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While 440037287c5 "[PATCH] switch all filesystems over to
d_obtain_alias" removed some cases where fh_to_dentry() and
fh_to_parent() could return NULL, there are still a few NULL returns
left in individual filesystems. Thus it was a mistake for that commit
to remove the handling of NULL returns in the callers.
Revert those parts of 440037287c5 which removed the NULL handling.
(We could, alternatively, modify all implementations to return -ESTALE
instead of NULL, but that proves to require fixing a number of
filesystems, and in some cases it's arguably more natural to return
NULL.)
Thanks to David for original patch and Linus, Christoph, and Hugh for
review.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Cc: David Howells <dhowells@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Changeset a238b790d5f99c7832f9b73ac8847025815b85f7 (Call fasync()
functions without the BKL) introduced a race which could leave
file->f_flags in a state inconsistent with what the underlying
driver/filesystem believes. Revert that change, and also fix the same
races in ioctl_fioasync() and ioctl_fionbio().
This is a minimal, short-term fix; the real fix will not involve the
BKL.
Reported-by: Oleg Nesterov <oleg@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: stable@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/bdev
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/bdev:
[PATCH] fix bogus argument of blkdev_put() in pktcdvd
[PATCH 2/2] documnt FMODE_ constants
[PATCH 1/2] kill FMODE_NDELAY_NOW
[PATCH] clean up blkdev_get a little bit
[PATCH] Fix block dev compat ioctl handling
[PATCH] kill obsolete temporary comment in swsusp_close()
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When project quota is active and is being used for directory tree
quota control, we disallow rename outside the current directory
tree. This requires a check to be made after all the inodes
involved in the rename are locked. We fail to unlock the inodes
correctly if we disallow the rename when the target is outside the
current directory tree. This results in a hang on the next access
to the inodes involved in failed rename.
Reported-by: Arkadiusz Miskiewicz <arekm@maven.pl>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Tested-by: Arkadiusz Miskiewicz <arekm@maven.pl>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
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Update FMODE_NDELAY before each ioctl call so that we can kill the
magic FMODE_NDELAY_NOW. It would be even better to do this directly
in setfl(), but for that we'd need to have FMODE_NDELAY for all files,
not just block special files.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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The way the bd_claim for the FMODE_EXCL case is implemented is rather
confusing. Clean it up to the most logical style.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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* 'for-2.6.28' of git://linux-nfs.org/~bfields/linux:
NLM: client-side nlm_lookup_host() should avoid matching on srcaddr
nfsd: use of unitialized list head on error exit in nfs4recover.c
Add a reference to sunrpc in svc_addsock
nfsd: clean up grace period on early exit
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* 'linux-next' of git://git.infradead.org/ubifs-2.6:
UBIFS: pre-allocate bulk-read buffer
UBIFS: do not allocate too much
UBIFS: do not print scary memory allocation warnings
UBIFS: allow for gaps when dirtying the LPT
UBIFS: fix compilation warnings
MAINTAINERS: change UBI/UBIFS git tree URLs
UBIFS: endian handling fixes and annotations
UBIFS: remove printk
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kernel-doc handles macros now (it has for quite some time), so change the
ntfs_debug() macro's kernel-doc to be just before the macro instead of
before a phony function prototype.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Anton Altaparmakov <aia21@cantab.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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It has been thought that the per-user file descriptors limit would also
limit the resources that a normal user can request via the epoll
interface. Vegard Nossum reported a very simple program (a modified
version attached) that can make a normal user to request a pretty large
amount of kernel memory, well within the its maximum number of fds. To
solve such problem, default limits are now imposed, and /proc based
configuration has been introduced. A new directory has been created,
named /proc/sys/fs/epoll/ and inside there, there are two configuration
points:
max_user_instances = Maximum number of devices - per user
max_user_watches = Maximum number of "watched" fds - per user
The current default for "max_user_watches" limits the memory used by epoll
to store "watches", to 1/32 of the amount of the low RAM. As example, a
256MB 32bit machine, will have "max_user_watches" set to roughly 90000.
That should be enough to not break existing heavy epoll users. The
default value for "max_user_instances" is set to 128, that should be
enough too.
This also changes the userspace, because a new error code can now come out
from EPOLL_CTL_ADD (-ENOSPC). The EMFILE from epoll_create() was already
listed, so that should be ok.
[akpm@linux-foundation.org: use get_current_user()]
Signed-off-by: Davide Libenzi <davidel@xmailserver.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: <stable@kernel.org>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Reported-by: Vegard Nossum <vegardno@ifi.uio.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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We're panicing in ocfs2_read_blocks_sync() if a jbd-managed buffer is seen.
At first glance, this seems ok but in reality it can happen. My test case
was to just run 'exorcist'. A struct inode is being pushed out of memory but
is then re-read at a later time, before the buffer has been checkpointed by
jbd. This causes a BUG to be hit in ocfs2_read_blocks_sync().
Reviewed-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
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In init_dlmfs_fs(), if calling kmem_cache_create() failed, the code will use return value from
calling bdi_init(). The correct behavior should be set status as -ENOMEM before going to "bail:".
Signed-off-by: Coly Li <coyli@suse.de>
Acked-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
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In ocfs2_unlock_ast(), call wake_up() on lockres before releasing
the spin lock on it. As soon as the spin lock is released, the
lockres can be freed.
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
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The locking_state dump, ocfs2_dlm_seq_show, reads the lvb on locks where it
has not yet been initialized by a lock call.
Signed-off-by: David Teigland <teigland@redhat.com>
Acked-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
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This patch fixes two typos in comments of ocfs2.
Signed-off-by: Coly Li <coyli@suse.de>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
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* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6:
[CIFS] fix regression in cifs_write_begin/cifs_write_end
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udf_clear_inode() can leave behind buffers on mapping's i_private list (when
we truncated preallocation). Call invalidate_inode_buffers() so that the list
is properly cleaned-up before we return from udf_clear_inode(). This is ugly
and suggest that we should cleanup preallocation earlier than in clear_inode()
but currently there's no such call available since drop_inode() is called under
inode lock and thus is unusable for disk operations.
Signed-off-by: Jan Kara <jack@suse.cz>
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The conversion to write_begin/write_end interfaces had a bug where we
were passing a bad parameter to cifs_readpage_worker. Rather than
passing the page offset of the start of the write, we needed to pass the
offset of the beginning of the page. This was reliably showing up as
data corruption in the fsx-linux test from LTP.
It also became evident that this code was occasionally doing unnecessary
read calls. Optimize those away by using the PG_checked flag to indicate
that the unwritten part of the page has been initialized.
CC: Nick Piggin <npiggin@suse.de>
Acked-by: Dave Kleikamp <shaggy@us.ibm.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
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Since commit c98451bd, the loop in nlm_lookup_host() unconditionally
compares the host's h_srcaddr field to the incoming source address.
For client-side nlm_host entries, both are always AF_UNSPEC, so this
check is unnecessary.
Since commit 781b61a6, which added support for AF_INET6 addresses to
nlm_cmp_addr(), nlm_cmp_addr() now returns FALSE for AF_UNSPEC
addresses, which causes nlm_lookup_host() to create a fresh nlm_host
entry every time it is called on the client.
These extra entries will eventually expire once the server is
unmounted, so the impact of this regression, introduced with lockd
IPv6 support in 2.6.28, should be minor.
We could fix this by adding an arm in nlm_cmp_addr() for AF_UNSPEC
addresses, but really, nlm_lookup_host() shouldn't be matching on the
srcaddr field for client-side nlm_host lookups.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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Thanks to Matthew Dodd for this bug report:
A file label issue while running SELinux in MLS mode provoked the
following bug, which is a result of use before init on a 'struct list_head'.
In nfsd4_list_rec_dir() if the call to dentry_open() fails the 'goto
out' skips INIT_LIST_HEAD() which results in the normally improbable
case where list_entry() returns NULL.
Trace follows.
NFSD: Using /var/lib/nfs/v4recovery as the NFSv4 state recovery directory
SELinux: Context unconfined_t:object_r:var_lib_nfs_t:s0 is not valid
(left unmapped).
type=1400 audit(1227298063.609:282): avc: denied { read } for
pid=1890 comm="rpc.nfsd" name="v4recovery" dev=dm-0 ino=148726
scontext=system_u:system_r:nfsd_t:s0-s15:c0.c1023
tcontext=system_u:object_r:unlabeled_t:s15:c0.c1023 tclass=dir
BUG: unable to handle kernel NULL pointer dereference at 00000004
IP: [<c050894e>] list_del+0x6/0x60
*pde = 0d9ce067 *pte = 00000000
Oops: 0000 [#1] SMP
Modules linked in: nfsd lockd nfs_acl auth_rpcgss exportfs autofs4
sunrpc ipv6 dm_multipath scsi_dh ppdev parport_pc sg parport floppy
ata_piix pata_acpi ata_generic libata pcnet32 i2c_piix4 mii pcspkr
i2c_core dm_snapshot dm_zero dm_mirror dm_log dm_mod BusLogic sd_mod
scsi_mod crc_t10dif ext3 jbd mbcache uhci_hcd ohci_hcd ehci_hcd [last
unloaded: microcode]
Pid: 1890, comm: rpc.nfsd Not tainted (2.6.27.5-37.fc9.i686 #1)
EIP: 0060:[<c050894e>] EFLAGS: 00010217 CPU: 0
EIP is at list_del+0x6/0x60
EAX: 00000000 EBX: 00000000 ECX: 00000000 EDX: cd99e480
ESI: cf9caed8 EDI: 00000000 EBP: cf9caebc ESP: cf9caeb8
DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
Process rpc.nfsd (pid: 1890, ti=cf9ca000 task=cf4de580 task.ti=cf9ca000)
Stack: 00000000 cf9caef0 d0a9f139 c0496d04 d0a9f217 fffffff3 00000000
00000000
00000000 00000000 cf32b220 00000000 00000008 00000801 cf9caefc
d0a9f193
00000000 cf9caf08 d0a9b6ea 00000000 cf9caf1c d0a874f2 cf9c3004
00000008
Call Trace:
[<d0a9f139>] ? nfsd4_list_rec_dir+0xf3/0x13a [nfsd]
[<c0496d04>] ? do_path_lookup+0x12d/0x175
[<d0a9f217>] ? load_recdir+0x0/0x26 [nfsd]
[<d0a9f193>] ? nfsd4_recdir_load+0x13/0x34 [nfsd]
[<d0a9b6ea>] ? nfs4_state_start+0x2a/0xc5 [nfsd]
[<d0a874f2>] ? nfsd_svc+0x51/0xff [nfsd]
[<d0a87f2d>] ? write_svc+0x0/0x1e [nfsd]
[<d0a87f48>] ? write_svc+0x1b/0x1e [nfsd]
[<d0a87854>] ? nfsctl_transaction_write+0x3a/0x61 [nfsd]
[<c04b6a4e>] ? sys_nfsservctl+0x116/0x154
[<c04975c1>] ? putname+0x24/0x2f
[<c04975c1>] ? putname+0x24/0x2f
[<c048d49f>] ? do_sys_open+0xad/0xb7
[<c048d337>] ? filp_close+0x50/0x5a
[<c048d4eb>] ? sys_open+0x1e/0x26
[<c0403cca>] ? syscall_call+0x7/0xb
[<c064007b>] ? init_cyrix+0x185/0x490
=======================
Code: 75 e1 8b 53 08 8d 4b 04 8d 46 04 e8 75 00 00 00 8b 53 10 8d 4b 0c
8d 46 0c e8 67 00 00 00 5b 5e 5f 5d c3 90 90 55 89 e5 53 89 c3 <8b> 40
04 8b 00 39 d8 74 16 50 53 68 3e d6 6f c0 6a 30 68 78 d6
EIP: [<c050894e>] list_del+0x6/0x60 SS:ESP 0068:cf9caeb8
---[ end trace a89c4ad091c4ad53 ]---
Cc: Matthew N. Dodd <Matthew.Dodd@spart.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
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If nfsd was shut down before the grace period ended, we could end up
with a freed object still on grace_list. Thanks to Jeff Moyer for
reporting the resulting list corruption warnings.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Tested-by: Jeff Moyer <jmoyer@redhat.com>
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To avoid memory allocation failure during bulk-read, pre-allocate
a bulk-read buffer, so that if there is only one bulk-reader at
a time, it would just use the pre-allocated buffer and would not
do any memory allocation. However, if there are more than 1 bulk-
reader, then only one reader would use the pre-allocated buffer,
while the other reader would allocate the buffer for itself.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
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Bulk-read allocates 128KiB or more using kmalloc. The allocation
starts failing often when the memory gets fragmented. UBIFS still
works fine in this case, because it falls-back to standard
(non-optimized) read method, though. This patch teaches bulk-read
to allocate exactly the amount of memory it needs, instead of
allocating 128KiB every time.
This patch is also a preparation to the further fix where we'll
have a pre-allocated bulk-read buffer as well. For example, now
the @bu object is prepared in 'ubifs_bulk_read()', so we could
path either pre-allocated or allocated information to
'ubifs_do_bulk_read()' later. Or teaching 'ubifs_do_bulk_read()'
not to allocate 'bu->buf' if it is already there.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
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Bulk-read allocates a lot of memory with 'kmalloc()', and when it
is/gets fragmented 'kmalloc()' fails with a scarry warning. But
because bulk-read is just an optimization, UBIFS keeps working fine.
Supress the warning by passing __GFP_NOWARN option to 'kmalloc()'.
This patch also introduces a macro for the magic 128KiB constant.
This is just neater.
Note, this is not really fixes the problem we had, but just hides
the warnings. The further patches fix the problem.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
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* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6:
[CIFS] Do not attempt to close invalidated file handles
[CIFS] fix check for dead tcon in smb_init
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If a connection with open file handles has gone down
and come back up and reconnected without reopening
the file handle yet, do not attempt to send an SMB close
request for this handle in cifs_close. We were
checking for the connection being invalid in cifs_close
but since the connection may have been reconnected
we also need to check whether the file handle
was marked invalid (otherwise we could close the
wrong file handle by accident).
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
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fs/hostfs/hostfs_user.c defines do_readlink() as non-static, and so does
fs/xfs/linux-2.6/xfs_ioctl.c when CONFIG_XFS_DEBUG=y. So rename
do_readlink() in hostfs to hostfs_do_readlink().
I think it's better if XFS guys will also rename their do_readlink(),
it's not necessary to use such a general name.
Signed-off-by: WANG Cong <wangcong@zeuux.org>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Peter Cordes is sorry that he rm'ed his swapfiles while they were in use,
he then had no pathname to swapoff. It's a curious little oversight, but
not one worth a lot of hackery. Kudos to Willy Tarreau for turning this
around from a discussion of synthetic pathnames to how to prevent unlink.
Mimic immutable: prohibit unlinking an active swapfile in may_delete()
(and don't worry my little head over the tiny race window).
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: Willy Tarreau <w@1wt.eu>
Acked-by: Christoph Hellwig <hch@infradead.org>
Cc: Peter Cordes <peter@cordes.ca>
Cc: Bodo Eggert <7eggert@gmx.de>
Cc: David Newall <davidn@davidnewall.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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I have received some reports of out-of-memory errors on some older AMD
architectures. These errors are what I would expect to see if
crypt_stat->key were split between two separate pages. eCryptfs should
not assume that any of the memory sent through virt_to_scatterlist() is
all contained in a single page, and so this patch allocates two
scatterlist structs instead of one when processing keys. I have received
confirmation from one person affected by this bug that this patch resolves
the issue for him, and so I am submitting it for inclusion in a future
stable release.
Note that virt_to_scatterlist() runs sg_init_table() on the scatterlist
structs passed to it, so the calls to sg_init_table() in
decrypt_passphrase_encrypted_session_key() are redundant.
Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com>
Reported-by: Paulo J. S. Silva <pjssilva@ime.usp.br>
Cc: "Leon Woestenberg" <leon.woestenberg@gmail.com>
Cc: Tim Gardner <tim.gardner@canonical.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This was recently changed to check for need_reconnect, but should
actually be a check for a tidStatus of CifsExiting.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
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Block ext devt conversion missed md_autodetect_dev() call in
rescan_partitions() leaving md autodetect unable to see partitions.
Fix it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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Make add_partition() return pointer to the new hd_struct on success
and ERR_PTR() value on failure. This change will be used to fix md
autodetection bug.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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Partition stats structure was not freed on devt allocation failure
path. Fix it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
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* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6:
prevent cifs_writepages() from skipping unwritten pages
Fixed parsing of mount options when doing DFS submount
[CIFS] Fix check for tcon seal setting and fix oops on failed mount from earlier patch
[CIFS] Fix build break
cifs: reinstate sharing of tree connections
[CIFS] minor cleanup to cifs_mount
cifs: reinstate sharing of SMB sessions sans races
cifs: disable sharing session and tcon and add new TCP sharing code
[CIFS] clean up server protocol handling
[CIFS] remove unused list, add new cifs sock list to prepare for mount/umount fix
[CIFS] Fix cifs reconnection flags
[CIFS] Can't rely on iov length and base when kernel_recvmsg returns error
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Fixes a data corruption under heavy stress in which pages could be left
dirty after all open instances of a inode have been closed.
In order to write contiguous pages whenever possible, cifs_writepages()
asks pagevec_lookup_tag() for more pages than it may write at one time.
Normally, it then resets index just past the last page written before calling
pagevec_lookup_tag() again.
If cifs_writepages() can't write the first page returned, it wasn't resetting
index, and the next call to pagevec_lookup_tag() resulted in skipping all of
the pages it previously returned, even though cifs_writepages() did nothing
with them. This can result in data loss when the file descriptor is about
to be closed.
This patch ensures that index gets set back to the next returned page so
that none get skipped.
Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Cc: Shirish S Pargaonkar <shirishp@us.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
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Since these hit the same routines, and are relatively small, it is easier to review
them as one patch.
Fixed incorrect handling of the last option in some cases
Fixed prefixpath handling convert path_consumed into host depended string length (in bytes)
Use non default separator if it is provided in the original mount options
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Igor Mammedov <niallain@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
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earlier patch
set tcon->ses earlier
If the inital tree connect fails, we'll end up calling cifs_put_smb_ses
with a NULL pointer. Fix it by setting the tcon->ses earlier.
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
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Signed-off-by: Steve French <sfrench@us.ibm.com>
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Use a similar approach to the SMB session sharing. Add a list of tcons
attached to each SMB session. Move the refcount to non-atomic. Protect
all of the above with the cifs_tcp_ses_lock. Add functions to
properly find and put references to the tcons.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
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D'oh...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Reported-and-tested-by: Peter Palfrader <peter@palfrader.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Inotify watch removals suck violently.
To kick the watch out we need (in this order) inode->inotify_mutex and
ih->mutex. That's fine if we have a hold on inode; however, for all
other cases we need to make damn sure we don't race with umount. We can
*NOT* just grab a reference to a watch - inotify_unmount_inodes() will
happily sail past it and we'll end with reference to inode potentially
outliving its superblock.
Ideally we just want to grab an active reference to superblock if we
can; that will make sure we won't go into inotify_umount_inodes() until
we are done. Cleanup is just deactivate_super().
However, that leaves a messy case - what if we *are* racing with
umount() and active references to superblock can't be acquired anymore?
We can bump ->s_count, grab ->s_umount, which will almost certainly wait
until the superblock is shut down and the watch in question is pining
for fjords. That's fine, but there is a problem - we might have hit the
window between ->s_active getting to 0 / ->s_count - below S_BIAS (i.e.
the moment when superblock is past the point of no return and is heading
for shutdown) and the moment when deactivate_super() acquires
->s_umount.
We could just do drop_super() yield() and retry, but that's rather
antisocial and this stuff is luser-triggerable. OTOH, having grabbed
->s_umount and having found that we'd got there first (i.e. that
->s_root is non-NULL) we know that we won't race with
inotify_umount_inodes().
So we could grab a reference to watch and do the rest as above, just
with drop_super() instead of deactivate_super(), right? Wrong. We had
to drop ih->mutex before we could grab ->s_umount. So the watch
could've been gone already.
That still can be dealt with - we need to save watch->wd, do idr_find()
and compare its result with our pointer. If they match, we either have
the damn thing still alive or we'd lost not one but two races at once,
the watch had been killed and a new one got created with the same ->wd
at the same address. That couldn't have happened in inotify_destroy(),
but inotify_rm_wd() could run into that. Still, "new one got created"
is not a problem - we have every right to kill it or leave it alone,
whatever's more convenient.
So we can use idr_find(...) == watch && watch->inode->i_sb == sb as
"grab it and kill it" check. If it's been our original watch, we are
fine, if it's a newcomer - nevermind, just pretend that we'd won the
race and kill the fscker anyway; we are safe since we know that its
superblock won't be going away.
And yes, this is far beyond mere "not very pretty"; so's the entire
concept of inotify to start with.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Signed-off-by: Steve French <sfrench@us.ibm.com>
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We do this by abandoning the global list of SMB sessions and instead
moving to a per-server list. This entails adding a new list head to the
TCP_Server_Info struct. The refcounting for the cifsSesInfo is moved to
a non-atomic variable. We have to protect it by a lock anyway, so there's
no benefit to making it an atomic. The list and refcount are protected
by the global cifs_tcp_ses_lock.
The patch also adds a new routines to find and put SMB sessions and
that properly take and put references under the lock.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
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The code that allows these structs to be shared is extremely racy.
Disable the sharing of SMB and tcon structs for now until we can
come up with a way to do this that's race free.
We want to continue to share TCP sessions, however since they are
required for multiuser mounts. For that, implement a new (hopefully
race-free) scheme. Add a new global list of TCP sessions, and take
care to get a reference to it whenever we're dealing with one.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
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We're currently declaring both a sockaddr_in and sockaddr6_in on the
stack, but we really only need storage for one of them. Declare a
sockaddr struct and cast it to the proper type. Also, eliminate the
protocolType field in the TCP_Server_Info struct. It's redundant since
we have a sa_family field in the sockaddr anyway.
We may need to revisit this if SCTP is ever implemented, but for now
this will simplify the code.
CIFS over IPv6 also has a number of problems currently. This fixes all
of them that I found. Eventually, it would be nice to move more of the
code to be protocol independent, but this is a start.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
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mount/umount fix
Also adds two lines missing from the previous patch (for the need reconnect flag in the
/proc/fs/cifs/DebugData handling)
The new global_cifs_sock_list is added, and initialized in init_cifs but not used yet.
Jeff Layton will be adding code in to use that and to remove the GlobalTcon and GlobalSMBSession
lists.
CC: Jeff Layton <jlayton@redhat.com>
CC: Shirish Pargaonkar <shirishp@us.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/teigland/dlm
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/teigland/dlm:
dlm: fix shutdown cleanup
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In preparation for Jeff's big umount/mount fixes to remove the possibility of
various races in cifs mount and linked list handling of sessions, sockets and
tree connections, this patch cleans up some repetitive code in cifs_mount,
and addresses a problem with ses->status and tcon->tidStatus in which we
were overloading the "need_reconnect" state with other status in that
field. So the "need_reconnect" flag has been broken out from those
two state fields (need reconnect was not mutually exclusive from some of the
other possible tid and ses states). In addition, a few exit cases in
cifs_mount were cleaned up, and a problem with a tcon flag (for lease support)
was not being set consistently for the 2nd mount of the same share
CC: Jeff Layton <jlayton@redhat.com>
CC: Shirish Pargaonkar <shirishp@us.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
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Fixes a regression from commit 0f8e0d9a317406612700426fad3efab0b7bbc467,
"dlm: allow multiple lockspace creates".
An extraneous 'else' slipped into a code fragment being moved from
release_lockspace() to dlm_release_lockspace(). The result of the
unwanted 'else' is that dlm threads and structures are not stopped
and cleaned up when the final dlm lockspace is removed. Trying to
create a new lockspace again afterward will fail with
"kmem_cache_create: duplicate cache dlm_conn" because the cache
was not previously destroyed.
Signed-off-by: David Teigland <teigland@redhat.com>
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Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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