: fix fallocate deadlock on inode extent lock
Btrfs: kill btrfs_cache_create
Btrfs: don't export symbols
Btrfs: simplify makefile
Btrfs: try to keep a healthy ratio of metadata vs data block groups
This changes btrfs_read_locked_inode() to peek ahead in the btree for acl items.
If it is certain a given inode has no acls, it will set the in memory acl
fields to null to avoid acl lookups completely.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Linus noticed the btrfs code to cache acls wasn't properly caching
a NULL acl when the inode didn't have any acls. This meant the common
case of no acls resulted in expensive btree searches every time the
kernel checked permissions (which is quite often).
This is a modified version of Linus' original patch:
Properly set initial acl fields to BTRFS_ACL_NOT_CACHED in the inode.
This forces an acl lookup when permission checks are done.
Fix btrfs_get_acl to avoid lookups and locking when the inode acls fields
are set to null.
Fix btrfs_get_acl to use the right return value from __btrfs_getxattr
when deciding to cache a NULL acl. It was storing a NULL acl when
__btrfs_getxattr return -ENOENT, but __btrfs_getxattr was actually returning
-ENODATA for this case.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-quota-2.6:
ext2: missing unlock in ext2_quota_write()
quota: remove obsolete comments in fs/quota/Makefile
The inode->i_mutex should be unlocked.
Found by smatch (http://repo.or.cz/w/smatch.git). Compile tested.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Get rid of useless comments and the equally useless obj-y
initialization.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Just happened to notice a bunch of %llu vs u64 warnings. Here's a patch
to cast them all.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
A small warning popped up on ia64 because inode-map.c was comparing a
u64 object id with the ULL FIRST_FREE_OBJECTID. My first thought was
that all the OBJECTID constants should contain the u64 cast because
btrfs code deals entirely in u64s. But then I saw how large that was,
and figured I'd just fix the max() call.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Btrfs has printks for various IO errors, including bad checksums and
mismatches between what we expect the block headers to contain and what
we actually find on the disk.
Longer term we need a real reporting mechanism for this, but for now
printk is going to have to do.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Previously, we updated a device's size prior to attempting a shrink
operation. This patch moves the device resizing logic to only happen if
the shrink completes successfully. In the process, it introduces a new
field to btrfs_device -- disk_total_bytes -- to track the on-disk size.
Signed-off-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
