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_sb.h" 20 #include "xfs_inum.h" 21 #include "xfs_log.h" 22 #include "xfs_ag.h" 23 #include "xfs_mount.h" 24 #include "xfs_quota.h" 25 #include "xfs_trans.h" 26 #include "xfs_alloc_btree.h" 27 #include "xfs_bmap_btree.h" 28 #include "xfs_ialloc_btree.h" 29 #include "xfs_btree.h" 30 #include "xfs_inode.h" 31 #include "xfs_alloc.h" 32 #include "xfs_error.h" 33 #include "xfs_discard.h" 34 #include "xfs_trace.h" 35 36 STATIC int 37 xfs_trim_extents( 38 struct xfs_mount *mp, 39 xfs_agnumber_t agno, 40 xfs_fsblock_t start, 41 xfs_fsblock_t end, 42 xfs_fsblock_t minlen, 43 __uint64_t *blocks_trimmed) 44 { 45 struct block_device *bdev = mp->m_ddev_targp->bt_bdev; 46 struct xfs_btree_cur *cur; 47 struct xfs_buf *agbp; 48 struct xfs_perag *pag; 49 int error; 50 int i; 51 52 pag = xfs_perag_get(mp, agno); 53 54 error = xfs_alloc_read_agf(mp, NULL, agno, 0, &agbp); 55 if (error || !agbp) 56 goto out_put_perag; 57 58 cur = xfs_allocbt_init_cursor(mp, NULL, agbp, agno, XFS_BTNUM_CNT); 59 60 /* 61 * Force out the log. This means any transactions that might have freed 62 * space before we took the AGF buffer lock are now on disk, and the 63 * volatile disk cache is flushed. 64 */ 65 xfs_log_force(mp, XFS_LOG_SYNC); 66 67 /* 68 * Look up the longest btree in the AGF and start with it. 69 */ 70 error = xfs_alloc_lookup_le(cur, 0, 71 XFS_BUF_TO_AGF(agbp)->agf_longest, &i); 72 if (error) 73 goto out_del_cursor; 74 75 /* 76 * Loop until we are done with all extents that are large 77 * enough to be worth discarding. 78 */ 79 while (i) { 80 xfs_agblock_t fbno; 81 xfs_extlen_t flen; 82 83 error = xfs_alloc_get_rec(cur, &fbno, &flen, &i); 84 if (error) 85 goto out_del_cursor; 86 XFS_WANT_CORRUPTED_GOTO(i == 1, out_del_cursor); 87 ASSERT(flen <= XFS_BUF_TO_AGF(agbp)->agf_longest); 88 89 /* 90 * Too small? Give up. 91 */ 92 if (flen < minlen) { 93 trace_xfs_discard_toosmall(mp, agno, fbno, flen); 94 goto out_del_cursor; 95 } 96 97 /* 98 * If the extent is entirely outside of the range we are 99 * supposed to discard skip it. Do not bother to trim 100 * down partially overlapping ranges for now. 101 */ 102 if (XFS_AGB_TO_FSB(mp, agno, fbno) + flen < start || 103 XFS_AGB_TO_FSB(mp, agno, fbno) > end) { 104 trace_xfs_discard_exclude(mp, agno, fbno, flen); 105 goto next_extent; 106 } 107 108 /* 109 * If any blocks in the range are still busy, skip the 110 * discard and try again the next time. 111 */ 112 if (xfs_alloc_busy_search(mp, agno, fbno, flen)) { 113 trace_xfs_discard_busy(mp, agno, fbno, flen); 114 goto next_extent; 115 } 116 117 trace_xfs_discard_extent(mp, agno, fbno, flen); 118 error = -blkdev_issue_discard(bdev, 119 XFS_AGB_TO_DADDR(mp, agno, fbno), 120 XFS_FSB_TO_BB(mp, flen), 121 GFP_NOFS, 0); 122 if (error) 123 goto out_del_cursor; 124 *blocks_trimmed += flen; 125 126 next_extent: 127 error = xfs_btree_decrement(cur, 0, &i); 128 if (error) 129 goto out_del_cursor; 130 } 131 132 out_del_cursor: 133 xfs_btree_del_cursor(cur, error ? XFS_BTREE_ERROR : XFS_BTREE_NOERROR); 134 xfs_buf_relse(agbp); 135 out_put_perag: 136 xfs_perag_put(pag); 137 return error; 138 } 139 140 int 141 xfs_ioc_trim( 142 struct xfs_mount *mp, 143 struct fstrim_range __user *urange) 144 { 145 struct request_queue *q = mp->m_ddev_targp->bt_bdev->bd_disk->queue; 146 unsigned int granularity = q->limits.discard_granularity; 147 struct fstrim_range range; 148 xfs_fsblock_t start, end, minlen; 149 xfs_agnumber_t start_agno, end_agno, agno; 150 __uint64_t blocks_trimmed = 0; 151 int error, last_error = 0; 152 153 if (!capable(CAP_SYS_ADMIN)) 154 return -XFS_ERROR(EPERM); 155 if (!blk_queue_discard(q)) 156 return -XFS_ERROR(EOPNOTSUPP); 157 if (copy_from_user(&range, urange, sizeof(range))) 158 return -XFS_ERROR(EFAULT); 159 160 /* 161 * Truncating down the len isn't actually quite correct, but using 162 * XFS_B_TO_FSB would mean we trivially get overflows for values 163 * of ULLONG_MAX or slightly lower. And ULLONG_MAX is the default 164 * used by the fstrim application. In the end it really doesn't 165 * matter as trimming blocks is an advisory interface. 166 */ 167 start = XFS_B_TO_FSBT(mp, range.start); 168 end = start + XFS_B_TO_FSBT(mp, range.len) - 1; 169 minlen = XFS_B_TO_FSB(mp, max_t(u64, granularity, range.minlen)); 170 171 if (start >= mp->m_sb.sb_dblocks) 172 return -XFS_ERROR(EINVAL); 173 if (end > mp->m_sb.sb_dblocks - 1) 174 end = mp->m_sb.sb_dblocks - 1; 175 176 start_agno = XFS_FSB_TO_AGNO(mp, start); 177 end_agno = XFS_FSB_TO_AGNO(mp, end); 178 179 for (agno = start_agno; agno <= end_agno; agno++) { 180 error = -xfs_trim_extents(mp, agno, start, end, minlen, 181 &blocks_trimmed); 182 if (error) 183 last_error = error; 184 } 185 186 if (last_error) 187 return last_error; 188 189 range.len = XFS_FSB_TO_B(mp, blocks_trimmed); 190 if (copy_to_user(urange, &range, sizeof(range))) 191 return -XFS_ERROR(EFAULT); 192 return 0; 193 } 194 195 int 196 xfs_discard_extents( 197 struct xfs_mount *mp, 198 struct list_head *list) 199 { 200 struct xfs_busy_extent *busyp; 201 int error = 0; 202 203 list_for_each_entry(busyp, list, list) { 204 trace_xfs_discard_extent(mp, busyp->agno, busyp->bno, 205 busyp->length); 206 207 error = -blkdev_issue_discard(mp->m_ddev_targp->bt_bdev, 208 XFS_AGB_TO_DADDR(mp, busyp->agno, busyp->bno), 209 XFS_FSB_TO_BB(mp, busyp->length), 210 GFP_NOFS, 0); 211 if (error && error != EOPNOTSUPP) { 212 xfs_info(mp, 213 "discard failed for extent [0x%llu,%u], error %d", 214 (unsigned long long)busyp->bno, 215 busyp->length, 216 error); 217 return error; 218 } 219 } 220 221 return 0; 222 } 223