Commit Graph

105 Commits

Author SHA1 Message Date
Linus Torvalds 96e80a7851 Merge git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-next
* git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-next:
  Squashfs: fix i_blocks calculation with extended regular files
  Squashfs: fix mount time sanity check for corrupted superblock
  Squashfs: optimise squashfs_cache_get entry search
  Squashfs: Update documentation to include xattrs
  Squashfs: add missing block release on error condition
2012-01-13 10:34:57 -08:00
Al Viro 6b520e0565 vfs: fix the stupidity with i_dentry in inode destructors
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>
2012-01-03 22:52:40 -05:00
Phillip Lougher 3d4a1c80c4 Squashfs: fix i_blocks calculation with extended regular files
The le64_to_cpu() forces the calculation to be unsigned, with
the effect that it can underflow leading to an incorrect large
value.

This bug only triggers in rare(ish) circumstances, an empty file
encoded as an extended regular file or a completely sparse file.
Normally empty files are encoded as a regular file rather than as
an extended regular file (and the regular file i_blocks calculation
doesn't have this bug).  To save space regular file inodes are
optimised to encode the most commonly occurring files.  Less
common regular files are encoded using extended regular file inodes
which contain extra information.

Empty files with nlinks greater than 1, and or empty files
with extended attributes are encoded using extended regular file
inodes and they will hit this bug.

Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
2012-01-03 04:00:43 +00:00
Phillip Lougher cc37f75a9f Squashfs: fix mount time sanity check for corrupted superblock
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>
2012-01-02 17:47:14 +00:00
Ajeet Yadav d7fbd89338 Squashfs: optimise squashfs_cache_get entry search
squashfs_cache_get() iterates over all entries to search for
 block its looking for. Often get() / put() are called for
 same block.

If we cache the current entry index, then we can optimise the
subsequent *_get() calls.

Signed-off-by: Ajeet Yadav <ajeet.yadav.77@gmail.com>
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
2011-12-30 01:24:13 +00:00
Phillip Lougher e552a59668 Squashfs: add missing block release on error condition
squashfs_read_metadata forgets to release the cache block if
an error has occurred.

Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
2011-12-30 01:20:14 +00:00
Linus Torvalds 044595d4e4 Merge git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-next
* git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-next:
  Squashfs: Add an option to set dev block size to 4K
2011-11-04 16:48:37 -07:00
Phillip Lougher 7657cacf47 Squashfs: Add an option to set dev block size to 4K
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>
2011-11-02 17:25:50 +00:00
Miklos Szeredi bfe8684869 filesystems: add set_nlink()
Replace remaining direct i_nlink updates with a new set_nlink()
updater function.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Tested-by: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2011-11-02 12:53:43 +01:00
Paul Bolle 395cf9691d doc: fix broken references
There are numerous broken references to Documentation files (in other
Documentation files, in comments, etc.). These broken references are
caused by typo's in the references, and by renames or removals of the
Documentation files. Some broken references are simply odd.

Fix these broken references, sometimes by dropping the irrelevant text
they were part of.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-09-27 18:08:04 +02:00
Linus Torvalds 91d44d9999 Merge git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-linus
* git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-linus:
  Squashfs: Make ZLIB compression support optional
  Squashfs: Update documentation for XZ and add squashfs-tools devel tree
2011-07-25 22:50:35 -07:00
Phillip Lougher cc6d349714 Squashfs: Make ZLIB compression support optional
Squashfs now supports XZ and LZO compression in addition to ZLIB.
As such it no longer makes sense to always include ZLIB support.
In particular embedded systems may only use LZO or XZ compression, and
the ability to exclude ZLIB support will reduce kernel size.

Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
2011-07-22 03:01:28 +01:00
Al Viro a9049376ee make d_splice_alias(ERR_PTR(err), dentry) = ERR_PTR(err)
... and simplify the living hell out of callers

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 01:44:26 -04:00
Al Viro 0c1aa9a952 deuglify squashfs_lookup()
d_splice_alias(NULL, dentry) is equivalent to d_add(dentry, NULL), NULL
so no need for that if (inode) ... in there (or ERR_PTR(0), for that
matter)

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 01:44:24 -04:00
Linus Torvalds 2ff55e98d6 Merge git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-linus
* git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-linus:
  Squashfs: Fix sanity check patches on big-endian systems
2011-05-29 11:19:45 -07:00
Phillip Lougher d5b72ce15e Squashfs: Fix sanity check patches on big-endian systems
le64 values should be swapped when accessing on
big-endian systems.

Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
2011-05-29 10:03:09 +01:00
Linus Torvalds bc9bc72e2f Merge git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-linus
* git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-linus:
  Squashfs: update email address
  Squashfs: add extra sanity checks at mount time
  Squashfs: add sanity checks to fragment reading at mount time
  Squashfs: add sanity checks to lookup table reading at mount time
  Squashfs: add sanity checks to id reading at mount time
  Squashfs: add sanity checks to xattr reading at mount time
  Squashfs: reverse order of filesystem table reading
  Squashfs: move table allocation into squashfs_read_table()
2011-05-26 17:27:35 -07:00
Phillip Lougher d7f2ff6718 Squashfs: update email address
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>
2011-05-26 10:49:11 +01:00
Phillip Lougher 1094a4a611 Squashfs: add extra sanity checks at mount time
Add some extra sanity checks of the inode and directory structures.

Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
2011-05-25 18:21:33 +01:00
Phillip Lougher 1cac63cc9b Squashfs: add sanity checks to fragment reading at mount time
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>
2011-05-25 18:21:33 +01:00
Phillip Lougher ac51a0a713 Squashfs: add sanity checks to lookup table reading at mount time
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>
2011-05-25 18:21:32 +01:00
Phillip Lougher 37986f63c8 Squashfs: add sanity checks to id reading at mount time
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>
2011-05-25 18:21:32 +01:00
Phillip Lougher 6f04864515 Squashfs: add sanity checks to xattr reading at mount time
These checks add sanity checking of the mount-time xattr structures.

Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
2011-05-25 18:21:31 +01:00
Phillip Lougher 76e002f755 Squashfs: reverse order of filesystem table reading
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>
2011-05-25 18:21:31 +01:00
Phillip Lougher 82de647e1f Squashfs: move table allocation into squashfs_read_table()
This eliminates a lot of duplicate code.

Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
2011-05-25 18:21:31 +01:00
Justin P. Mattock 70f23fd66b treewide: fix a few typos in comments
- kenrel -> kernel
- whetehr -> whether
- ttt -> tt
- sss -> ss

Signed-off-by: Justin P. Mattock <justinmattock@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-05-10 10:16:21 +02:00
Lucas De Marchi 25985edced Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 11:26:23 -03:00
Phillip Lougher 117a91e0f2 Squashfs: Use vmalloc rather than kmalloc for zlib workspace
Bugzilla bug 31422 reports occasional "page allocation failure. order:4"
at Squashfs mount time.  Fix this by making zlib workspace allocation
use vmalloc rather than kmalloc.

Reported-by: Mehmet Giritli <mehmet@giritli.eu>
Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
2011-03-22 23:01:26 +00:00
Phillip Lougher 44cff8a9ee Squashfs: handle corruption of directory structure
Handle the rare case where a directory metadata block is uncompressed and
corrupted, leading to a kernel oops in directory scanning (memcpy).
Normally corruption is detected at the decompression stage and dealt with
then, however, this will not happen if:

- metadata isn't compressed (users can optionally request no metadata
  compression), or
- the compressed metadata block was larger than the original, in which
  case the uncompressed version was used, or
- the data was corrupt after decompression

This patch fixes this by adding some sanity checks against known maximum
values.

Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
2011-03-16 01:04:18 +00:00
Phillip Lougher 003a3194d3 Squashfs: wrap squashfs_mount() definition
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>
2011-02-28 18:43:48 +00:00
Phillip Lougher 3ad126641c Squashfs: xz_wrapper doesn't need to include squashfs_fs_i.h anymore
Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
2011-02-28 18:35:44 +00:00
Phillip Lougher 681ffe2e43 Squashfs: Update Kconfig help text to include xz compression
Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
2011-02-28 18:35:28 +00:00
Phillip Lougher ff750311d3 Squashfs: add compression options support to xz decompressor
Pass the dictionary size used to compress datablocks.  Using a
dictionary size less than the block size saves memory overhead, in many
cases without adversely affecting compression ratio.

Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
2011-02-28 18:34:24 +00:00
Phillip Lougher b7fc0ff09d Squashfs: extend decompressor framework to handle compression options
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>
2011-02-28 18:21:59 +00:00
Phillip Lougher 3689456b4b squashfs: fix use of uninitialised variable in zlib & xz decompressors
Fix potential use of uninitialised variable caused by recent
decompressor code optimisations.

In zlib_uncompress (zlib_wrapper.c) we have

	int zlib_err, zlib_init = 0;
	...
	do {
		...
			if (avail == 0) {
				offset = 0;
				put_bh(bh[k++]);
				continue;
			}
		...
		zlib_err = zlib_inflate(stream, Z_SYNC_FLUSH);
		...
	} while (zlib_err == Z_OK);

If continue is executed (avail == 0) then the while condition will be
evaluated testing zlib_err, which is uninitialised first time around the
loop.

Fix this by getting rid of the 'if (avail == 0)' condition test, this
edge condition should not be being handled in the decompressor code, and
instead handle it generically in the caller code.

Similarly for xz_wrapper.c.

Incidentally, on most architectures (bar Mips and Parisc), no
uninitialised variable warning is generated by gcc, this is because the
while condition test on continue is optimised out and not performed
(when executing continue zlib_err has not been changed since entering
the loop, and logically if the while condition was true previously, then
it's still true).

Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
Reported-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-26 10:50:05 +10:00
Phillip Lougher 01a678c5a2 Squashfs: simplify CONFIG_SQUASHFS_LZO handling
Get rid of messy repeated #if(n)def CONFIG_SQUASHFS_LZO code
in decompressor.c

Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
2011-01-13 21:38:46 +00:00
Phillip Lougher 8fcd97216f Squashfs: move squashfs_i() definition from squashfs.h
Move squashfs_i() definition out of squashfs.h, this eliminates
the need to #include squashfs_fs_i.h from numerous files.

Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
2011-01-13 21:24:15 +00:00
Phillip Lougher 6197fd8678 Squashfs: get rid of default n in Kconfig
As pointed out by Geert Uytterhoeven, "default n" is the default,
no reason to specify it.

Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
2011-01-13 21:21:52 +00:00
Phillip Lougher e7ee11f0ec Squashfs: add missing check in zlib_wrapper
On file system corruption zlib can return Z_STREAM_OK with
input buffers remaining, which will not be released.

Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
2011-01-13 21:21:00 +00:00
Phillip Lougher 170cf02165 Squashfs: remove unnecessary variable in zlib_wrapper
Get rid of unnecessary bytes variable, and remove redundant
initialisation of zlib_err.

Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
2011-01-13 21:20:52 +00:00
Phillip Lougher 7a43ae5237 Squashfs: Add XZ compression configuration option
Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
2011-01-13 21:16:52 +00:00
Phillip Lougher 81bb8debd0 Squashfs: add XZ compression support
Add support for reading file systems compressed with the
XZ compression algorithm.

This patch adds the XZ decompressor wrapper code.

Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
2011-01-13 20:51:20 +00:00
Nick Piggin fa0d7e3de6 fs: icache RCU free inodes
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>
2011-01-07 17:50:26 +11:00
Linus Torvalds 162164f7e9 Merge git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-linus
* git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-linus:
  Squashfs: fix function prototype
  Squashfs: fix use of __le64 annotated variable
2010-10-29 08:48:58 -07:00
Al Viro 152a083666 new helper: mount_bdev()
... and switch of the obvious get_sb_bdev() users to ->mount()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-29 04:16:13 -04:00
Phillip Lougher 5f3b321da1 Squashfs: fix function prototype
The fourth argument should be unsigned.  Also add missing include
so that the function prototype is defined in xattr_id.c

This fixes a couple of sparse warnings.

Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
2010-10-28 17:44:19 +01:00
Phillip Lougher 07724586b4 Squashfs: fix use of __le64 annotated variable
This fixes a sparse with endian checking warning.

Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
2010-10-28 17:44:11 +01:00
Linus Torvalds 092e0e7e52 Merge branch 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl
* 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
  vfs: make no_llseek the default
  vfs: don't use BKL in default_llseek
  llseek: automatically add .llseek fop
  libfs: use generic_file_llseek for simple_attr
  mac80211: disallow seeks in minstrel debug code
  lirc: make chardev nonseekable
  viotape: use noop_llseek
  raw: use explicit llseek file operations
  ibmasmfs: use generic_file_llseek
  spufs: use llseek in all file operations
  arm/omap: use generic_file_llseek in iommu_debug
  lkdtm: use generic_file_llseek in debugfs
  net/wireless: use generic_file_llseek in debugfs
  drm: use noop_llseek
2010-10-22 10:52:56 -07:00
Arnd Bergmann 6038f373a3 llseek: automatically add .llseek fop
All file_operations should get a .llseek operation so we can make
nonseekable_open the default for future file operations without a
.llseek pointer.

The three cases that we can automatically detect are no_llseek, seq_lseek
and default_llseek. For cases where we can we can automatically prove that
the file offset is always ignored, we use noop_llseek, which maintains
the current behavior of not returning an error from a seek.

New drivers should normally not use noop_llseek but instead use no_llseek
and call nonseekable_open at open time.  Existing drivers can be converted
to do the same when the maintainer knows for certain that no user code
relies on calling seek on the device file.

The generated code is often incorrectly indented and right now contains
comments that clarify for each added line why a specific variant was
chosen. In the version that gets submitted upstream, the comments will
be gone and I will manually fix the indentation, because there does not
seem to be a way to do that using coccinelle.

Some amount of new code is currently sitting in linux-next that should get
the same modifications, which I will do at the end of the merge window.

Many thanks to Julia Lawall for helping me learn to write a semantic
patch that does all this.

===== begin semantic patch =====
// This adds an llseek= method to all file operations,
// as a preparation for making no_llseek the default.
//
// The rules are
// - use no_llseek explicitly if we do nonseekable_open
// - use seq_lseek for sequential files
// - use default_llseek if we know we access f_pos
// - use noop_llseek if we know we don't access f_pos,
//   but we still want to allow users to call lseek
//
@ open1 exists @
identifier nested_open;
@@
nested_open(...)
{
<+...
nonseekable_open(...)
...+>
}

@ open exists@
identifier open_f;
identifier i, f;
identifier open1.nested_open;
@@
int open_f(struct inode *i, struct file *f)
{
<+...
(
nonseekable_open(...)
|
nested_open(...)
)
...+>
}

@ read disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
<+...
(
   *off = E
|
   *off += E
|
   func(..., off, ...)
|
   E = *off
)
...+>
}

@ read_no_fpos disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
... when != off
}

@ write @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
<+...
(
  *off = E
|
  *off += E
|
  func(..., off, ...)
|
  E = *off
)
...+>
}

@ write_no_fpos @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
... when != off
}

@ fops0 @
identifier fops;
@@
struct file_operations fops = {
 ...
};

@ has_llseek depends on fops0 @
identifier fops0.fops;
identifier llseek_f;
@@
struct file_operations fops = {
...
 .llseek = llseek_f,
...
};

@ has_read depends on fops0 @
identifier fops0.fops;
identifier read_f;
@@
struct file_operations fops = {
...
 .read = read_f,
...
};

@ has_write depends on fops0 @
identifier fops0.fops;
identifier write_f;
@@
struct file_operations fops = {
...
 .write = write_f,
...
};

@ has_open depends on fops0 @
identifier fops0.fops;
identifier open_f;
@@
struct file_operations fops = {
...
 .open = open_f,
...
};

// use no_llseek if we call nonseekable_open
////////////////////////////////////////////
@ nonseekable1 depends on !has_llseek && has_open @
identifier fops0.fops;
identifier nso ~= "nonseekable_open";
@@
struct file_operations fops = {
...  .open = nso, ...
+.llseek = no_llseek, /* nonseekable */
};

@ nonseekable2 depends on !has_llseek @
identifier fops0.fops;
identifier open.open_f;
@@
struct file_operations fops = {
...  .open = open_f, ...
+.llseek = no_llseek, /* open uses nonseekable */
};

// use seq_lseek for sequential files
/////////////////////////////////////
@ seq depends on !has_llseek @
identifier fops0.fops;
identifier sr ~= "seq_read";
@@
struct file_operations fops = {
...  .read = sr, ...
+.llseek = seq_lseek, /* we have seq_read */
};

// use default_llseek if there is a readdir
///////////////////////////////////////////
@ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier readdir_e;
@@
// any other fop is used that changes pos
struct file_operations fops = {
... .readdir = readdir_e, ...
+.llseek = default_llseek, /* readdir is present */
};

// use default_llseek if at least one of read/write touches f_pos
/////////////////////////////////////////////////////////////////
@ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read.read_f;
@@
// read fops use offset
struct file_operations fops = {
... .read = read_f, ...
+.llseek = default_llseek, /* read accesses f_pos */
};

@ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write.write_f;
@@
// write fops use offset
struct file_operations fops = {
... .write = write_f, ...
+	.llseek = default_llseek, /* write accesses f_pos */
};

// Use noop_llseek if neither read nor write accesses f_pos
///////////////////////////////////////////////////////////

@ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
identifier write_no_fpos.write_f;
@@
// write fops use offset
struct file_operations fops = {
...
 .write = write_f,
 .read = read_f,
...
+.llseek = noop_llseek, /* read and write both use no f_pos */
};

@ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write_no_fpos.write_f;
@@
struct file_operations fops = {
... .write = write_f, ...
+.llseek = noop_llseek, /* write uses no f_pos */
};

@ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
@@
struct file_operations fops = {
... .read = read_f, ...
+.llseek = noop_llseek, /* read uses no f_pos */
};

@ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
@@
struct file_operations fops = {
...
+.llseek = noop_llseek, /* no read or write fn */
};
===== End semantic patch =====

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Julia Lawall <julia@diku.dk>
Cc: Christoph Hellwig <hch@infradead.org>
2010-10-15 15:53:27 +02:00
Arnd Bergmann 3dbc4b32d0 BKL: Remove BKL from squashfs
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>
2010-10-04 21:10:50 +02:00