diff options
| -rw-r--r-- | fs/ext4/inode.c | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index f1ee0229ac12..f81f45f5db73 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -3436,14 +3436,26 @@ static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length, map.m_len = min_t(loff_t, (offset + length - 1) >> blkbits, EXT4_MAX_LOGICAL_BLOCK) - map.m_lblk + 1; - if (flags & IOMAP_WRITE) + if (flags & IOMAP_WRITE) { + /* + * We check here if the blocks are already allocated, then we + * don't need to start a journal txn and we can directly return + * the mapping information. This could boost performance + * especially in multi-threaded overwrite requests. + */ + if (offset + length <= i_size_read(inode)) { + ret = ext4_map_blocks(NULL, inode, &map, 0); + if (ret > 0 && (map.m_flags & EXT4_MAP_MAPPED)) + goto out; + } ret = ext4_iomap_alloc(inode, &map, flags); - else + } else { ret = ext4_map_blocks(NULL, inode, &map, 0); + } if (ret < 0) return ret; - +out: ext4_set_iomap(inode, iomap, &map, offset, length); return 0; |