https://github.com/torvalds/linux
Tip revision: 527e9316f8ec44bd53d90fb9f611fa7ffff52bb9 authored by Linus Torvalds on 06 December 2015, 23:43:12 UTC
Linux 4.4-rc4
Linux 4.4-rc4
Tip revision: 527e931
jfs_discard.c
/*
* Copyright (C) Tino Reichardt, 2012
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
* the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/blkdev.h>
#include "jfs_incore.h"
#include "jfs_superblock.h"
#include "jfs_discard.h"
#include "jfs_dmap.h"
#include "jfs_debug.h"
/*
* NAME: jfs_issue_discard()
*
* FUNCTION: TRIM the specified block range on device, if supported
*
* PARAMETERS:
* ip - pointer to in-core inode
* blkno - starting block number to be trimmed (0..N)
* nblocks - number of blocks to be trimmed
*
* RETURN VALUES:
* none
*
* serialization: IREAD_LOCK(ipbmap) held on entry/exit;
*/
void jfs_issue_discard(struct inode *ip, u64 blkno, u64 nblocks)
{
struct super_block *sb = ip->i_sb;
int r = 0;
r = sb_issue_discard(sb, blkno, nblocks, GFP_NOFS, 0);
if (unlikely(r != 0)) {
jfs_err("JFS: sb_issue_discard" \
"(%p, %llu, %llu, GFP_NOFS, 0) = %d => failed!\n",
sb, (unsigned long long)blkno,
(unsigned long long)nblocks, r);
}
jfs_info("JFS: sb_issue_discard" \
"(%p, %llu, %llu, GFP_NOFS, 0) = %d\n",
sb, (unsigned long long)blkno,
(unsigned long long)nblocks, r);
return;
}
/*
* NAME: jfs_ioc_trim()
*
* FUNCTION: attempt to discard (TRIM) all free blocks from the
* filesystem.
*
* PARAMETERS:
* ip - pointer to in-core inode;
* range - the range, given by user space
*
* RETURN VALUES:
* 0 - success
* -EIO - i/o error
*/
int jfs_ioc_trim(struct inode *ip, struct fstrim_range *range)
{
struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap;
struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap;
struct super_block *sb = ipbmap->i_sb;
int agno, agno_end;
u64 start, end, minlen;
u64 trimmed = 0;
/**
* convert byte values to block size of filesystem:
* start: First Byte to trim
* len: number of Bytes to trim from start
* minlen: minimum extent length in Bytes
*/
start = range->start >> sb->s_blocksize_bits;
end = start + (range->len >> sb->s_blocksize_bits) - 1;
minlen = range->minlen >> sb->s_blocksize_bits;
if (minlen == 0)
minlen = 1;
if (minlen > bmp->db_agsize ||
start >= bmp->db_mapsize ||
range->len < sb->s_blocksize)
return -EINVAL;
if (end >= bmp->db_mapsize)
end = bmp->db_mapsize - 1;
/**
* we trim all ag's within the range
*/
agno = BLKTOAG(start, JFS_SBI(ip->i_sb));
agno_end = BLKTOAG(end, JFS_SBI(ip->i_sb));
while (agno <= agno_end) {
trimmed += dbDiscardAG(ip, agno, minlen);
agno++;
}
range->len = trimmed << sb->s_blocksize_bits;
return 0;
}