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authorLinus Torvalds <torvalds@linux-foundation.org>2013-11-21 02:25:39 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2013-11-21 02:25:39 +0400
commitb5898cd057001336888b6aff601385b5f5e79b01 (patch)
tree80f456b6b879c84800f7006e98b29e9c6bdd3831 /include
parent2a46eed54a28c1e3de701ca4237ce4f8bebf14c6 (diff)
parent31dec1327e377b6d91a8a6c92b5cd8513939a233 (diff)
downloadlinux-b5898cd057001336888b6aff601385b5f5e79b01.tar.xz
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs bits and pieces from Al Viro: "Assorted bits that got missed in the first pull request + fixes for a couple of coredump regressions" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fold try_to_ascend() into the sole remaining caller dcache.c: get rid of pointless macros take read_seqbegin_or_lock() and friends to seqlock.h consolidate simple ->d_delete() instances gfs2: endianness misannotations dump_emit(): use __kernel_write(), not vfs_write() dump_align(): fix the dumb braino
Diffstat (limited to 'include')
-rw-r--r--include/linux/fs.h2
-rw-r--r--include/linux/seqlock.h29
2 files changed, 31 insertions, 0 deletions
diff --git a/include/linux/fs.h b/include/linux/fs.h
index bf5d574ebdf4..121f11f001c0 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2622,7 +2622,9 @@ extern int simple_write_begin(struct file *file, struct address_space *mapping,
extern int simple_write_end(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned copied,
struct page *page, void *fsdata);
+extern int always_delete_dentry(const struct dentry *);
extern struct inode *alloc_anon_inode(struct super_block *);
+extern const struct dentry_operations simple_dentry_operations;
extern struct dentry *simple_lookup(struct inode *, struct dentry *, unsigned int flags);
extern ssize_t generic_read_dir(struct file *, char __user *, size_t, loff_t *);
diff --git a/include/linux/seqlock.h b/include/linux/seqlock.h
index 1e8a8b6e837d..cf87a24c0f92 100644
--- a/include/linux/seqlock.h
+++ b/include/linux/seqlock.h
@@ -354,6 +354,35 @@ static inline void read_sequnlock_excl(seqlock_t *sl)
spin_unlock(&sl->lock);
}
+/**
+ * read_seqbegin_or_lock - begin a sequence number check or locking block
+ * @lock: sequence lock
+ * @seq : sequence number to be checked
+ *
+ * First try it once optimistically without taking the lock. If that fails,
+ * take the lock. The sequence number is also used as a marker for deciding
+ * whether to be a reader (even) or writer (odd).
+ * N.B. seq must be initialized to an even number to begin with.
+ */
+static inline void read_seqbegin_or_lock(seqlock_t *lock, int *seq)
+{
+ if (!(*seq & 1)) /* Even */
+ *seq = read_seqbegin(lock);
+ else /* Odd */
+ read_seqlock_excl(lock);
+}
+
+static inline int need_seqretry(seqlock_t *lock, int seq)
+{
+ return !(seq & 1) && read_seqretry(lock, seq);
+}
+
+static inline void done_seqretry(seqlock_t *lock, int seq)
+{
+ if (seq & 1)
+ read_sequnlock_excl(lock);
+}
+
static inline void read_seqlock_excl_bh(seqlock_t *sl)
{
spin_lock_bh(&sl->lock);