Reduce some branches and memory accesses in dcache lookup by adding dentry
flags to indicate common d_ops are set, rather than having to check them.
This saves a pointer memory access (dentry->d_op) in common path lookup
situations, and saves another pointer load and branch in cases where we
have d_op but not the particular operation.
Patched with:
git grep -E '[.>]([[:space:]])*d_op([[:space:]])*=' | xargs sed -e 's/\([^\t ]*\)->d_op = \(.*\);/d_set_d_op(\1, \2);/' -e 's/\([^\t ]*\)\.d_op = \(.*\);/d_set_d_op(\&\1, \2);/' -i
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Change d_compare so it may be called from lock-free RCU lookups. This
does put significant restrictions on what may be done from the callback,
however there don't seem to have been any problems with in-tree fses.
If some strange use case pops up that _really_ cannot cope with the
rcu-walk rules, we can just add new rcu-unaware callbacks, which would
cause name lookup to drop out of rcu-walk mode.
For in-tree filesystems, this is just a mechanical change.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
As in other file systems, we can replace the big kernel lock
with a private mutex in isofs. This means we can now access
multiple file systems concurrently, but it also means that
we serialize readdir and lookup across sleeping operations
which previously released the big kernel lock. This should
not matter though, as these operations are in practice
serialized through the hardware access.
The isofs_get_blocks functions now does not take any lock
any more, it used to recursively get the BKL. After looking
at the code for hours, I convinced myself that it was never
needed here anyway, because it only reads constant fields
of the inode and writes to a buffer head array that is
at this time only visible to the caller.
The get_sb and fill_super operations do not need the locking
at all because they operate on a file system that is either
about to be created or to be destroyed but in either case
is not visible to other threads.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Remove unused variables from isofs_sb_info (used to be some mount
options), unify variables for option to use 0/1 (some options used
'y'/'n'), use bit fields for option flags in superblock.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When a directory on isofs is corrupted, we did not check whether length of the
name in a directory entry and the length of the directory entry itself are
consistent. This could lead to possible access beyond the end of buffer when
the length of the name was too big. Add this sanity check to directory
reading code.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Stop the ISOFS filesystem from using read_inode(). Make isofs_read_inode()
return an error code, and make isofs_iget() pass it on.
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Jan Kara <jack@ucw.cz>
Acked-by: Christoph Hellwig <hch@lst.de>
Cc: "Dave Young" <hidave.darkstar@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
shut up those:
fs/isofs/namei.c: In function 'isofs_lookup':
fs/isofs/namei.c:161: warning: 'offset' may be used uninitialized in this function
fs/isofs/namei.c:161: warning: 'block' may be used uninitialized in this function
By the way, they get overwritten at the end of isofs_find_entry().
Signed-off-by: Borislav Petkov <bbpetkov@yahoo.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs/isofs/* had a bunch of CodingStyle issues.
* Indentation was a mix of spaces and tabs
* "int * foo" instead of "int *foo"
* "while ( foo )" instead of "while (foo)"
* if (foo) blah; on one line instead of two
* Missing printk KERN_ levels
* lots of trailing whitespace
* lines >80 columns changed to wrap.
* Unnecessary prototype removed by shuffling code order in C file.
Should be no functional changes other than slight size increase due to
printk changes. Further improvement possible, but this is a start..
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove redundant NULL check in isofs_lookup() as d_splice_alias() can take
NULL inode as input.
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The current isofs treatment of hidden files is flawed in two ways. First,
it does not provide sufficient granularity; it hides both 'hidden' files
and 'associated' files (resource fork for Mac files). Second, the default
behavior to completely strip hidden files, while an admirable
implementation of the spec, is a poor choice given the real world use of
hidden files as a poor mans copy protection scheme for MSDOS and Windows
based systems. A longer description of this is available here:
http://www.uwsg.iu.edu/hypermail/linux/kernel/0205.3/0267.html
This patch was originally built after a few private conversations with Alan
Cox; I shamefully failed to persist in seeing it go forward, I hope to make
amends now.
This patch introduces granularity by allowing explicit control for both
hidden and associated files. It also reverses the default so that by
default, hidden files are treated as regular files on the iso9660 file
system.
This allow Wine to process Windows CDs, including those that are hybrid
Mac/Windows CDs properly and completely, without our having to go muck up
peoples fstabs as we do now. (I have tested this with such a hybrid +
hidden CD and have verified that this patch works as claimed).
Signed-off-by: Jeremy White <jwhite@codeweavers.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
fs/isofs includes trimmed down to something resembling sanity.
Kernel-only parts of linux/iso_fs.h and entire linux/iso_fs_{sb,i}.h
moved to fs/isofs/isofs.h.
A lot of useless #include in fs/isofs/*.c killed.
Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
