| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Christoph Hellwig | 5547 | 34.94% | 43 | 14.63% |
| Brian Foster | 3479 | 21.91% | 30 | 10.20% |
| David Chinner | 3084 | 19.43% | 83 | 28.23% |
| Darrick J. Wong | 3073 | 19.36% | 98 | 33.33% |
| Eric Sandeen | 168 | 1.06% | 10 | 3.40% |
| Chandan Babu R | 145 | 0.91% | 2 | 0.68% |
| Nathan Scott | 105 | 0.66% | 4 | 1.36% |
| zhengbin | 72 | 0.45% | 1 | 0.34% |
| Geoffrey Wehrman | 38 | 0.24% | 1 | 0.34% |
| Jan Kara | 37 | 0.23% | 3 | 1.02% |
| Russell Cattelan | 33 | 0.21% | 2 | 0.68% |
| Barry Naujok | 22 | 0.14% | 1 | 0.34% |
| Omar Sandoval | 13 | 0.08% | 1 | 0.34% |
| Yingping Lu | 13 | 0.08% | 1 | 0.34% |
| Carlos Maiolino | 11 | 0.07% | 4 | 1.36% |
| Hsiang Kao | 8 | 0.05% | 1 | 0.34% |
| Bill O'Donnell | 6 | 0.04% | 1 | 0.34% |
| Marcin Ślusarz | 6 | 0.04% | 1 | 0.34% |
| Namjae Jeon | 5 | 0.03% | 1 | 0.34% |
| Jason A. Donenfeld | 4 | 0.03% | 2 | 0.68% |
| Ian Kent | 3 | 0.02% | 1 | 0.34% |
| Slark Xiao | 1 | 0.01% | 1 | 0.34% |
| Glen Overby | 1 | 0.01% | 1 | 0.34% |
| Joe Perches | 1 | 0.01% | 1 | 0.34% |
| Total | 15875 | 294 |
// SPDX-License-Identifier: GPL-2.0 /* * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc. * All Rights Reserved. */ #include "xfs.h" #include "xfs_fs.h" #include "xfs_format.h" #include "xfs_log_format.h" #include "xfs_shared.h" #include "xfs_trans_resv.h" #include "xfs_bit.h" #include "xfs_mount.h" #include "xfs_defer.h" #include "xfs_btree.h" #include "xfs_rmap.h" #include "xfs_alloc_btree.h" #include "xfs_alloc.h" #include "xfs_extent_busy.h" #include "xfs_errortag.h" #include "xfs_error.h" #include "xfs_trace.h" #include "xfs_trans.h" #include "xfs_buf_item.h" #include "xfs_log.h" #include "xfs_ag.h" #include "xfs_ag_resv.h" #include "xfs_bmap.h" struct kmem_cache *xfs_extfree_item_cache; struct workqueue_struct *xfs_alloc_wq; #define XFS_ABSDIFF(a,b) (((a) <= (b)) ? ((b) - (a)) : ((a) - (b))) #define XFSA_FIXUP_BNO_OK 1 #define XFSA_FIXUP_CNT_OK 2 /* * Size of the AGFL. For CRC-enabled filesystes we steal a couple of slots in * the beginning of the block for a proper header with the location information * and CRC. */ unsigned int xfs_agfl_size( struct xfs_mount *mp) { unsigned int size = mp->m_sb.sb_sectsize; if (xfs_has_crc(mp)) size -= sizeof(struct xfs_agfl); return size / sizeof(xfs_agblock_t); } unsigned int xfs_refc_block( struct xfs_mount *mp) { if (xfs_has_rmapbt(mp)) return XFS_RMAP_BLOCK(mp) + 1; if (xfs_has_finobt(mp)) return XFS_FIBT_BLOCK(mp) + 1; return XFS_IBT_BLOCK(mp) + 1; } xfs_extlen_t xfs_prealloc_blocks( struct xfs_mount *mp) { if (xfs_has_reflink(mp)) return xfs_refc_block(mp) + 1; if (xfs_has_rmapbt(mp)) return XFS_RMAP_BLOCK(mp) + 1; if (xfs_has_finobt(mp)) return XFS_FIBT_BLOCK(mp) + 1; return XFS_IBT_BLOCK(mp) + 1; } /* * The number of blocks per AG that we withhold from xfs_mod_fdblocks to * guarantee that we can refill the AGFL prior to allocating space in a nearly * full AG. Although the space described by the free space btrees, the * blocks used by the freesp btrees themselves, and the blocks owned by the * AGFL are counted in the ondisk fdblocks, it's a mistake to let the ondisk * free space in the AG drop so low that the free space btrees cannot refill an * empty AGFL up to the minimum level. Rather than grind through empty AGs * until the fs goes down, we subtract this many AG blocks from the incore * fdblocks to ensure user allocation does not overcommit the space the * filesystem needs for the AGFLs. The rmap btree uses a per-AG reservation to * withhold space from xfs_mod_fdblocks, so we do not account for that here. */ #define XFS_ALLOCBT_AGFL_RESERVE 4 /* * Compute the number of blocks that we set aside to guarantee the ability to * refill the AGFL and handle a full bmap btree split. * * In order to avoid ENOSPC-related deadlock caused by out-of-order locking of * AGF buffer (PV 947395), we place constraints on the relationship among * actual allocations for data blocks, freelist blocks, and potential file data * bmap btree blocks. However, these restrictions may result in no actual space * allocated for a delayed extent, for example, a data block in a certain AG is * allocated but there is no additional block for the additional bmap btree * block due to a split of the bmap btree of the file. The result of this may * lead to an infinite loop when the file gets flushed to disk and all delayed * extents need to be actually allocated. To get around this, we explicitly set * aside a few blocks which will not be reserved in delayed allocation. * * For each AG, we need to reserve enough blocks to replenish a totally empty * AGFL and 4 more to handle a potential split of the file's bmap btree. */ unsigned int xfs_alloc_set_aside( struct xfs_mount *mp) { return mp->m_sb.sb_agcount * (XFS_ALLOCBT_AGFL_RESERVE + 4); } /* * When deciding how much space to allocate out of an AG, we limit the * allocation maximum size to the size the AG. However, we cannot use all the * blocks in the AG - some are permanently used by metadata. These * blocks are generally: * - the AG superblock, AGF, AGI and AGFL * - the AGF (bno and cnt) and AGI btree root blocks, and optionally * the AGI free inode and rmap btree root blocks. * - blocks on the AGFL according to xfs_alloc_set_aside() limits * - the rmapbt root block * * The AG headers are sector sized, so the amount of space they take up is * dependent on filesystem geometry. The others are all single blocks. */ unsigned int xfs_alloc_ag_max_usable( struct xfs_mount *mp) { unsigned int blocks; blocks = XFS_BB_TO_FSB(mp, XFS_FSS_TO_BB(mp, 4)); /* ag headers */ blocks += XFS_ALLOCBT_AGFL_RESERVE; blocks += 3; /* AGF, AGI btree root blocks */ if (xfs_has_finobt(mp)) blocks++; /* finobt root block */ if (xfs_has_rmapbt(mp)) blocks++; /* rmap root block */ if (xfs_has_reflink(mp)) blocks++; /* refcount root block */ return mp->m_sb.sb_agblocks - blocks; } /* * Lookup the record equal to [bno, len] in the btree given by cur. */ STATIC int /* error */ xfs_alloc_lookup_eq( struct xfs_btree_cur *cur, /* btree cursor */ xfs_agblock_t bno, /* starting block of extent */ xfs_extlen_t len, /* length of extent */ int *stat) /* success/failure */ { int error; cur->bc_rec.a.ar_startblock = bno; cur->bc_rec.a.ar_blockcount = len; error = xfs_btree_lookup(cur, XFS_LOOKUP_EQ, stat); cur->bc_ag.abt.active = (*stat == 1); return error; } /* * Lookup the first record greater than or equal to [bno, len] * in the btree given by cur. */ int /* error */ xfs_alloc_lookup_ge( struct xfs_btree_cur *cur, /* btree cursor */ xfs_agblock_t bno, /* starting block of extent */ xfs_extlen_t len, /* length of extent */ int *stat) /* success/failure */ { int error; cur->bc_rec.a.ar_startblock = bno; cur->bc_rec.a.ar_blockcount = len; error = xfs_btree_lookup(cur, XFS_LOOKUP_GE, stat); cur->bc_ag.abt.active = (*stat == 1); return error; } /* * Lookup the first record less than or equal to [bno, len] * in the btree given by cur. */ int /* error */ xfs_alloc_lookup_le( struct xfs_btree_cur *cur, /* btree cursor */ xfs_agblock_t bno, /* starting block of extent */ xfs_extlen_t len, /* length of extent */ int *stat) /* success/failure */ { int error; cur->bc_rec.a.ar_startblock = bno; cur->bc_rec.a.ar_blockcount = len; error = xfs_btree_lookup(cur, XFS_LOOKUP_LE, stat); cur->bc_ag.abt.active = (*stat == 1); return error; } static inline bool xfs_alloc_cur_active( struct xfs_btree_cur *cur) { return cur && cur->bc_ag.abt.active; } /* * Update the record referred to by cur to the value given * by [bno, len]. * This either works (return 0) or gets an EFSCORRUPTED error. */ STATIC int /* error */ xfs_alloc_update( struct xfs_btree_cur *cur, /* btree cursor */ xfs_agblock_t bno, /* starting block of extent */ xfs_extlen_t len) /* length of extent */ { union xfs_btree_rec rec; rec.alloc.ar_startblock = cpu_to_be32(bno); rec.alloc.ar_blockcount = cpu_to_be32(len); return xfs_btree_update(cur, &rec); } /* Convert the ondisk btree record to its incore representation. */ void xfs_alloc_btrec_to_irec( const union xfs_btree_rec *rec, struct xfs_alloc_rec_incore *irec) { irec->ar_startblock = be32_to_cpu(rec->alloc.ar_startblock); irec->ar_blockcount = be32_to_cpu(rec->alloc.ar_blockcount); } /* Simple checks for free space records. */ xfs_failaddr_t xfs_alloc_check_irec( struct xfs_perag *pag, const struct xfs_alloc_rec_incore *irec) { if (irec->ar_blockcount == 0) return __this_address; /* check for valid extent range, including overflow */ if (!xfs_verify_agbext(pag, irec->ar_startblock, irec->ar_blockcount)) return __this_address; return NULL; } static inline int xfs_alloc_complain_bad_rec( struct xfs_btree_cur *cur, xfs_failaddr_t fa, const struct xfs_alloc_rec_incore *irec) { struct xfs_mount *mp = cur->bc_mp; xfs_warn(mp, "%s Freespace BTree record corruption in AG %d detected at %pS!", cur->bc_btnum == XFS_BTNUM_BNO ? "Block" : "Size", cur->bc_ag.pag->pag_agno, fa); xfs_warn(mp, "start block 0x%x block count 0x%x", irec->ar_startblock, irec->ar_blockcount); return -EFSCORRUPTED; } /* * Get the data from the pointed-to record. */ int /* error */ xfs_alloc_get_rec( struct xfs_btree_cur *cur, /* btree cursor */ xfs_agblock_t *bno, /* output: starting block of extent */ xfs_extlen_t *len, /* output: length of extent */ int *stat) /* output: success/failure */ { struct xfs_alloc_rec_incore irec; union xfs_btree_rec *rec; xfs_failaddr_t fa; int error; error = xfs_btree_get_rec(cur, &rec, stat); if (error || !(*stat)) return error; xfs_alloc_btrec_to_irec(rec, &irec); fa = xfs_alloc_check_irec(cur->bc_ag.pag, &irec); if (fa) return xfs_alloc_complain_bad_rec(cur, fa, &irec); *bno = irec.ar_startblock; *len = irec.ar_blockcount; return 0; } /* * Compute aligned version of the found extent. * Takes alignment and min length into account. */ STATIC bool xfs_alloc_compute_aligned( xfs_alloc_arg_t *args, /* allocation argument structure */ xfs_agblock_t foundbno, /* starting block in found extent */ xfs_extlen_t foundlen, /* length in found extent */ xfs_agblock_t *resbno, /* result block number */ xfs_extlen_t *reslen, /* result length */ unsigned *busy_gen) { xfs_agblock_t bno = foundbno; xfs_extlen_t len = foundlen; xfs_extlen_t diff; bool busy; /* Trim busy sections out of found extent */ busy = xfs_extent_busy_trim(args, &bno, &len, busy_gen); /* * If we have a largish extent that happens to start before min_agbno, * see if we can shift it into range... */ if (bno < args->min_agbno && bno + len > args->min_agbno) { diff = args->min_agbno - bno; if (len > diff) { bno += diff; len -= diff; } } if (args->alignment > 1 && len >= args->minlen) { xfs_agblock_t aligned_bno = roundup(bno, args->alignment); diff = aligned_bno - bno; *resbno = aligned_bno; *reslen = diff >= len ? 0 : len - diff; } else { *resbno = bno; *reslen = len; } return busy; } /* * Compute best start block and diff for "near" allocations. * freelen >= wantlen already checked by caller. */ STATIC xfs_extlen_t /* difference value (absolute) */ xfs_alloc_compute_diff( xfs_agblock_t wantbno, /* target starting block */ xfs_extlen_t wantlen, /* target length */ xfs_extlen_t alignment, /* target alignment */ int datatype, /* are we allocating data? */ xfs_agblock_t freebno, /* freespace's starting block */ xfs_extlen_t freelen, /* freespace's length */ xfs_agblock_t *newbnop) /* result: best start block from free */ { xfs_agblock_t freeend; /* end of freespace extent */ xfs_agblock_t newbno1; /* return block number */ xfs_agblock_t newbno2; /* other new block number */ xfs_extlen_t newlen1=0; /* length with newbno1 */ xfs_extlen_t newlen2=0; /* length with newbno2 */ xfs_agblock_t wantend; /* end of target extent */ bool userdata = datatype & XFS_ALLOC_USERDATA; ASSERT(freelen >= wantlen); freeend = freebno + freelen; wantend = wantbno + wantlen; /* * We want to allocate from the start of a free extent if it is past * the desired block or if we are allocating user data and the free * extent is before desired block. The second case is there to allow * for contiguous allocation from the remaining free space if the file * grows in the short term. */ if (freebno >= wantbno || (userdata && freeend < wantend)) { if ((newbno1 = roundup(freebno, alignment)) >= freeend) newbno1 = NULLAGBLOCK; } else if (freeend >= wantend && alignment > 1) { newbno1 = roundup(wantbno, alignment); newbno2 = newbno1 - alignment; if (newbno1 >= freeend) newbno1 = NULLAGBLOCK; else newlen1 = XFS_EXTLEN_MIN(wantlen, freeend - newbno1); if (newbno2 < freebno) newbno2 = NULLAGBLOCK; else newlen2 = XFS_EXTLEN_MIN(wantlen, freeend - newbno2); if (newbno1 != NULLAGBLOCK && newbno2 != NULLAGBLOCK) { if (newlen1 < newlen2 || (newlen1 == newlen2 && XFS_ABSDIFF(newbno1, wantbno) > XFS_ABSDIFF(newbno2, wantbno))) newbno1 = newbno2; } else if (newbno2 != NULLAGBLOCK) newbno1 = newbno2; } else if (freeend >= wantend) { newbno1 = wantbno; } else if (alignment > 1) { newbno1 = roundup(freeend - wantlen, alignment); if (newbno1 > freeend - wantlen && newbno1 - alignment >= freebno) newbno1 -= alignment; else if (newbno1 >= freeend) newbno1 = NULLAGBLOCK; } else newbno1 = freeend - wantlen; *newbnop = newbno1; return newbno1 == NULLAGBLOCK ? 0 : XFS_ABSDIFF(newbno1, wantbno); } /* * Fix up the length, based on mod and prod. * len should be k * prod + mod for some k. * If len is too small it is returned unchanged. * If len hits maxlen it is left alone. */ STATIC void xfs_alloc_fix_len( xfs_alloc_arg_t *args) /* allocation argument structure */ { xfs_extlen_t k; xfs_extlen_t rlen; ASSERT(args->mod < args->prod); rlen = args->len; ASSERT(rlen >= args->minlen); ASSERT(rlen <= args->maxlen); if (args->prod <= 1 || rlen < args->mod || rlen == args->maxlen || (args->mod == 0 && rlen < args->prod)) return; k = rlen % args->prod; if (k == args->mod) return; if (k > args->mod) rlen = rlen - (k - args->mod); else rlen = rlen - args->prod + (args->mod - k); /* casts to (int) catch length underflows */ if ((int)rlen < (int)args->minlen) return; ASSERT(rlen >= args->minlen && rlen <= args->maxlen); ASSERT(rlen % args->prod == args->mod); ASSERT(args->pag->pagf_freeblks + args->pag->pagf_flcount >= rlen + args->minleft); args->len = rlen; } /* * Update the two btrees, logically removing from freespace the extent * starting at rbno, rlen blocks. The extent is contained within the * actual (current) free extent fbno for flen blocks. * Flags are passed in indicating whether the cursors are set to the * relevant records. */ STATIC int /* error code */ xfs_alloc_fixup_trees( struct xfs_btree_cur *cnt_cur, /* cursor for by-size btree */ struct xfs_btree_cur *bno_cur, /* cursor for by-block btree */ xfs_agblock_t fbno, /* starting block of free extent */ xfs_extlen_t flen, /* length of free extent */ xfs_agblock_t rbno, /* starting block of returned extent */ xfs_extlen_t rlen, /* length of returned extent */ int flags) /* flags, XFSA_FIXUP_... */ { int error; /* error code */ int i; /* operation results */ xfs_agblock_t nfbno1; /* first new free startblock */ xfs_agblock_t nfbno2; /* second new free startblock */ xfs_extlen_t nflen1=0; /* first new free length */ xfs_extlen_t nflen2=0; /* second new free length */ struct xfs_mount *mp; mp = cnt_cur->bc_mp; /* * Look up the record in the by-size tree if necessary. */ if (flags & XFSA_FIXUP_CNT_OK) { #ifdef DEBUG if ((error = xfs_alloc_get_rec(cnt_cur, &nfbno1, &nflen1, &i))) return error; if (XFS_IS_CORRUPT(mp, i != 1 || nfbno1 != fbno || nflen1 != flen)) return -EFSCORRUPTED; #endif } else { if ((error = xfs_alloc_lookup_eq(cnt_cur, fbno, flen, &i))) return error; if (XFS_IS_CORRUPT(mp, i != 1)) return -EFSCORRUPTED; } /* * Look up the record in the by-block tree if necessary. */ if (flags & XFSA_FIXUP_BNO_OK) { #ifdef DEBUG if ((error = xfs_alloc_get_rec(bno_cur, &nfbno1, &nflen1, &i))) return error; if (XFS_IS_CORRUPT(mp, i != 1 || nfbno1 != fbno || nflen1 != flen)) return -EFSCORRUPTED; #endif } else { if ((error = xfs_alloc_lookup_eq(bno_cur, fbno, flen, &i))) return error; if (XFS_IS_CORRUPT(mp, i != 1)) return -EFSCORRUPTED; } #ifdef DEBUG if (bno_cur->bc_nlevels == 1 && cnt_cur->bc_nlevels == 1) { struct xfs_btree_block *bnoblock; struct xfs_btree_block *cntblock; bnoblock = XFS_BUF_TO_BLOCK(bno_cur->bc_levels[0].bp); cntblock = XFS_BUF_TO_BLOCK(cnt_cur->bc_levels[0].bp); if (XFS_IS_CORRUPT(mp, bnoblock->bb_numrecs != cntblock->bb_numrecs)) return -EFSCORRUPTED; } #endif /* * Deal with all four cases: the allocated record is contained * within the freespace record, so we can have new freespace * at either (or both) end, or no freespace remaining. */ if (rbno == fbno && rlen == flen) nfbno1 = nfbno2 = NULLAGBLOCK; else if (rbno == fbno) { nfbno1 = rbno + rlen; nflen1 = flen - rlen; nfbno2 = NULLAGBLOCK; } else if (rbno + rlen == fbno + flen) { nfbno1 = fbno; nflen1 = flen - rlen; nfbno2 = NULLAGBLOCK; } else { nfbno1 = fbno; nflen1 = rbno - fbno; nfbno2 = rbno + rlen; nflen2 = (fbno + flen) - nfbno2; } /* * Delete the entry from the by-size btree. */ if ((error = xfs_btree_delete(cnt_cur, &i))) return error; if (XFS_IS_CORRUPT(mp, i != 1)) return -EFSCORRUPTED; /* * Add new by-size btree entry(s). */ if (nfbno1 != NULLAGBLOCK) { if ((error = xfs_alloc_lookup_eq(cnt_cur, nfbno1, nflen1, &i))) return error; if (XFS_IS_CORRUPT(mp, i != 0)) return -EFSCORRUPTED; if ((error = xfs_btree_insert(cnt_cur, &i))) return error; if (XFS_IS_CORRUPT(mp, i != 1)) return -EFSCORRUPTED; } if (nfbno2 != NULLAGBLOCK) { if ((error = xfs_alloc_lookup_eq(cnt_cur, nfbno2, nflen2, &i))) return error; if (XFS_IS_CORRUPT(mp, i != 0)) return -EFSCORRUPTED; if ((error = xfs_btree_insert(cnt_cur, &i))) return error; if (XFS_IS_CORRUPT(mp, i != 1)) return -EFSCORRUPTED; } /* * Fix up the by-block btree entry(s). */ if (nfbno1 == NULLAGBLOCK) { /* * No remaining freespace, just delete the by-block tree entry. */ if ((error = xfs_btree_delete(bno_cur, &i))) return error; if (XFS_IS_CORRUPT(mp, i != 1)) return -EFSCORRUPTED; } else { /* * Update the by-block entry to start later|be shorter. */ if ((error = xfs_alloc_update(bno_cur, nfbno1, nflen1))) return error; } if (nfbno2 != NULLAGBLOCK) { /* * 2 resulting free entries, need to add one. */ if ((error = xfs_alloc_lookup_eq(bno_cur, nfbno2, nflen2, &i))) return error; if (XFS_IS_CORRUPT(mp, i != 0)) return -EFSCORRUPTED; if ((error = xfs_btree_insert(bno_cur, &i))) return error; if (XFS_IS_CORRUPT(mp, i != 1)) return -EFSCORRUPTED; } return 0; } /* * We do not verify the AGFL contents against AGF-based index counters here, * even though we may have access to the perag that contains shadow copies. We * don't know if the AGF based counters have been checked, and if they have they * still may be inconsistent because they haven't yet been reset on the first * allocation after the AGF has been read in. * * This means we can only check that all agfl entries contain valid or null * values because we can't reliably determine the active range to exclude * NULLAGBNO as a valid value. * * However, we can't even do that for v4 format filesystems because there are * old versions of mkfs out there that does not initialise the AGFL to known, * verifiable values. HEnce we can't tell the difference between a AGFL block * allocated by mkfs and a corrupted AGFL block here on v4 filesystems. * * As a result, we can only fully validate AGFL block numbers when we pull them * from the freelist in xfs_alloc_get_freelist(). */ static xfs_failaddr_t xfs_agfl_verify( struct xfs_buf *bp) { struct xfs_mount *mp = bp->b_mount; struct xfs_agfl *agfl = XFS_BUF_TO_AGFL(bp); __be32 *agfl_bno = xfs_buf_to_agfl_bno(bp); int i; if (!xfs_has_crc(mp)) return NULL; if (!xfs_verify_magic(bp, agfl->agfl_magicnum)) return __this_address; if (!uuid_equal(&agfl->agfl_uuid, &mp->m_sb.sb_meta_uuid)) return __this_address; /* * during growfs operations, the perag is not fully initialised, * so we can't use it for any useful checking. growfs ensures we can't * use it by using uncached buffers that don't have the perag attached * so we can detect and avoid this problem. */ if (bp->b_pag && be32_to_cpu(agfl->agfl_seqno) != bp->b_pag->pag_agno) return __this_address; for (i = 0; i < xfs_agfl_size(mp); i++) { if (be32_to_cpu(agfl_bno[i]) != NULLAGBLOCK && be32_to_cpu(agfl_bno[i]) >= mp->m_sb.sb_agblocks) return __this_address; } if (!xfs_log_check_lsn(mp, be64_to_cpu(XFS_BUF_TO_AGFL(bp)->agfl_lsn))) return __this_address; return NULL; } static void xfs_agfl_read_verify( struct xfs_buf *bp) { struct xfs_mount *mp = bp->b_mount; xfs_failaddr_t fa; /* * There is no verification of non-crc AGFLs because mkfs does not * initialise the AGFL to zero or NULL. Hence the only valid part of the * AGFL is what the AGF says is active. We can't get to the AGF, so we * can't verify just those entries are valid. */ if (!xfs_has_crc(mp)) return; if (!xfs_buf_verify_cksum(bp, XFS_AGFL_CRC_OFF)) xfs_verifier_error(bp, -EFSBADCRC, __this_address); else { fa = xfs_agfl_verify(bp); if (fa) xfs_verifier_error(bp, -EFSCORRUPTED, fa); } } static void xfs_agfl_write_verify( struct xfs_buf *bp) { struct xfs_mount *mp = bp->b_mount; struct xfs_buf_log_item *bip = bp->b_log_item; xfs_failaddr_t fa; /* no verification of non-crc AGFLs */ if (!xfs_has_crc(mp)) return; fa = xfs_agfl_verify(bp); if (fa) { xfs_verifier_error(bp, -EFSCORRUPTED, fa); return; } if (bip) XFS_BUF_TO_AGFL(bp)->agfl_lsn = cpu_to_be64(bip->bli_item.li_lsn); xfs_buf_update_cksum(bp, XFS_AGFL_CRC_OFF); } const struct xfs_buf_ops xfs_agfl_buf_ops = { .name = "xfs_agfl", .magic = { cpu_to_be32(XFS_AGFL_MAGIC), cpu_to_be32(XFS_AGFL_MAGIC) }, .verify_read = xfs_agfl_read_verify, .verify_write = xfs_agfl_write_verify, .verify_struct = xfs_agfl_verify, }; /* * Read in the allocation group free block array. */ int xfs_alloc_read_agfl( struct xfs_perag *pag, struct xfs_trans *tp, struct xfs_buf **bpp) { struct xfs_mount *mp = pag->pag_mount; struct xfs_buf *bp; int error; error = xfs_trans_read_buf( mp, tp, mp->m_ddev_targp, XFS_AG_DADDR(mp, pag->pag_agno, XFS_AGFL_DADDR(mp)), XFS_FSS_TO_BB(mp, 1), 0, &bp, &xfs_agfl_buf_ops); if (error) return error; xfs_buf_set_ref(bp, XFS_AGFL_REF); *bpp = bp; return 0; } STATIC int xfs_alloc_update_counters( struct xfs_trans *tp, struct xfs_buf *agbp, long len) { struct xfs_agf *agf = agbp->b_addr; agbp->b_pag->pagf_freeblks += len; be32_add_cpu(&agf->agf_freeblks, len); if (unlikely(be32_to_cpu(agf->agf_freeblks) > be32_to_cpu(agf->agf_length))) { xfs_buf_mark_corrupt(agbp); return -EFSCORRUPTED; } xfs_alloc_log_agf(tp, agbp, XFS_AGF_FREEBLKS); return 0; } /* * Block allocation algorithm and data structures. */ struct xfs_alloc_cur { struct xfs_btree_cur *cnt; /* btree cursors */ struct xfs_btree_cur *bnolt; struct xfs_btree_cur *bnogt; xfs_extlen_t cur_len;/* current search length */ xfs_agblock_t rec_bno;/* extent startblock */ xfs_extlen_t rec_len;/* extent length */ xfs_agblock_t bno; /* alloc bno */ xfs_extlen_t len; /* alloc len */ xfs_extlen_t diff; /* diff from search bno */ unsigned int busy_gen;/* busy state */ bool busy; }; /* * Set up cursors, etc. in the extent allocation cursor. This function can be * called multiple times to reset an initialized structure without having to * reallocate cursors. */ static int xfs_alloc_cur_setup( struct xfs_alloc_arg *args, struct xfs_alloc_cur *acur) { int error; int i; acur->cur_len = args->maxlen; acur->rec_bno = 0; acur->rec_len = 0; acur->bno = 0; acur->len = 0; acur->diff = -1; acur->busy = false; acur->busy_gen = 0; /* * Perform an initial cntbt lookup to check for availability of maxlen * extents. If this fails, we'll return -ENOSPC to signal the caller to * attempt a small allocation. */ if (!acur->cnt) acur->cnt = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp, args->pag, XFS_BTNUM_CNT); error = xfs_alloc_lookup_ge(acur->cnt, 0, args->maxlen, &i); if (error) return error; /* * Allocate the bnobt left and right search cursors. */ if (!acur->bnolt) acur->bnolt = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp, args->pag, XFS_BTNUM_BNO); if (!acur->bnogt) acur->bnogt = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp, args->pag, XFS_BTNUM_BNO); return i == 1 ? 0 : -ENOSPC; } static void xfs_alloc_cur_close( struct xfs_alloc_cur *acur, bool error) { int cur_error = XFS_BTREE_NOERROR; if (error) cur_error = XFS_BTREE_ERROR; if (acur->cnt) xfs_btree_del_cursor(acur->cnt, cur_error); if (acur->bnolt) xfs_btree_del_cursor(acur->bnolt, cur_error); if (acur->bnogt) xfs_btree_del_cursor(acur->bnogt, cur_error); acur->cnt = acur->bnolt = acur->bnogt = NULL; } /* * Check an extent for allocation and track the best available candidate in the * allocation structure. The cursor is deactivated if it has entered an out of * range state based on allocation arguments. Optionally return the extent * extent geometry and allocation status if requested by the caller. */ static int xfs_alloc_cur_check( struct xfs_alloc_arg *args, struct xfs_alloc_cur *acur, struct xfs_btree_cur *cur, int *new) { int error, i; xfs_agblock_t bno, bnoa, bnew; xfs_extlen_t len, lena, diff = -1; bool busy; unsigned busy_gen = 0; bool deactivate = false; bool isbnobt = cur->bc_btnum == XFS_BTNUM_BNO; *new = 0; error = xfs_alloc_get_rec(cur, &bno, &len, &i); if (error) return error; if (XFS_IS_CORRUPT(args->mp, i != 1)) return -EFSCORRUPTED; /* * Check minlen and deactivate a cntbt cursor if out of acceptable size * range (i.e., walking backwards looking for a minlen extent). */ if (len < args->minlen) { deactivate = !isbnobt; goto out; } busy = xfs_alloc_compute_aligned(args, bno, len, &bnoa, &lena, &busy_gen); acur->busy |= busy; if (busy) acur->busy_gen = busy_gen; /* deactivate a bnobt cursor outside of locality range */ if (bnoa < args->min_agbno || bnoa > args->max_agbno) { deactivate = isbnobt; goto out; } if (lena < args->minlen) goto out; args->len = XFS_EXTLEN_MIN(lena, args->maxlen); xfs_alloc_fix_len(args); ASSERT(args->len >= args->minlen); if (args->len < acur->len) goto out; /* * We have an aligned record that satisfies minlen and beats or matches * the candidate extent size. Compare locality for near allocation mode. */ diff = xfs_alloc_compute_diff(args->agbno, args->len, args->alignment, args->datatype, bnoa, lena, &bnew); if (bnew == NULLAGBLOCK) goto out; /* * Deactivate a bnobt cursor with worse locality than the current best. */ if (diff > acur->diff) { deactivate = isbnobt; goto out; } ASSERT(args->len > acur->len || (args->len == acur->len && diff <= acur->diff)); acur->rec_bno = bno; acur->rec_len = len; acur->bno = bnew; acur->len = args->len; acur->diff = diff; *new = 1; /* * We're done if we found a perfect allocation. This only deactivates * the current cursor, but this is just an optimization to terminate a * cntbt search that otherwise runs to the edge of the tree. */ if (acur->diff == 0 && acur->len == args->maxlen) deactivate = true; out: if (deactivate) cur->bc_ag.abt.active = false; trace_xfs_alloc_cur_check(args->mp, cur->bc_btnum, bno, len, diff, *new); return 0; } /* * Complete an allocation of a candidate extent. Remove the extent from both * trees and update the args structure. */ STATIC int xfs_alloc_cur_finish( struct xfs_alloc_arg *args, struct xfs_alloc_cur *acur) { struct xfs_agf __maybe_unused *agf = args->agbp->b_addr; int error; ASSERT(acur->cnt && acur->bnolt); ASSERT(acur->bno >= acur->rec_bno); ASSERT(acur->bno + acur->len <= acur->rec_bno + acur->rec_len); ASSERT(acur->rec_bno + acur->rec_len <= be32_to_cpu(agf->agf_length)); error = xfs_alloc_fixup_trees(acur->cnt, acur->bnolt, acur->rec_bno, acur->rec_len, acur->bno, acur->len, 0); if (error) return error; args->agbno = acur->bno; args->len = acur->len; args->wasfromfl = 0; trace_xfs_alloc_cur(args); return 0; } /* * Locality allocation lookup algorithm. This expects a cntbt cursor and uses * bno optimized lookup to search for extents with ideal size and locality. */ STATIC int xfs_alloc_cntbt_iter( struct xfs_alloc_arg *args, struct xfs_alloc_cur *acur) { struct xfs_btree_cur *cur = acur->cnt; xfs_agblock_t bno; xfs_extlen_t len, cur_len; int error; int i; if (!xfs_alloc_cur_active(cur)) return 0; /* locality optimized lookup */ cur_len = acur->cur_len; error = xfs_alloc_lookup_ge(cur, args->agbno, cur_len, &i); if (error) return error; if (i == 0) return 0; error = xfs_alloc_get_rec(cur, &bno, &len, &i); if (error) return error; /* check the current record and update search length from it */ error = xfs_alloc_cur_check(args, acur, cur, &i); if (error) return error; ASSERT(len >= acur->cur_len); acur->cur_len = len; /* * We looked up the first record >= [agbno, len] above. The agbno is a * secondary key and so the current record may lie just before or after * agbno. If it is past agbno, check the previous record too so long as * the length matches as it may be closer. Don't check a smaller record * because that could deactivate our cursor. */ if (bno > args->agbno) { error = xfs_btree_decrement(cur, 0, &i); if (!error && i) { error = xfs_alloc_get_rec(cur, &bno, &len, &i); if (!error && i && len == acur->cur_len) error = xfs_alloc_cur_check(args, acur, cur, &i); } if (error) return error; } /* * Increment the search key until we find at least one allocation * candidate or if the extent we found was larger. Otherwise, double the * search key to optimize the search. Efficiency is more important here * than absolute best locality. */ cur_len <<= 1; if (!acur->len || acur->cur_len >= cur_len) acur->cur_len++; else acur->cur_len = cur_len; return error; } /* * Deal with the case where only small freespaces remain. Either return the * contents of the last freespace record, or allocate space from the freelist if * there is nothing in the tree. */ STATIC int /* error */ xfs_alloc_ag_vextent_small( struct xfs_alloc_arg *args, /* allocation argument structure */ struct xfs_btree_cur *ccur, /* optional by-size cursor */ xfs_agblock_t *fbnop, /* result block number */ xfs_extlen_t *flenp, /* result length */ int *stat) /* status: 0-freelist, 1-normal/none */ { struct xfs_agf *agf = args->agbp->b_addr; int error = 0; xfs_agblock_t fbno = NULLAGBLOCK; xfs_extlen_t flen = 0; int i = 0; /* * If a cntbt cursor is provided, try to allocate the largest record in * the tree. Try the AGFL if the cntbt is empty, otherwise fail the * allocation. Make sure to respect minleft even when pulling from the * freelist. */ if (ccur) error = xfs_btree_decrement(ccur, 0, &i); if (error) goto error; if (i) { error = xfs_alloc_get_rec(ccur, &fbno, &flen, &i); if (error) goto error; if (XFS_IS_CORRUPT(args->mp, i != 1)) { error = -EFSCORRUPTED; goto error; } goto out; } if (args->minlen != 1 || args->alignment != 1 || args->resv == XFS_AG_RESV_AGFL || be32_to_cpu(agf->agf_flcount) <= args->minleft) goto out; error = xfs_alloc_get_freelist(args->pag, args->tp, args->agbp, &fbno, 0); if (error) goto error; if (fbno == NULLAGBLOCK) goto out; xfs_extent_busy_reuse(args->mp, args->pag, fbno, 1, (args->datatype & XFS_ALLOC_NOBUSY)); if (args->datatype & XFS_ALLOC_USERDATA) { struct xfs_buf *bp; error = xfs_trans_get_buf(args->tp, args->mp->m_ddev_targp, XFS_AGB_TO_DADDR(args->mp, args->agno, fbno), args->mp->m_bsize, 0, &bp); if (error) goto error; xfs_trans_binval(args->tp, bp); } *fbnop = args->agbno = fbno; *flenp = args->len = 1; if (XFS_IS_CORRUPT(args->mp, fbno >= be32_to_cpu(agf->agf_length))) { error = -EFSCORRUPTED; goto error; } args->wasfromfl = 1; trace_xfs_alloc_small_freelist(args); /* * If we're feeding an AGFL block to something that doesn't live in the * free space, we need to clear out the OWN_AG rmap. */ error = xfs_rmap_free(args->tp, args->agbp, args->pag, fbno, 1, &XFS_RMAP_OINFO_AG); if (error) goto error; *stat = 0; return 0; out: /* * Can't do the allocation, give up. */ if (flen < args->minlen) { args->agbno = NULLAGBLOCK; trace_xfs_alloc_small_notenough(args); flen = 0; } *fbnop = fbno; *flenp = flen; *stat = 1; trace_xfs_alloc_small_done(args); return 0; error: trace_xfs_alloc_small_error(args); return error; } /* * Allocate a variable extent at exactly agno/bno. * Extent's length (returned in *len) will be between minlen and maxlen, * and of the form k * prod + mod unless there's nothing that large. * Return the starting a.g. block (bno), or NULLAGBLOCK if we can't do it. */ STATIC int /* error */ xfs_alloc_ag_vextent_exact( xfs_alloc_arg_t *args) /* allocation argument structure */ { struct xfs_agf __maybe_unused *agf = args->agbp->b_addr; struct xfs_btree_cur *bno_cur;/* by block-number btree cursor */ struct xfs_btree_cur *cnt_cur;/* by count btree cursor */ int error; xfs_agblock_t fbno; /* start block of found extent */ xfs_extlen_t flen; /* length of found extent */ xfs_agblock_t tbno; /* start block of busy extent */ xfs_extlen_t tlen; /* length of busy extent */ xfs_agblock_t tend; /* end block of busy extent */ int i; /* success/failure of operation */ unsigned busy_gen; ASSERT(args->alignment == 1); /* * Allocate/initialize a cursor for the by-number freespace btree. */ bno_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp, args->pag, XFS_BTNUM_BNO); /* * Lookup bno and minlen in the btree (minlen is irrelevant, really). * Look for the closest free block <= bno, it must contain bno * if any free block does. */ error = xfs_alloc_lookup_le(bno_cur, args->agbno, args->minlen, &i); if (error) goto error0; if (!i) goto not_found; /* * Grab the freespace record. */ error = xfs_alloc_get_rec(bno_cur, &fbno, &flen, &i); if (error) goto error0; if (XFS_IS_CORRUPT(args->mp, i != 1)) { error = -EFSCORRUPTED; goto error0; } ASSERT(fbno <= args->agbno); /* * Check for overlapping busy extents. */ tbno = fbno; tlen = flen; xfs_extent_busy_trim(args, &tbno, &tlen, &busy_gen); /* * Give up if the start of the extent is busy, or the freespace isn't * long enough for the minimum request. */ if (tbno > args->agbno) goto not_found; if (tlen < args->minlen) goto not_found; tend = tbno + tlen; if (tend < args->agbno + args->minlen) goto not_found; /* * End of extent will be smaller of the freespace end and the * maximal requested end. * * Fix the length according to mod and prod if given. */ args->len = XFS_AGBLOCK_MIN(tend, args->agbno + args->maxlen) - args->agbno; xfs_alloc_fix_len(args); ASSERT(args->agbno + args->len <= tend); /* * We are allocating agbno for args->len * Allocate/initialize a cursor for the by-size btree. */ cnt_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp, args->pag, XFS_BTNUM_CNT); ASSERT(args->agbno + args->len <= be32_to_cpu(agf->agf_length)); error = xfs_alloc_fixup_trees(cnt_cur, bno_cur, fbno, flen, args->agbno, args->len, XFSA_FIXUP_BNO_OK); if (error) { xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR); goto error0; } xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR); xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR); args->wasfromfl = 0; trace_xfs_alloc_exact_done(args); return 0; not_found: /* Didn't find it, return null. */ xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR); args->agbno = NULLAGBLOCK; trace_xfs_alloc_exact_notfound(args); return 0; error0: xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR); trace_xfs_alloc_exact_error(args); return error; } /* * Search a given number of btree records in a given direction. Check each * record against the good extent we've already found. */ STATIC int xfs_alloc_walk_iter( struct xfs_alloc_arg *args, struct xfs_alloc_cur *acur, struct xfs_btree_cur *cur, bool increment, bool find_one, /* quit on first candidate */ int count, /* rec count (-1 for infinite) */ int *stat) { int error; int i; *stat = 0; /* * Search so long as the cursor is active or we find a better extent. * The cursor is deactivated if it extends beyond the range of the * current allocation candidate. */ while (xfs_alloc_cur_active(cur) && count) { error = xfs_alloc_cur_check(args, acur, cur, &i); if (error) return error; if (i == 1) { *stat = 1; if (find_one) break; } if (!xfs_alloc_cur_active(cur)) break; if (increment) error = xfs_btree_increment(cur, 0, &i); else error = xfs_btree_decrement(cur, 0, &i); if (error) return error; if (i == 0) cur->bc_ag.abt.active = false; if (count > 0) count--; } return 0; } /* * Search the by-bno and by-size btrees in parallel in search of an extent with * ideal locality based on the NEAR mode ->agbno locality hint. */ STATIC int xfs_alloc_ag_vextent_locality( struct xfs_alloc_arg *args, struct xfs_alloc_cur *acur, int *stat) { struct xfs_btree_cur *fbcur = NULL; int error; int i; bool fbinc; ASSERT(acur->len == 0); *stat = 0; error = xfs_alloc_lookup_ge(acur->cnt, args->agbno, acur->cur_len, &i); if (error) return error; error = xfs_alloc_lookup_le(acur->bnolt, args->agbno, 0, &i); if (error) return error; error = xfs_alloc_lookup_ge(acur->bnogt, args->agbno, 0, &i); if (error) return error; /* * Search the bnobt and cntbt in parallel. Search the bnobt left and * right and lookup the closest extent to the locality hint for each * extent size key in the cntbt. The entire search terminates * immediately on a bnobt hit because that means we've found best case * locality. Otherwise the search continues until the cntbt cursor runs * off the end of the tree. If no allocation candidate is found at this * point, give up on locality, walk backwards from the end of the cntbt * and take the first available extent. * * The parallel tree searches balance each other out to provide fairly * consistent performance for various situations. The bnobt search can * have pathological behavior in the worst case scenario of larger * allocation requests and fragmented free space. On the other hand, the * bnobt is able to satisfy most smaller allocation requests much more * quickly than the cntbt. The cntbt search can sift through fragmented * free space and sets of free extents for larger allocation requests * more quickly than the bnobt. Since the locality hint is just a hint * and we don't want to scan the entire bnobt for perfect locality, the * cntbt search essentially bounds the bnobt search such that we can * find good enough locality at reasonable performance in most cases. */ while (xfs_alloc_cur_active(acur->bnolt) || xfs_alloc_cur_active(acur->bnogt) || xfs_alloc_cur_active(acur->cnt)) { trace_xfs_alloc_cur_lookup(args); /* * Search the bnobt left and right. In the case of a hit, finish * the search in the opposite direction and we're done. */ error = xfs_alloc_walk_iter(args, acur, acur->bnolt, false, true, 1, &i); if (error) return error; if (i == 1) { trace_xfs_alloc_cur_left(args); fbcur = acur->bnogt; fbinc = true; break; } error = xfs_alloc_walk_iter(args, acur, acur->bnogt, true, true, 1, &i); if (error) return error; if (i == 1) { trace_xfs_alloc_cur_right(args); fbcur = acur->bnolt; fbinc = false; break; } /* * Check the extent with best locality based on the current * extent size search key and keep track of the best candidate. */ error = xfs_alloc_cntbt_iter(args, acur); if (error) return error; if (!xfs_alloc_cur_active(acur->cnt)) { trace_xfs_alloc_cur_lookup_done(args); break; } } /* * If we failed to find anything due to busy extents, return empty * handed so the caller can flush and retry. If no busy extents were * found, walk backwards from the end of the cntbt as a last resort. */ if (!xfs_alloc_cur_active(acur->cnt) && !acur->len && !acur->busy) { error = xfs_btree_decrement(acur->cnt, 0, &i); if (error) return error; if (i) { acur->cnt->bc_ag.abt.active = true; fbcur = acur->cnt; fbinc = false; } } /* * Search in the opposite direction for a better entry in the case of * a bnobt hit or walk backwards from the end of the cntbt. */ if (fbcur) { error = xfs_alloc_walk_iter(args, acur, fbcur, fbinc, true, -1, &i); if (error) return error; } if (acur->len) *stat = 1; return 0; } /* Check the last block of the cnt btree for allocations. */ static int xfs_alloc_ag_vextent_lastblock( struct xfs_alloc_arg *args, struct xfs_alloc_cur *acur, xfs_agblock_t *bno, xfs_extlen_t *len, bool *allocated) { int error; int i; #ifdef DEBUG /* Randomly don't execute the first algorithm. */ if (get_random_u32_below(2)) return 0; #endif /* * Start from the entry that lookup found, sequence through all larger * free blocks. If we're actually pointing at a record smaller than * maxlen, go to the start of this block, and skip all those smaller * than minlen. */ if (*len || args->alignment > 1) { acur->cnt->bc_levels[0].ptr = 1; do { error = xfs_alloc_get_rec(acur->cnt, bno, len, &i); if (error) return error; if (XFS_IS_CORRUPT(args->mp, i != 1)) return -EFSCORRUPTED; if (*len >= args->minlen) break; error = xfs_btree_increment(acur->cnt, 0, &i); if (error) return error; } while (i); ASSERT(*len >= args->minlen); if (!i) return 0; } error = xfs_alloc_walk_iter(args, acur, acur->cnt, true, false, -1, &i); if (error) return error; /* * It didn't work. We COULD be in a case where there's a good record * somewhere, so try again. */ if (acur->len == 0) return 0; trace_xfs_alloc_near_first(args); *allocated = true; return 0; } /* * Allocate a variable extent near bno in the allocation group agno. * Extent's length (returned in len) will be between minlen and maxlen, * and of the form k * prod + mod unless there's nothing that large. * Return the starting a.g. block, or NULLAGBLOCK if we can't do it. */ STATIC int xfs_alloc_ag_vextent_near( struct xfs_alloc_arg *args, uint32_t alloc_flags) { struct xfs_alloc_cur acur = {}; int error; /* error code */ int i; /* result code, temporary */ xfs_agblock_t bno; xfs_extlen_t len; /* handle uninitialized agbno range so caller doesn't have to */ if (!args->min_agbno && !args->max_agbno) args->max_agbno = args->mp->m_sb.sb_agblocks - 1; ASSERT(args->min_agbno <= args->max_agbno); /* clamp agbno to the range if it's outside */ if (args->agbno < args->min_agbno) args->agbno = args->min_agbno; if (args->agbno > args->max_agbno) args->agbno = args->max_agbno; /* Retry once quickly if we find busy extents before blocking. */ alloc_flags |= XFS_ALLOC_FLAG_TRYFLUSH; restart: len = 0; /* * Set up cursors and see if there are any free extents as big as * maxlen. If not, pick the last entry in the tree unless the tree is * empty. */ error = xfs_alloc_cur_setup(args, &acur); if (error == -ENOSPC) { error = xfs_alloc_ag_vextent_small(args, acur.cnt, &bno, &len, &i); if (error) goto out; if (i == 0 || len == 0) { trace_xfs_alloc_near_noentry(args); goto out; } ASSERT(i == 1); } else if (error) { goto out; } /* * First algorithm. * If the requested extent is large wrt the freespaces available * in this a.g., then the cursor will be pointing to a btree entry * near the right edge of the tree. If it's in the last btree leaf * block, then we just examine all the entries in that block * that are big enough, and pick the best one. */ if (xfs_btree_islastblock(acur.cnt, 0)) { bool allocated = false; error = xfs_alloc_ag_vextent_lastblock(args, &acur, &bno, &len, &allocated); if (error) goto out; if (allocated) goto alloc_finish; } /* * Second algorithm. Combined cntbt and bnobt search to find ideal * locality. */ error = xfs_alloc_ag_vextent_locality(args, &acur, &i); if (error) goto out; /* * If we couldn't get anything, give up. */ if (!acur.len) { if (acur.busy) { /* * Our only valid extents must have been busy. Flush and * retry the allocation again. If we get an -EAGAIN * error, we're being told that a deadlock was avoided * and the current transaction needs committing before * the allocation can be retried. */ trace_xfs_alloc_near_busy(args); error = xfs_extent_busy_flush(args->tp, args->pag, acur.busy_gen, alloc_flags); if (error) goto out; alloc_flags &= ~XFS_ALLOC_FLAG_TRYFLUSH; goto restart; } trace_xfs_alloc_size_neither(args); args->agbno = NULLAGBLOCK; goto out; } alloc_finish: /* fix up btrees on a successful allocation */ error = xfs_alloc_cur_finish(args, &acur); out: xfs_alloc_cur_close(&acur, error); return error; } /* * Allocate a variable extent anywhere in the allocation group agno. * Extent's length (returned in len) will be between minlen and maxlen, * and of the form k * prod + mod unless there's nothing that large. * Return the starting a.g. block, or NULLAGBLOCK if we can't do it. */ static int xfs_alloc_ag_vextent_size( struct xfs_alloc_arg *args, uint32_t alloc_flags) { struct xfs_agf *agf = args->agbp->b_addr; struct xfs_btree_cur *bno_cur; struct xfs_btree_cur *cnt_cur; xfs_agblock_t fbno; /* start of found freespace */ xfs_extlen_t flen; /* length of found freespace */ xfs_agblock_t rbno; /* returned block number */ xfs_extlen_t rlen; /* length of returned extent */ bool busy; unsigned busy_gen; int error; int i; /* Retry once quickly if we find busy extents before blocking. */ alloc_flags |= XFS_ALLOC_FLAG_TRYFLUSH; restart: /* * Allocate and initialize a cursor for the by-size btree. */ cnt_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp, args->pag, XFS_BTNUM_CNT); bno_cur = NULL; /* * Look for an entry >= maxlen+alignment-1 blocks. */ if ((error = xfs_alloc_lookup_ge(cnt_cur, 0, args->maxlen + args->alignment - 1, &i))) goto error0; /* * If none then we have to settle for a smaller extent. In the case that * there are no large extents, this will return the last entry in the * tree unless the tree is empty. In the case that there are only busy * large extents, this will return the largest small extent unless there * are no smaller extents available. */ if (!i) { error = xfs_alloc_ag_vextent_small(args, cnt_cur, &fbno, &flen, &i); if (error) goto error0; if (i == 0 || flen == 0) { xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR); trace_xfs_alloc_size_noentry(args); return 0; } ASSERT(i == 1); busy = xfs_alloc_compute_aligned(args, fbno, flen, &rbno, &rlen, &busy_gen); } else { /* * Search for a non-busy extent that is large enough. */ for (;;) { error = xfs_alloc_get_rec(cnt_cur, &fbno, &flen, &i); if (error) goto error0; if (XFS_IS_CORRUPT(args->mp, i != 1)) { error = -EFSCORRUPTED; goto error0; } busy = xfs_alloc_compute_aligned(args, fbno, flen, &rbno, &rlen, &busy_gen); if (rlen >= args->maxlen) break; error = xfs_btree_increment(cnt_cur, 0, &i); if (error) goto error0; if (i) continue; /* * Our only valid extents must have been busy. Flush and * retry the allocation again. If we get an -EAGAIN * error, we're being told that a deadlock was avoided * and the current transaction needs committing before * the allocation can be retried. */ trace_xfs_alloc_size_busy(args); error = xfs_extent_busy_flush(args->tp, args->pag, busy_gen, alloc_flags); if (error) goto error0; alloc_flags &= ~XFS_ALLOC_FLAG_TRYFLUSH; xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR); goto restart; } } /* * In the first case above, we got the last entry in the * by-size btree. Now we check to see if the space hits maxlen * once aligned; if not, we search left for something better. * This can't happen in the second case above. */ rlen = XFS_EXTLEN_MIN(args->maxlen, rlen); if (XFS_IS_CORRUPT(args->mp, rlen != 0 && (rlen > flen || rbno + rlen > fbno + flen))) { error = -EFSCORRUPTED; goto error0; } if (rlen < args->maxlen) { xfs_agblock_t bestfbno; xfs_extlen_t bestflen; xfs_agblock_t bestrbno; xfs_extlen_t bestrlen; bestrlen = rlen; bestrbno = rbno; bestflen = flen; bestfbno = fbno; for (;;) { if ((error = xfs_btree_decrement(cnt_cur, 0, &i))) goto error0; if (i == 0) break; if ((error = xfs_alloc_get_rec(cnt_cur, &fbno, &flen, &i))) goto error0; if (XFS_IS_CORRUPT(args->mp, i != 1)) { error = -EFSCORRUPTED; goto error0; } if (flen < bestrlen) break; busy = xfs_alloc_compute_aligned(args, fbno, flen, &rbno, &rlen, &busy_gen); rlen = XFS_EXTLEN_MIN(args->maxlen, rlen); if (XFS_IS_CORRUPT(args->mp, rlen != 0 && (rlen > flen || rbno + rlen > fbno + flen))) { error = -EFSCORRUPTED; goto error0; } if (rlen > bestrlen) { bestrlen = rlen; bestrbno = rbno; bestflen = flen; bestfbno = fbno; if (rlen == args->maxlen) break; } } if ((error = xfs_alloc_lookup_eq(cnt_cur, bestfbno, bestflen, &i))) goto error0; if (XFS_IS_CORRUPT(args->mp, i != 1)) { error = -EFSCORRUPTED; goto error0; } rlen = bestrlen; rbno = bestrbno; flen = bestflen; fbno = bestfbno; } args->wasfromfl = 0; /* * Fix up the length. */ args->len = rlen; if (rlen < args->minlen) { if (busy) { /* * Our only valid extents must have been busy. Flush and * retry the allocation again. If we get an -EAGAIN * error, we're being told that a deadlock was avoided * and the current transaction needs committing before * the allocation can be retried. */ trace_xfs_alloc_size_busy(args); error = xfs_extent_busy_flush(args->tp, args->pag, busy_gen, alloc_flags); if (error) goto error0; alloc_flags &= ~XFS_ALLOC_FLAG_TRYFLUSH; xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR); goto restart; } goto out_nominleft; } xfs_alloc_fix_len(args); rlen = args->len; if (XFS_IS_CORRUPT(args->mp, rlen > flen)) { error = -EFSCORRUPTED; goto error0; } /* * Allocate and initialize a cursor for the by-block tree. */ bno_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp, args->pag, XFS_BTNUM_BNO); if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur, fbno, flen, rbno, rlen, XFSA_FIXUP_CNT_OK))) goto error0; xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR); xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR); cnt_cur = bno_cur = NULL; args->len = rlen; args->agbno = rbno; if (XFS_IS_CORRUPT(args->mp, args->agbno + args->len > be32_to_cpu(agf->agf_length))) { error = -EFSCORRUPTED; goto error0; } trace_xfs_alloc_size_done(args); return 0; error0: trace_xfs_alloc_size_error(args); if (cnt_cur) xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR); if (bno_cur) xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR); return error; out_nominleft: xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR); trace_xfs_alloc_size_nominleft(args); args->agbno = NULLAGBLOCK; return 0; } /* * Free the extent starting at agno/bno for length. */ STATIC int xfs_free_ag_extent( struct xfs_trans *tp, struct xfs_buf *agbp, xfs_agnumber_t agno, xfs_agblock_t bno, xfs_extlen_t len, const struct xfs_owner_info *oinfo, enum xfs_ag_resv_type type) { struct xfs_mount *mp; struct xfs_btree_cur *bno_cur; struct xfs_btree_cur *cnt_cur; xfs_agblock_t gtbno; /* start of right neighbor */ xfs_extlen_t gtlen; /* length of right neighbor */ xfs_agblock_t ltbno; /* start of left neighbor */ xfs_extlen_t ltlen; /* length of left neighbor */ xfs_agblock_t nbno; /* new starting block of freesp */ xfs_extlen_t nlen; /* new length of freespace */ int haveleft; /* have a left neighbor */ int haveright; /* have a right neighbor */ int i; int error; struct xfs_perag *pag = agbp->b_pag; bno_cur = cnt_cur = NULL; mp = tp->t_mountp; if (!xfs_rmap_should_skip_owner_update(oinfo)) { error = xfs_rmap_free(tp, agbp, pag, bno, len, oinfo); if (error) goto error0; } /* * Allocate and initialize a cursor for the by-block btree. */ bno_cur = xfs_allocbt_init_cursor(mp, tp, agbp, pag, XFS_BTNUM_BNO); /* * Look for a neighboring block on the left (lower block numbers) * that is contiguous with this space. */ if ((error = xfs_alloc_lookup_le(bno_cur, bno, len, &haveleft))) goto error0; if (haveleft) { /* * There is a block to our left. */ if ((error = xfs_alloc_get_rec(bno_cur, <bno, <len, &i))) goto error0; if (XFS_IS_CORRUPT(mp, i != 1)) { error = -EFSCORRUPTED; goto error0; } /* * It's not contiguous, though. */ if (ltbno + ltlen < bno) haveleft = 0; else { /* * If this failure happens the request to free this * space was invalid, it's (partly) already free. * Very bad. */ if (XFS_IS_CORRUPT(mp, ltbno + ltlen > bno)) { error = -EFSCORRUPTED; goto error0; } } } /* * Look for a neighboring block on the right (higher block numbers) * that is contiguous with this space. */ if ((error = xfs_btree_increment(bno_cur, 0, &haveright))) goto error0; if (haveright) { /* * There is a block to our right. */ if ((error = xfs_alloc_get_rec(bno_cur, >bno, >len, &i))) goto error0; if (XFS_IS_CORRUPT(mp, i != 1)) { error = -EFSCORRUPTED; goto error0; } /* * It's not contiguous, though. */ if (bno + len < gtbno) haveright = 0; else { /* * If this failure happens the request to free this * space was invalid, it's (partly) already free. * Very bad. */ if (XFS_IS_CORRUPT(mp, bno + len > gtbno)) { error = -EFSCORRUPTED; goto error0; } } } /* * Now allocate and initialize a cursor for the by-size tree. */ cnt_cur = xfs_allocbt_init_cursor(mp, tp, agbp, pag, XFS_BTNUM_CNT); /* * Have both left and right contiguous neighbors. * Merge all three into a single free block. */ if (haveleft && haveright) { /* * Delete the old by-size entry on the left. */ if ((error = xfs_alloc_lookup_eq(cnt_cur, ltbno, ltlen, &i))) goto error0; if (XFS_IS_CORRUPT(mp, i != 1)) { error = -EFSCORRUPTED; goto error0; } if ((error = xfs_btree_delete(cnt_cur, &i))) goto error0; if (XFS_IS_CORRUPT(mp, i != 1)) { error = -EFSCORRUPTED; goto error0; } /* * Delete the old by-size entry on the right. */ if ((error = xfs_alloc_lookup_eq(cnt_cur, gtbno, gtlen, &i))) goto error0; if (XFS_IS_CORRUPT(mp, i != 1)) { error = -EFSCORRUPTED; goto error0; } if ((error = xfs_btree_delete(cnt_cur, &i))) goto error0; if (XFS_IS_CORRUPT(mp, i != 1)) { error = -EFSCORRUPTED; goto error0; } /* * Delete the old by-block entry for the right block. */ if ((error = xfs_btree_delete(bno_cur, &i))) goto error0; if (XFS_IS_CORRUPT(mp, i != 1)) { error = -EFSCORRUPTED; goto error0; } /* * Move the by-block cursor back to the left neighbor. */ if ((error = xfs_btree_decrement(bno_cur, 0, &i))) goto error0; if (XFS_IS_CORRUPT(mp, i != 1)) { error = -EFSCORRUPTED; goto error0; } #ifdef DEBUG /* * Check that this is the right record: delete didn't * mangle the cursor. */ { xfs_agblock_t xxbno; xfs_extlen_t xxlen; if ((error = xfs_alloc_get_rec(bno_cur, &xxbno, &xxlen, &i))) goto error0; if (XFS_IS_CORRUPT(mp, i != 1 || xxbno != ltbno || xxlen != ltlen)) { error = -EFSCORRUPTED; goto error0; } } #endif /* * Update remaining by-block entry to the new, joined block. */ nbno = ltbno; nlen = len + ltlen + gtlen; if ((error = xfs_alloc_update(bno_cur, nbno, nlen))) goto error0; } /* * Have only a left contiguous neighbor. * Merge it together with the new freespace. */ else if (haveleft) { /* * Delete the old by-size entry on the left. */ if ((error = xfs_alloc_lookup_eq(cnt_cur, ltbno, ltlen, &i))) goto error0; if (XFS_IS_CORRUPT(mp, i != 1)) { error = -EFSCORRUPTED; goto error0; } if ((error = xfs_btree_delete(cnt_cur, &i))) goto error0; if (XFS_IS_CORRUPT(mp, i != 1)) { error = -EFSCORRUPTED; goto error0; } /* * Back up the by-block cursor to the left neighbor, and * update its length. */ if ((error = xfs_btree_decrement(bno_cur, 0, &i))) goto error0; if (XFS_IS_CORRUPT(mp, i != 1)) { error = -EFSCORRUPTED; goto error0; } nbno = ltbno; nlen = len + ltlen; if ((error = xfs_alloc_update(bno_cur, nbno, nlen))) goto error0; } /* * Have only a right contiguous neighbor. * Merge it together with the new freespace. */ else if (haveright) { /* * Delete the old by-size entry on the right. */ if ((error = xfs_alloc_lookup_eq(cnt_cur, gtbno, gtlen, &i))) goto error0; if (XFS_IS_CORRUPT(mp, i != 1)) { error = -EFSCORRUPTED; goto error0; } if ((error = xfs_btree_delete(cnt_cur, &i))) goto error0; if (XFS_IS_CORRUPT(mp, i != 1)) { error = -EFSCORRUPTED; goto error0; } /* * Update the starting block and length of the right * neighbor in the by-block tree. */ nbno = bno; nlen = len + gtlen; if ((error = xfs_alloc_update(bno_cur, nbno, nlen))) goto error0; } /* * No contiguous neighbors. * Insert the new freespace into the by-block tree. */ else { nbno = bno; nlen = len; if ((error = xfs_btree_insert(bno_cur, &i))) goto error0; if (XFS_IS_CORRUPT(mp, i != 1)) { error = -EFSCORRUPTED; goto error0; } } xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR); bno_cur = NULL; /* * In all cases we need to insert the new freespace in the by-size tree. */ if ((error = xfs_alloc_lookup_eq(cnt_cur, nbno, nlen, &i))) goto error0; if (XFS_IS_CORRUPT(mp, i != 0)) { error = -EFSCORRUPTED; goto error0; } if ((error = xfs_btree_insert(cnt_cur, &i))) goto error0; if (XFS_IS_CORRUPT(mp, i != 1)) { error = -EFSCORRUPTED; goto error0; } xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR); cnt_cur = NULL; /* * Update the freespace totals in the ag and superblock. */ error = xfs_alloc_update_counters(tp, agbp, len); xfs_ag_resv_free_extent(agbp->b_pag, type, tp, len); if (error) goto error0; XFS_STATS_INC(mp, xs_freex); XFS_STATS_ADD(mp, xs_freeb, len); trace_xfs_free_extent(mp, agno, bno, len, type, haveleft, haveright); return 0; error0: trace_xfs_free_extent(mp, agno, bno, len, type, -1, -1); if (bno_cur) xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR); if (cnt_cur) xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR); return error; } /* * Visible (exported) allocation/free functions. * Some of these are used just by xfs_alloc_btree.c and this file. */ /* * Compute and fill in value of m_alloc_maxlevels. */ void xfs_alloc_compute_maxlevels( xfs_mount_t *mp) /* file system mount structure */ { mp->m_alloc_maxlevels = xfs_btree_compute_maxlevels(mp->m_alloc_mnr, (mp->m_sb.sb_agblocks + 1) / 2); ASSERT(mp->m_alloc_maxlevels <= xfs_allocbt_maxlevels_ondisk()); } /* * Find the length of the longest extent in an AG. The 'need' parameter * specifies how much space we're going to need for the AGFL and the * 'reserved' parameter tells us how many blocks in this AG are reserved for * other callers. */ xfs_extlen_t xfs_alloc_longest_free_extent( struct xfs_perag *pag, xfs_extlen_t need, xfs_extlen_t reserved) { xfs_extlen_t delta = 0; /* * If the AGFL needs a recharge, we'll have to subtract that from the * longest extent. */ if (need > pag->pagf_flcount) delta = need - pag->pagf_flcount; /* * If we cannot maintain others' reservations with space from the * not-longest freesp extents, we'll have to subtract /that/ from * the longest extent too. */ if (pag->pagf_freeblks - pag->pagf_longest < reserved) delta += reserved - (pag->pagf_freeblks - pag->pagf_longest); /* * If the longest extent is long enough to satisfy all the * reservations and AGFL rules in place, we can return this extent. */ if (pag->pagf_longest > delta) return min_t(xfs_extlen_t, pag->pag_mount->m_ag_max_usable, pag->pagf_longest - delta); /* Otherwise, let the caller try for 1 block if there's space. */ return pag->pagf_flcount > 0 || pag->pagf_longest > 0; } /* * Compute the minimum length of the AGFL in the given AG. If @pag is NULL, * return the largest possible minimum length. */ unsigned int xfs_alloc_min_freelist( struct xfs_mount *mp, struct xfs_perag *pag) { /* AG btrees have at least 1 level. */ static const uint8_t fake_levels[XFS_BTNUM_AGF] = {1, 1, 1}; const uint8_t *levels = pag ? pag->pagf_levels : fake_levels; unsigned int min_free; ASSERT(mp->m_alloc_maxlevels > 0); /* * For a btree shorter than the maximum height, the worst case is that * every level gets split and a new level is added, then while inserting * another entry to refill the AGFL, every level under the old root gets * split again. This is: * * (full height split reservation) + (AGFL refill split height) * = (current height + 1) + (current height - 1) * = (new height) + (new height - 2) * = 2 * new height - 2 * * For a btree of maximum height, the worst case is that every level * under the root gets split, then while inserting another entry to * refill the AGFL, every level under the root gets split again. This is * also: * * 2 * (current height - 1) * = 2 * (new height - 1) * = 2 * new height - 2 */ /* space needed by-bno freespace btree */ min_free = min_t(unsigned int, levels[XFS_BTNUM_BNOi] + 1, mp->m_alloc_maxlevels) * 2 - 2; /* space needed by-size freespace btree */ min_free += min_t(unsigned int, levels[XFS_BTNUM_CNTi] + 1, mp->m_alloc_maxlevels) * 2 - 2; /* space needed reverse mapping used space btree */ if (xfs_has_rmapbt(mp)) min_free += min_t(unsigned int, levels[XFS_BTNUM_RMAPi] + 1, mp->m_rmap_maxlevels) * 2 - 2; return min_free; } /* * Check if the operation we are fixing up the freelist for should go ahead or * not. If we are freeing blocks, we always allow it, otherwise the allocation * is dependent on whether the size and shape of free space available will * permit the requested allocation to take place. */ static bool xfs_alloc_space_available( struct xfs_alloc_arg *args, xfs_extlen_t min_free, int flags) { struct xfs_perag *pag = args->pag; xfs_extlen_t alloc_len, longest; xfs_extlen_t reservation; /* blocks that are still reserved */ int available; xfs_extlen_t agflcount; if (flags & XFS_ALLOC_FLAG_FREEING) return true; reservation = xfs_ag_resv_needed(pag, args->resv); /* do we have enough contiguous free space for the allocation? */ alloc_len = args->minlen + (args->alignment - 1) + args->minalignslop; longest = xfs_alloc_longest_free_extent(pag, min_free, reservation); if (longest < alloc_len) return false; /* * Do we have enough free space remaining for the allocation? Don't * account extra agfl blocks because we are about to defer free them, * making them unavailable until the current transaction commits. */ agflcount = min_t(xfs_extlen_t, pag->pagf_flcount, min_free); available = (int)(pag->pagf_freeblks + agflcount - reservation - min_free - args->minleft); if (available < (int)max(args->total, alloc_len)) return false; /* * Clamp maxlen to the amount of free space available for the actual * extent allocation. */ if (available < (int)args->maxlen && !(flags & XFS_ALLOC_FLAG_CHECK)) { args->maxlen = available; ASSERT(args->maxlen > 0); ASSERT(args->maxlen >= args->minlen); } return true; } int xfs_free_agfl_block( struct xfs_trans *tp, xfs_agnumber_t agno, xfs_agblock_t agbno, struct xfs_buf *agbp, struct xfs_owner_info *oinfo) { int error; struct xfs_buf *bp; error = xfs_free_ag_extent(tp, agbp, agno, agbno, 1, oinfo, XFS_AG_RESV_AGFL); if (error) return error; error = xfs_trans_get_buf(tp, tp->t_mountp->m_ddev_targp, XFS_AGB_TO_DADDR(tp->t_mountp, agno, agbno), tp->t_mountp->m_bsize, 0, &bp); if (error) return error; xfs_trans_binval(tp, bp); return 0; } /* * Check the agfl fields of the agf for inconsistency or corruption. * * The original purpose was to detect an agfl header padding mismatch between * current and early v5 kernels. This problem manifests as a 1-slot size * difference between the on-disk flcount and the active [first, last] range of * a wrapped agfl. * * However, we need to use these same checks to catch agfl count corruptions * unrelated to padding. This could occur on any v4 or v5 filesystem, so either * way, we need to reset the agfl and warn the user. * * Return true if a reset is required before the agfl can be used, false * otherwise. */ static bool xfs_agfl_needs_reset( struct xfs_mount *mp, struct xfs_agf *agf) { uint32_t f = be32_to_cpu(agf->agf_flfirst); uint32_t l = be32_to_cpu(agf->agf_fllast); uint32_t c = be32_to_cpu(agf->agf_flcount); int agfl_size = xfs_agfl_size(mp); int active; /* * The agf read verifier catches severe corruption of these fields. * Repeat some sanity checks to cover a packed -> unpacked mismatch if * the verifier allows it. */ if (f >= agfl_size || l >= agfl_size) return true; if (c > agfl_size) return true; /* * Check consistency between the on-disk count and the active range. An * agfl padding mismatch manifests as an inconsistent flcount. */ if (c && l >= f) active = l - f + 1; else if (c) active = agfl_size - f + l + 1; else active = 0; return active != c; } /* * Reset the agfl to an empty state. Ignore/drop any existing blocks since the * agfl content cannot be trusted. Warn the user that a repair is required to * recover leaked blocks. * * The purpose of this mechanism is to handle filesystems affected by the agfl * header padding mismatch problem. A reset keeps the filesystem online with a * relatively minor free space accounting inconsistency rather than suffer the * inevitable crash from use of an invalid agfl block. */ static void xfs_agfl_reset( struct xfs_trans *tp, struct xfs_buf *agbp, struct xfs_perag *pag) { struct xfs_mount *mp = tp->t_mountp; struct xfs_agf *agf = agbp->b_addr; ASSERT(xfs_perag_agfl_needs_reset(pag)); trace_xfs_agfl_reset(mp, agf, 0, _RET_IP_); xfs_warn(mp, "WARNING: Reset corrupted AGFL on AG %u. %d blocks leaked. " "Please unmount and run xfs_repair.", pag->pag_agno, pag->pagf_flcount); agf->agf_flfirst = 0; agf->agf_fllast = cpu_to_be32(xfs_agfl_size(mp) - 1); agf->agf_flcount = 0; xfs_alloc_log_agf(tp, agbp, XFS_AGF_FLFIRST | XFS_AGF_FLLAST | XFS_AGF_FLCOUNT); pag->pagf_flcount = 0; clear_bit(XFS_AGSTATE_AGFL_NEEDS_RESET, &pag->pag_opstate); } /* * Defer an AGFL block free. This is effectively equivalent to * xfs_free_extent_later() with some special handling particular to AGFL blocks. * * Deferring AGFL frees helps prevent log reservation overruns due to too many * allocation operations in a transaction. AGFL frees are prone to this problem * because for one they are always freed one at a time. Further, an immediate * AGFL block free can cause a btree join and require another block free before * the real allocation can proceed. Deferring the free disconnects freeing up * the AGFL slot from freeing the block. */ static int xfs_defer_agfl_block( struct xfs_trans *tp, xfs_agnumber_t agno, xfs_agblock_t agbno, struct xfs_owner_info *oinfo) { struct xfs_mount *mp = tp->t_mountp; struct xfs_extent_free_item *xefi; xfs_fsblock_t fsbno = XFS_AGB_TO_FSB(mp, agno, agbno); ASSERT(xfs_extfree_item_cache != NULL); ASSERT(oinfo != NULL); if (XFS_IS_CORRUPT(mp, !xfs_verify_fsbno(mp, fsbno))) return -EFSCORRUPTED; xefi = kmem_cache_zalloc(xfs_extfree_item_cache, GFP_KERNEL | __GFP_NOFAIL); xefi->xefi_startblock = fsbno; xefi->xefi_blockcount = 1; xefi->xefi_owner = oinfo->oi_owner; xefi->xefi_agresv = XFS_AG_RESV_AGFL; trace_xfs_agfl_free_defer(mp, agno, 0, agbno, 1); xfs_extent_free_get_group(mp, xefi); xfs_defer_add(tp, &xefi->xefi_list, &xfs_agfl_free_defer_type); return 0; } /* * Add the extent to the list of extents to be free at transaction end. * The list is maintained sorted (by block number). */ static int xfs_defer_extent_free( struct xfs_trans *tp, xfs_fsblock_t bno, xfs_filblks_t len, const struct xfs_owner_info *oinfo, enum xfs_ag_resv_type type, bool skip_discard, struct xfs_defer_pending **dfpp) { struct xfs_extent_free_item *xefi; struct xfs_mount *mp = tp->t_mountp; #ifdef DEBUG xfs_agnumber_t agno; xfs_agblock_t agbno; ASSERT(bno != NULLFSBLOCK); ASSERT(len > 0); ASSERT(len <= XFS_MAX_BMBT_EXTLEN); ASSERT(!isnullstartblock(bno)); agno = XFS_FSB_TO_AGNO(mp, bno); agbno = XFS_FSB_TO_AGBNO(mp, bno); ASSERT(agno < mp->m_sb.sb_agcount); ASSERT(agbno < mp->m_sb.sb_agblocks); ASSERT(len < mp->m_sb.sb_agblocks); ASSERT(agbno + len <= mp->m_sb.sb_agblocks); #endif ASSERT(xfs_extfree_item_cache != NULL); ASSERT(type != XFS_AG_RESV_AGFL); if (XFS_IS_CORRUPT(mp, !xfs_verify_fsbext(mp, bno, len))) return -EFSCORRUPTED; xefi = kmem_cache_zalloc(xfs_extfree_item_cache, GFP_KERNEL | __GFP_NOFAIL); xefi->xefi_startblock = bno; xefi->xefi_blockcount = (xfs_extlen_t)len; xefi->xefi_agresv = type; if (skip_discard) xefi->xefi_flags |= XFS_EFI_SKIP_DISCARD; if (oinfo) { ASSERT(oinfo->oi_offset == 0); if (oinfo->oi_flags & XFS_OWNER_INFO_ATTR_FORK) xefi->xefi_flags |= XFS_EFI_ATTR_FORK; if (oinfo->oi_flags & XFS_OWNER_INFO_BMBT_BLOCK) xefi->xefi_flags |= XFS_EFI_BMBT_BLOCK; xefi->xefi_owner = oinfo->oi_owner; } else { xefi->xefi_owner = XFS_RMAP_OWN_NULL; } trace_xfs_bmap_free_defer(mp, XFS_FSB_TO_AGNO(tp->t_mountp, bno), 0, XFS_FSB_TO_AGBNO(tp->t_mountp, bno), len); xfs_extent_free_get_group(mp, xefi); *dfpp = xfs_defer_add(tp, &xefi->xefi_list, &xfs_extent_free_defer_type); return 0; } int xfs_free_extent_later( struct xfs_trans *tp, xfs_fsblock_t bno, xfs_filblks_t len, const struct xfs_owner_info *oinfo, enum xfs_ag_resv_type type, bool skip_discard) { struct xfs_defer_pending *dontcare = NULL; return xfs_defer_extent_free(tp, bno, len, oinfo, type, skip_discard, &dontcare); } /* * Set up automatic freeing of unwritten space in the filesystem. * * This function attached a paused deferred extent free item to the * transaction. Pausing means that the EFI will be logged in the next * transaction commit, but the pending EFI will not be finished until the * pending item is unpaused. * * If the system goes down after the EFI has been persisted to the log but * before the pending item is unpaused, log recovery will find the EFI, fail to * find the EFD, and free the space. * * If the pending item is unpaused, the next transaction commit will log an EFD * without freeing the space. * * Caller must ensure that the tp, fsbno, len, oinfo, and resv flags of the * @args structure are set to the relevant values. */ int xfs_alloc_schedule_autoreap( const struct xfs_alloc_arg *args, bool skip_discard, struct xfs_alloc_autoreap *aarp) { int error; error = xfs_defer_extent_free(args->tp, args->fsbno, args->len, &args->oinfo, args->resv, skip_discard, &aarp->dfp); if (error) return error; xfs_defer_item_pause(args->tp, aarp->dfp); return 0; } /* * Cancel automatic freeing of unwritten space in the filesystem. * * Earlier, we created a paused deferred extent free item and attached it to * this transaction so that we could automatically roll back a new space * allocation if the system went down. Now we want to cancel the paused work * item by marking the EFI stale so we don't actually free the space, unpausing * the pending item and logging an EFD. * * The caller generally should have already mapped the space into the ondisk * filesystem. If the reserved space was partially used, the caller must call * xfs_free_extent_later to create a new EFI to free the unused space. */ void xfs_alloc_cancel_autoreap( struct xfs_trans *tp, struct xfs_alloc_autoreap *aarp) { struct xfs_defer_pending *dfp = aarp->dfp; struct xfs_extent_free_item *xefi; if (!dfp) return; list_for_each_entry(xefi, &dfp->dfp_work, xefi_list) xefi->xefi_flags |= XFS_EFI_CANCELLED; xfs_defer_item_unpause(tp, dfp); } /* * Commit automatic freeing of unwritten space in the filesystem. * * This unpauses an earlier _schedule_autoreap and commits to freeing the * allocated space. Call this if none of the reserved space was used. */ void xfs_alloc_commit_autoreap( struct xfs_trans *tp, struct xfs_alloc_autoreap *aarp) { if (aarp->dfp) xfs_defer_item_unpause(tp, aarp->dfp); } #ifdef DEBUG /* * Check if an AGF has a free extent record whose length is equal to * args->minlen. */ STATIC int xfs_exact_minlen_extent_available( struct xfs_alloc_arg *args, struct xfs_buf *agbp, int *stat) { struct xfs_btree_cur *cnt_cur; xfs_agblock_t fbno; xfs_extlen_t flen; int error = 0; cnt_cur = xfs_allocbt_init_cursor(args->mp, args->tp, agbp, args->pag, XFS_BTNUM_CNT); error = xfs_alloc_lookup_ge(cnt_cur, 0, args->minlen, stat); if (error) goto out; if (*stat == 0) { error = -EFSCORRUPTED; goto out; } error = xfs_alloc_get_rec(cnt_cur, &fbno, &flen, stat); if (error) goto out; if (*stat == 1 && flen != args->minlen) *stat = 0; out: xfs_btree_del_cursor(cnt_cur, error); return error; } #endif /* * Decide whether to use this allocation group for this allocation. * If so, fix up the btree freelist's size. */ int /* error */ xfs_alloc_fix_freelist( struct xfs_alloc_arg *args, /* allocation argument structure */ uint32_t alloc_flags) { struct xfs_mount *mp = args->mp; struct xfs_perag *pag = args->pag; struct xfs_trans *tp = args->tp; struct xfs_buf *agbp = NULL; struct xfs_buf *agflbp = NULL; struct xfs_alloc_arg targs; /* local allocation arguments */ xfs_agblock_t bno; /* freelist block */ xfs_extlen_t need; /* total blocks needed in freelist */ int error = 0; /* deferred ops (AGFL block frees) require permanent transactions */ ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES); if (!xfs_perag_initialised_agf(pag)) { error = xfs_alloc_read_agf(pag, tp, alloc_flags, &agbp); if (error) { /* Couldn't lock the AGF so skip this AG. */ if (error == -EAGAIN) error = 0; goto out_no_agbp; } } /* * If this is a metadata preferred pag and we are user data then try * somewhere else if we are not being asked to try harder at this * point */ if (xfs_perag_prefers_metadata(pag) && (args->datatype & XFS_ALLOC_USERDATA) && (alloc_flags & XFS_ALLOC_FLAG_TRYLOCK)) { ASSERT(!(alloc_flags & XFS_ALLOC_FLAG_FREEING)); goto out_agbp_relse; } need = xfs_alloc_min_freelist(mp, pag); if (!xfs_alloc_space_available(args, need, alloc_flags | XFS_ALLOC_FLAG_CHECK)) goto out_agbp_relse; /* * Get the a.g. freespace buffer. * Can fail if we're not blocking on locks, and it's held. */ if (!agbp) { error = xfs_alloc_read_agf(pag, tp, alloc_flags, &agbp); if (error) { /* Couldn't lock the AGF so skip this AG. */ if (error == -EAGAIN) error = 0; goto out_no_agbp; } } /* reset a padding mismatched agfl before final free space check */ if (xfs_perag_agfl_needs_reset(pag)) xfs_agfl_reset(tp, agbp, pag); /* If there isn't enough total space or single-extent, reject it. */ need = xfs_alloc_min_freelist(mp, pag); if (!xfs_alloc_space_available(args, need, alloc_flags)) goto out_agbp_relse; #ifdef DEBUG if (args->alloc_minlen_only) { int stat; error = xfs_exact_minlen_extent_available(args, agbp, &stat); if (error || !stat) goto out_agbp_relse; } #endif /* * Make the freelist shorter if it's too long. * * Note that from this point onwards, we will always release the agf and * agfl buffers on error. This handles the case where we error out and * the buffers are clean or may not have been joined to the transaction * and hence need to be released manually. If they have been joined to * the transaction, then xfs_trans_brelse() will handle them * appropriately based on the recursion count and dirty state of the * buffer. * * XXX (dgc): When we have lots of free space, does this buy us * anything other than extra overhead when we need to put more blocks * back on the free list? Maybe we should only do this when space is * getting low or the AGFL is more than half full? * * The NOSHRINK flag prevents the AGFL from being shrunk if it's too * big; the NORMAP flag prevents AGFL expand/shrink operations from * updating the rmapbt. Both flags are used in xfs_repair while we're * rebuilding the rmapbt, and neither are used by the kernel. They're * both required to ensure that rmaps are correctly recorded for the * regenerated AGFL, bnobt, and cntbt. See repair/phase5.c and * repair/rmap.c in xfsprogs for details. */ memset(&targs, 0, sizeof(targs)); /* struct copy below */ if (alloc_flags & XFS_ALLOC_FLAG_NORMAP) targs.oinfo = XFS_RMAP_OINFO_SKIP_UPDATE; else targs.oinfo = XFS_RMAP_OINFO_AG; while (!(alloc_flags & XFS_ALLOC_FLAG_NOSHRINK) && pag->pagf_flcount > need) { error = xfs_alloc_get_freelist(pag, tp, agbp, &bno, 0); if (error) goto out_agbp_relse; /* defer agfl frees */ error = xfs_defer_agfl_block(tp, args->agno, bno, &targs.oinfo); if (error) goto out_agbp_relse; } targs.tp = tp; targs.mp = mp; targs.agbp = agbp; targs.agno = args->agno; targs.alignment = targs.minlen = targs.prod = 1; targs.pag = pag; error = xfs_alloc_read_agfl(pag, tp, &agflbp); if (error) goto out_agbp_relse; /* Make the freelist longer if it's too short. */ while (pag->pagf_flcount < need) { targs.agbno = 0; targs.maxlen = need - pag->pagf_flcount; targs.resv = XFS_AG_RESV_AGFL; /* Allocate as many blocks as possible at once. */ error = xfs_alloc_ag_vextent_size(&targs, alloc_flags); if (error) goto out_agflbp_relse; /* * Stop if we run out. Won't happen if callers are obeying * the restrictions correctly. Can happen for free calls * on a completely full ag. */ if (targs.agbno == NULLAGBLOCK) { if (alloc_flags & XFS_ALLOC_FLAG_FREEING) break; goto out_agflbp_relse; } if (!xfs_rmap_should_skip_owner_update(&targs.oinfo)) { error = xfs_rmap_alloc(tp, agbp, pag, targs.agbno, targs.len, &targs.oinfo); if (error) goto out_agflbp_relse; } error = xfs_alloc_update_counters(tp, agbp, -((long)(targs.len))); if (error) goto out_agflbp_relse; /* * Put each allocated block on the list. */ for (bno = targs.agbno; bno < targs.agbno + targs.len; bno++) { error = xfs_alloc_put_freelist(pag, tp, agbp, agflbp, bno, 0); if (error) goto out_agflbp_relse; } } xfs_trans_brelse(tp, agflbp); args->agbp = agbp; return 0; out_agflbp_relse: xfs_trans_brelse(tp, agflbp); out_agbp_relse: if (agbp) xfs_trans_brelse(tp, agbp); out_no_agbp: args->agbp = NULL; return error; } /* * Get a block from the freelist. * Returns with the buffer for the block gotten. */ int xfs_alloc_get_freelist( struct xfs_perag *pag, struct xfs_trans *tp, struct xfs_buf *agbp, xfs_agblock_t *bnop, int btreeblk) { struct xfs_agf *agf = agbp->b_addr; struct xfs_buf *agflbp; xfs_agblock_t bno; __be32 *agfl_bno; int error; uint32_t logflags; struct xfs_mount *mp = tp->t_mountp; /* * Freelist is empty, give up. */ if (!agf->agf_flcount) { *bnop = NULLAGBLOCK; return 0; } /* * Read the array of free blocks. */ error = xfs_alloc_read_agfl(pag, tp, &agflbp); if (error) return error; /* * Get the block number and update the data structures. */ agfl_bno = xfs_buf_to_agfl_bno(agflbp); bno = be32_to_cpu(agfl_bno[be32_to_cpu(agf->agf_flfirst)]); if (XFS_IS_CORRUPT(tp->t_mountp, !xfs_verify_agbno(pag, bno))) return -EFSCORRUPTED; be32_add_cpu(&agf->agf_flfirst, 1); xfs_trans_brelse(tp, agflbp); if (be32_to_cpu(agf->agf_flfirst) == xfs_agfl_size(mp)) agf->agf_flfirst = 0; ASSERT(!xfs_perag_agfl_needs_reset(pag)); be32_add_cpu(&agf->agf_flcount, -1); pag->pagf_flcount--; logflags = XFS_AGF_FLFIRST | XFS_AGF_FLCOUNT; if (btreeblk) { be32_add_cpu(&agf->agf_btreeblks, 1); pag->pagf_btreeblks++; logflags |= XFS_AGF_BTREEBLKS; } xfs_alloc_log_agf(tp, agbp, logflags); *bnop = bno; return 0; } /* * Log the given fields from the agf structure. */ void xfs_alloc_log_agf( struct xfs_trans *tp, struct xfs_buf *bp, uint32_t fields) { int first; /* first byte offset */ int last; /* last byte offset */ static const short offsets[] = { offsetof(xfs_agf_t, agf_magicnum), offsetof(xfs_agf_t, agf_versionnum), offsetof(xfs_agf_t, agf_seqno), offsetof(xfs_agf_t, agf_length), offsetof(xfs_agf_t, agf_roots[0]), offsetof(xfs_agf_t, agf_levels[0]), offsetof(xfs_agf_t, agf_flfirst), offsetof(xfs_agf_t, agf_fllast), offsetof(xfs_agf_t, agf_flcount), offsetof(xfs_agf_t, agf_freeblks), offsetof(xfs_agf_t, agf_longest), offsetof(xfs_agf_t, agf_btreeblks), offsetof(xfs_agf_t, agf_uuid), offsetof(xfs_agf_t, agf_rmap_blocks), offsetof(xfs_agf_t, agf_refcount_blocks), offsetof(xfs_agf_t, agf_refcount_root), offsetof(xfs_agf_t, agf_refcount_level), /* needed so that we don't log the whole rest of the structure: */ offsetof(xfs_agf_t, agf_spare64), sizeof(xfs_agf_t) }; trace_xfs_agf(tp->t_mountp, bp->b_addr, fields, _RET_IP_); xfs_trans_buf_set_type(tp, bp, XFS_BLFT_AGF_BUF); xfs_btree_offsets(fields, offsets, XFS_AGF_NUM_BITS, &first, &last); xfs_trans_log_buf(tp, bp, (uint)first, (uint)last); } /* * Put the block on the freelist for the allocation group. */ int xfs_alloc_put_freelist( struct xfs_perag *pag, struct xfs_trans *tp, struct xfs_buf *agbp, struct xfs_buf *agflbp, xfs_agblock_t bno, int btreeblk) { struct xfs_mount *mp = tp->t_mountp; struct xfs_agf *agf = agbp->b_addr; __be32 *blockp; int error; uint32_t logflags; __be32 *agfl_bno; int startoff; if (!agflbp) { error = xfs_alloc_read_agfl(pag, tp, &agflbp); if (error) return error; } be32_add_cpu(&agf->agf_fllast, 1); if (be32_to_cpu(agf->agf_fllast) == xfs_agfl_size(mp)) agf->agf_fllast = 0; ASSERT(!xfs_perag_agfl_needs_reset(pag)); be32_add_cpu(&agf->agf_flcount, 1); pag->pagf_flcount++; logflags = XFS_AGF_FLLAST | XFS_AGF_FLCOUNT; if (btreeblk) { be32_add_cpu(&agf->agf_btreeblks, -1); pag->pagf_btreeblks--; logflags |= XFS_AGF_BTREEBLKS; } xfs_alloc_log_agf(tp, agbp, logflags); ASSERT(be32_to_cpu(agf->agf_flcount) <= xfs_agfl_size(mp)); agfl_bno = xfs_buf_to_agfl_bno(agflbp); blockp = &agfl_bno[be32_to_cpu(agf->agf_fllast)]; *blockp = cpu_to_be32(bno); startoff = (char *)blockp - (char *)agflbp->b_addr; xfs_alloc_log_agf(tp, agbp, logflags); xfs_trans_buf_set_type(tp, agflbp, XFS_BLFT_AGFL_BUF); xfs_trans_log_buf(tp, agflbp, startoff, startoff + sizeof(xfs_agblock_t) - 1); return 0; } /* * Check that this AGF/AGI header's sequence number and length matches the AG * number and size in fsblocks. */ xfs_failaddr_t xfs_validate_ag_length( struct xfs_buf *bp, uint32_t seqno, uint32_t length) { struct xfs_mount *mp = bp->b_mount; /* * During growfs operations, the perag is not fully initialised, * so we can't use it for any useful checking. growfs ensures we can't * use it by using uncached buffers that don't have the perag attached * so we can detect and avoid this problem. */ if (bp->b_pag && seqno != bp->b_pag->pag_agno) return __this_address; /* * Only the last AG in the filesystem is allowed to be shorter * than the AG size recorded in the superblock. */ if (length != mp->m_sb.sb_agblocks) { /* * During growfs, the new last AG can get here before we * have updated the superblock. Give it a pass on the seqno * check. */ if (bp->b_pag && seqno != mp->m_sb.sb_agcount - 1) return __this_address; if (length < XFS_MIN_AG_BLOCKS) return __this_address; if (length > mp->m_sb.sb_agblocks) return __this_address; } return NULL; } /* * Verify the AGF is consistent. * * We do not verify the AGFL indexes in the AGF are fully consistent here * because of issues with variable on-disk structure sizes. Instead, we check * the agfl indexes for consistency when we initialise the perag from the AGF * information after a read completes. * * If the index is inconsistent, then we mark the perag as needing an AGFL * reset. The first AGFL update performed then resets the AGFL indexes and * refills the AGFL with known good free blocks, allowing the filesystem to * continue operating normally at the cost of a few leaked free space blocks. */ static xfs_failaddr_t xfs_agf_verify( struct xfs_buf *bp) { struct xfs_mount *mp = bp->b_mount; struct xfs_agf *agf = bp->b_addr; xfs_failaddr_t fa; uint32_t agf_seqno = be32_to_cpu(agf->agf_seqno); uint32_t agf_length = be32_to_cpu(agf->agf_length); if (xfs_has_crc(mp)) { if (!uuid_equal(&agf->agf_uuid, &mp->m_sb.sb_meta_uuid)) return __this_address; if (!xfs_log_check_lsn(mp, be64_to_cpu(agf->agf_lsn))) return __this_address; } if (!xfs_verify_magic(bp, agf->agf_magicnum)) return __this_address; if (!XFS_AGF_GOOD_VERSION(be32_to_cpu(agf->agf_versionnum))) return __this_address; /* * Both agf_seqno and agf_length need to validated before anything else * block number related in the AGF or AGFL can be checked. */ fa = xfs_validate_ag_length(bp, agf_seqno, agf_length); if (fa) return fa; if (be32_to_cpu(agf->agf_flfirst) >= xfs_agfl_size(mp)) return __this_address; if (be32_to_cpu(agf->agf_fllast) >= xfs_agfl_size(mp)) return __this_address; if (be32_to_cpu(agf->agf_flcount) > xfs_agfl_size(mp)) return __this_address; if (be32_to_cpu(agf->agf_freeblks) < be32_to_cpu(agf->agf_longest) || be32_to_cpu(agf->agf_freeblks) > agf_length) return __this_address; if (be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNO]) < 1 || be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNT]) < 1 || be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNO]) > mp->m_alloc_maxlevels || be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNT]) > mp->m_alloc_maxlevels) return __this_address; if (xfs_has_lazysbcount(mp) && be32_to_cpu(agf->agf_btreeblks) > agf_length) return __this_address; if (xfs_has_rmapbt(mp)) { if (be32_to_cpu(agf->agf_rmap_blocks) > agf_length) return __this_address; if (be32_to_cpu(agf->agf_levels[XFS_BTNUM_RMAP]) < 1 || be32_to_cpu(agf->agf_levels[XFS_BTNUM_RMAP]) > mp->m_rmap_maxlevels) return __this_address; } if (xfs_has_reflink(mp)) { if (be32_to_cpu(agf->agf_refcount_blocks) > agf_length) return __this_address; if (be32_to_cpu(agf->agf_refcount_level) < 1 || be32_to_cpu(agf->agf_refcount_level) > mp->m_refc_maxlevels) return __this_address; } return NULL; } static void xfs_agf_read_verify( struct xfs_buf *bp) { struct xfs_mount *mp = bp->b_mount; xfs_failaddr_t fa; if (xfs_has_crc(mp) && !xfs_buf_verify_cksum(bp, XFS_AGF_CRC_OFF)) xfs_verifier_error(bp, -EFSBADCRC, __this_address); else { fa = xfs_agf_verify(bp); if (XFS_TEST_ERROR(fa, mp, XFS_ERRTAG_ALLOC_READ_AGF)) xfs_verifier_error(bp, -EFSCORRUPTED, fa); } } static void xfs_agf_write_verify( struct xfs_buf *bp) { struct xfs_mount *mp = bp->b_mount; struct xfs_buf_log_item *bip = bp->b_log_item; struct xfs_agf *agf = bp->b_addr; xfs_failaddr_t fa; fa = xfs_agf_verify(bp); if (fa) { xfs_verifier_error(bp, -EFSCORRUPTED, fa); return; } if (!xfs_has_crc(mp)) return; if (bip) agf->agf_lsn = cpu_to_be64(bip->bli_item.li_lsn); xfs_buf_update_cksum(bp, XFS_AGF_CRC_OFF); } const struct xfs_buf_ops xfs_agf_buf_ops = { .name = "xfs_agf", .magic = { cpu_to_be32(XFS_AGF_MAGIC), cpu_to_be32(XFS_AGF_MAGIC) }, .verify_read = xfs_agf_read_verify, .verify_write = xfs_agf_write_verify, .verify_struct = xfs_agf_verify, }; /* * Read in the allocation group header (free/alloc section). */ int xfs_read_agf( struct xfs_perag *pag, struct xfs_trans *tp, int flags, struct xfs_buf **agfbpp) { struct xfs_mount *mp = pag->pag_mount; int error; trace_xfs_read_agf(pag->pag_mount, pag->pag_agno); error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, XFS_AG_DADDR(mp, pag->pag_agno, XFS_AGF_DADDR(mp)), XFS_FSS_TO_BB(mp, 1), flags, agfbpp, &xfs_agf_buf_ops); if (error) return error; xfs_buf_set_ref(*agfbpp, XFS_AGF_REF); return 0; } /* * Read in the allocation group header (free/alloc section) and initialise the * perag structure if necessary. If the caller provides @agfbpp, then return the * locked buffer to the caller, otherwise free it. */ int xfs_alloc_read_agf( struct xfs_perag *pag, struct xfs_trans *tp, int flags, struct xfs_buf **agfbpp) { struct xfs_buf *agfbp; struct xfs_agf *agf; int error; int allocbt_blks; trace_xfs_alloc_read_agf(pag->pag_mount, pag->pag_agno); /* We don't support trylock when freeing. */ ASSERT((flags & (XFS_ALLOC_FLAG_FREEING | XFS_ALLOC_FLAG_TRYLOCK)) != (XFS_ALLOC_FLAG_FREEING | XFS_ALLOC_FLAG_TRYLOCK)); error = xfs_read_agf(pag, tp, (flags & XFS_ALLOC_FLAG_TRYLOCK) ? XBF_TRYLOCK : 0, &agfbp); if (error) return error; agf = agfbp->b_addr; if (!xfs_perag_initialised_agf(pag)) { pag->pagf_freeblks = be32_to_cpu(agf->agf_freeblks); pag->pagf_btreeblks = be32_to_cpu(agf->agf_btreeblks); pag->pagf_flcount = be32_to_cpu(agf->agf_flcount); pag->pagf_longest = be32_to_cpu(agf->agf_longest); pag->pagf_levels[XFS_BTNUM_BNOi] = be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNOi]); pag->pagf_levels[XFS_BTNUM_CNTi] = be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNTi]); pag->pagf_levels[XFS_BTNUM_RMAPi] = be32_to_cpu(agf->agf_levels[XFS_BTNUM_RMAPi]); pag->pagf_refcount_level = be32_to_cpu(agf->agf_refcount_level); if (xfs_agfl_needs_reset(pag->pag_mount, agf)) set_bit(XFS_AGSTATE_AGFL_NEEDS_RESET, &pag->pag_opstate); else clear_bit(XFS_AGSTATE_AGFL_NEEDS_RESET, &pag->pag_opstate); /* * Update the in-core allocbt counter. Filter out the rmapbt * subset of the btreeblks counter because the rmapbt is managed * by perag reservation. Subtract one for the rmapbt root block * because the rmap counter includes it while the btreeblks * counter only tracks non-root blocks. */ allocbt_blks = pag->pagf_btreeblks; if (xfs_has_rmapbt(pag->pag_mount)) allocbt_blks -= be32_to_cpu(agf->agf_rmap_blocks) - 1; if (allocbt_blks > 0) atomic64_add(allocbt_blks, &pag->pag_mount->m_allocbt_blks); set_bit(XFS_AGSTATE_AGF_INIT, &pag->pag_opstate); } #ifdef DEBUG else if (!xfs_is_shutdown(pag->pag_mount)) { ASSERT(pag->pagf_freeblks == be32_to_cpu(agf->agf_freeblks)); ASSERT(pag->pagf_btreeblks == be32_to_cpu(agf->agf_btreeblks)); ASSERT(pag->pagf_flcount == be32_to_cpu(agf->agf_flcount)); ASSERT(pag->pagf_longest == be32_to_cpu(agf->agf_longest)); ASSERT(pag->pagf_levels[XFS_BTNUM_BNOi] == be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNOi])); ASSERT(pag->pagf_levels[XFS_BTNUM_CNTi] == be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNTi])); } #endif if (agfbpp) *agfbpp = agfbp; else xfs_trans_brelse(tp, agfbp); return 0; } /* * Pre-proces allocation arguments to set initial state that we don't require * callers to set up correctly, as well as bounds check the allocation args * that are set up. */ static int xfs_alloc_vextent_check_args( struct xfs_alloc_arg *args, xfs_fsblock_t target, xfs_agnumber_t *minimum_agno) { struct xfs_mount *mp = args->mp; xfs_agblock_t agsize; args->fsbno = NULLFSBLOCK; *minimum_agno = 0; if (args->tp->t_highest_agno != NULLAGNUMBER) *minimum_agno = args->tp->t_highest_agno; /* * Just fix this up, for the case where the last a.g. is shorter * (or there's only one a.g.) and the caller couldn't easily figure * that out (xfs_bmap_alloc). */ agsize = mp->m_sb.sb_agblocks; if (args->maxlen > agsize) args->maxlen = agsize; if (args->alignment == 0) args->alignment = 1; ASSERT(args->minlen > 0); ASSERT(args->maxlen > 0); ASSERT(args->alignment > 0); ASSERT(args->resv != XFS_AG_RESV_AGFL); ASSERT(XFS_FSB_TO_AGNO(mp, target) < mp->m_sb.sb_agcount); ASSERT(XFS_FSB_TO_AGBNO(mp, target) < agsize); ASSERT(args->minlen <= args->maxlen); ASSERT(args->minlen <= agsize); ASSERT(args->mod < args->prod); if (XFS_FSB_TO_AGNO(mp, target) >= mp->m_sb.sb_agcount || XFS_FSB_TO_AGBNO(mp, target) >= agsize || args->minlen > args->maxlen || args->minlen > agsize || args->mod >= args->prod) { trace_xfs_alloc_vextent_badargs(args); return -ENOSPC; } if (args->agno != NULLAGNUMBER && *minimum_agno > args->agno) { trace_xfs_alloc_vextent_skip_deadlock(args); return -ENOSPC; } return 0; } /* * Prepare an AG for allocation. If the AG is not prepared to accept the * allocation, return failure. * * XXX(dgc): The complexity of "need_pag" will go away as all caller paths are * modified to hold their own perag references. */ static int xfs_alloc_vextent_prepare_ag( struct xfs_alloc_arg *args, uint32_t alloc_flags) { bool need_pag = !args->pag; int error; if (need_pag) args->pag = xfs_perag_get(args->mp, args->agno); args->agbp = NULL; error = xfs_alloc_fix_freelist(args, alloc_flags); if (error) { trace_xfs_alloc_vextent_nofix(args); if (need_pag) xfs_perag_put(args->pag); args->agbno = NULLAGBLOCK; return error; } if (!args->agbp) { /* cannot allocate in this AG at all */ trace_xfs_alloc_vextent_noagbp(args); args->agbno = NULLAGBLOCK; return 0; } args->wasfromfl = 0; return 0; } /* * Post-process allocation results to account for the allocation if it succeed * and set the allocated block number correctly for the caller. * * XXX: we should really be returning ENOSPC for ENOSPC, not * hiding it behind a "successful" NULLFSBLOCK allocation. */ static int xfs_alloc_vextent_finish( struct xfs_alloc_arg *args, xfs_agnumber_t minimum_agno, int alloc_error, bool drop_perag) { struct xfs_mount *mp = args->mp; int error = 0; /* * We can end up here with a locked AGF. If we failed, the caller is * likely going to try to allocate again with different parameters, and * that can widen the AGs that are searched for free space. If we have * to do BMBT block allocation, we have to do a new allocation. * * Hence leaving this function with the AGF locked opens up potential * ABBA AGF deadlocks because a future allocation attempt in this * transaction may attempt to lock a lower number AGF. * * We can't release the AGF until the transaction is commited, so at * this point we must update the "first allocation" tracker to point at * this AG if the tracker is empty or points to a lower AG. This allows * the next allocation attempt to be modified appropriately to avoid * deadlocks. */ if (args->agbp && (args->tp->t_highest_agno == NULLAGNUMBER || args->agno > minimum_agno)) args->tp->t_highest_agno = args->agno; /* * If the allocation failed with an error or we had an ENOSPC result, * preserve the returned error whilst also marking the allocation result * as "no extent allocated". This ensures that callers that fail to * capture the error will still treat it as a failed allocation. */ if (alloc_error || args->agbno == NULLAGBLOCK) { args->fsbno = NULLFSBLOCK; error = alloc_error; goto out_drop_perag; } args->fsbno = XFS_AGB_TO_FSB(mp, args->agno, args->agbno); ASSERT(args->len >= args->minlen); ASSERT(args->len <= args->maxlen); ASSERT(args->agbno % args->alignment == 0); XFS_AG_CHECK_DADDR(mp, XFS_FSB_TO_DADDR(mp, args->fsbno), args->len); /* if not file data, insert new block into the reverse map btree */ if (!xfs_rmap_should_skip_owner_update(&args->oinfo)) { error = xfs_rmap_alloc(args->tp, args->agbp, args->pag, args->agbno, args->len, &args->oinfo); if (error) goto out_drop_perag; } if (!args->wasfromfl) { error = xfs_alloc_update_counters(args->tp, args->agbp, -((long)(args->len))); if (error) goto out_drop_perag; ASSERT(!xfs_extent_busy_search(mp, args->pag, args->agbno, args->len)); } xfs_ag_resv_alloc_extent(args->pag, args->resv, args); XFS_STATS_INC(mp, xs_allocx); XFS_STATS_ADD(mp, xs_allocb, args->len); trace_xfs_alloc_vextent_finish(args); out_drop_perag: if (drop_perag && args->pag) { xfs_perag_rele(args->pag); args->pag = NULL; } return error; } /* * Allocate within a single AG only. This uses a best-fit length algorithm so if * you need an exact sized allocation without locality constraints, this is the * fastest way to do it. * * Caller is expected to hold a perag reference in args->pag. */ int xfs_alloc_vextent_this_ag( struct xfs_alloc_arg *args, xfs_agnumber_t agno) { struct xfs_mount *mp = args->mp; xfs_agnumber_t minimum_agno; uint32_t alloc_flags = 0; int error; ASSERT(args->pag != NULL); ASSERT(args->pag->pag_agno == agno); args->agno = agno; args->agbno = 0; trace_xfs_alloc_vextent_this_ag(args); error = xfs_alloc_vextent_check_args(args, XFS_AGB_TO_FSB(mp, agno, 0), &minimum_agno); if (error) { if (error == -ENOSPC) return 0; return error; } error = xfs_alloc_vextent_prepare_ag(args, alloc_flags); if (!error && args->agbp) error = xfs_alloc_ag_vextent_size(args, alloc_flags); return xfs_alloc_vextent_finish(args, minimum_agno, error, false); } /* * Iterate all AGs trying to allocate an extent starting from @start_ag. * * If the incoming allocation type is XFS_ALLOCTYPE_NEAR_BNO, it means the * allocation attempts in @start_agno have locality information. If we fail to * allocate in that AG, then we revert to anywhere-in-AG for all the other AGs * we attempt to allocation in as there is no locality optimisation possible for * those allocations. * * On return, args->pag may be left referenced if we finish before the "all * failed" return point. The allocation finish still needs the perag, and * so the caller will release it once they've finished the allocation. * * When we wrap the AG iteration at the end of the filesystem, we have to be * careful not to wrap into AGs below ones we already have locked in the * transaction if we are doing a blocking iteration. This will result in an * out-of-order locking of AGFs and hence can cause deadlocks. */ static int xfs_alloc_vextent_iterate_ags( struct xfs_alloc_arg *args, xfs_agnumber_t minimum_agno, xfs_agnumber_t start_agno, xfs_agblock_t target_agbno, uint32_t alloc_flags) { struct xfs_mount *mp = args->mp; xfs_agnumber_t restart_agno = minimum_agno; xfs_agnumber_t agno; int error = 0; if (alloc_flags & XFS_ALLOC_FLAG_TRYLOCK) restart_agno = 0; restart: for_each_perag_wrap_range(mp, start_agno, restart_agno, mp->m_sb.sb_agcount, agno, args->pag) { args->agno = agno; error = xfs_alloc_vextent_prepare_ag(args, alloc_flags); if (error) break; if (!args->agbp) { trace_xfs_alloc_vextent_loopfailed(args); continue; } /* * Allocation is supposed to succeed now, so break out of the * loop regardless of whether we succeed or not. */ if (args->agno == start_agno && target_agbno) { args->agbno = target_agbno; error = xfs_alloc_ag_vextent_near(args, alloc_flags); } else { args->agbno = 0; error = xfs_alloc_ag_vextent_size(args, alloc_flags); } break; } if (error) { xfs_perag_rele(args->pag); args->pag = NULL; return error; } if (args->agbp) return 0; /* * We didn't find an AG we can alloation from. If we were given * constraining flags by the caller, drop them and retry the allocation * without any constraints being set. */ if (alloc_flags & XFS_ALLOC_FLAG_TRYLOCK) { alloc_flags &= ~XFS_ALLOC_FLAG_TRYLOCK; restart_agno = minimum_agno; goto restart; } ASSERT(args->pag == NULL); trace_xfs_alloc_vextent_allfailed(args); return 0; } /* * Iterate from the AGs from the start AG to the end of the filesystem, trying * to allocate blocks. It starts with a near allocation attempt in the initial * AG, then falls back to anywhere-in-ag after the first AG fails. It will wrap * back to zero if allowed by previous allocations in this transaction, * otherwise will wrap back to the start AG and run a second blocking pass to * the end of the filesystem. */ int xfs_alloc_vextent_start_ag( struct xfs_alloc_arg *args, xfs_fsblock_t target) { struct xfs_mount *mp = args->mp; xfs_agnumber_t minimum_agno; xfs_agnumber_t start_agno; xfs_agnumber_t rotorstep = xfs_rotorstep; bool bump_rotor = false; uint32_t alloc_flags = XFS_ALLOC_FLAG_TRYLOCK; int error; ASSERT(args->pag == NULL); args->agno = NULLAGNUMBER; args->agbno = NULLAGBLOCK; trace_xfs_alloc_vextent_start_ag(args); error = xfs_alloc_vextent_check_args(args, target, &minimum_agno); if (error) { if (error == -ENOSPC) return 0; return error; } if ((args->datatype & XFS_ALLOC_INITIAL_USER_DATA) && xfs_is_inode32(mp)) { target = XFS_AGB_TO_FSB(mp, ((mp->m_agfrotor / rotorstep) % mp->m_sb.sb_agcount), 0); bump_rotor = 1; } start_agno = max(minimum_agno, XFS_FSB_TO_AGNO(mp, target)); error = xfs_alloc_vextent_iterate_ags(args, minimum_agno, start_agno, XFS_FSB_TO_AGBNO(mp, target), alloc_flags); if (bump_rotor) { if (args->agno == start_agno) mp->m_agfrotor = (mp->m_agfrotor + 1) % (mp->m_sb.sb_agcount * rotorstep); else mp->m_agfrotor = (args->agno * rotorstep + 1) % (mp->m_sb.sb_agcount * rotorstep); } return xfs_alloc_vextent_finish(args, minimum_agno, error, true); } /* * Iterate from the agno indicated via @target through to the end of the * filesystem attempting blocking allocation. This does not wrap or try a second * pass, so will not recurse into AGs lower than indicated by the target. */ int xfs_alloc_vextent_first_ag( struct xfs_alloc_arg *args, xfs_fsblock_t target) { struct xfs_mount *mp = args->mp; xfs_agnumber_t minimum_agno; xfs_agnumber_t start_agno; uint32_t alloc_flags = XFS_ALLOC_FLAG_TRYLOCK; int error; ASSERT(args->pag == NULL); args->agno = NULLAGNUMBER; args->agbno = NULLAGBLOCK; trace_xfs_alloc_vextent_first_ag(args); error = xfs_alloc_vextent_check_args(args, target, &minimum_agno); if (error) { if (error == -ENOSPC) return 0; return error; } start_agno = max(minimum_agno, XFS_FSB_TO_AGNO(mp, target)); error = xfs_alloc_vextent_iterate_ags(args, minimum_agno, start_agno, XFS_FSB_TO_AGBNO(mp, target), alloc_flags); return xfs_alloc_vextent_finish(args, minimum_agno, error, true); } /* * Allocate at the exact block target or fail. Caller is expected to hold a * perag reference in args->pag. */ int xfs_alloc_vextent_exact_bno( struct xfs_alloc_arg *args, xfs_fsblock_t target) { struct xfs_mount *mp = args->mp; xfs_agnumber_t minimum_agno; int error; ASSERT(args->pag != NULL); ASSERT(args->pag->pag_agno == XFS_FSB_TO_AGNO(mp, target)); args->agno = XFS_FSB_TO_AGNO(mp, target); args->agbno = XFS_FSB_TO_AGBNO(mp, target); trace_xfs_alloc_vextent_exact_bno(args); error = xfs_alloc_vextent_check_args(args, target, &minimum_agno); if (error) { if (error == -ENOSPC) return 0; return error; } error = xfs_alloc_vextent_prepare_ag(args, 0); if (!error && args->agbp) error = xfs_alloc_ag_vextent_exact(args); return xfs_alloc_vextent_finish(args, minimum_agno, error, false); } /* * Allocate an extent as close to the target as possible. If there are not * viable candidates in the AG, then fail the allocation. * * Caller may or may not have a per-ag reference in args->pag. */ int xfs_alloc_vextent_near_bno( struct xfs_alloc_arg *args, xfs_fsblock_t target) { struct xfs_mount *mp = args->mp; xfs_agnumber_t minimum_agno; bool needs_perag = args->pag == NULL; uint32_t alloc_flags = 0; int error; if (!needs_perag) ASSERT(args->pag->pag_agno == XFS_FSB_TO_AGNO(mp, target)); args->agno = XFS_FSB_TO_AGNO(mp, target); args->agbno = XFS_FSB_TO_AGBNO(mp, target); trace_xfs_alloc_vextent_near_bno(args); error = xfs_alloc_vextent_check_args(args, target, &minimum_agno); if (error) { if (error == -ENOSPC) return 0; return error; } if (needs_perag) args->pag = xfs_perag_grab(mp, args->agno); error = xfs_alloc_vextent_prepare_ag(args, alloc_flags); if (!error && args->agbp) error = xfs_alloc_ag_vextent_near(args, alloc_flags); return xfs_alloc_vextent_finish(args, minimum_agno, error, needs_perag); } /* Ensure that the freelist is at full capacity. */ int xfs_free_extent_fix_freelist( struct xfs_trans *tp, struct xfs_perag *pag, struct xfs_buf **agbp) { struct xfs_alloc_arg args; int error; memset(&args, 0, sizeof(struct xfs_alloc_arg)); args.tp = tp; args.mp = tp->t_mountp; args.agno = pag->pag_agno; args.pag = pag; /* * validate that the block number is legal - the enables us to detect * and handle a silent filesystem corruption rather than crashing. */ if (args.agno >= args.mp->m_sb.sb_agcount) return -EFSCORRUPTED; error = xfs_alloc_fix_freelist(&args, XFS_ALLOC_FLAG_FREEING); if (error) return error; *agbp = args.agbp; return 0; } /* * Free an extent. * Just break up the extent address and hand off to xfs_free_ag_extent * after fixing up the freelist. */ int __xfs_free_extent( struct xfs_trans *tp, struct xfs_perag *pag, xfs_agblock_t agbno, xfs_extlen_t len, const struct xfs_owner_info *oinfo, enum xfs_ag_resv_type type, bool skip_discard) { struct xfs_mount *mp = tp->t_mountp; struct xfs_buf *agbp; struct xfs_agf *agf; int error; unsigned int busy_flags = 0; ASSERT(len != 0); ASSERT(type != XFS_AG_RESV_AGFL); if (XFS_TEST_ERROR(false, mp, XFS_ERRTAG_FREE_EXTENT)) return -EIO; error = xfs_free_extent_fix_freelist(tp, pag, &agbp); if (error) return error; agf = agbp->b_addr; if (XFS_IS_CORRUPT(mp, agbno >= mp->m_sb.sb_agblocks)) { error = -EFSCORRUPTED; goto err_release; } /* validate the extent size is legal now we have the agf locked */ if (XFS_IS_CORRUPT(mp, agbno + len > be32_to_cpu(agf->agf_length))) { error = -EFSCORRUPTED; goto err_release; } error = xfs_free_ag_extent(tp, agbp, pag->pag_agno, agbno, len, oinfo, type); if (error) goto err_release; if (skip_discard) busy_flags |= XFS_EXTENT_BUSY_SKIP_DISCARD; xfs_extent_busy_insert(tp, pag, agbno, len, busy_flags); return 0; err_release: xfs_trans_brelse(tp, agbp); return error; } struct xfs_alloc_query_range_info { xfs_alloc_query_range_fn fn; void *priv; }; /* Format btree record and pass to our callback. */ STATIC int xfs_alloc_query_range_helper( struct xfs_btree_cur *cur, const union xfs_btree_rec *rec, void *priv) { struct xfs_alloc_query_range_info *query = priv; struct xfs_alloc_rec_incore irec; xfs_failaddr_t fa; xfs_alloc_btrec_to_irec(rec, &irec); fa = xfs_alloc_check_irec(cur->bc_ag.pag, &irec); if (fa) return xfs_alloc_complain_bad_rec(cur, fa, &irec); return query->fn(cur, &irec, query->priv); } /* Find all free space within a given range of blocks. */ int xfs_alloc_query_range( struct xfs_btree_cur *cur, const struct xfs_alloc_rec_incore *low_rec, const struct xfs_alloc_rec_incore *high_rec, xfs_alloc_query_range_fn fn, void *priv) { union xfs_btree_irec low_brec = { .a = *low_rec }; union xfs_btree_irec high_brec = { .a = *high_rec }; struct xfs_alloc_query_range_info query = { .priv = priv, .fn = fn }; ASSERT(cur->bc_btnum == XFS_BTNUM_BNO); return xfs_btree_query_range(cur, &low_brec, &high_brec, xfs_alloc_query_range_helper, &query); } /* Find all free space records. */ int xfs_alloc_query_all( struct xfs_btree_cur *cur, xfs_alloc_query_range_fn fn, void *priv) { struct xfs_alloc_query_range_info query; ASSERT(cur->bc_btnum == XFS_BTNUM_BNO); query.priv = priv; query.fn = fn; return xfs_btree_query_all(cur, xfs_alloc_query_range_helper, &query); } /* * Scan part of the keyspace of the free space and tell us if the area has no * records, is fully mapped by records, or is partially filled. */ int xfs_alloc_has_records( struct xfs_btree_cur *cur, xfs_agblock_t bno, xfs_extlen_t len, enum xbtree_recpacking *outcome) { union xfs_btree_irec low; union xfs_btree_irec high; memset(&low, 0, sizeof(low)); low.a.ar_startblock = bno; memset(&high, 0xFF, sizeof(high)); high.a.ar_startblock = bno + len - 1; return xfs_btree_has_records(cur, &low, &high, NULL, outcome); } /* * Walk all the blocks in the AGFL. The @walk_fn can return any negative * error code or XFS_ITER_*. */ int xfs_agfl_walk( struct xfs_mount *mp, struct xfs_agf *agf, struct xfs_buf *agflbp, xfs_agfl_walk_fn walk_fn, void *priv) { __be32 *agfl_bno; unsigned int i; int error; agfl_bno = xfs_buf_to_agfl_bno(agflbp); i = be32_to_cpu(agf->agf_flfirst); /* Nothing to walk in an empty AGFL. */ if (agf->agf_flcount == cpu_to_be32(0)) return 0; /* Otherwise, walk from first to last, wrapping as needed. */ for (;;) { error = walk_fn(mp, be32_to_cpu(agfl_bno[i]), priv); if (error) return error; if (i == be32_to_cpu(agf->agf_fllast)) break; if (++i == xfs_agfl_size(mp)) i = 0; } return 0; } int __init xfs_extfree_intent_init_cache(void) { xfs_extfree_item_cache = kmem_cache_create("xfs_extfree_intent", sizeof(struct xfs_extent_free_item), 0, 0, NULL); return xfs_extfree_item_cache != NULL ? 0 : -ENOMEM; } void xfs_extfree_intent_destroy_cache(void) { kmem_cache_destroy(xfs_extfree_item_cache); xfs_extfree_item_cache = NULL; }
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