In case of mode mismatch, do *not* blindly close the descriptor
another openers might be using right now. Open the underlying
file with currently sufficient mode, then
* if current mode has grown so that it's sufficient for
us now, just close our new fd
* if current mode has grown and our fd is *not* enough
to cover it, close and repeat.
* otherwise, install our fd if the file hadn't been
opened at all or dup2() our fd over the current one (and close
our fd).
Critical section is protected by mutex; yes, system-wide. All
we do under it is a bunch of comparison and maybe an overwriting
dup2() on host.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
calculating size, then doing allocation, then filling the
path is a Bad Idea(tm), since the ancestors can be renamed,
leading to buffer overrun.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
builds path relative to fs root, called under dcache_lock,
doesn't append any nonsense to unlinked ones.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
We will calculate it in all callers anyway, so there's no
need to duplicate that inside. Moreover, that way we lose
all failure exits in init_inode(), so it doesn't need to
return anything.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
There are only two call sites; in one (hostfs_iget()) it's actually
a no-op and in another (fill_super()) it's easier to expand the
damn thing and use what we know about its arguments to simplify
it.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
We need to wait for completion of possible writeback in progress
before we clear on-disk inode during deletion.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
simply don't hash the inodes that don't have real inumber instead of
skipping them during iget5_locked(); as the result, simple iget_locked()
would do and we can get rid of cramfs ->drop_inode() as well.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Essentially, the minimal variant of ->evict_inode(). It's
a trimmed-down clear_inode(), sans any fs callbacks. Once
it returns we know that no async writeback will be happening;
every ->evict_inode() instance should do that once and do that
before doing anything ->write_inode() could interfere with
(e.g. freeing the on-disk inode).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
All call chains to clear_inode() pass through evict_inode() and
clear_inode() should be called by evict_inode() exactly once.
So we can pull i_bdev/i_cdev detaching up to evict_inode() itself.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Hybrid of ->clear_inode() and ->delete_inode(); if present, does
all fs work to be done when in-core inode is about to be gone,
for whatever reason.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
add I_CLEAR instead of replacing I_FREEING with it. I_CLEAR is
equivalent to I_FREEING for almost all code looking at either;
it's there to keep track of having called clear_inode() exactly
once per inode lifetime, at some point after having set I_FREEING.
I_CLEAR and I_FREEING never get set at the same time with the
current code, so we can switch to setting i_flags to I_FREEING | I_CLEAR
instead of I_CLEAR without loss of information. As the result of
such change, checks become simpler and the amount of code that needs
to know about I_CLEAR shrinks a lot.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Convert XFS to the new truncate sequence. We still can have errors after
updating the file size in xfs_setattr, but these are real I/O errors and lead
to a transaction abort and filesystem shutdown, so they are not an issue.
Errors from ->write_begin and write_end can now be handled correctly because
we can actually get rid of the delalloc extents while previous the buffer
state was stipped in block_invalidatepage.
There is still no error handling for ->direct_IO, because doing so will need
some major restructuring given that we only have the iolock shared and do not
hold i_mutex at all. Fortunately leaving the normally allocated blocks behind
there is not a major issue and this will get cleaned up by xfs_free_eofblock
later.
Note: the patch is against Al's vfs.git tree as that contains the nessecary
preparations. I'd prefer to get it applied there so that we can get some
testing in linux-next.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
These changes are crafted based on the similar
conversion done to ext2 by Nick Piggin.
* Remove the deprecated ->truncate vector. Let exofs_setattr
take care of on-disk size updates.
* Call truncate_pagecache on the unused pages if
write_begin/end fails.
* Cleanup exofs_delete_inode that did stupid inode
writes and updates on an inode that will be
removed.
* And finally get rid of exofs_get_block. We never
had any blocks it was all for calling nobh_truncate_page.
nobh_truncate_page is not actually needed in exofs since
the last page is complete and gone, just like all the other
pages. There is no partial blocks in exofs.
I've tested with this patch, and there are no apparent
failures, so far.
CC: Nick Piggin <npiggin@suse.de>
CC: Christoph Hellwig <hch@lst.de>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Make sure we check the truncate constraints early on in ->setattr by adding
those checks to inode_change_ok. Also clean up and document inode_change_ok
to make this obvious.
As a fallout we don't have to call inode_newsize_ok from simple_setsize and
simplify it down to a truncate_setsize which doesn't return an error. This
simplifies a lot of setattr implementations and means we use truncate_setsize
almost everywhere. Get rid of fat_setsize now that it's trivial and mark
ext2_setsize static to make the calling convention obvious.
Keep the inode_newsize_ok in vmtruncate for now as all callers need an
audit for its removal anyway.
Note: setattr code in ecryptfs doesn't call inode_change_ok at all and
needs a deeper audit, but that is left for later.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Make sure we call inode_change_ok before doing any changes in ->setattr,
and make sure to call it even if our fs wants to ignore normal UNIX
permissions, but use the ATTR_FORCE to skip those.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Replace inode_setattr with opencoded variants of it in all callers. This
moves the remaining call to vmtruncate into the filesystem methods where it
can be replaced with the proper truncate sequence.
In a few cases it was obvious that we would never end up calling vmtruncate
so it was left out in the opencoded variant:
spufs: explicitly checks for ATTR_SIZE earlier
btrfs,hugetlbfs,logfs,dlmfs: explicitly clears ATTR_SIZE earlier
ufs: contains an opencoded simple_seattr + truncate that sets the filesize just above
In addition to that ncpfs called inode_setattr with handcrafted iattrs,
which allowed to trim down the opencoded variant.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
With the new truncate sequence every filesystem that wants to support file
size changes on disk needs to implement its own ->setattr. So instead
of calling inode_setattr which supports size changes call into a simple
method that doesn't support this. simple_setattr is almost what we
want except that it does not mark the inode dirty after changes. Given
that marking the inode dirty is a no-op for the simple in-memory filesystems
that use simple_setattr currently just add the mark_inode_dirty call.
Also add a WARN_ON for the presence of a truncate method to simple_setattr
to catch new instances of it during the transition period.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Despite its name it's now a generic implementation of ->setattr, but
rather a helper to copy attributes from a struct iattr to the inode.
Rename it to setattr_copy to reflect this fact.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
For the new truncate sequence every filesystem that wants to truncate on-disk
state needs a seattr method. Convert the remaining filesystems that implement
the truncate inode operation to have its own setattr method.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Move the call to vmtruncate to get rid of accessive blocks to the callers
in preparation of the new truncate sequence and rename the non-truncating
version to block_write_begin.
While we're at it also remove several unused arguments to block_write_begin.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Split up the block_write_begin implementation - __block_write_begin is a new
trivial wrapper for block_prepare_write that always takes an already
allocated page and can be either called from block_write_begin or filesystem
code that already has a page allocated. Remove the handling of already
allocated pages from block_write_begin after switching all callers that
do it to __block_write_begin.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
For filesystem that implement directories in pagecache we call
block_write_begin with an already allocated page for this code, while the
normal regular file write path uses the default block_write_begin behaviour.
Get rid of the __foofs_write_begin helper and opencode the normal write_begin
call in foofs_write_begin, while adding a new foofs_prepare_chunk helper for
the directory code. The added benefit is that foofs_prepare_chunk has
a much saner calling convention.
Note that the interruptible flag passed into block_write_begin is always
ignored if we already pass in a page (see next patch for details), and
we never were doing truncations of exessive blocks for this case either so we
can switch directly to block_write_begin_newtrunc.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Move the call to vmtruncate to get rid of accessive blocks to the callers
in preparation of the new truncate sequence and rename the non-truncating
version to cont_write_begin.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Move the call to vmtruncate to get rid of accessive blocks to the only
remaining caller and rename the non-truncating version to nobh_write_begin.
Get rid of the superflous file argument to it while we're at it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Move the call to vmtruncate to get rid of accessive blocks to the callers
in prepearation of the new truncate calling sequence. This was only done
for DIO_LOCKING filesystems, so the __blockdev_direct_IO_newtrunc variant
was not needed anyway. Get rid of blockdev_direct_IO_no_locking and
its _newtrunc variant while at it as just opencoding the two additional
paramters is shorted than the name suffix.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
a) count file openers correctly; i_count use was completely wrong
b) use new mutex for exclusion between final close/open/truncate,
to protect tailpacking logics. i_mutex use was wrong and resulted
in deadlocks.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
I have encountered the same problem that Eric Sandeen described in
this post
http://lkml.org/lkml/fancy/2010/4/23/467
while experimenting with stackable filesystems.
The reason seems to be that ecryptfs calls lookup_one_len() to get the
lower dentry, which in turn calls the lower parent dirs d_revalidate()
with a NULL nameidata object.
If ecryptfs is the underlaying filesystem, the NULL pointer dereference
occurs, since ecryptfs is not prepared to handle a NULL nameidata.
I know that this cant happen any more, since it is no longer allowed to
mount ecryptfs upon itself.
But maybe this patch it useful nevertheless, since the problem would still
apply for an underlaying filesystem that implements d_revalidate() and is
not prepared to handle a NULL nameidata (I dont know if there actually
is such a fs).
With this patch (against 2.6.35-rc5) ecryptfs uses the vfs_lookup_path()
function instead of lookup_one_len() which ensures that the nameidata
passed to the lower filesystems d_revalidate().
Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
The comments in the code indicate that file_info should be released if the
function fails. This releasing is done at the label out_free, not out.
The semantic match that finds this problem is as follows:
(http://www.emn.fr/x-info/coccinelle/)
// <smpl>
@r exists@
local idexpression x;
statement S;
expression E;
identifier f,f1,l;
position p1,p2;
expression *ptr != NULL;
@@
x@p1 = kmem_cache_zalloc(...);
...
if (x == NULL) S
<... when != x
when != if (...) { <+...x...+> }
(
x->f1 = E
|
(x->f1 == NULL || ...)
|
f(...,x->f1,...)
)
...>
(
return <+...x...+>;
|
return@p2 ...;
)
@script:python@
p1 << r.p1;
p2 << r.p2;
@@
print "* file: %s kmem_cache_zalloc %s" % (p1[0].file,p1[0].line)
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Cc: stable@kernel.org
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
In ecryptfs_lookup_and_interpose_lower() the lower mount is not decremented
if allocation of a dentry info struct failed. As a result the lower filesystem
cant be unmounted any more (since it is considered busy). This patch corrects
the reference counting.
Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Cc: stable@kernel.org
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Lower filesystems that only implemented unlocked_ioctl weren't being
passed ioctl calls because eCryptfs only checked for
lower_file->f_op->ioctl and returned -ENOTTY if it was NULL.
eCryptfs shouldn't implement ioctl(), since it doesn't require the BKL.
This patch introduces ecryptfs_unlocked_ioctl() and
ecryptfs_compat_ioctl(), which passes the calls on to the lower file
system.
https://bugs.launchpad.net/ecryptfs/+bug/469664
Reported-by: James Dupin <james.dupin@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Fix warning seen with "make -j24 CONFIG_DEBUG_SECTION_MISMATCH=y V=1":
fs/ecryptfs/messaging.c: In function 'ecryptfs_process_response':
fs/ecryptfs/messaging.c:276: warning: 'daemon' may be used uninitialized in this function
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Handling of autofs ioctl numbers does not need to be generic
and can easily be done directly in autofs itself.
This also pushes the BKL into autofs and autofs4 ioctl
methods.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ian Kent <raven@themaw.net>
Cc: Autofs <autofs@linux.kernel.org>
Cc: John Kacur <jkacur@redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
quiet the warning:
fs/omfs/file.c: In function 'omfs_get_block':
fs/omfs/file.c:225: warning: 'new_block' may be used uninitialized in
this function
new_block is used properly by the call to omfs_grow_extent()
Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Signed-off-by: Bob Copeland <me@bobcopeland.com>
* 'bkl/core' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing:
do_coredump: Do not take BKL
init: Remove the BKL from startup code
* 'for-2.6.36' of git://linux-nfs.org/~bfields/linux: (34 commits)
nfsd4: fix file open accounting for RDWR opens
nfsd: don't allow setting maxblksize after svc created
nfsd: initialize nfsd versions before creating svc
net: sunrpc: removed duplicated #include
nfsd41: Fix a crash when a callback is retried
nfsd: fix startup/shutdown order bug
nfsd: minor nfsd read api cleanup
gcc-4.6: nfsd: fix initialized but not read warnings
nfsd4: share file descriptors between stateid's
nfsd4: fix openmode checking on IO using lock stateid
nfsd4: miscellaneous process_open2 cleanup
nfsd4: don't pretend to support write delegations
nfsd: bypass readahead cache when have struct file
nfsd: minor nfsd_svc() cleanup
nfsd: move more into nfsd_startup()
nfsd: just keep single lockd reference for nfsd
nfsd: clean up nfsd_create_serv error handling
nfsd: fix error handling in __write_ports_addxprt
nfsd: fix error handling when starting nfsd with rpcbind down
nfsd4: fix v4 state shutdown error paths
...
Fix the module init error handling. There are a bunch of goto labels for
aborting the init procedure at different points and just undoing what needs
undoing - they aren't all in the right places, however.
This can lead to an oops like the following:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000020
IP: [<ffffffff81042a31>] destroy_workqueue+0x17/0xc0
...
Modules linked in: kafs(+) dns_resolver rxkad af_rxrpc fscache
Pid: 2171, comm: insmod Not tainted 2.6.35-cachefs+ #319 DG965RY/
...
Process insmod (pid: 2171, threadinfo ffff88003ca6a000, task ffff88003dcc3050)
...
Call Trace:
[<ffffffffa0055994>] afs_callback_update_kill+0x10/0x12 [kafs]
[<ffffffffa007d1c5>] afs_init+0x190/0x1ce [kafs]
[<ffffffffa007d035>] ? afs_init+0x0/0x1ce [kafs]
[<ffffffff810001ef>] do_one_initcall+0x59/0x14e
[<ffffffff8105f7ee>] sys_init_module+0x9c/0x1de
[<ffffffff81001eab>] system_call_fastpath+0x16/0x1b
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'nfs-for-2.6.36' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6: (42 commits)
NFS: NFSv4.1 is no longer a "developer only" feature
NFS: NFS_V4 is no longer an EXPERIMENTAL feature
NFS: Fix /proc/mount for legacy binary interface
NFS: Fix the locking in nfs4_callback_getattr
SUNRPC: Defer deleting the security context until gss_do_free_ctx()
SUNRPC: prevent task_cleanup running on freed xprt
SUNRPC: Reduce asynchronous RPC task stack usage
SUNRPC: Move the bound cred to struct rpc_rqst
SUNRPC: Clean up of rpc_bindcred()
SUNRPC: Move remaining RPC client related task initialisation into clnt.c
SUNRPC: Ensure that rpc_exit() always wakes up a sleeping task
SUNRPC: Make the credential cache hashtable size configurable
SUNRPC: Store the hashtable size in struct rpc_cred_cache
NFS: Ensure the AUTH_UNIX credcache is allocated dynamically
NFS: Fix the NFS users of rpc_restart_call()
SUNRPC: The function rpc_restart_call() should return success/failure
NFSv4: Get rid of the bogus RPC_ASSASSINATED(task) checks
NFSv4: Clean up the process of renewing the NFSv4 lease
NFSv4.1: Handle NFS4ERR_DELAY on SEQUENCE correctly
NFS: nfs_rename() should not have to flush out writebacks
...
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2: (45 commits)
nilfs2: reject filesystem with unsupported block size
nilfs2: avoid rec_len overflow with 64KB block size
nilfs2: simplify nilfs_get_page function
nilfs2: reject incompatible filesystem
nilfs2: add feature set fields to super block
nilfs2: clarify byte offset in super block format
nilfs2: apply read-ahead for nilfs_btree_lookup_contig
nilfs2: introduce check flag to btree node buffer
nilfs2: add btree get block function with readahead option
nilfs2: add read ahead mode to nilfs_btnode_submit_block
nilfs2: fix buffer head leak in nilfs_btnode_submit_block
nilfs2: eliminate inline keywords in btree implementation
nilfs2: get maximum number of child nodes from bmap object
nilfs2: reduce repetitive calculation of max number of child nodes
nilfs2: optimize calculation of min/max number of btree node children
nilfs2: remove redundant pointer checks in bmap lookup functions
nilfs2: get rid of nilfs_bmap_union
nilfs2: unify bmap set_target_v operations
nilfs2: get rid of nilfs_btree uses
nilfs2: get rid of nilfs_direct uses
...
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (40 commits)
ext4: Adding error check after calling ext4_mb_regular_allocator()
ext4: Fix dirtying of journalled buffers in data=journal mode
ext4: re-inline ext4_rec_len_(to|from)_disk functions
jbd2: Remove t_handle_lock from start_this_handle()
jbd2: Change j_state_lock to be a rwlock_t
jbd2: Use atomic variables to avoid taking t_handle_lock in jbd2_journal_stop
ext4: Add mount options in superblock
ext4: force block allocation on quota_off
ext4: fix freeze deadlock under IO
ext4: drop inode from orphan list if ext4_delete_inode() fails
ext4: check to make make sure bd_dev is set before dereferencing it
jbd2: Make barrier messages less scary
ext4: don't print scary messages for allocation failures post-abort
ext4: fix EFBIG edge case when writing to large non-extent file
ext4: fix ext4_get_blocks references
ext4: Always journal quota file modifications
ext4: Fix potential memory leak in ext4_fill_super
ext4: Don't error out the fs if the user tries to make a file too big
ext4: allocate stripe-multiple IOs on stripe boundaries
ext4: move aio completion after unwritten extent conversion
...
Fix up conflicts in fs/ext4/inode.c as per Ted.
Fix up xfs conflicts as per earlier xfs merge.
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6:
ext3: Fix dirtying of journalled buffers in data=journal mode
ext3: default to ordered mode
quota: Use mark_inode_dirty_sync instead of mark_inode_dirty
quota: Change quota error message to print out disk and function name
MAINTAINERS: Update entries of ext2 and ext3
MAINTAINERS: Update address of Andreas Dilger
ext3: Avoid filesystem corruption after a crash under heavy delete load
ext3: remove vestiges of nobh support
ext3: Fix set but unused variables
quota: clean up quota active checks
quota: Clean up the namespace in dqblk_xfs.h
quota: check quota reservation on remove_dquot_ref
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/teigland/dlm:
fs/dlm: Drop unnecessary null test
dlm: use genl_register_family_with_ops()
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-udf-2.6:
udf: super.c Fix warning: variable 'sbi' set but not used
udf: remove duplicated #include
* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6:
[DNS RESOLVER] Minor typo correction
DNS: Fixes for the DNS query module
cifs: Include linux/err.h for IS_ERR and PTR_ERR
DNS: Make AFS go to the DNS for AFSDB records for unknown cells
DNS: Separate out CIFS DNS Resolver code
cifs: account for new creduid=0x%x parameter in spnego upcall string
cifs: reduce false positives with inode aliasing serverino autodisable
CIFS: Make cifs_convert_address() take a const src pointer and a length
cifs: show features compiled in as part of DebugData
cifs: update README
Fix up trivial conflicts in fs/cifs/cifsfs.c due to workqueue changes
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (55 commits)
workqueue: mark init_workqueues() as early_initcall()
workqueue: explain for_each_*cwq_cpu() iterators
fscache: fix build on !CONFIG_SYSCTL
slow-work: kill it
gfs2: use workqueue instead of slow-work
drm: use workqueue instead of slow-work
cifs: use workqueue instead of slow-work
fscache: drop references to slow-work
fscache: convert operation to use workqueue instead of slow-work
fscache: convert object to use workqueue instead of slow-work
workqueue: fix how cpu number is stored in work->data
workqueue: fix mayday_mask handling on UP
workqueue: fix build problem on !CONFIG_SMP
workqueue: fix locking in retry path of maybe_create_worker()
async: use workqueue for worker pool
workqueue: remove WQ_SINGLE_CPU and use WQ_UNBOUND instead
workqueue: implement unbound workqueue
workqueue: prepare for WQ_UNBOUND implementation
libata: take advantage of cmwq and remove concurrency limitations
workqueue: fix worker management invocation without pending works
...
Fixed up conflicts in fs/cifs/* as per Tejun. Other trivial conflicts in
include/linux/workqueue.h, kernel/trace/Kconfig and kernel/workqueue.c
Whe the first inode for a bdi is marked dirty, we wake up the bdi thread which
should take care of the periodic background write-out. However, the write-out
will actually start only 'dirty_writeback_interval' centisecs later, so we can
delay the wake-up.
This change was requested by Nick Piggin who pointed out that if we delay the
wake-up, we weed out 2 unnecessary contex switches, which matters because
'__mark_inode_dirty()' is a hot-path function.
This patch introduces a new function - 'bdi_wakeup_thread_delayed()', which
sets up a timer to wake-up the bdi thread and returns. So the wake-up is
delayed.
We also delete the timer in bdi threads just before writing-back. And
synchronously delete it when unregistering bdi. At the unregister point the bdi
does not have any users, so no one can arm it again.
Since now we take 'bdi->wb_lock' in the timer, which can execute in softirq
context, we have to use 'spin_lock_bh()' for 'bdi->wb_lock'. This patch makes
this change as well.
This patch also moves the 'bdi_wb_init()' function down in the file to avoid
forward-declaration of 'bdi_wakeup_thread_delayed()'.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Finally, we can get rid of unnecessary wake-ups in bdi threads, which are very
bad for battery-driven devices.
There are two types of activities bdi threads do:
1. process bdi works from the 'bdi->work_list'
2. periodic write-back
So there are 2 sources of wake-up events for bdi threads:
1. 'bdi_queue_work()' - submits bdi works
2. '__mark_inode_dirty()' - adds dirty I/O to bdi's
The former already has bdi wake-up code. The latter does not, and this patch
adds it.
'__mark_inode_dirty()' is hot-path function, but this patch adds another
'spin_lock(&bdi->wb_lock)' there. However, it is taken only in rare cases when
the bdi has no dirty inodes. So adding this spinlock should be fine and should
not affect performance.
This patch makes sure bdi threads and the forker thread do not wake-up if there
is nothing to do. The forker thread will nevertheless wake up at least every
5 min. to check whether it has to kill a bdi thread. This can also be optimized,
but is not worth it.
This patch also tidies up the warning about unregistered bid, and turns it from
an ugly crocodile to a simple 'WARN()' statement.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Currently, bdi threads can decide to exit if there were no useful activities
for 5 minutes. However, this causes nasty races: we can easily oops in the
'bdi_queue_work()' if the bdi thread decides to exit while we are waking it up.
And even if we do not oops, but the bdi tread exits immediately after we wake
it up, we'd lose the wake-up event and have an unnecessary delay (up to 5 secs)
in the bdi work processing.
This patch makes the forker thread to be the central place which not only
creates bdi threads, but also kills them if they were inactive long enough.
This better design-wise.
Another reason why this change was done is to prepare for the further changes
which will prevent the bdi threads from waking up every 5 sec and wasting
power. Indeed, when the task does not wake up periodically anymore, it won't be
able to exit either.
This patch also moves the the 'wake_up_bit()' call from the bdi thread to the
forker thread as well. So now the forker thread sets the BDI_pending bit, then
forks the task or kills it, then clears the bit and wakes up the waiting
process.
The only process which may wain on the bit is 'bdi_wb_shutdown()'. This
function was changed as well - now it first removes the bdi from the
'bdi_list', then waits on the 'BDI_pending' bit. Once it wakes up, it is
guaranteed that the forker thread won't race with it, because the bdi is not
visible. Note, the forker thread sets the 'BDI_pending' bit under the
'bdi->wb_lock' which is essential for proper serialization.
And additionally, when we change 'bdi->wb.task', we now take the
'bdi->work_lock', to make sure that we do not lose wake-ups which we otherwise
would when raced with, say, 'bdi_queue_work()'.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Currently bdi threads use local variable 'last_active' which stores last time
when the bdi thread did some useful work. Move this local variable to 'struct
bdi_writeback'. This is just a preparation for the further patches which will
make the forker thread decide when bdi threads should be killed.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
The forker thread removes bdis from 'bdi_list' before forking the bdi thread.
But this is wrong for at least 2 reasons.
Reason #1: if we temporary remove a bdi from the list, we may miss works which
would otherwise be given to us.
Reason #2: this is racy; indeed, 'bdi_wb_shutdown()' expects that bdis are
always in the 'bdi_list' (see 'bdi_remove_from_list()'), and when
it races with the forker thread, it can shut down the bdi thread
at the same time as the forker creates it.
This patch makes sure the forker thread never removes bdis from 'bdi_list'
(which was suggested by Christoph Hellwig).
In order to make sure that we do not race with 'bdi_wb_shutdown()', we have to
hold the 'bdi_lock' while walking the 'bdi_list' and setting the 'BDI_pending'
flag.
NOTE! The error path is interesting. Currently, when we fail to create a bdi
thread, we move the bdi to the tail of 'bdi_list'. But if we never remove the
bdi from the list, we cannot move it to the tail either, because then we can
mess up the RCU readers which walk the list. And also, we'll have the race
described above in "Reason #2".
But I not think that adding to the tail is any important so I just do not do
that.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Currently, bdi threads ('bdi_writeback_thread()') can lose wake-ups. For
example, if 'bdi_queue_work()' is executed after the bdi thread have had
finished 'wb_do_writeback()' but before it called
'schedule_timeout_interruptible()'.
To fix this issue, we have to check whether we have works to process after we
have changed the task state to 'TASK_INTERRUPTIBLE'.
This patch also clean-ups handling of the cases when 'dirty_writeback_interval'
is zero or non-zero.
Additionally, this patch also removes unneeded 'list_empty_careful()' call.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
The write-back code mixes words "thread" and "task" for the same things. This
is not a big deal, but still an inconsistency.
hch: a convention I tend to use and I've seen in various places
is to always use _task for the storage of the task_struct pointer,
and thread everywhere else. This especially helps with having
foo_thread for the actual thread and foo_task for a global
variable keeping the task_struct pointer
This patch renames:
* 'bdi_add_default_flusher_task()' -> 'bdi_add_default_flusher_thread()'
* 'bdi_forker_task()' -> 'bdi_forker_thread()'
because bdi threads are 'bdi_writeback_thread()', so these names are more
consistent.
This patch also amends commentaries and makes them refer the forker and bdi
threads as "thread", not "task".
Also, while on it, make 'bdi_add_default_flusher_thread()' declaration use
'static void' instead of 'void static' and make checkpatch.pl happy.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
83ba7b07 cleans up the writeback.
So we don't use wb any more in get_next_work_item.
Let's remove unnecessary argument.
CC: Christoph Hellwig <hch@lst.de>
Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
SPLICE_F_NONBLOCK is clearly documented to only affect blocking on the
pipe. In __generic_file_splice_read(), however, it causes an EAGAIN
if the page is currently being read.
This makes it impossible to write an application that only wants
failure if the pipe is full. For example if the same process is
handling both ends of a pipe and isn't otherwise able to determine
whether a splice to the pipe will fill it or not.
We could make the read non-blocking on O_NONBLOCK or some other splice
flag, but for now this is the simplest fix.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
CC: stable@kernel.org
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
The open and release block_device_operations are currently
called with the BKL held. In order to change that, we must
first make sure that all drivers that currently rely
on this have no regressions.
This blindly pushes the BKL into all .open and .release
operations for all block drivers to prepare for the
next step. The drivers can subsequently replace the BKL
with their own locks or remove it completely when it can
be shown that it is not needed.
The functions blkdev_get and blkdev_put are the only
remaining users of the big kernel lock in the block
layer, besides a few uses in the ioctl code, none
of which need to serialize with blkdev_{get,put}.
Most of these two functions is also under the protection
of bdev->bd_mutex, including the actual calls to
->open and ->release, and the common code does not
access any global data structures that need the BKL.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Tracing high level background writeback events is good, but it doesn't
give the entire picture. Add visibility into write throttling to catch IO
dispatched by foreground throttling of processing dirtying lots of pages.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Trace queue/sched/exec parts of the writeback loop. This provides
insight into when and why flusher threads are scheduled to run. e.g
a sync invocation leaves traces like:
sync-[...]: writeback_queue: bdi 8:0: sb_dev 8:1 nr_pages=7712 sync_mode=0 kupdate=0 range_cyclic=0 background=0
flush-8:0-[...]: writeback_exec: bdi 8:0: sb_dev 8:1 nr_pages=7712 sync_mode=0 kupdate=0 range_cyclic=0 background=0
This also lays the foundation for adding more writeback tracing to
provide deeper insight into the whole writeback path.
The original tracing code is from Jens Axboe, though this version is
a rewrite as a result of the code being traced changing
significantly.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
No real bugs I believe, just some dead code, and some
shut up code.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Move all code for the writeback thread into fs/fs-writeback.c instead of
splitting it over two functions in two files.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
The wb_list member of struct backing_device_info always has exactly one
element. Just use the direct bdi->wb pointer instead and simplify some
code.
Also remove bdi_task_init which is now trivial to prepare for the next
patch.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Remove the current bio flags and reuse the request flags for the bio, too.
This allows to more easily trace the type of I/O from the filesystem
down to the block driver. There were two flags in the bio that were
missing in the requests: BIO_RW_UNPLUG and BIO_RW_AHEAD. Also I've
renamed two request flags that had a superflous RW in them.
Note that the flags are in bio.h despite having the REQ_ name - as
blkdev.h includes bio.h that is the only way to go for now.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
A barrier request should by defintion have priority in get_request
and let the queue be unplugged immediately as it's blocking all forward
progress due to the queue draining.
Most filesystems already get this implicitly by the way how submit_bh
treats the buffer_ordered flag, and gfs2 sets it explicitly. But btrfs
and XFS are still forgetting to set the flag, as is blkdev_issue_flush
and some places in DM/MD.
For XFS on metadata heavy workloads this gives a consistent speedup
in the 2-3% range.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Commit f9d7562fdb "nfsd4: share file
descriptors between stateid's" didn't correctly account for O_RDWR opens.
Symptoms include leaked files, resulting in failures to unmount and/or
warnings about orphaned inodes on reboot.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
It's harmless to set this after the server is created, but also
ineffective, since the value is only used at the time of
svc_create_pooled(). So fail the attempt, in keeping with the pattern
set by write_versions, write_{lease,grace}time and write_recoverydir.
(This could break userspace that tried to write to nfsd/max_block_size
between setting up sockets and starting the server. However, such code
wouldn't have worked anyway, and I don't know of any examples--rpc.nfsd
in nfs-utils, probably the only user of the interface, doesn't do that.)
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Commit 59db4a0c10 "nfsd: move more into
nfsd_startup()" inadvertently moved nfsd_versions after
nfsd_create_svc(). On older distributions using an rpc.nfsd that does
not explicitly set the list of nfsd versions, this results in
svc-create_pooled() being called with an empty versions array. The
resulting incomplete initialization leads to a NULL dereference in
svc_process_common() the first time a client accesses the server.
Move nfsd_reset_versions() back before the svc_create_pooled(); this
time, put it closer to the svc_create_pooled() call, to make this
mistake more difficult in the future.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
If a callback is retried at nfsd4_cb_recall_done() due to
some error, the returned rpc reply crashes here:
@@ -514,6 +514,7 @@ decode_cb_sequence(struct xdr_stream *xdr, struct nfsd4_cb_sequence *res,
u32 dummy;
__be32 *p;
+ BUG_ON(!res);
if (res->cbs_minorversion == 0)
return 0;
[BUG_ON added for demonstration]
This is because the nfsd4_cb_done_sequence() has NULLed out
the task->tk_msg.rpc_resp pointer.
Also eventually the rpc would use the new slot without making
sure it is free by calling nfsd41_cb_setup_sequence().
This problem was introduced by a 4.1 protocol addition patch:
[0421b5c5] nfsd41: Backchannel: Implement cb_recall over NFSv4.1
Which was overlooking the possibility of an RPC callback retries.
For not-4.1 case redoing the _prepare is harmless.
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Al Viro
Christoph Hellwig
Boaz Harrosh
Christoph Hellwig
Lino Sanfilippo
Julia Lawall
Tyler Hicks
Prarit Bhargava
Frederic Weisbecker
Arnd Bergmann
David Woodhouse
Bill Pemberton
Linus Torvalds
David Howells
Artem Bityutskiy
Jens Axboe
Minchan Kim
Miklos Szeredi
Dave Chinner
Dave Chinner
Andi Kleen
J. Bruce Fields
J. Bruce Fields