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>

1 files changed, 64 insertions, 74 deletions

diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 79b77a51a322..20f1c03b6077 100644
--- 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);