From 66fc061bda3526650328b73f69985da3518c4256 Mon Sep 17 00:00:00 2001 From: Steven Whitehouse Date: Wed, 8 Feb 2012 12:58:32 +0000 Subject: GFS2: FITRIM ioctl support The FITRIM ioctl provides an alternative way to send discard requests to the underlying device. Using the discard mount option results in every freed block generating a discard request to the block device. This can be slow, since many block devices can only process discard requests of larger sizes, and also such operations can be time consuming. Rather than using the discard mount option, FITRIM allows a sweep of the filesystem on an occasional basis, and also to optionally avoid sending down discard requests for smaller regions. In GFS2 FITRIM will work at resource group granularity. There is a flag for each resource group which keeps track of which resource groups have been trimmed. This flag is reset whenever a deallocation occurs in the resource group, and set whenever a successful FITRIM of that resource group has taken place. This helps to reduce repeated discard requests for the same block ranges, again improving performance. Signed-off-by: Steven Whitehouse --- fs/gfs2/file.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'fs/gfs2/file.c') diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c index c5fb3597f696..310f2fb6f7ea 100644 --- a/fs/gfs2/file.c +++ b/fs/gfs2/file.c @@ -313,6 +313,8 @@ static long gfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) return gfs2_get_flags(filp, (u32 __user *)arg); case FS_IOC_SETFLAGS: return gfs2_set_flags(filp, (u32 __user *)arg); + case FITRIM: + return gfs2_fitrim(filp, (void __user *)arg); } return -ENOTTY; } -- cgit v1.2.3