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   */
jfs_issue_discard(struct inode * ip,u64 blkno,u64 nblocks)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   */
jfs_ioc_trim(struct inode * ip,struct fstrim_range * range)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;
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  	down_read(&sb->s_umount);
87  	bmp = JFS_SBI(ip->i_sb)->bmap;
88  
89  	if (minlen > bmp->db_agsize ||
90  	    start >= bmp->db_mapsize ||
91  	    range->len < sb->s_blocksize) {
92  		up_read(&sb->s_umount);
93  		return -EINVAL;
94  	}
95  
96  	if (end >= bmp->db_mapsize)
97  		end = bmp->db_mapsize - 1;
98  
99  	/**
100  	 * we trim all ag's within the range
101  	 */
102  	agno = BLKTOAG(start, JFS_SBI(ip->i_sb));
103  	agno_end = BLKTOAG(end, JFS_SBI(ip->i_sb));
104  	while (agno <= agno_end) {
105  		trimmed += dbDiscardAG(ip, agno, minlen);
106  		agno++;
107  	}
108  
109  	up_read(&sb->s_umount);
110  	range->len = trimmed << sb->s_blocksize_bits;
111  
112  	return 0;
113  }
114