There's no reason to call rcu_barrier() on every
deactivate_locked_super(). We only need to make sure that all delayed rcu
free inodes are flushed before we destroy related cache.
Removing rcu_barrier() from deactivate_locked_super() affects some fast
paths. E.g. on my machine exit_group() of a last process in IPC
namespace takes 0.07538s. rcu_barrier() takes 0.05188s of that time.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Merge tag 'squashfs-updates' of git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-next
Pull squashfs updates from Phillip Lougher:
"Add an extra mount time sanity check, plus some code cleanups and bug
fixes."
* tag 'squashfs-updates' of git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-next:
Squashfs: add mount time sanity check for block_size and block_log match
Squashfs: fix f_pos check in get_dir_index_using_offset
Squashfs: get rid of obsolete definitions in header file
Squashfs: remove redundant length initialisation in squashfs_lookup
Squashfs: remove redundant length initialisation in squashfs_readdir
Squashfs: update comment removing reference to zlib only
Squashfs: use define instead of constant
Squashfs currently has a sanity check for block_size less than or
equal to the maximum block_size (1 Mbyte). This catches some
superblock corruption, but obviously with a block_size maximum
of 1 Mbyte there's 7 correct values (4K, 8K, 16K, 32K, ... etc) and
a lot of incorrect values which are not caught by this check.
The Squashfs superblock, however, has both a block_size and
a block_log (2^block_log == block_size). Checking that the block_size
matches the block_log is a much more robust check. Corruption of the
superblock is unlikely to produce values which match, and it also
ensures the block_size is an exact power of two.
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Seeing that just about every destructor got that INIT_LIST_HEAD() copied into
it, there is no point whatsoever keeping this INIT_LIST_HEAD in inode_init_once();
the cost of taking it into inode_init_always() will be negligible for pipes
and sockets and negative for everything else. Not to mention the removal of
boilerplate code from ->destroy_inode() instances...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
A Squashfs filesystem containing nothing but an empty directory,
although unusual and ultimately pointless, is still valid.
The directory_table >= next_table sanity check rejects these
filesystems as invalid because the directory_table is empty and
equal to next_table.
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
This commit adds an option to set the device block size used to 4K.
By default Squashfs sets the device block size (sb_min_blocksize) to 1K
or the smallest block size supported by the block device (if larger).
This, because blocks are packed together and unaligned in Squashfs,
should reduce latency.
This, however, gives poor performance on MTD NAND devices where
the optimal I/O size is 4K (even though the devices can support
smaller block sizes).
Using a 4K device block size may also improve overall I/O
performance for some file access patterns (e.g. sequential
accesses of files in filesystem order) on all media.
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
My existing email address may stop working in a month or two, so update
email to one that will continue working.
Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
Fsfuzzer generates corrupted filesystems which throw a warn_on in
kmalloc. One of these is due to a corrupted superblock fragments field.
Fix this by checking that the number of bytes to be read (and allocated)
does not extend into the next filesystem structure.
Also add a couple of other sanity checks of the mount-time fragment table
structures.
Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
Fsfuzzer generates corrupted filesystems which throw a warn_on in
kmalloc. One of these is due to a corrupted superblock inodes field.
Fix this by checking that the number of bytes to be read (and allocated)
does not extend into the next filesystem structure.
Also add a couple of other sanity checks of the mount-time lookup table
structures.
Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
Fsfuzzer generates corrupted filesystems which throw a warn_on in
kmalloc. One of these is due to a corrupted superblock no_ids field.
Fix this by checking that the number of bytes to be read (and allocated)
does not extend into the next filesystem structure.
Also add a couple of other sanity checks of the mount-time id table
structures.
Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
Reverse order of table reading from mostly first to last in placement
order, to last to first. This is to enable extra superblock sanity
checks to be added in later patches.
Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
Squashfs_get_sb() to squashfs_mount() conversion (commit 152a0836)
results in line over 80 characters.
Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
Extend decompressor framework to handle compression options stored in
the filesystem. These options can be used by the relevant decompressor
at initialisation time to over-ride defaults.
The presence of compression options in the filesystem is indicated by
the COMP_OPT filesystem flag. If present the data is read from the
filesystem and passed to the decompressor init function. The decompressor
init function signature has been extended to take this data.
Also update the init function signature in the glib, lzo and xz
decompressor wrappers.
Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
RCU free the struct inode. This will allow:
- Subsequent store-free path walking patch. The inode must be consulted for
permissions when walking, so an RCU inode reference is a must.
- sb_inode_list_lock to be moved inside i_lock because sb list walkers who want
to take i_lock no longer need to take sb_inode_list_lock to walk the list in
the first place. This will simplify and optimize locking.
- Could remove some nested trylock loops in dcache code
- Could potentially simplify things a bit in VM land. Do not need to take the
page lock to follow page->mapping.
The downsides of this is the performance cost of using RCU. In a simple
creat/unlink microbenchmark, performance drops by about 10% due to inability to
reuse cache-hot slab objects. As iterations increase and RCU freeing starts
kicking over, this increases to about 20%.
In cases where inode lifetimes are longer (ie. many inodes may be allocated
during the average life span of a single inode), a lot of this cache reuse is
not applicable, so the regression caused by this patch is smaller.
The cache-hot regression could largely be avoided by using SLAB_DESTROY_BY_RCU,
however this adds some complexity to list walking and store-free path walking,
so I prefer to implement this at a later date, if it is shown to be a win in
real situations. I haven't found a regression in any non-micro benchmark so I
doubt it will be a problem.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
The BKL is only used in put_super and fill_super, which are both protected
by the superblocks s_umount rw_semaphore. Therefore it is safe to remove
the BKL entirely.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Phillip Lougher <phillip@lougher.demon.co.uk>
This patch is a preparation necessary to remove the BKL from do_new_mount().
It explicitly adds calls to lock_kernel()/unlock_kernel() around
get_sb/fill_super operations for filesystems that still uses the BKL.
I've read through all the code formerly covered by the BKL inside
do_kern_mount() and have satisfied myself that it doesn't need the BKL
any more.
do_kern_mount() is already called without the BKL when mounting the rootfs
and in nfsctl. do_kern_mount() calls vfs_kern_mount(), which is called
from various places without BKL: simple_pin_fs(), nfs_do_clone_mount()
through nfs_follow_mountpoint(), afs_mntpt_do_automount() through
afs_mntpt_follow_link(). Both later functions are actually the filesystems
follow_link inode operation. vfs_kern_mount() is calling the specified
get_sb function and lets the filesystem do its job by calling the given
fill_super function.
Therefore I think it is safe to push down the BKL from the VFS to the
low-level filesystems get_sb/fill_super operation.
[arnd: do not add the BKL to those file systems that already
don't use it elsewhere]
Signed-off-by: Jan Blunck <jblunck@infradead.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Christoph Hellwig <hch@infradead.org>
Add new extended inode types that store the xattr_id field.
Also add the necessary code changes to make xattrs visibile.
Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
This patch adds support for mapping xattr ids (stored in inodes)
into the on-disk location of the xattrs themselves.
Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
Fix warn_on triggered by mounting a fsfuzzer corrupted file system, where
the root inode has been corrupted.
Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
Reported-by: Steve Grubb <sgrubb@redhat.com>
This adds a decompressor framework which allows multiple compression
algorithms to be cleanly supported.
Also update zlib wrapper and other code to use the new framework.
Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
Move zlib buffer init/destroy code into separate wrapper file. Also
make zlib z_stream field a void * removing the need to include zlib.h
for most files.
Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
* Remove smp_lock.h from files which don't need it (including some headers!)
* Add smp_lock.h to files which do need it
* Make smp_lock.h include conditional in hardirq.h
It's needed only for one kernel_locked() usage which is under CONFIG_PREEMPT
This will make hardirq.h inclusion cheaper for every PREEMPT=n config
(which includes allmodconfig/allyesconfig, BTW)
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Move BKL into ->put_super from the only caller. A couple of
filesystems had trivial enough ->put_super (only kfree and NULLing of
s_fs_info + stuff in there) to not get any locking: coda, cramfs, efs,
hugetlbfs, omfs, qnx4, shmem, all others got the full treatment. Most
of them probably don't need it, but I'd rather sort that out individually.
Preferably after all the other BKL pushdowns in that area.
[AV: original used to move lock_super() down as well; these changes are
removed since we don't do lock_super() at all in generic_shutdown_super()
now]
[AV: fuse, btrfs and xfs are known to need no damn BKL, exempt]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Normally the block size (by default 128K) will be larger than the
page size, unless a non-standard block size has been specified in
Mksquashfs, and the page size is larger than 4K.
Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
Make squashfs return f_fsid info for statfs(2).
Signed-off-by: Coly Li <coly.li@suse.de>
Cc: Phillip Lougher <phillip@lougher.demon.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This fixes a code regression caused by the recent mainlining changes.
The recent code changes call zlib_inflate repeatedly, decompressing into
separate 4K buffers, this code didn't check for the possibility that
zlib_inflate might ask for too many buffers when decompressing corrupted
data.
Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
Use the standard magic.h for btrfs and squashfs.
Signed-off-by: Qinghuang Feng <qhfeng.kernel@gmail.com>
Cc: Phillip Lougher <phillip@lougher.demon.co.uk>
Cc: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kirill A. Shutemov