xref: /linux/fs/jfs/jfs_discard.c (revision b6ebbac51bedf9e98e837688bc838f400196da5e)
1 /*
2  *   Copyright (C) Tino Reichardt, 2012
3  *
4  *   This program is free software;  you can redistribute it and/or modify
5  *   it under the terms of the GNU General Public License as published by
6  *   the Free Software Foundation; either version 2 of the License, or
7  *   (at your option) any later version.
8  *
9  *   This program is distributed in the hope that it will be useful,
10  *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
11  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
12  *   the GNU General Public License for more details.
13  *
14  *   You should have received a copy of the GNU General Public License
15  *   along with this program;  if not, write to the Free Software
16  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17  */
18 
19 #include <linux/fs.h>
20 #include <linux/slab.h>
21 #include <linux/blkdev.h>
22 
23 #include "jfs_incore.h"
24 #include "jfs_superblock.h"
25 #include "jfs_discard.h"
26 #include "jfs_dmap.h"
27 #include "jfs_debug.h"
28 
29 
30 /*
31  * NAME:	jfs_issue_discard()
32  *
33  * FUNCTION:	TRIM the specified block range on device, if supported
34  *
35  * PARAMETERS:
36  *	ip	- pointer to in-core inode
37  *	blkno	- starting block number to be trimmed (0..N)
38  *	nblocks	- number of blocks to be trimmed
39  *
40  * RETURN VALUES:
41  *	none
42  *
43  * serialization: IREAD_LOCK(ipbmap) held on entry/exit;
44  */
45 void jfs_issue_discard(struct inode *ip, u64 blkno, u64 nblocks)
46 {
47 	struct super_block *sb = ip->i_sb;
48 	int r = 0;
49 
50 	r = sb_issue_discard(sb, blkno, nblocks, GFP_NOFS, 0);
51 	if (unlikely(r != 0)) {
52 		jfs_err("JFS: sb_issue_discard(%p, %llu, %llu, GFP_NOFS, 0) = %d => failed!",
53 			sb, (unsigned long long)blkno,
54 			(unsigned long long)nblocks, r);
55 	}
56 
57 	jfs_info("JFS: sb_issue_discard(%p, %llu, %llu, GFP_NOFS, 0) = %d",
58 		sb, (unsigned long long)blkno,
59 		(unsigned long long)nblocks, r);
60 
61 	return;
62 }
63 
64 /*
65  * NAME:	jfs_ioc_trim()
66  *
67  * FUNCTION:	attempt to discard (TRIM) all free blocks from the
68  *              filesystem.
69  *
70  * PARAMETERS:
71  *	ip	- pointer to in-core inode;
72  *	range	- the range, given by user space
73  *
74  * RETURN VALUES:
75  *	0	- success
76  *	-EIO	- i/o error
77  */
78 int jfs_ioc_trim(struct inode *ip, struct fstrim_range *range)
79 {
80 	struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap;
81 	struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap;
82 	struct super_block *sb = ipbmap->i_sb;
83 	int agno, agno_end;
84 	u64 start, end, minlen;
85 	u64 trimmed = 0;
86 
87 	/**
88 	 * convert byte values to block size of filesystem:
89 	 * start:	First Byte to trim
90 	 * len:		number of Bytes to trim from start
91 	 * minlen:	minimum extent length in Bytes
92 	 */
93 	start = range->start >> sb->s_blocksize_bits;
94 	end = start + (range->len >> sb->s_blocksize_bits) - 1;
95 	minlen = range->minlen >> sb->s_blocksize_bits;
96 	if (minlen == 0)
97 		minlen = 1;
98 
99 	if (minlen > bmp->db_agsize ||
100 	    start >= bmp->db_mapsize ||
101 	    range->len < sb->s_blocksize)
102 		return -EINVAL;
103 
104 	if (end >= bmp->db_mapsize)
105 		end = bmp->db_mapsize - 1;
106 
107 	/**
108 	 * we trim all ag's within the range
109 	 */
110 	agno = BLKTOAG(start, JFS_SBI(ip->i_sb));
111 	agno_end = BLKTOAG(end, JFS_SBI(ip->i_sb));
112 	while (agno <= agno_end) {
113 		trimmed += dbDiscardAG(ip, agno, minlen);
114 		agno++;
115 	}
116 	range->len = trimmed << sb->s_blocksize_bits;
117 
118 	return 0;
119 }
120