1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2010 Red Hat, Inc. 4 * All Rights Reserved. 5 */ 6 #include "xfs.h" 7 #include "xfs_format.h" 8 #include "xfs_log_format.h" 9 #include "xfs_trans_resv.h" 10 #include "xfs_sb.h" 11 #include "xfs_mount.h" 12 #include "xfs_quota.h" 13 #include "xfs_inode.h" 14 #include "xfs_btree.h" 15 #include "xfs_alloc_btree.h" 16 #include "xfs_alloc.h" 17 #include "xfs_error.h" 18 #include "xfs_extent_busy.h" 19 #include "xfs_discard.h" 20 #include "xfs_trace.h" 21 #include "xfs_log.h" 22 23 STATIC int 24 xfs_trim_extents( 25 struct xfs_mount *mp, 26 xfs_agnumber_t agno, 27 xfs_daddr_t start, 28 xfs_daddr_t end, 29 xfs_daddr_t minlen, 30 uint64_t *blocks_trimmed) 31 { 32 struct block_device *bdev = mp->m_ddev_targp->bt_bdev; 33 struct xfs_btree_cur *cur; 34 struct xfs_buf *agbp; 35 struct xfs_perag *pag; 36 int error; 37 int i; 38 39 pag = xfs_perag_get(mp, agno); 40 41 /* 42 * Force out the log. This means any transactions that might have freed 43 * space before we take the AGF buffer lock are now on disk, and the 44 * volatile disk cache is flushed. 45 */ 46 xfs_log_force(mp, XFS_LOG_SYNC); 47 48 error = xfs_alloc_read_agf(mp, NULL, agno, 0, &agbp); 49 if (error || !agbp) 50 goto out_put_perag; 51 52 cur = xfs_allocbt_init_cursor(mp, NULL, agbp, agno, XFS_BTNUM_CNT); 53 54 /* 55 * Look up the longest btree in the AGF and start with it. 56 */ 57 error = xfs_alloc_lookup_ge(cur, 0, 58 be32_to_cpu(XFS_BUF_TO_AGF(agbp)->agf_longest), &i); 59 if (error) 60 goto out_del_cursor; 61 62 /* 63 * Loop until we are done with all extents that are large 64 * enough to be worth discarding. 65 */ 66 while (i) { 67 xfs_agblock_t fbno; 68 xfs_extlen_t flen; 69 xfs_daddr_t dbno; 70 xfs_extlen_t dlen; 71 72 error = xfs_alloc_get_rec(cur, &fbno, &flen, &i); 73 if (error) 74 goto out_del_cursor; 75 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, out_del_cursor); 76 ASSERT(flen <= be32_to_cpu(XFS_BUF_TO_AGF(agbp)->agf_longest)); 77 78 /* 79 * use daddr format for all range/len calculations as that is 80 * the format the range/len variables are supplied in by 81 * userspace. 82 */ 83 dbno = XFS_AGB_TO_DADDR(mp, agno, fbno); 84 dlen = XFS_FSB_TO_BB(mp, flen); 85 86 /* 87 * Too small? Give up. 88 */ 89 if (dlen < minlen) { 90 trace_xfs_discard_toosmall(mp, agno, fbno, flen); 91 goto out_del_cursor; 92 } 93 94 /* 95 * If the extent is entirely outside of the range we are 96 * supposed to discard skip it. Do not bother to trim 97 * down partially overlapping ranges for now. 98 */ 99 if (dbno + dlen < start || dbno > end) { 100 trace_xfs_discard_exclude(mp, agno, fbno, flen); 101 goto next_extent; 102 } 103 104 /* 105 * If any blocks in the range are still busy, skip the 106 * discard and try again the next time. 107 */ 108 if (xfs_extent_busy_search(mp, agno, fbno, flen)) { 109 trace_xfs_discard_busy(mp, agno, fbno, flen); 110 goto next_extent; 111 } 112 113 trace_xfs_discard_extent(mp, agno, fbno, flen); 114 error = blkdev_issue_discard(bdev, dbno, dlen, GFP_NOFS, 0); 115 if (error) 116 goto out_del_cursor; 117 *blocks_trimmed += flen; 118 119 next_extent: 120 error = xfs_btree_decrement(cur, 0, &i); 121 if (error) 122 goto out_del_cursor; 123 124 if (fatal_signal_pending(current)) { 125 error = -ERESTARTSYS; 126 goto out_del_cursor; 127 } 128 } 129 130 out_del_cursor: 131 xfs_btree_del_cursor(cur, error); 132 xfs_buf_relse(agbp); 133 out_put_perag: 134 xfs_perag_put(pag); 135 return error; 136 } 137 138 /* 139 * trim a range of the filesystem. 140 * 141 * Note: the parameters passed from userspace are byte ranges into the 142 * filesystem which does not match to the format we use for filesystem block 143 * addressing. FSB addressing is sparse (AGNO|AGBNO), while the incoming format 144 * is a linear address range. Hence we need to use DADDR based conversions and 145 * comparisons for determining the correct offset and regions to trim. 146 */ 147 int 148 xfs_ioc_trim( 149 struct xfs_mount *mp, 150 struct fstrim_range __user *urange) 151 { 152 struct request_queue *q = bdev_get_queue(mp->m_ddev_targp->bt_bdev); 153 unsigned int granularity = q->limits.discard_granularity; 154 struct fstrim_range range; 155 xfs_daddr_t start, end, minlen; 156 xfs_agnumber_t start_agno, end_agno, agno; 157 uint64_t blocks_trimmed = 0; 158 int error, last_error = 0; 159 160 if (!capable(CAP_SYS_ADMIN)) 161 return -EPERM; 162 if (!blk_queue_discard(q)) 163 return -EOPNOTSUPP; 164 if (copy_from_user(&range, urange, sizeof(range))) 165 return -EFAULT; 166 167 /* 168 * Truncating down the len isn't actually quite correct, but using 169 * BBTOB would mean we trivially get overflows for values 170 * of ULLONG_MAX or slightly lower. And ULLONG_MAX is the default 171 * used by the fstrim application. In the end it really doesn't 172 * matter as trimming blocks is an advisory interface. 173 */ 174 if (range.start >= XFS_FSB_TO_B(mp, mp->m_sb.sb_dblocks) || 175 range.minlen > XFS_FSB_TO_B(mp, mp->m_ag_max_usable) || 176 range.len < mp->m_sb.sb_blocksize) 177 return -EINVAL; 178 179 start = BTOBB(range.start); 180 end = start + BTOBBT(range.len) - 1; 181 minlen = BTOBB(max_t(u64, granularity, range.minlen)); 182 183 if (end > XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks) - 1) 184 end = XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks)- 1; 185 186 start_agno = xfs_daddr_to_agno(mp, start); 187 end_agno = xfs_daddr_to_agno(mp, end); 188 189 for (agno = start_agno; agno <= end_agno; agno++) { 190 error = xfs_trim_extents(mp, agno, start, end, minlen, 191 &blocks_trimmed); 192 if (error) { 193 last_error = error; 194 if (error == -ERESTARTSYS) 195 break; 196 } 197 } 198 199 if (last_error) 200 return last_error; 201 202 range.len = XFS_FSB_TO_B(mp, blocks_trimmed); 203 if (copy_to_user(urange, &range, sizeof(range))) 204 return -EFAULT; 205 return 0; 206 } 207