From 5ee8dd41427034dedf11bbcc89b4b086695b8466 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Mon, 17 Jun 2013 09:56:00 -0400 Subject: [PATCH] ext4: remove while loop in mpage_map_and_submit_extent() The while loop in mpage_map_and_submit_extent() is pointless; this function is only called if mpd.map.m_len is non-zero, and at the end of the while loop, mpage_map_and_submit_buffers sets mpd.map.m_len to be zero on success. (And on a failure, we return out of the while loop anyway.) Hence, the body of the while loop is guaranteed to execute once and exactly once. This also fixes a gcc warning complaining that err might be left uninitialized. Signed-off-by: "Theodore Ts'o" Cc: Jan Kara --- fs/ext4/inode.c | 66 ++++++++++++++++++++++++------------------------- 1 file changed, 32 insertions(+), 34 deletions(-) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 06136b5a2027..38777cbf61c9 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -2157,44 +2157,42 @@ static int mpage_map_and_submit_extent(handle_t *handle, mpd->io_submit.io_end->offset = ((loff_t)map->m_lblk) << inode->i_blkbits; - while (map->m_len) { - err = mpage_map_one_extent(handle, mpd); - if (err < 0) { - struct super_block *sb = inode->i_sb; + err = mpage_map_one_extent(handle, mpd); + if (err < 0) { + struct super_block *sb = inode->i_sb; - /* - * Need to commit transaction to free blocks. Let upper - * layers sort it out. - */ - if (err == -ENOSPC && ext4_count_free_clusters(sb)) - return -ENOSPC; - - if (!(EXT4_SB(sb)->s_mount_flags & EXT4_MF_FS_ABORTED)) { - ext4_msg(sb, KERN_CRIT, - "Delayed block allocation failed for " - "inode %lu at logical offset %llu with" - " max blocks %u with error %d", - inode->i_ino, - (unsigned long long)map->m_lblk, - (unsigned)map->m_len, err); - ext4_msg(sb, KERN_CRIT, - "This should not happen!! Data will " - "be lost\n"); - if (err == -ENOSPC) - ext4_print_free_blocks(inode); - } - /* invalidate all the pages */ - mpage_release_unused_pages(mpd, true); - return err; - } /* - * Update buffer state, submit mapped pages, and get us new - * extent to map + * Need to commit transaction to free blocks. Let upper + * layers sort it out. */ - err = mpage_map_and_submit_buffers(mpd); - if (err < 0) - return err; + if (err == -ENOSPC && ext4_count_free_clusters(sb)) + return -ENOSPC; + + if (!(EXT4_SB(sb)->s_mount_flags & EXT4_MF_FS_ABORTED)) { + ext4_msg(sb, KERN_CRIT, + "Delayed block allocation failed for " + "inode %lu at logical offset %llu with" + " max blocks %u with error %d", + inode->i_ino, + (unsigned long long)map->m_lblk, + (unsigned)map->m_len, err); + ext4_msg(sb, KERN_CRIT, + "This should not happen!! Data will " + "be lost\n"); + if (err == -ENOSPC) + ext4_print_free_blocks(inode); + } + /* invalidate all the pages */ + mpage_release_unused_pages(mpd, true); + return err; } + /* + * Update buffer state, submit mapped pages, and get us new + * extent to map + */ + err = mpage_map_and_submit_buffers(mpd); + if (err < 0) + return err; /* Update on-disk size after IO is submitted */ disksize = ((loff_t)mpd->first_page) << PAGE_CACHE_SHIFT; -- 2.39.5