/* rwsem.h: R/W semaphores, public interface * * Written by David Howells (dhowells@redhat.com). * Derived from asm-i386/semaphore.h */ #ifndef _LINUX_RWSEM_H #define _LINUX_RWSEM_H #include #include #include #include #include struct rw_semaphore; #ifdef CONFIG_RWSEM_GENERIC_SPINLOCK #include /* use a generic implementation */ #else #include /* use an arch-specific implementation */ #endif /* * lock for reading */ extern void down_read(struct rw_semaphore *sem); /* * trylock for reading -- returns 1 if successful, 0 if contention */ extern int down_read_trylock(struct rw_semaphore *sem); /* * lock for writing */ extern void down_write(struct rw_semaphore *sem); /* * trylock for writing -- returns 1 if successful, 0 if contention */ extern int down_write_trylock(struct rw_semaphore *sem); /* * release a read lock */ extern void up_read(struct rw_semaphore *sem); /* * release a write lock */ extern void up_write(struct rw_semaphore *sem); /* * downgrade write lock to read lock */ extern void downgrade_write(struct rw_semaphore *sem); #ifdef CONFIG_DEBUG_LOCK_ALLOC /* * nested locking. NOTE: rwsems are not allowed to recurse * (which occurs if the same task tries to acquire the same * lock instance multiple times), but multiple locks of the * same lock class might be taken, if the order of the locks * is always the same. This ordering rule can be expressed * to lockdep via the _nested() APIs, but enumerating the * subclasses that are used. (If the nesting relationship is * static then another method for expressing nested locking is * the explicit definition of lock class keys and the use of * lockdep_set_class() at lock initialization time. * See Documentation/lockdep-design.txt for more details.) */ extern void down_read_nested(struct rw_semaphore *sem, int subclass); extern void down_write_nested(struct rw_semaphore *sem, int subclass); /* * Take/release a lock when not the owner will release it. * * [ This API should be avoided as much as possible - the * proper abstraction for this case is completions. ] */ extern void down_read_non_owner(struct rw_semaphore *sem); extern void up_read_non_owner(struct rw_semaphore *sem); #else # define down_read_nested(sem, subclass) down_read(sem) # define down_write_nested(sem, subclass) down_write(sem) # define down_read_non_owner(sem) down_read(sem) # define up_read_non_owner(sem) up_read(sem) #endif #endif /* _LINUX_RWSEM_H */ '>commitdiffstats
path: root/fs/mpage.c
Commit message (Expand)AuthorAgeFilesLines
* Pagecache zeroing: zero_user_segment, zero_user_segments and zero_userChristoph Lameter2008-02-051-5/+2
* mm: buffered write cleanupNick Piggin2007-10-161-8/+2
* Drop 'size' argument from bio_endio and bi_end_ioNeilBrown2007-10-101-10/+2
* consolidate generic_writepages and mpage_writepagesMiklos Szeredi2007-05-111-129/+45
* fs: convert core functions to zero_user_pageNate Diller2007-05-091-10/+5
* Factor outstanding I/O error handlingGuillaume Chazarain2007-05-081-14/+2
* [PATCH] BLOCK: Dissociate generic_writepages() from mpage stuff [try #6]David Howells2006-09-301-0/+2
* [PATCH] writeback: fix range handlingOGAWA Hirofumi2006-06-231-12/+10
* [PATCH] map multiple blocks for mpage_readpages()Badari Pulavarty2006-03-261-19/+85