xref: /openbmc/linux/fs/jfs/jfs_discard.c (revision 37744fee)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *   Copyright (C) Tino Reichardt, 2012
4  */
5 
6 #include <linux/fs.h>
7 #include <linux/slab.h>
8 #include <linux/blkdev.h>
9 
10 #include "jfs_incore.h"
11 #include "jfs_superblock.h"
12 #include "jfs_discard.h"
13 #include "jfs_dmap.h"
14 #include "jfs_debug.h"
15 
16 
17 /*
18  * NAME:	jfs_issue_discard()
19  *
20  * FUNCTION:	TRIM the specified block range on device, if supported
21  *
22  * PARAMETERS:
23  *	ip	- pointer to in-core inode
24  *	blkno	- starting block number to be trimmed (0..N)
25  *	nblocks	- number of blocks to be trimmed
26  *
27  * RETURN VALUES:
28  *	none
29  *
30  * serialization: IREAD_LOCK(ipbmap) held on entry/exit;
31  */
32 void jfs_issue_discard(struct inode *ip, u64 blkno, u64 nblocks)
33 {
34 	struct super_block *sb = ip->i_sb;
35 	int r = 0;
36 
37 	r = sb_issue_discard(sb, blkno, nblocks, GFP_NOFS, 0);
38 	if (unlikely(r != 0)) {
39 		jfs_err("JFS: sb_issue_discard(%p, %llu, %llu, GFP_NOFS, 0) = %d => failed!",
40 			sb, (unsigned long long)blkno,
41 			(unsigned long long)nblocks, r);
42 	}
43 
44 	jfs_info("JFS: sb_issue_discard(%p, %llu, %llu, GFP_NOFS, 0) = %d",
45 		sb, (unsigned long long)blkno,
46 		(unsigned long long)nblocks, r);
47 
48 	return;
49 }
50 
51 /*
52  * NAME:	jfs_ioc_trim()
53  *
54  * FUNCTION:	attempt to discard (TRIM) all free blocks from the
55  *              filesystem.
56  *
57  * PARAMETERS:
58  *	ip	- pointer to in-core inode;
59  *	range	- the range, given by user space
60  *
61  * RETURN VALUES:
62  *	0	- success
63  *	-EIO	- i/o error
64  */
65 int jfs_ioc_trim(struct inode *ip, struct fstrim_range *range)
66 {
67 	struct inode *ipbmap = JFS_SBI(ip->i_sb)->ipbmap;
68 	struct bmap *bmp = JFS_SBI(ip->i_sb)->bmap;
69 	struct super_block *sb = ipbmap->i_sb;
70 	int agno, agno_end;
71 	u64 start, end, minlen;
72 	u64 trimmed = 0;
73 
74 	/**
75 	 * convert byte values to block size of filesystem:
76 	 * start:	First Byte to trim
77 	 * len:		number of Bytes to trim from start
78 	 * minlen:	minimum extent length in Bytes
79 	 */
80 	start = range->start >> sb->s_blocksize_bits;
81 	end = start + (range->len >> sb->s_blocksize_bits) - 1;
82 	minlen = range->minlen >> sb->s_blocksize_bits;
83 	if (minlen == 0)
84 		minlen = 1;
85 
86 	if (minlen > bmp->db_agsize ||
87 	    start >= bmp->db_mapsize ||
88 	    range->len < sb->s_blocksize)
89 		return -EINVAL;
90 
91 	if (end >= bmp->db_mapsize)
92 		end = bmp->db_mapsize - 1;
93 
94 	/**
95 	 * we trim all ag's within the range
96 	 */
97 	agno = BLKTOAG(start, JFS_SBI(ip->i_sb));
98 	agno_end = BLKTOAG(end, JFS_SBI(ip->i_sb));
99 	while (agno <= agno_end) {
100 		trimmed += dbDiscardAG(ip, agno, minlen);
101 		agno++;
102 	}
103 	range->len = trimmed << sb->s_blocksize_bits;
104 
105 	return 0;
106 }
107