xref: /linux/fs/jfs/jfs_discard.c (revision cc04a46f11ea046ed53e2c832ae29e4790f7e35f)
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" \
53 			"(%p, %llu, %llu, GFP_NOFS, 0) = %d => failed!\n",
54 			sb, (unsigned long long)blkno,
55 			(unsigned long long)nblocks, r);
56 	}
57 
58 	jfs_info("JFS: sb_issue_discard" \
59 		"(%p, %llu, %llu, GFP_NOFS, 0) = %d\n",
60 		sb, (unsigned long long)blkno,
61 		(unsigned long long)nblocks, r);
62 
63 	return;
64 }
65 
66 /*
67  * NAME:	jfs_ioc_trim()
68  *
69  * FUNCTION:	attempt to discard (TRIM) all free blocks from the
70  *              filesystem.
71  *
72  * PARAMETERS:
73  *	ip	- pointer to in-core inode;
74  *	range	- the range, given by user space
75  *
76  * RETURN VALUES:
77  *	0	- success
78  *	-EIO	- i/o error
79  */
80 int jfs_ioc_trim(struct inode *ip, struct fstrim_range *range)
81 {
82 	struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap;
83 	struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap;
84 	struct super_block *sb = ipbmap->i_sb;
85 	int agno, agno_end;
86 	u64 start, end, minlen;
87 	u64 trimmed = 0;
88 
89 	/**
90 	 * convert byte values to block size of filesystem:
91 	 * start:	First Byte to trim
92 	 * len:		number of Bytes to trim from start
93 	 * minlen:	minimum extent length in Bytes
94 	 */
95 	start = range->start >> sb->s_blocksize_bits;
96 	end = start + (range->len >> sb->s_blocksize_bits) - 1;
97 	minlen = range->minlen >> sb->s_blocksize_bits;
98 	if (minlen == 0)
99 		minlen = 1;
100 
101 	if (minlen > bmp->db_agsize ||
102 	    start >= bmp->db_mapsize ||
103 	    range->len < sb->s_blocksize)
104 		return -EINVAL;
105 
106 	if (end >= bmp->db_mapsize)
107 		end = bmp->db_mapsize - 1;
108 
109 	/**
110 	 * we trim all ag's within the range
111 	 */
112 	agno = BLKTOAG(start, JFS_SBI(ip->i_sb));
113 	agno_end = BLKTOAG(end, JFS_SBI(ip->i_sb));
114 	while (agno <= agno_end) {
115 		trimmed += dbDiscardAG(ip, agno, minlen);
116 		agno++;
117 	}
118 	range->len = trimmed << sb->s_blocksize_bits;
119 
120 	return 0;
121 }
122