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_shared.h" 8 #include "xfs_format.h" 9 #include "xfs_log_format.h" 10 #include "xfs_trans_resv.h" 11 #include "xfs_sb.h" 12 #include "xfs_mount.h" 13 #include "xfs_btree.h" 14 #include "xfs_alloc_btree.h" 15 #include "xfs_alloc.h" 16 #include "xfs_error.h" 17 #include "xfs_extent_busy.h" 18 #include "xfs_trace.h" 19 #include "xfs_log.h" 20 21 STATIC int 22 xfs_trim_extents( 23 struct xfs_mount *mp, 24 xfs_agnumber_t agno, 25 xfs_daddr_t start, 26 xfs_daddr_t end, 27 xfs_daddr_t minlen, 28 uint64_t *blocks_trimmed) 29 { 30 struct block_device *bdev = mp->m_ddev_targp->bt_bdev; 31 struct xfs_btree_cur *cur; 32 struct xfs_buf *agbp; 33 struct xfs_perag *pag; 34 int error; 35 int i; 36 37 pag = xfs_perag_get(mp, agno); 38 39 /* 40 * Force out the log. This means any transactions that might have freed 41 * space before we take the AGF buffer lock are now on disk, and the 42 * volatile disk cache is flushed. 43 */ 44 xfs_log_force(mp, XFS_LOG_SYNC); 45 46 error = xfs_alloc_read_agf(mp, NULL, agno, 0, &agbp); 47 if (error || !agbp) 48 goto out_put_perag; 49 50 cur = xfs_allocbt_init_cursor(mp, NULL, agbp, agno, XFS_BTNUM_CNT); 51 52 /* 53 * Look up the longest btree in the AGF and start with it. 54 */ 55 error = xfs_alloc_lookup_ge(cur, 0, 56 be32_to_cpu(XFS_BUF_TO_AGF(agbp)->agf_longest), &i); 57 if (error) 58 goto out_del_cursor; 59 60 /* 61 * Loop until we are done with all extents that are large 62 * enough to be worth discarding. 63 */ 64 while (i) { 65 xfs_agblock_t fbno; 66 xfs_extlen_t flen; 67 xfs_daddr_t dbno; 68 xfs_extlen_t dlen; 69 70 error = xfs_alloc_get_rec(cur, &fbno, &flen, &i); 71 if (error) 72 goto out_del_cursor; 73 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, out_del_cursor); 74 ASSERT(flen <= be32_to_cpu(XFS_BUF_TO_AGF(agbp)->agf_longest)); 75 76 /* 77 * use daddr format for all range/len calculations as that is 78 * the format the range/len variables are supplied in by 79 * userspace. 80 */ 81 dbno = XFS_AGB_TO_DADDR(mp, agno, fbno); 82 dlen = XFS_FSB_TO_BB(mp, flen); 83 84 /* 85 * Too small? Give up. 86 */ 87 if (dlen < minlen) { 88 trace_xfs_discard_toosmall(mp, agno, fbno, flen); 89 goto out_del_cursor; 90 } 91 92 /* 93 * If the extent is entirely outside of the range we are 94 * supposed to discard skip it. Do not bother to trim 95 * down partially overlapping ranges for now. 96 */ 97 if (dbno + dlen < start || dbno > end) { 98 trace_xfs_discard_exclude(mp, agno, fbno, flen); 99 goto next_extent; 100 } 101 102 /* 103 * If any blocks in the range are still busy, skip the 104 * discard and try again the next time. 105 */ 106 if (xfs_extent_busy_search(mp, agno, fbno, flen)) { 107 trace_xfs_discard_busy(mp, agno, fbno, flen); 108 goto next_extent; 109 } 110 111 trace_xfs_discard_extent(mp, agno, fbno, flen); 112 error = blkdev_issue_discard(bdev, dbno, dlen, GFP_NOFS, 0); 113 if (error) 114 goto out_del_cursor; 115 *blocks_trimmed += flen; 116 117 next_extent: 118 error = xfs_btree_decrement(cur, 0, &i); 119 if (error) 120 goto out_del_cursor; 121 122 if (fatal_signal_pending(current)) { 123 error = -ERESTARTSYS; 124 goto out_del_cursor; 125 } 126 } 127 128 out_del_cursor: 129 xfs_btree_del_cursor(cur, error); 130 xfs_buf_relse(agbp); 131 out_put_perag: 132 xfs_perag_put(pag); 133 return error; 134 } 135 136 /* 137 * trim a range of the filesystem. 138 * 139 * Note: the parameters passed from userspace are byte ranges into the 140 * filesystem which does not match to the format we use for filesystem block 141 * addressing. FSB addressing is sparse (AGNO|AGBNO), while the incoming format 142 * is a linear address range. Hence we need to use DADDR based conversions and 143 * comparisons for determining the correct offset and regions to trim. 144 */ 145 int 146 xfs_ioc_trim( 147 struct xfs_mount *mp, 148 struct fstrim_range __user *urange) 149 { 150 struct request_queue *q = bdev_get_queue(mp->m_ddev_targp->bt_bdev); 151 unsigned int granularity = q->limits.discard_granularity; 152 struct fstrim_range range; 153 xfs_daddr_t start, end, minlen; 154 xfs_agnumber_t start_agno, end_agno, agno; 155 uint64_t blocks_trimmed = 0; 156 int error, last_error = 0; 157 158 if (!capable(CAP_SYS_ADMIN)) 159 return -EPERM; 160 if (!blk_queue_discard(q)) 161 return -EOPNOTSUPP; 162 163 /* 164 * We haven't recovered the log, so we cannot use our bnobt-guided 165 * storage zapping commands. 166 */ 167 if (mp->m_flags & XFS_MOUNT_NORECOVERY) 168 return -EROFS; 169 170 if (copy_from_user(&range, urange, sizeof(range))) 171 return -EFAULT; 172 173 range.minlen = max_t(u64, granularity, range.minlen); 174 minlen = BTOBB(range.minlen); 175 /* 176 * Truncating down the len isn't actually quite correct, but using 177 * BBTOB would mean we trivially get overflows for values 178 * of ULLONG_MAX or slightly lower. And ULLONG_MAX is the default 179 * used by the fstrim application. In the end it really doesn't 180 * matter as trimming blocks is an advisory interface. 181 */ 182 if (range.start >= XFS_FSB_TO_B(mp, mp->m_sb.sb_dblocks) || 183 range.minlen > XFS_FSB_TO_B(mp, mp->m_ag_max_usable) || 184 range.len < mp->m_sb.sb_blocksize) 185 return -EINVAL; 186 187 start = BTOBB(range.start); 188 end = start + BTOBBT(range.len) - 1; 189 190 if (end > XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks) - 1) 191 end = XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks)- 1; 192 193 start_agno = xfs_daddr_to_agno(mp, start); 194 end_agno = xfs_daddr_to_agno(mp, end); 195 196 for (agno = start_agno; agno <= end_agno; agno++) { 197 error = xfs_trim_extents(mp, agno, start, end, minlen, 198 &blocks_trimmed); 199 if (error) { 200 last_error = error; 201 if (error == -ERESTARTSYS) 202 break; 203 } 204 } 205 206 if (last_error) 207 return last_error; 208 209 range.len = XFS_FSB_TO_B(mp, blocks_trimmed); 210 if (copy_to_user(urange, &range, sizeof(range))) 211 return -EFAULT; 212 return 0; 213 } 214