From 3c6fe77017bc6ce489f231c35fed3220b6691836 Mon Sep 17 00:00:00 2001 From: Greg Harm Date: Mon, 31 Oct 2011 18:41:47 -0400 Subject: [PATCH] ext4: Don't normalize an falloc request if it can fit in 1 extent. If an fallocate request fits in EXT_UNINIT_MAX_LEN, then set the EXT4_GET_BLOCKS_NO_NORMALIZE flag. For larger fallocate requests, let mballoc.c normalize the request. This fixes a problem where large requests were being split into non-contiguous extents due to commit 556b27abf73: ext4: do not normalize block requests from fallocate. Testing: *) Checked that 8.x MB falloc'ed files are still laid down next to each other (contiguously). *) Checked that the maximum size extent (127.9MB) is allocated as 1 extent. *) Checked that a 1GB file is somewhat contiguous (often 5-6 non-contiguous extents now). *) Checked that a 120MB file can still be falloc'ed even if there are no single extents large enough to hold it. Signed-off-by: Greg Harm Signed-off-by: "Theodore Ts'o" --- fs/ext4/extents.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index a5c8caaaa099..2798945a1920 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -4337,10 +4337,16 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len) trace_ext4_fallocate_exit(inode, offset, max_blocks, ret); return ret; } - flags = EXT4_GET_BLOCKS_CREATE_UNINIT_EXT | - EXT4_GET_BLOCKS_NO_NORMALIZE; + flags = EXT4_GET_BLOCKS_CREATE_UNINIT_EXT; if (mode & FALLOC_FL_KEEP_SIZE) flags |= EXT4_GET_BLOCKS_KEEP_SIZE; + /* + * Don't normalize the request if it can fit in one extent so + * that it doesn't get unnecessarily split into multiple + * extents. + */ + if (len <= EXT_UNINIT_MAX_LEN << blkbits) + flags |= EXT4_GET_BLOCKS_NO_NORMALIZE; retry: while (ret >= 0 && ret < max_blocks) { map.m_lblk = map.m_lblk + ret; -- 2.39.2