1 /* 2 * Copyright (C) 2010 Red Hat, Inc. 3 * All Rights Reserved. 4 * 5 * This program is free software; you can redistribute it and/or 6 * modify it under the terms of the GNU General Public License as 7 * published by the Free Software Foundation. 8 * 9 * This program is distributed in the hope that it would be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, write the Free Software Foundation, 16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 17 */ 18 #include "xfs.h" 19 #include "xfs_format.h" 20 #include "xfs_log_format.h" 21 #include "xfs_trans_resv.h" 22 #include "xfs_sb.h" 23 #include "xfs_mount.h" 24 #include "xfs_quota.h" 25 #include "xfs_inode.h" 26 #include "xfs_btree.h" 27 #include "xfs_alloc_btree.h" 28 #include "xfs_alloc.h" 29 #include "xfs_error.h" 30 #include "xfs_extent_busy.h" 31 #include "xfs_discard.h" 32 #include "xfs_trace.h" 33 #include "xfs_log.h" 34 35 STATIC int 36 xfs_trim_extents( 37 struct xfs_mount *mp, 38 xfs_agnumber_t agno, 39 xfs_daddr_t start, 40 xfs_daddr_t end, 41 xfs_daddr_t minlen, 42 __uint64_t *blocks_trimmed) 43 { 44 struct block_device *bdev = mp->m_ddev_targp->bt_bdev; 45 struct xfs_btree_cur *cur; 46 struct xfs_buf *agbp; 47 struct xfs_perag *pag; 48 int error; 49 int i; 50 51 pag = xfs_perag_get(mp, agno); 52 53 error = xfs_alloc_read_agf(mp, NULL, agno, 0, &agbp); 54 if (error || !agbp) 55 goto out_put_perag; 56 57 cur = xfs_allocbt_init_cursor(mp, NULL, agbp, agno, XFS_BTNUM_CNT); 58 59 /* 60 * Force out the log. This means any transactions that might have freed 61 * space before we took the AGF buffer lock are now on disk, and the 62 * volatile disk cache is flushed. 63 */ 64 xfs_log_force(mp, XFS_LOG_SYNC); 65 66 /* 67 * Look up the longest btree in the AGF and start with it. 68 */ 69 error = xfs_alloc_lookup_ge(cur, 0, 70 be32_to_cpu(XFS_BUF_TO_AGF(agbp)->agf_longest), &i); 71 if (error) 72 goto out_del_cursor; 73 74 /* 75 * Loop until we are done with all extents that are large 76 * enough to be worth discarding. 77 */ 78 while (i) { 79 xfs_agblock_t fbno; 80 xfs_extlen_t flen; 81 xfs_daddr_t dbno; 82 xfs_extlen_t dlen; 83 84 error = xfs_alloc_get_rec(cur, &fbno, &flen, &i); 85 if (error) 86 goto out_del_cursor; 87 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, out_del_cursor); 88 ASSERT(flen <= be32_to_cpu(XFS_BUF_TO_AGF(agbp)->agf_longest)); 89 90 /* 91 * use daddr format for all range/len calculations as that is 92 * the format the range/len variables are supplied in by 93 * userspace. 94 */ 95 dbno = XFS_AGB_TO_DADDR(mp, agno, fbno); 96 dlen = XFS_FSB_TO_BB(mp, flen); 97 98 /* 99 * Too small? Give up. 100 */ 101 if (dlen < minlen) { 102 trace_xfs_discard_toosmall(mp, agno, fbno, flen); 103 goto out_del_cursor; 104 } 105 106 /* 107 * If the extent is entirely outside of the range we are 108 * supposed to discard skip it. Do not bother to trim 109 * down partially overlapping ranges for now. 110 */ 111 if (dbno + dlen < start || dbno > end) { 112 trace_xfs_discard_exclude(mp, agno, fbno, flen); 113 goto next_extent; 114 } 115 116 /* 117 * If any blocks in the range are still busy, skip the 118 * discard and try again the next time. 119 */ 120 if (xfs_extent_busy_search(mp, agno, fbno, flen)) { 121 trace_xfs_discard_busy(mp, agno, fbno, flen); 122 goto next_extent; 123 } 124 125 trace_xfs_discard_extent(mp, agno, fbno, flen); 126 error = blkdev_issue_discard(bdev, dbno, dlen, GFP_NOFS, 0); 127 if (error) 128 goto out_del_cursor; 129 *blocks_trimmed += flen; 130 131 next_extent: 132 error = xfs_btree_decrement(cur, 0, &i); 133 if (error) 134 goto out_del_cursor; 135 136 if (fatal_signal_pending(current)) { 137 error = -ERESTARTSYS; 138 goto out_del_cursor; 139 } 140 } 141 142 out_del_cursor: 143 xfs_btree_del_cursor(cur, error ? XFS_BTREE_ERROR : XFS_BTREE_NOERROR); 144 xfs_buf_relse(agbp); 145 out_put_perag: 146 xfs_perag_put(pag); 147 return error; 148 } 149 150 /* 151 * trim a range of the filesystem. 152 * 153 * Note: the parameters passed from userspace are byte ranges into the 154 * filesystem which does not match to the format we use for filesystem block 155 * addressing. FSB addressing is sparse (AGNO|AGBNO), while the incoming format 156 * is a linear address range. Hence we need to use DADDR based conversions and 157 * comparisons for determining the correct offset and regions to trim. 158 */ 159 int 160 xfs_ioc_trim( 161 struct xfs_mount *mp, 162 struct fstrim_range __user *urange) 163 { 164 struct request_queue *q = bdev_get_queue(mp->m_ddev_targp->bt_bdev); 165 unsigned int granularity = q->limits.discard_granularity; 166 struct fstrim_range range; 167 xfs_daddr_t start, end, minlen; 168 xfs_agnumber_t start_agno, end_agno, agno; 169 __uint64_t blocks_trimmed = 0; 170 int error, last_error = 0; 171 172 if (!capable(CAP_SYS_ADMIN)) 173 return -EPERM; 174 if (!blk_queue_discard(q)) 175 return -EOPNOTSUPP; 176 if (copy_from_user(&range, urange, sizeof(range))) 177 return -EFAULT; 178 179 /* 180 * Truncating down the len isn't actually quite correct, but using 181 * BBTOB would mean we trivially get overflows for values 182 * of ULLONG_MAX or slightly lower. And ULLONG_MAX is the default 183 * used by the fstrim application. In the end it really doesn't 184 * matter as trimming blocks is an advisory interface. 185 */ 186 if (range.start >= XFS_FSB_TO_B(mp, mp->m_sb.sb_dblocks) || 187 range.minlen > XFS_FSB_TO_B(mp, mp->m_ag_max_usable) || 188 range.len < mp->m_sb.sb_blocksize) 189 return -EINVAL; 190 191 start = BTOBB(range.start); 192 end = start + BTOBBT(range.len) - 1; 193 minlen = BTOBB(max_t(u64, granularity, range.minlen)); 194 195 if (end > XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks) - 1) 196 end = XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks)- 1; 197 198 start_agno = xfs_daddr_to_agno(mp, start); 199 end_agno = xfs_daddr_to_agno(mp, end); 200 201 for (agno = start_agno; agno <= end_agno; agno++) { 202 error = xfs_trim_extents(mp, agno, start, end, minlen, 203 &blocks_trimmed); 204 if (error) { 205 last_error = error; 206 if (error == -ERESTARTSYS) 207 break; 208 } 209 } 210 211 if (last_error) 212 return last_error; 213 214 range.len = XFS_FSB_TO_B(mp, blocks_trimmed); 215 if (copy_to_user(urange, &range, sizeof(range))) 216 return -EFAULT; 217 return 0; 218 } 219