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_daddr_t start, 41 xfs_daddr_t end, 42 xfs_daddr_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_ge(cur, 0, 71 be32_to_cpu(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 xfs_daddr_t dbno; 83 xfs_extlen_t dlen; 84 85 error = xfs_alloc_get_rec(cur, &fbno, &flen, &i); 86 if (error) 87 goto out_del_cursor; 88 XFS_WANT_CORRUPTED_GOTO(i == 1, out_del_cursor); 89 ASSERT(flen <= be32_to_cpu(XFS_BUF_TO_AGF(agbp)->agf_longest)); 90 91 /* 92 * use daddr format for all range/len calculations as that is 93 * the format the range/len variables are supplied in by 94 * userspace. 95 */ 96 dbno = XFS_AGB_TO_DADDR(mp, agno, fbno); 97 dlen = XFS_FSB_TO_BB(mp, flen); 98 99 /* 100 * Too small? Give up. 101 */ 102 if (dlen < minlen) { 103 trace_xfs_discard_toosmall(mp, agno, fbno, flen); 104 goto out_del_cursor; 105 } 106 107 /* 108 * If the extent is entirely outside of the range we are 109 * supposed to discard skip it. Do not bother to trim 110 * down partially overlapping ranges for now. 111 */ 112 if (dbno + dlen < start || dbno > end) { 113 trace_xfs_discard_exclude(mp, agno, fbno, flen); 114 goto next_extent; 115 } 116 117 /* 118 * If any blocks in the range are still busy, skip the 119 * discard and try again the next time. 120 */ 121 if (xfs_alloc_busy_search(mp, agno, fbno, flen)) { 122 trace_xfs_discard_busy(mp, agno, fbno, flen); 123 goto next_extent; 124 } 125 126 trace_xfs_discard_extent(mp, agno, fbno, flen); 127 error = -blkdev_issue_discard(bdev, dbno, dlen, GFP_NOFS, 0); 128 if (error) 129 goto out_del_cursor; 130 *blocks_trimmed += flen; 131 132 next_extent: 133 error = xfs_btree_decrement(cur, 0, &i); 134 if (error) 135 goto out_del_cursor; 136 } 137 138 out_del_cursor: 139 xfs_btree_del_cursor(cur, error ? XFS_BTREE_ERROR : XFS_BTREE_NOERROR); 140 xfs_buf_relse(agbp); 141 out_put_perag: 142 xfs_perag_put(pag); 143 return error; 144 } 145 146 /* 147 * trim a range of the filesystem. 148 * 149 * Note: the parameters passed from userspace are byte ranges into the 150 * filesystem which does not match to the format we use for filesystem block 151 * addressing. FSB addressing is sparse (AGNO|AGBNO), while the incoming format 152 * is a linear address range. Hence we need to use DADDR based conversions and 153 * comparisons for determining the correct offset and regions to trim. 154 */ 155 int 156 xfs_ioc_trim( 157 struct xfs_mount *mp, 158 struct fstrim_range __user *urange) 159 { 160 struct request_queue *q = mp->m_ddev_targp->bt_bdev->bd_disk->queue; 161 unsigned int granularity = q->limits.discard_granularity; 162 struct fstrim_range range; 163 xfs_daddr_t start, end, minlen; 164 xfs_agnumber_t start_agno, end_agno, agno; 165 __uint64_t blocks_trimmed = 0; 166 int error, last_error = 0; 167 168 if (!capable(CAP_SYS_ADMIN)) 169 return -XFS_ERROR(EPERM); 170 if (!blk_queue_discard(q)) 171 return -XFS_ERROR(EOPNOTSUPP); 172 if (copy_from_user(&range, urange, sizeof(range))) 173 return -XFS_ERROR(EFAULT); 174 175 /* 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 start = BTOBB(range.start); 183 end = start + BTOBBT(range.len) - 1; 184 minlen = BTOBB(max_t(u64, granularity, range.minlen)); 185 186 if (XFS_BB_TO_FSB(mp, start) >= mp->m_sb.sb_dblocks) 187 return -XFS_ERROR(EINVAL); 188 if (end > XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks) - 1) 189 end = XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks)- 1; 190 191 start_agno = xfs_daddr_to_agno(mp, start); 192 end_agno = xfs_daddr_to_agno(mp, end); 193 194 for (agno = start_agno; agno <= end_agno; agno++) { 195 error = -xfs_trim_extents(mp, agno, start, end, minlen, 196 &blocks_trimmed); 197 if (error) 198 last_error = error; 199 } 200 201 if (last_error) 202 return last_error; 203 204 range.len = XFS_FSB_TO_B(mp, blocks_trimmed); 205 if (copy_to_user(urange, &range, sizeof(range))) 206 return -XFS_ERROR(EFAULT); 207 return 0; 208 } 209 210 int 211 xfs_discard_extents( 212 struct xfs_mount *mp, 213 struct list_head *list) 214 { 215 struct xfs_busy_extent *busyp; 216 int error = 0; 217 218 list_for_each_entry(busyp, list, list) { 219 trace_xfs_discard_extent(mp, busyp->agno, busyp->bno, 220 busyp->length); 221 222 error = -blkdev_issue_discard(mp->m_ddev_targp->bt_bdev, 223 XFS_AGB_TO_DADDR(mp, busyp->agno, busyp->bno), 224 XFS_FSB_TO_BB(mp, busyp->length), 225 GFP_NOFS, 0); 226 if (error && error != EOPNOTSUPP) { 227 xfs_info(mp, 228 "discard failed for extent [0x%llu,%u], error %d", 229 (unsigned long long)busyp->bno, 230 busyp->length, 231 error); 232 return error; 233 } 234 } 235 236 return 0; 237 } 238