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_mount.h" 12 #include "xfs_btree.h" 13 #include "xfs_alloc_btree.h" 14 #include "xfs_alloc.h" 15 #include "xfs_discard.h" 16 #include "xfs_error.h" 17 #include "xfs_extent_busy.h" 18 #include "xfs_trace.h" 19 #include "xfs_log.h" 20 #include "xfs_ag.h" 21 22 STATIC int 23 xfs_trim_extents( 24 struct xfs_perag *pag, 25 xfs_daddr_t start, 26 xfs_daddr_t end, 27 xfs_daddr_t minlen, 28 uint64_t *blocks_trimmed) 29 { 30 struct xfs_mount *mp = pag->pag_mount; 31 struct block_device *bdev = mp->m_ddev_targp->bt_bdev; 32 struct xfs_btree_cur *cur; 33 struct xfs_buf *agbp; 34 struct xfs_agf *agf; 35 int error; 36 int i; 37 38 /* 39 * Force out the log. This means any transactions that might have freed 40 * space before we take the AGF buffer lock are now on disk, and the 41 * volatile disk cache is flushed. 42 */ 43 xfs_log_force(mp, XFS_LOG_SYNC); 44 45 error = xfs_alloc_read_agf(pag, NULL, 0, &agbp); 46 if (error) 47 return error; 48 agf = agbp->b_addr; 49 50 cur = xfs_allocbt_init_cursor(mp, NULL, agbp, pag, 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, be32_to_cpu(agf->agf_longest), &i); 56 if (error) 57 goto out_del_cursor; 58 59 /* 60 * Loop until we are done with all extents that are large 61 * enough to be worth discarding. 62 */ 63 while (i) { 64 xfs_agblock_t fbno; 65 xfs_extlen_t flen; 66 xfs_daddr_t dbno; 67 xfs_extlen_t dlen; 68 69 error = xfs_alloc_get_rec(cur, &fbno, &flen, &i); 70 if (error) 71 break; 72 if (XFS_IS_CORRUPT(mp, i != 1)) { 73 error = -EFSCORRUPTED; 74 break; 75 } 76 ASSERT(flen <= be32_to_cpu(agf->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, pag->pag_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, pag->pag_agno, fbno, flen); 91 break; 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, pag->pag_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, pag, fbno, flen)) { 109 trace_xfs_discard_busy(mp, pag->pag_agno, fbno, flen); 110 goto next_extent; 111 } 112 113 trace_xfs_discard_extent(mp, pag->pag_agno, fbno, flen); 114 error = blkdev_issue_discard(bdev, dbno, dlen, GFP_NOFS); 115 if (error) 116 break; 117 *blocks_trimmed += flen; 118 119 next_extent: 120 error = xfs_btree_decrement(cur, 0, &i); 121 if (error) 122 break; 123 124 if (fatal_signal_pending(current)) { 125 error = -ERESTARTSYS; 126 break; 127 } 128 } 129 130 out_del_cursor: 131 xfs_btree_del_cursor(cur, error); 132 xfs_buf_relse(agbp); 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 xfs_perag *pag; 151 unsigned int granularity = 152 bdev_discard_granularity(mp->m_ddev_targp->bt_bdev); 153 struct fstrim_range range; 154 xfs_daddr_t start, end, minlen; 155 xfs_agnumber_t agno; 156 uint64_t blocks_trimmed = 0; 157 int error, last_error = 0; 158 159 if (!capable(CAP_SYS_ADMIN)) 160 return -EPERM; 161 if (!bdev_max_discard_sectors(mp->m_ddev_targp->bt_bdev)) 162 return -EOPNOTSUPP; 163 164 /* 165 * We haven't recovered the log, so we cannot use our bnobt-guided 166 * storage zapping commands. 167 */ 168 if (xfs_has_norecovery(mp)) 169 return -EROFS; 170 171 if (copy_from_user(&range, urange, sizeof(range))) 172 return -EFAULT; 173 174 range.minlen = max_t(u64, granularity, range.minlen); 175 minlen = BTOBB(range.minlen); 176 /* 177 * Truncating down the len isn't actually quite correct, but using 178 * BBTOB would mean we trivially get overflows for values 179 * of ULLONG_MAX or slightly lower. And ULLONG_MAX is the default 180 * used by the fstrim application. In the end it really doesn't 181 * matter as trimming blocks is an advisory interface. 182 */ 183 if (range.start >= XFS_FSB_TO_B(mp, mp->m_sb.sb_dblocks) || 184 range.minlen > XFS_FSB_TO_B(mp, mp->m_ag_max_usable) || 185 range.len < mp->m_sb.sb_blocksize) 186 return -EINVAL; 187 188 start = BTOBB(range.start); 189 end = start + BTOBBT(range.len) - 1; 190 191 if (end > XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks) - 1) 192 end = XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks) - 1; 193 194 agno = xfs_daddr_to_agno(mp, start); 195 for_each_perag_range(mp, agno, xfs_daddr_to_agno(mp, end), pag) { 196 error = xfs_trim_extents(pag, start, end, minlen, 197 &blocks_trimmed); 198 if (error) { 199 last_error = error; 200 if (error == -ERESTARTSYS) { 201 xfs_perag_rele(pag); 202 break; 203 } 204 } 205 } 206 207 if (last_error) 208 return last_error; 209 210 range.len = XFS_FSB_TO_B(mp, blocks_trimmed); 211 if (copy_to_user(urange, &range, sizeof(range))) 212 return -EFAULT; 213 return 0; 214 } 215