ext4: move ext4_file_dio_write() into ext4_file_write()

This commit doesn't actually change anything; it just moves code
around in preparation for some code simplification work.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>

diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 79b77a5..20f1c03 100644 (file)
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -92,82 +92,15 @@ ext4_unaligned_aio(struct inode *inode, const struct iovec *iov,
 }
 
 static ssize_t
-ext4_file_dio_write(struct kiocb *iocb, const struct iovec *iov,
-                   unsigned long nr_segs, loff_t pos)
+ext4_file_write(struct kiocb *iocb, const struct iovec *iov,
+               unsigned long nr_segs, loff_t pos)
 {
        struct file *file = iocb->ki_filp;
-       struct inode *inode = file->f_mapping->host;
+       struct inode *inode = file_inode(iocb->ki_filp);
        struct blk_plug plug;
        int unaligned_aio = 0;
-       ssize_t ret;
        int overwrite = 0;
        size_t length = iov_length(iov, nr_segs);
-
-       if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS) &&
-           !is_sync_kiocb(iocb))
-               unaligned_aio = ext4_unaligned_aio(inode, iov, nr_segs, pos);
-
-       /* Unaligned direct AIO must be serialized; see comment above */
-       if (unaligned_aio) {
-               mutex_lock(ext4_aio_mutex(inode));
-               ext4_unwritten_wait(inode);
-       }
-
-       mutex_lock(&inode->i_mutex);
-       blk_start_plug(&plug);
-
-       iocb->private = &overwrite;
-
-       /* check whether we do a DIO overwrite or not */
-       if (ext4_should_dioread_nolock(inode) && !unaligned_aio &&
-           !file->f_mapping->nrpages && pos + length <= i_size_read(inode)) {
-               struct ext4_map_blocks map;
-               unsigned int blkbits = inode->i_blkbits;
-               int err, len;
-
-               map.m_lblk = pos >> blkbits;
-               map.m_len = (EXT4_BLOCK_ALIGN(pos + length, blkbits) >> blkbits)
-                       - map.m_lblk;
-               len = map.m_len;
-
-               err = ext4_map_blocks(NULL, inode, &map, 0);
-               /*
-                * 'err==len' means that all of blocks has been preallocated no
-                * matter they are initialized or not.  For excluding
-                * unwritten extents, we need to check m_flags.  There are
-                * two conditions that indicate for initialized extents.
-                * 1) If we hit extent cache, EXT4_MAP_MAPPED flag is returned;
-                * 2) If we do a real lookup, non-flags are returned.
-                * So we should check these two conditions.
-                */
-               if (err == len && (map.m_flags & EXT4_MAP_MAPPED))
-                       overwrite = 1;
-       }
-
-       ret = __generic_file_aio_write(iocb, iov, nr_segs);
-       mutex_unlock(&inode->i_mutex);
-
-       if (ret > 0) {
-               ssize_t err;
-
-               err = generic_write_sync(file, iocb->ki_pos - ret, ret);
-               if (err < 0)
-                       ret = err;
-       }
-       blk_finish_plug(&plug);
-
-       if (unaligned_aio)
-               mutex_unlock(ext4_aio_mutex(inode));
-
-       return ret;
-}
-
-static ssize_t
-ext4_file_write(struct kiocb *iocb, const struct iovec *iov,
-               unsigned long nr_segs, loff_t pos)
-{
-       struct file *file = iocb->ki_filp;
-       struct inode *inode = file_inode(iocb->ki_filp);
        ssize_t ret;
 
        BUG_ON(iocb->ki_pos != pos);
@@ -179,7 +112,6 @@ ext4_file_write(struct kiocb *iocb, const struct iovec *iov,
 
        if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
                struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
-               size_t length = iov_length(iov, nr_segs);
 
                if ((pos > sbi->s_bitmap_maxbytes ||
                    (pos == sbi->s_bitmap_maxbytes && length > 0)))
@@ -191,9 +123,67 @@ ext4_file_write(struct kiocb *iocb, const struct iovec *iov,
                }
        }
 
-       if (unlikely(iocb->ki_filp->f_flags & O_DIRECT))
-               ret = ext4_file_dio_write(iocb, iov, nr_segs, pos);
-       else {
+       if (unlikely(iocb->ki_filp->f_flags & O_DIRECT)) {
+               if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS) &&
+                   !is_sync_kiocb(iocb))
+                       unaligned_aio = ext4_unaligned_aio(inode, iov,
+                                                          nr_segs, pos);
+
+               /* Unaligned direct AIO must be serialized; see comment above */
+               if (unaligned_aio) {
+                       mutex_lock(ext4_aio_mutex(inode));
+                       ext4_unwritten_wait(inode);
+               }
+
+               mutex_lock(&inode->i_mutex);
+               blk_start_plug(&plug);
+
+               iocb->private = &overwrite;
+
+               /* check whether we do a DIO overwrite or not */
+               if (ext4_should_dioread_nolock(inode) && !unaligned_aio &&
+                   !file->f_mapping->nrpages && pos + length <= i_size_read(inode)) {
+                       struct ext4_map_blocks map;
+                       unsigned int blkbits = inode->i_blkbits;
+                       int err, len;
+
+                       map.m_lblk = pos >> blkbits;
+                       map.m_len = (EXT4_BLOCK_ALIGN(pos + length, blkbits) >> blkbits)
+                               - map.m_lblk;
+                       len = map.m_len;
+
+                       err = ext4_map_blocks(NULL, inode, &map, 0);
+                       /*
+                        * 'err==len' means that all of blocks has
+                        * been preallocated no matter they are
+                        * initialized or not.  For excluding
+                        * unwritten extents, we need to check
+                        * m_flags.  There are two conditions that
+                        * indicate for initialized extents.  1) If we
+                        * hit extent cache, EXT4_MAP_MAPPED flag is
+                        * returned; 2) If we do a real lookup,
+                        * non-flags are returned.  So we should check
+                        * these two conditions.
+                        */
+                       if (err == len && (map.m_flags & EXT4_MAP_MAPPED))
+                               overwrite = 1;
+               }
+
+               ret = __generic_file_aio_write(iocb, iov, nr_segs);
+               mutex_unlock(&inode->i_mutex);
+
+               if (ret > 0) {
+                       ssize_t err;
+
+                       err = generic_write_sync(file, iocb->ki_pos - ret, ret);
+                       if (err < 0)
+                               ret = err;
+               }
+               blk_finish_plug(&plug);
+
+               if (unaligned_aio)
+                       mutex_unlock(ext4_aio_mutex(inode));
+       } else {
                mutex_lock(&inode->i_mutex);
                ret = __generic_file_aio_write(iocb, iov, nr_segs);
                mutex_unlock(&inode->i_mutex);