#include "reiserfs.h" #include /* * The previous reiserfs locking scheme was heavily based on * the tricky properties of the Bkl: * * - it was acquired recursively by a same task * - the performances relied on the release-while-schedule() property * * Now that we replace it by a mutex, we still want to keep the same * recursive property to avoid big changes in the code structure. * We use our own lock_owner here because the owner field on a mutex * is only available in SMP or mutex debugging, also we only need this field * for this mutex, no need for a system wide mutex facility. * * Also this lock is often released before a call that could block because * reiserfs performances were partially based on the release while schedule() * property of the Bkl. */ void reiserfs_write_lock(struct super_block *s) { struct reiserfs_sb_info *sb_i = REISERFS_SB(s); if (sb_i->lock_owner != current) { mutex_lock(&sb_i->lock); sb_i->lock_owner = current; } /* No need to protect it, only the current task touches it */ sb_i->lock_depth++; } void reiserfs_write_unlock(struct super_block *s) { struct reiserfs_sb_info *sb_i = REISERFS_SB(s); /* * Are we unlocking without even holding the lock? * Such a situation must raise a BUG() if we don't want * to corrupt the data. */ BUG_ON(sb_i->lock_owner != current); if (--sb_i->lock_depth == -1) { sb_i->lock_owner = NULL; mutex_unlock(&sb_i->lock); } } int __must_check reiserfs_write_unlock_nested(struct super_block *s) { struct reiserfs_sb_info *sb_i = REISERFS_SB(s); int depth; /* this can happen when the lock isn't always held */ if (sb_i->lock_owner != current) return -1; depth = sb_i->lock_depth; sb_i->lock_depth = -1; sb_i->lock_owner = NULL; mutex_unlock(&sb_i->lock); return depth; } void reiserfs_write_lock_nested(struct super_block *s, int depth) { struct reiserfs_sb_info *sb_i = REISERFS_SB(s); /* this can happen when the lock isn't always held */ if (depth == -1) return; mutex_lock(&sb_i->lock); sb_i->lock_owner = current; sb_i->lock_depth = depth; } /* * Utility function to force a BUG if it is called without the superblock * write lock held. caller is the string printed just before calling BUG() */ void reiserfs_check_lock_depth(struct super_block *sb, char *caller) { struct reiserfs_sb_info *sb_i = REISERFS_SB(sb); WARN_ON(sb_i->lock_depth < 0); } #ifdef CONFIG_REISERFS_CHECK void reiserfs_lock_check_recursive(struct super_block *sb) { struct reiserfs_sb_info *sb_i = REISERFS_SB(sb); WARN_ONCE((sb_i->lock_depth > 0), "Unwanted recursive reiserfs lock!\n"); } #endif 'search'/>
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authorCihangir Akturk <cakturk@gmail.com>2016-12-17 19:42:17 +0200
committerJonathan Corbet <corbet@lwn.net>2016-12-27 13:08:42 -0700
commit36f671be1db1b17d3d4ab0c8b47f81ccb1efcb75 (patch)
treed79b8821d94660c65279378b04474e23f2e01b22 /include/acpi/platform
parent66115335fbb411365c23349b2fbe7e041eabbaf2 (diff)
Documentation/unaligned-memory-access.txt: fix incorrect comparison operator
In the actual implementation ether_addr_equal function tests for equality to 0 when returning. It seems in commit 0d74c4 it is somehow overlooked to change this operator to reflect the actual function. Signed-off-by: Cihangir Akturk <cakturk@gmail.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Diffstat (limited to 'include/acpi/platform')