Commit f76ddff6 authored by Liu Bo's avatar Liu Bo Committed by Greg Kroah-Hartman

Btrfs: adjust outstanding_extents counter properly when dio write is split


[ Upstream commit c2931667 ]

Currently how btrfs dio deals with split dio write is not good
enough if dio write is split into several segments due to the
lack of contiguous space, a large dio write like 'dd bs=1G count=1'
can end up with incorrect outstanding_extents counter and endio
would complain loudly with an assertion.

This fixes the problem by compensating the outstanding_extents
counter in inode if a large dio write gets split.
Reported-by: default avatarAnand Jain <anand.jain@oracle.com>
Tested-by: default avatarAnand Jain <anand.jain@oracle.com>
Signed-off-by: default avatarLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarSasha Levin <alexander.levin@verizon.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 49fc90b4
......@@ -7648,11 +7648,18 @@ static void adjust_dio_outstanding_extents(struct inode *inode,
* within our reservation, otherwise we need to adjust our inode
* counter appropriately.
*/
if (dio_data->outstanding_extents) {
if (dio_data->outstanding_extents >= num_extents) {
dio_data->outstanding_extents -= num_extents;
} else {
/*
* If dio write length has been split due to no large enough
* contiguous space, we need to compensate our inode counter
* appropriately.
*/
u64 num_needed = num_extents - dio_data->outstanding_extents;
spin_lock(&BTRFS_I(inode)->lock);
BTRFS_I(inode)->outstanding_extents += num_extents;
BTRFS_I(inode)->outstanding_extents += num_needed;
spin_unlock(&BTRFS_I(inode)->lock);
}
}
......
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