fs: fork splice_file_range() from do_splice_direct()

[linux-2.6-block.git] / include / linux / fs.h

diff --git a/include/linux/fs.h b/include/linux/fs.h
index c27c324ba58ac0a90aecc945b25bc14d992d4625..04422a0eccddd59f962a30b947ded81f685baddf 100644 (file)
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -454,7 +454,7 @@ extern const struct address_space_operations empty_aops;
  *   It is also used to block modification of page cache contents through
  *   memory mappings.
  * @gfp_mask: Memory allocation flags to use for allocating pages.
- * @i_mmap_writable: Number of VM_SHARED mappings.
+ * @i_mmap_writable: Number of VM_SHARED, VM_MAYWRITE mappings.
  * @nr_thps: Number of THPs in the pagecache (non-shmem only).
  * @i_mmap: Tree of private and shared mappings.
  * @i_mmap_rwsem: Protects @i_mmap and @i_mmap_writable.
@@ -557,7 +557,7 @@ static inline int mapping_mapped(struct address_space *mapping)
 
 /*
  * Might pages of this file have been modified in userspace?
- * Note that i_mmap_writable counts all VM_SHARED vmas: do_mmap
+ * Note that i_mmap_writable counts all VM_SHARED, VM_MAYWRITE vmas: do_mmap
  * marks vma as VM_SHARED if it is shared, and the file was opened for
  * writing i.e. vma may be mprotected writable even if now readonly.
  *
@@ -1270,7 +1270,7 @@ struct super_block {
 
        const struct dentry_operations *s_d_op; /* default d_op for dentries */
 
-       struct shrinker s_shrink;       /* per-sb shrinker handle */
+       struct shrinker *s_shrink;      /* per-sb shrinker handle */
 
        /* Number of inodes with nlink == 0 but still referenced */
        atomic_long_t s_remove_count;
@@ -1645,9 +1645,70 @@ static inline bool __sb_start_write_trylock(struct super_block *sb, int level)
 #define __sb_writers_release(sb, lev)  \
        percpu_rwsem_release(&(sb)->s_writers.rw_sem[(lev)-1], 1, _THIS_IP_)
 
+/**
+ * __sb_write_started - check if sb freeze level is held
+ * @sb: the super we write to
+ * @level: the freeze level
+ *
+ * > 0 sb freeze level is held
+ *   0 sb freeze level is not held
+ * < 0 !CONFIG_LOCKDEP/LOCK_STATE_UNKNOWN
+ */
+static inline int __sb_write_started(const struct super_block *sb, int level)
+{
+       return lockdep_is_held_type(sb->s_writers.rw_sem + level - 1, 1);
+}
+
+/**
+ * sb_write_started - check if SB_FREEZE_WRITE is held
+ * @sb: the super we write to
+ *
+ * May be false positive with !CONFIG_LOCKDEP/LOCK_STATE_UNKNOWN.
+ */
 static inline bool sb_write_started(const struct super_block *sb)
 {
-       return lockdep_is_held_type(sb->s_writers.rw_sem + SB_FREEZE_WRITE - 1, 1);
+       return __sb_write_started(sb, SB_FREEZE_WRITE);
+}
+
+/**
+ * sb_write_not_started - check if SB_FREEZE_WRITE is not held
+ * @sb: the super we write to
+ *
+ * May be false positive with !CONFIG_LOCKDEP/LOCK_STATE_UNKNOWN.
+ */
+static inline bool sb_write_not_started(const struct super_block *sb)
+{
+       return __sb_write_started(sb, SB_FREEZE_WRITE) <= 0;
+}
+
+/**
+ * file_write_started - check if SB_FREEZE_WRITE is held
+ * @file: the file we write to
+ *
+ * May be false positive with !CONFIG_LOCKDEP/LOCK_STATE_UNKNOWN.
+ * May be false positive with !S_ISREG, because file_start_write() has
+ * no effect on !S_ISREG.
+ */
+static inline bool file_write_started(const struct file *file)
+{
+       if (!S_ISREG(file_inode(file)->i_mode))
+               return true;
+       return sb_write_started(file_inode(file)->i_sb);
+}
+
+/**
+ * file_write_not_started - check if SB_FREEZE_WRITE is not held
+ * @file: the file we write to
+ *
+ * May be false positive with !CONFIG_LOCKDEP/LOCK_STATE_UNKNOWN.
+ * May be false positive with !S_ISREG, because file_start_write() has
+ * no effect on !S_ISREG.
+ */
+static inline bool file_write_not_started(const struct file *file)
+{
+       if (!S_ISREG(file_inode(file)->i_mode))
+               return true;
+       return sb_write_not_started(file_inode(file)->i_sb);
 }
 
 /**
@@ -2991,8 +3052,6 @@ ssize_t copy_splice_read(struct file *in, loff_t *ppos,
                         size_t len, unsigned int flags);
 extern ssize_t iter_file_splice_write(struct pipe_inode_info *,
                struct file *, loff_t *, size_t, unsigned int);
-extern long do_splice_direct(struct file *in, loff_t *ppos, struct file *out,
-               loff_t *opos, size_t len, unsigned int flags);
 
 
 extern void