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.h" 21 #include "xfs_trans.h" 22 #include "xfs_sb.h" 23 #include "xfs_ag.h" 24 #include "xfs_mount.h" 25 #include "xfs_quota.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_extent_busy.h" 34 #include "xfs_discard.h" 35 #include "xfs_trace.h" 36 37 STATIC int 38 xfs_trim_extents( 39 struct xfs_mount *mp, 40 xfs_agnumber_t agno, 41 xfs_daddr_t start, 42 xfs_daddr_t end, 43 xfs_daddr_t minlen, 44 __uint64_t *blocks_trimmed) 45 { 46 struct block_device *bdev = mp->m_ddev_targp->bt_bdev; 47 struct xfs_btree_cur *cur; 48 struct xfs_buf *agbp; 49 struct xfs_perag *pag; 50 int error; 51 int i; 52 53 pag = xfs_perag_get(mp, agno); 54 55 error = xfs_alloc_read_agf(mp, NULL, agno, 0, &agbp); 56 if (error || !agbp) 57 goto out_put_perag; 58 59 cur = xfs_allocbt_init_cursor(mp, NULL, agbp, agno, XFS_BTNUM_CNT); 60 61 /* 62 * Force out the log. This means any transactions that might have freed 63 * space before we took the AGF buffer lock are now on disk, and the 64 * volatile disk cache is flushed. 65 */ 66 xfs_log_force(mp, XFS_LOG_SYNC); 67 68 /* 69 * Look up the longest btree in the AGF and start with it. 70 */ 71 error = xfs_alloc_lookup_ge(cur, 0, 72 be32_to_cpu(XFS_BUF_TO_AGF(agbp)->agf_longest), &i); 73 if (error) 74 goto out_del_cursor; 75 76 /* 77 * Loop until we are done with all extents that are large 78 * enough to be worth discarding. 79 */ 80 while (i) { 81 xfs_agblock_t fbno; 82 xfs_extlen_t flen; 83 xfs_daddr_t dbno; 84 xfs_extlen_t dlen; 85 86 error = xfs_alloc_get_rec(cur, &fbno, &flen, &i); 87 if (error) 88 goto out_del_cursor; 89 XFS_WANT_CORRUPTED_GOTO(i == 1, out_del_cursor); 90 ASSERT(flen <= be32_to_cpu(XFS_BUF_TO_AGF(agbp)->agf_longest)); 91 92 /* 93 * use daddr format for all range/len calculations as that is 94 * the format the range/len variables are supplied in by 95 * userspace. 96 */ 97 dbno = XFS_AGB_TO_DADDR(mp, agno, fbno); 98 dlen = XFS_FSB_TO_BB(mp, flen); 99 100 /* 101 * Too small? Give up. 102 */ 103 if (dlen < minlen) { 104 trace_xfs_discard_toosmall(mp, agno, fbno, flen); 105 goto out_del_cursor; 106 } 107 108 /* 109 * If the extent is entirely outside of the range we are 110 * supposed to discard skip it. Do not bother to trim 111 * down partially overlapping ranges for now. 112 */ 113 if (dbno + dlen < start || dbno > end) { 114 trace_xfs_discard_exclude(mp, agno, fbno, flen); 115 goto next_extent; 116 } 117 118 /* 119 * If any blocks in the range are still busy, skip the 120 * discard and try again the next time. 121 */ 122 if (xfs_extent_busy_search(mp, agno, fbno, flen)) { 123 trace_xfs_discard_busy(mp, agno, fbno, flen); 124 goto next_extent; 125 } 126 127 trace_xfs_discard_extent(mp, agno, fbno, flen); 128 error = -blkdev_issue_discard(bdev, dbno, dlen, GFP_NOFS, 0); 129 if (error) 130 goto out_del_cursor; 131 *blocks_trimmed += flen; 132 133 next_extent: 134 error = xfs_btree_decrement(cur, 0, &i); 135 if (error) 136 goto out_del_cursor; 137 } 138 139 out_del_cursor: 140 xfs_btree_del_cursor(cur, error ? XFS_BTREE_ERROR : XFS_BTREE_NOERROR); 141 xfs_buf_relse(agbp); 142 out_put_perag: 143 xfs_perag_put(pag); 144 return error; 145 } 146 147 /* 148 * trim a range of the filesystem. 149 * 150 * Note: the parameters passed from userspace are byte ranges into the 151 * filesystem which does not match to the format we use for filesystem block 152 * addressing. FSB addressing is sparse (AGNO|AGBNO), while the incoming format 153 * is a linear address range. Hence we need to use DADDR based conversions and 154 * comparisons for determining the correct offset and regions to trim. 155 */ 156 int 157 xfs_ioc_trim( 158 struct xfs_mount *mp, 159 struct fstrim_range __user *urange) 160 { 161 struct request_queue *q = mp->m_ddev_targp->bt_bdev->bd_disk->queue; 162 unsigned int granularity = q->limits.discard_granularity; 163 struct fstrim_range range; 164 xfs_daddr_t start, end, minlen; 165 xfs_agnumber_t start_agno, end_agno, agno; 166 __uint64_t blocks_trimmed = 0; 167 int error, last_error = 0; 168 169 if (!capable(CAP_SYS_ADMIN)) 170 return -XFS_ERROR(EPERM); 171 if (!blk_queue_discard(q)) 172 return -XFS_ERROR(EOPNOTSUPP); 173 if (copy_from_user(&range, urange, sizeof(range))) 174 return -XFS_ERROR(EFAULT); 175 176 /* 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, XFS_ALLOC_AG_MAX_USABLE(mp))) 185 return -XFS_ERROR(EINVAL); 186 187 start = BTOBB(range.start); 188 end = start + BTOBBT(range.len) - 1; 189 minlen = BTOBB(max_t(u64, granularity, range.minlen)); 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 start_agno = xfs_daddr_to_agno(mp, start); 195 end_agno = xfs_daddr_to_agno(mp, end); 196 197 for (agno = start_agno; agno <= end_agno; agno++) { 198 error = -xfs_trim_extents(mp, agno, start, end, minlen, 199 &blocks_trimmed); 200 if (error) 201 last_error = error; 202 } 203 204 if (last_error) 205 return last_error; 206 207 range.len = XFS_FSB_TO_B(mp, blocks_trimmed); 208 if (copy_to_user(urange, &range, sizeof(range))) 209 return -XFS_ERROR(EFAULT); 210 return 0; 211 } 212 213 int 214 xfs_discard_extents( 215 struct xfs_mount *mp, 216 struct list_head *list) 217 { 218 struct xfs_extent_busy *busyp; 219 int error = 0; 220 221 list_for_each_entry(busyp, list, list) { 222 trace_xfs_discard_extent(mp, busyp->agno, busyp->bno, 223 busyp->length); 224 225 error = -blkdev_issue_discard(mp->m_ddev_targp->bt_bdev, 226 XFS_AGB_TO_DADDR(mp, busyp->agno, busyp->bno), 227 XFS_FSB_TO_BB(mp, busyp->length), 228 GFP_NOFS, 0); 229 if (error && error != EOPNOTSUPP) { 230 xfs_info(mp, 231 "discard failed for extent [0x%llu,%u], error %d", 232 (unsigned long long)busyp->bno, 233 busyp->length, 234 error); 235 return error; 236 } 237 } 238 239 return 0; 240 } 241