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* staging: pohmelfs: remove drivers/staging/pohmelfsEvgeniy Polyakov2012-02-091-120/+0Star
| | | | | | | | New pohmelfs is coming, and it is time to remove deadly old design https://lkml.org/lkml/2012/2/8/293 Signed-off-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* fs: dcache remove dcache_lockNick Piggin2011-01-071-2/+0Star
| | | | | | dcache_lock no longer protects anything. remove it. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
* fs: Use rename lock and RCU for multi-step operationsNick Piggin2011-01-071-3/+12
| | | | | | | | | | | | | | | | | | | | | The remaining usages for dcache_lock is to allow atomic, multi-step read-side operations over the directory tree by excluding modifications to the tree. Also, to walk in the leaf->root direction in the tree where we don't have a natural d_lock ordering. This could be accomplished by taking every d_lock, but this would mean a huge number of locks and actually gets very tricky. Solve this instead by using the rename seqlock for multi-step read-side operations, retry in case of a rename so we don't walk up the wrong parent. Concurrent dentry insertions are not serialised against. Concurrent deletes are tricky when walking up the directory: our parent might have been deleted when dropping locks so also need to check and retry for that. We can also use the rename lock in cases where livelock is a worry (and it is introduced in subsequent patch). Signed-off-by: Nick Piggin <npiggin@kernel.dk>
* fs: fs_struct rwlock to spinlockNick Piggin2010-08-181-4/+4
| | | | | | | | | | | | | | | | | fs: fs_struct rwlock to spinlock struct fs_struct.lock is an rwlock with the read-side used to protect root and pwd members while taking references to them. Taking a reference to a path typically requires just 2 atomic ops, so the critical section is very small. Parallel read-side operations would have cacheline contention on the lock, the dentry, and the vfsmount cachelines, so the rwlock is unlikely to ever give a real parallelism increase. Replace it with a spinlock to avoid one or two atomic operations in typical path lookup fastpath. Signed-off-by: Nick Piggin <npiggin@kernel.dk> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo2010-03-301-1/+0Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | implicit slab.h inclusion from percpu.h 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>
* Staging: pohmelfs: should include fs_struct.hAlexander Beregalov2009-04-031-1/+1
| | | | | | | | | | | | | | | | | drivers/staging/pohmelfs/path_entry.c: In function 'pohmelfs_construct_path_string': drivers/staging/pohmelfs/path_entry.c:48: error: dereferencing pointer to incomplete type drivers/staging/pohmelfs/path_entry.c:49: error: dereferencing pointer to incomplete type drivers/staging/pohmelfs/path_entry.c:50: error: dereferencing pointer to incomplete type drivers/staging/pohmelfs/path_entry.c: In function 'pohmelfs_path_length': drivers/staging/pohmelfs/path_entry.c:95: error: dereferencing pointer to incomplete type drivers/staging/pohmelfs/path_entry.c:96: error: dereferencing pointer to incomplete type drivers/staging/pohmelfs/path_entry.c:97: error: dereferencing pointer to incomplete type Signed-off-by: Alexander Beregalov <a.beregalov@gmail.com> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* Staging: pohmelfs: directory operations.Evgeniy Polyakov2009-04-031-0/+114
This patch implementes all supported directory operations like directory reading, object lookup, creation, removal and so on. Currently object removal is not optimized at all. Signed-off-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>