From: Jan Kara <jack@suse.cz>
To: Ted Tso <tytso@mit.edu>
Cc: <linux-ext4@vger.kernel.org>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
Jan Kara <jack@suse.cz>
Subject: [PATCH] ext4: Trim allocation requests to group size
Date: Tue, 10 Jan 2017 10:32:01 +0100 [thread overview]
Message-ID: <20170110093201.1403-1-jack@suse.cz> (raw)
If filesystem groups are artifically small (using parameter -g to
mkfs.ext4), ext4_mb_normalize_request() can result in a request that is
larger than a block group. Trim the request size to not confuse
allocation code.
Reported-by: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/ext4/mballoc.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 7ae43c59bc79..2e9fc7a61048 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -3123,6 +3123,13 @@ ext4_mb_normalize_request(struct ext4_allocation_context *ac,
if (ar->pright && start + size - 1 >= ar->lright)
size -= start + size - ar->lright;
+ /*
+ * Trim allocation request for filesystems with artificially small
+ * groups.
+ */
+ if (size > EXT4_BLOCKS_PER_GROUP(ac->ac_sb))
+ size = EXT4_BLOCKS_PER_GROUP(ac->ac_sb);
+
end = start + size;
/* check we don't cross already preallocated blocks */
--
2.10.2
next reply other threads:[~2017-01-10 9:32 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-10 9:32 Jan Kara [this message]
2017-02-01 19:07 ` [PATCH] ext4: Trim allocation requests to group size Theodore Ts'o
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