diff options
Diffstat (limited to 'fs/xfs/libxfs/xfs_alloc.c')
| -rw-r--r-- | fs/xfs/libxfs/xfs_alloc.c | 3187 |
1 files changed, 3187 insertions, 0 deletions
diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c new file mode 100644 index 000000000..b3a9043b0 --- /dev/null +++ b/fs/xfs/libxfs/xfs_alloc.c @@ -0,0 +1,3187 @@ +// 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_sb.h" +#include "xfs_mount.h" +#include "xfs_defer.h" +#include "xfs_inode.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_cksum.h" +#include "xfs_trace.h" +#include "xfs_trans.h" +#include "xfs_buf_item.h" +#include "xfs_log.h" +#include "xfs_ag_resv.h" +#include "xfs_bmap.h" + +extern kmem_zone_t *xfs_bmap_free_item_zone; + +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 + +STATIC int xfs_alloc_ag_vextent_exact(xfs_alloc_arg_t *); +STATIC int xfs_alloc_ag_vextent_near(xfs_alloc_arg_t *); +STATIC int xfs_alloc_ag_vextent_size(xfs_alloc_arg_t *); +STATIC int xfs_alloc_ag_vextent_small(xfs_alloc_arg_t *, + xfs_btree_cur_t *, xfs_agblock_t *, xfs_extlen_t *, int *); + +/* + * 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_sb_version_hascrc(&mp->m_sb)) + size -= sizeof(struct xfs_agfl); + + return size / sizeof(xfs_agblock_t); +} + +unsigned int +xfs_refc_block( + struct xfs_mount *mp) +{ + if (xfs_sb_version_hasrmapbt(&mp->m_sb)) + return XFS_RMAP_BLOCK(mp) + 1; + if (xfs_sb_version_hasfinobt(&mp->m_sb)) + return XFS_FIBT_BLOCK(mp) + 1; + return XFS_IBT_BLOCK(mp) + 1; +} + +xfs_extlen_t +xfs_prealloc_blocks( + struct xfs_mount *mp) +{ + if (xfs_sb_version_hasreflink(&mp->m_sb)) + return xfs_refc_block(mp) + 1; + if (xfs_sb_version_hasrmapbt(&mp->m_sb)) + return XFS_RMAP_BLOCK(mp) + 1; + if (xfs_sb_version_hasfinobt(&mp->m_sb)) + return XFS_FIBT_BLOCK(mp) + 1; + return XFS_IBT_BLOCK(mp) + 1; +} + +/* + * 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. + * + * We need to reserve 4 fsbs _per AG_ for the freelist 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_ALLOC_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_ALLOC_AGFL_RESERVE; + blocks += 3; /* AGF, AGI btree root blocks */ + if (xfs_sb_version_hasfinobt(&mp->m_sb)) + blocks++; /* finobt root block */ + if (xfs_sb_version_hasrmapbt(&mp->m_sb)) + blocks++; /* rmap root block */ + if (xfs_sb_version_hasreflink(&mp->m_sb)) + 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 */ +{ + cur->bc_rec.a.ar_startblock = bno; + cur->bc_rec.a.ar_blockcount = len; + return xfs_btree_lookup(cur, XFS_LOOKUP_EQ, stat); +} + +/* + * 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 */ +{ + cur->bc_rec.a.ar_startblock = bno; + cur->bc_rec.a.ar_blockcount = len; + return xfs_btree_lookup(cur, XFS_LOOKUP_GE, stat); +} + +/* + * 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 */ +{ + cur->bc_rec.a.ar_startblock = bno; + cur->bc_rec.a.ar_blockcount = len; + return xfs_btree_lookup(cur, XFS_LOOKUP_LE, stat); +} + +/* + * 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); +} + +/* + * 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_mount *mp = cur->bc_mp; + xfs_agnumber_t agno = cur->bc_private.a.agno; + union xfs_btree_rec *rec; + int error; + + error = xfs_btree_get_rec(cur, &rec, stat); + if (error || !(*stat)) + return error; + + *bno = be32_to_cpu(rec->alloc.ar_startblock); + *len = be32_to_cpu(rec->alloc.ar_blockcount); + + if (*len == 0) + goto out_bad_rec; + + /* check for valid extent range, including overflow */ + if (!xfs_verify_agbno(mp, agno, *bno)) + goto out_bad_rec; + if (*bno > *bno + *len) + goto out_bad_rec; + if (!xfs_verify_agbno(mp, agno, *bno + *len - 1)) + goto out_bad_rec; + + return 0; + +out_bad_rec: + xfs_warn(mp, + "%s Freespace BTree record corruption in AG %d detected!", + cur->bc_btnum == XFS_BTNUM_BNO ? "Block" : "Size", agno); + xfs_warn(mp, + "start block 0x%x block count 0x%x", *bno, *len); + return -EFSCORRUPTED; +} + +/* + * 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 = xfs_alloc_is_userdata(datatype); + + 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( + xfs_btree_cur_t *cnt_cur, /* cursor for by-size btree */ + xfs_btree_cur_t *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; + XFS_WANT_CORRUPTED_RETURN(mp, + i == 1 && nfbno1 == fbno && nflen1 == flen); +#endif + } else { + if ((error = xfs_alloc_lookup_eq(cnt_cur, fbno, flen, &i))) + return error; + XFS_WANT_CORRUPTED_RETURN(mp, i == 1); + } + /* + * 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; + XFS_WANT_CORRUPTED_RETURN(mp, + i == 1 && nfbno1 == fbno && nflen1 == flen); +#endif + } else { + if ((error = xfs_alloc_lookup_eq(bno_cur, fbno, flen, &i))) + return error; + XFS_WANT_CORRUPTED_RETURN(mp, i == 1); + } + +#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_bufs[0]); + cntblock = XFS_BUF_TO_BLOCK(cnt_cur->bc_bufs[0]); + + XFS_WANT_CORRUPTED_RETURN(mp, + bnoblock->bb_numrecs == cntblock->bb_numrecs); + } +#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; + XFS_WANT_CORRUPTED_RETURN(mp, i == 1); + /* + * Add new by-size btree entry(s). + */ + if (nfbno1 != NULLAGBLOCK) { + if ((error = xfs_alloc_lookup_eq(cnt_cur, nfbno1, nflen1, &i))) + return error; + XFS_WANT_CORRUPTED_RETURN(mp, i == 0); + if ((error = xfs_btree_insert(cnt_cur, &i))) + return error; + XFS_WANT_CORRUPTED_RETURN(mp, i == 1); + } + if (nfbno2 != NULLAGBLOCK) { + if ((error = xfs_alloc_lookup_eq(cnt_cur, nfbno2, nflen2, &i))) + return error; + XFS_WANT_CORRUPTED_RETURN(mp, i == 0); + if ((error = xfs_btree_insert(cnt_cur, &i))) + return error; + XFS_WANT_CORRUPTED_RETURN(mp, i == 1); + } + /* + * 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; + XFS_WANT_CORRUPTED_RETURN(mp, i == 1); + } 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; + XFS_WANT_CORRUPTED_RETURN(mp, i == 0); + if ((error = xfs_btree_insert(bno_cur, &i))) + return error; + XFS_WANT_CORRUPTED_RETURN(mp, i == 1); + } + return 0; +} + +static xfs_failaddr_t +xfs_agfl_verify( + struct xfs_buf *bp) +{ + struct xfs_mount *mp = bp->b_target->bt_mount; + struct xfs_agfl *agfl = XFS_BUF_TO_AGFL(bp); + int i; + + /* + * 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_sb_version_hascrc(&mp->m_sb)) + return NULL; + + if (!uuid_equal(&agfl->agfl_uuid, &mp->m_sb.sb_meta_uuid)) + return __this_address; + if (be32_to_cpu(agfl->agfl_magicnum) != XFS_AGFL_MAGIC) + 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->agfl_bno[i]) != NULLAGBLOCK && + be32_to_cpu(agfl->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_target->bt_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_sb_version_hascrc(&mp->m_sb)) + 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_target->bt_mount; + struct xfs_buf_log_item *bip = bp->b_log_item; + xfs_failaddr_t fa; + + /* no verification of non-crc AGFLs */ + if (!xfs_sb_version_hascrc(&mp->m_sb)) + 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", + .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 /* error */ +xfs_alloc_read_agfl( + xfs_mount_t *mp, /* mount point structure */ + xfs_trans_t *tp, /* transaction pointer */ + xfs_agnumber_t agno, /* allocation group number */ + xfs_buf_t **bpp) /* buffer for the ag free block array */ +{ + xfs_buf_t *bp; /* return value */ + int error; + + ASSERT(agno != NULLAGNUMBER); + error = xfs_trans_read_buf( + mp, tp, mp->m_ddev_targp, + XFS_AG_DADDR(mp, 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_perag *pag, + struct xfs_buf *agbp, + long len) +{ + struct xfs_agf *agf = XFS_BUF_TO_AGF(agbp); + + pag->pagf_freeblks += len; + be32_add_cpu(&agf->agf_freeblks, len); + + xfs_trans_agblocks_delta(tp, len); + if (unlikely(be32_to_cpu(agf->agf_freeblks) > + be32_to_cpu(agf->agf_length))) + return -EFSCORRUPTED; + + xfs_alloc_log_agf(tp, agbp, XFS_AGF_FREEBLKS); + return 0; +} + +/* + * Allocation group level functions. + */ + +/* + * Allocate a variable extent in the allocation group agno. + * Type and bno are used to determine where in the allocation group the + * extent will start. + * 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 /* error */ +xfs_alloc_ag_vextent( + xfs_alloc_arg_t *args) /* argument structure for allocation */ +{ + int error=0; + + ASSERT(args->minlen > 0); + ASSERT(args->maxlen > 0); + ASSERT(args->minlen <= args->maxlen); + ASSERT(args->mod < args->prod); + ASSERT(args->alignment > 0); + + /* + * Branch to correct routine based on the type. + */ + args->wasfromfl = 0; + switch (args->type) { + case XFS_ALLOCTYPE_THIS_AG: + error = xfs_alloc_ag_vextent_size(args); + break; + case XFS_ALLOCTYPE_NEAR_BNO: + error = xfs_alloc_ag_vextent_near(args); + break; + case XFS_ALLOCTYPE_THIS_BNO: + error = xfs_alloc_ag_vextent_exact(args); + break; + default: + ASSERT(0); + /* NOTREACHED */ + } + + if (error || args->agbno == NULLAGBLOCK) + return error; + + ASSERT(args->len >= args->minlen); + ASSERT(args->len <= args->maxlen); + ASSERT(!args->wasfromfl || args->resv != XFS_AG_RESV_AGFL); + ASSERT(args->agbno % args->alignment == 0); + + /* 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->agno, + args->agbno, args->len, &args->oinfo); + if (error) + return error; + } + + if (!args->wasfromfl) { + error = xfs_alloc_update_counters(args->tp, args->pag, + args->agbp, + -((long)(args->len))); + if (error) + return error; + + ASSERT(!xfs_extent_busy_search(args->mp, args->agno, + args->agbno, args->len)); + } + + xfs_ag_resv_alloc_extent(args->pag, args->resv, args); + + XFS_STATS_INC(args->mp, xs_allocx); + XFS_STATS_ADD(args->mp, xs_allocb, args->len); + 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 */ +{ + xfs_btree_cur_t *bno_cur;/* by block-number btree cursor */ + xfs_btree_cur_t *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->agno, 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; + XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, 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->agno, XFS_BTNUM_CNT); + ASSERT(args->agbno + args->len <= + be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->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 the btree in a given direction via the search cursor and compare + * the records found against the good extent we've already found. + */ +STATIC int +xfs_alloc_find_best_extent( + struct xfs_alloc_arg *args, /* allocation argument structure */ + struct xfs_btree_cur **gcur, /* good cursor */ + struct xfs_btree_cur **scur, /* searching cursor */ + xfs_agblock_t gdiff, /* difference for search comparison */ + xfs_agblock_t *sbno, /* extent found by search */ + xfs_extlen_t *slen, /* extent length */ + xfs_agblock_t *sbnoa, /* aligned extent found by search */ + xfs_extlen_t *slena, /* aligned extent length */ + int dir) /* 0 = search right, 1 = search left */ +{ + xfs_agblock_t new; + xfs_agblock_t sdiff; + int error; + int i; + unsigned busy_gen; + + /* The good extent is perfect, no need to search. */ + if (!gdiff) + goto out_use_good; + + /* + * Look until we find a better one, run out of space or run off the end. + */ + do { + error = xfs_alloc_get_rec(*scur, sbno, slen, &i); + if (error) + goto error0; + XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0); + xfs_alloc_compute_aligned(args, *sbno, *slen, + sbnoa, slena, &busy_gen); + + /* + * The good extent is closer than this one. + */ + if (!dir) { + if (*sbnoa > args->max_agbno) + goto out_use_good; + if (*sbnoa >= args->agbno + gdiff) + goto out_use_good; + } else { + if (*sbnoa < args->min_agbno) + goto out_use_good; + if (*sbnoa <= args->agbno - gdiff) + goto out_use_good; + } + + /* + * Same distance, compare length and pick the best. + */ + if (*slena >= args->minlen) { + args->len = XFS_EXTLEN_MIN(*slena, args->maxlen); + xfs_alloc_fix_len(args); + + sdiff = xfs_alloc_compute_diff(args->agbno, args->len, + args->alignment, + args->datatype, *sbnoa, + *slena, &new); + + /* + * Choose closer size and invalidate other cursor. + */ + if (sdiff < gdiff) + goto out_use_search; + goto out_use_good; + } + + if (!dir) + error = xfs_btree_increment(*scur, 0, &i); + else + error = xfs_btree_decrement(*scur, 0, &i); + if (error) + goto error0; + } while (i); + +out_use_good: + xfs_btree_del_cursor(*scur, XFS_BTREE_NOERROR); + *scur = NULL; + return 0; + +out_use_search: + xfs_btree_del_cursor(*gcur, XFS_BTREE_NOERROR); + *gcur = NULL; + return 0; + +error0: + /* caller invalidates cursors */ + return error; +} + +/* + * 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 /* error */ +xfs_alloc_ag_vextent_near( + xfs_alloc_arg_t *args) /* allocation argument structure */ +{ + xfs_btree_cur_t *bno_cur_gt; /* cursor for bno btree, right side */ + xfs_btree_cur_t *bno_cur_lt; /* cursor for bno btree, left side */ + xfs_btree_cur_t *cnt_cur; /* cursor for count btree */ + xfs_agblock_t gtbno; /* start bno of right side entry */ + xfs_agblock_t gtbnoa; /* aligned ... */ + xfs_extlen_t gtdiff; /* difference to right side entry */ + xfs_extlen_t gtlen; /* length of right side entry */ + xfs_extlen_t gtlena; /* aligned ... */ + xfs_agblock_t gtnew; /* useful start bno of right side */ + int error; /* error code */ + int i; /* result code, temporary */ + int j; /* result code, temporary */ + xfs_agblock_t ltbno; /* start bno of left side entry */ + xfs_agblock_t ltbnoa; /* aligned ... */ + xfs_extlen_t ltdiff; /* difference to left side entry */ + xfs_extlen_t ltlen; /* length of left side entry */ + xfs_extlen_t ltlena; /* aligned ... */ + xfs_agblock_t ltnew; /* useful start bno of left side */ + xfs_extlen_t rlen; /* length of returned extent */ + bool busy; + unsigned busy_gen; +#ifdef DEBUG + /* + * Randomly don't execute the first algorithm. + */ + int dofirst; /* set to do first algorithm */ + + dofirst = prandom_u32() & 1; +#endif + + /* handle unitialized 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; + +restart: + bno_cur_lt = NULL; + bno_cur_gt = NULL; + ltlen = 0; + gtlena = 0; + ltlena = 0; + busy = false; + + /* + * Get a cursor for the by-size btree. + */ + cnt_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp, + args->agno, XFS_BTNUM_CNT); + + /* + * See if there are any free extents as big as maxlen. + */ + if ((error = xfs_alloc_lookup_ge(cnt_cur, 0, args->maxlen, &i))) + goto error0; + /* + * If none, then pick up the last entry in the tree unless the + * tree is empty. + */ + if (!i) { + if ((error = xfs_alloc_ag_vextent_small(args, cnt_cur, <bno, + <len, &i))) + goto error0; + if (i == 0 || ltlen == 0) { + xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR); + trace_xfs_alloc_near_noentry(args); + return 0; + } + ASSERT(i == 1); + } + args->wasfromfl = 0; + + /* + * 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. + * This is written as a while loop so we can break out of it, + * but we never loop back to the top. + */ + while (xfs_btree_islastblock(cnt_cur, 0)) { + xfs_extlen_t bdiff; + int besti=0; + xfs_extlen_t blen=0; + xfs_agblock_t bnew=0; + +#ifdef DEBUG + if (dofirst) + break; +#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 (ltlen || args->alignment > 1) { + cnt_cur->bc_ptrs[0] = 1; + do { + if ((error = xfs_alloc_get_rec(cnt_cur, <bno, + <len, &i))) + goto error0; + XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0); + if (ltlen >= args->minlen) + break; + if ((error = xfs_btree_increment(cnt_cur, 0, &i))) + goto error0; + } while (i); + ASSERT(ltlen >= args->minlen); + if (!i) + break; + } + i = cnt_cur->bc_ptrs[0]; + for (j = 1, blen = 0, bdiff = 0; + !error && j && (blen < args->maxlen || bdiff > 0); + error = xfs_btree_increment(cnt_cur, 0, &j)) { + /* + * For each entry, decide if it's better than + * the previous best entry. + */ + if ((error = xfs_alloc_get_rec(cnt_cur, <bno, <len, &i))) + goto error0; + XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0); + busy = xfs_alloc_compute_aligned(args, ltbno, ltlen, + <bnoa, <lena, &busy_gen); + if (ltlena < args->minlen) + continue; + if (ltbnoa < args->min_agbno || ltbnoa > args->max_agbno) + continue; + args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen); + xfs_alloc_fix_len(args); + ASSERT(args->len >= args->minlen); + if (args->len < blen) + continue; + ltdiff = xfs_alloc_compute_diff(args->agbno, args->len, + args->alignment, args->datatype, ltbnoa, + ltlena, <new); + if (ltnew != NULLAGBLOCK && + (args->len > blen || ltdiff < bdiff)) { + bdiff = ltdiff; + bnew = ltnew; + blen = args->len; + besti = cnt_cur->bc_ptrs[0]; + } + } + /* + * It didn't work. We COULD be in a case where + * there's a good record somewhere, so try again. + */ + if (blen == 0) + break; + /* + * Point at the best entry, and retrieve it again. + */ + cnt_cur->bc_ptrs[0] = besti; + if ((error = xfs_alloc_get_rec(cnt_cur, <bno, <len, &i))) + goto error0; + XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0); + ASSERT(ltbno + ltlen <= be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length)); + args->len = blen; + + /* + * We are allocating starting at bnew for blen blocks. + */ + args->agbno = bnew; + ASSERT(bnew >= ltbno); + ASSERT(bnew + blen <= ltbno + ltlen); + /* + * Set up a cursor for the by-bno tree. + */ + bno_cur_lt = xfs_allocbt_init_cursor(args->mp, args->tp, + args->agbp, args->agno, XFS_BTNUM_BNO); + /* + * Fix up the btree entries. + */ + if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur_lt, ltbno, + ltlen, bnew, blen, XFSA_FIXUP_CNT_OK))) + goto error0; + xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR); + xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR); + + trace_xfs_alloc_near_first(args); + return 0; + } + /* + * Second algorithm. + * Search in the by-bno tree to the left and to the right + * simultaneously, until in each case we find a space big enough, + * or run into the edge of the tree. When we run into the edge, + * we deallocate that cursor. + * If both searches succeed, we compare the two spaces and pick + * the better one. + * With alignment, it's possible for both to fail; the upper + * level algorithm that picks allocation groups for allocations + * is not supposed to do this. + */ + /* + * Allocate and initialize the cursor for the leftward search. + */ + bno_cur_lt = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp, + args->agno, XFS_BTNUM_BNO); + /* + * Lookup <= bno to find the leftward search's starting point. + */ + if ((error = xfs_alloc_lookup_le(bno_cur_lt, args->agbno, args->maxlen, &i))) + goto error0; + if (!i) { + /* + * Didn't find anything; use this cursor for the rightward + * search. + */ + bno_cur_gt = bno_cur_lt; + bno_cur_lt = NULL; + } + /* + * Found something. Duplicate the cursor for the rightward search. + */ + else if ((error = xfs_btree_dup_cursor(bno_cur_lt, &bno_cur_gt))) + goto error0; + /* + * Increment the cursor, so we will point at the entry just right + * of the leftward entry if any, or to the leftmost entry. + */ + if ((error = xfs_btree_increment(bno_cur_gt, 0, &i))) + goto error0; + if (!i) { + /* + * It failed, there are no rightward entries. + */ + xfs_btree_del_cursor(bno_cur_gt, XFS_BTREE_NOERROR); + bno_cur_gt = NULL; + } + /* + * Loop going left with the leftward cursor, right with the + * rightward cursor, until either both directions give up or + * we find an entry at least as big as minlen. + */ + do { + if (bno_cur_lt) { + if ((error = xfs_alloc_get_rec(bno_cur_lt, <bno, <len, &i))) + goto error0; + XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0); + busy |= xfs_alloc_compute_aligned(args, ltbno, ltlen, + <bnoa, <lena, &busy_gen); + if (ltlena >= args->minlen && ltbnoa >= args->min_agbno) + break; + if ((error = xfs_btree_decrement(bno_cur_lt, 0, &i))) + goto error0; + if (!i || ltbnoa < args->min_agbno) { + xfs_btree_del_cursor(bno_cur_lt, + XFS_BTREE_NOERROR); + bno_cur_lt = NULL; + } + } + if (bno_cur_gt) { + if ((error = xfs_alloc_get_rec(bno_cur_gt, >bno, >len, &i))) + goto error0; + XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0); + busy |= xfs_alloc_compute_aligned(args, gtbno, gtlen, + >bnoa, >lena, &busy_gen); + if (gtlena >= args->minlen && gtbnoa <= args->max_agbno) + break; + if ((error = xfs_btree_increment(bno_cur_gt, 0, &i))) + goto error0; + if (!i || gtbnoa > args->max_agbno) { + xfs_btree_del_cursor(bno_cur_gt, + XFS_BTREE_NOERROR); + bno_cur_gt = NULL; + } + } + } while (bno_cur_lt || bno_cur_gt); + + /* + * Got both cursors still active, need to find better entry. + */ + if (bno_cur_lt && bno_cur_gt) { + if (ltlena >= args->minlen) { + /* + * Left side is good, look for a right side entry. + */ + args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen); + xfs_alloc_fix_len(args); + ltdiff = xfs_alloc_compute_diff(args->agbno, args->len, + args->alignment, args->datatype, ltbnoa, + ltlena, <new); + + error = xfs_alloc_find_best_extent(args, + &bno_cur_lt, &bno_cur_gt, + ltdiff, >bno, >len, + >bnoa, >lena, + 0 /* search right */); + } else { + ASSERT(gtlena >= args->minlen); + + /* + * Right side is good, look for a left side entry. + */ + args->len = XFS_EXTLEN_MIN(gtlena, args->maxlen); + xfs_alloc_fix_len(args); + gtdiff = xfs_alloc_compute_diff(args->agbno, args->len, + args->alignment, args->datatype, gtbnoa, + gtlena, >new); + + error = xfs_alloc_find_best_extent(args, + &bno_cur_gt, &bno_cur_lt, + gtdiff, <bno, <len, + <bnoa, <lena, + 1 /* search left */); + } + + if (error) + goto error0; + } + + /* + * If we couldn't get anything, give up. + */ + if (bno_cur_lt == NULL && bno_cur_gt == NULL) { + xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR); + + if (busy) { + trace_xfs_alloc_near_busy(args); + xfs_extent_busy_flush(args->mp, args->pag, busy_gen); + goto restart; + } + trace_xfs_alloc_size_neither(args); + args->agbno = NULLAGBLOCK; + return 0; + } + + /* + * At this point we have selected a freespace entry, either to the + * left or to the right. If it's on the right, copy all the + * useful variables to the "left" set so we only have one + * copy of this code. + */ + if (bno_cur_gt) { + bno_cur_lt = bno_cur_gt; + bno_cur_gt = NULL; + ltbno = gtbno; + ltbnoa = gtbnoa; + ltlen = gtlen; + ltlena = gtlena; + j = 1; + } else + j = 0; + + /* + * Fix up the length and compute the useful address. + */ + args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen); + xfs_alloc_fix_len(args); + rlen = args->len; + (void)xfs_alloc_compute_diff(args->agbno, rlen, args->alignment, + args->datatype, ltbnoa, ltlena, <new); + ASSERT(ltnew >= ltbno); + ASSERT(ltnew + rlen <= ltbnoa + ltlena); + ASSERT(ltnew + rlen <= be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length)); + ASSERT(ltnew >= args->min_agbno && ltnew <= args->max_agbno); + args->agbno = ltnew; + + if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur_lt, ltbno, ltlen, + ltnew, rlen, XFSA_FIXUP_BNO_OK))) + goto error0; + + if (j) + trace_xfs_alloc_near_greater(args); + else + trace_xfs_alloc_near_lesser(args); + + xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR); + xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR); + return 0; + + error0: + trace_xfs_alloc_near_error(args); + if (cnt_cur != NULL) + xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR); + if (bno_cur_lt != NULL) + xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_ERROR); + if (bno_cur_gt != NULL) + xfs_btree_del_cursor(bno_cur_gt, XFS_BTREE_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 /* error */ +xfs_alloc_ag_vextent_size( + xfs_alloc_arg_t *args) /* allocation argument structure */ +{ + xfs_btree_cur_t *bno_cur; /* cursor for bno btree */ + xfs_btree_cur_t *cnt_cur; /* cursor for cnt btree */ + int error; /* error result */ + xfs_agblock_t fbno; /* start of found freespace */ + xfs_extlen_t flen; /* length of found freespace */ + int i; /* temp status variable */ + xfs_agblock_t rbno; /* returned block number */ + xfs_extlen_t rlen; /* length of returned extent */ + bool busy; + unsigned busy_gen; + +restart: + /* + * Allocate and initialize a cursor for the by-size btree. + */ + cnt_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp, + args->agno, XFS_BTNUM_CNT); + bno_cur = NULL; + busy = false; + + /* + * 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; + XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, 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 == 0) { + /* + * Our only valid extents must have been busy. + * Make it unbusy by forcing the log out and + * retrying. + */ + xfs_btree_del_cursor(cnt_cur, + XFS_BTREE_NOERROR); + trace_xfs_alloc_size_busy(args); + xfs_extent_busy_flush(args->mp, + args->pag, busy_gen); + 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); + XFS_WANT_CORRUPTED_GOTO(args->mp, rlen == 0 || + (rlen <= flen && rbno + rlen <= fbno + flen), 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; + XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0); + if (flen < bestrlen) + break; + busy = xfs_alloc_compute_aligned(args, fbno, flen, + &rbno, &rlen, &busy_gen); + rlen = XFS_EXTLEN_MIN(args->maxlen, rlen); + XFS_WANT_CORRUPTED_GOTO(args->mp, rlen == 0 || + (rlen <= flen && rbno + rlen <= fbno + flen), + 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; + XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, 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) { + xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR); + trace_xfs_alloc_size_busy(args); + xfs_extent_busy_flush(args->mp, args->pag, busy_gen); + goto restart; + } + goto out_nominleft; + } + xfs_alloc_fix_len(args); + + rlen = args->len; + XFS_WANT_CORRUPTED_GOTO(args->mp, rlen <= flen, error0); + /* + * Allocate and initialize a cursor for the by-block tree. + */ + bno_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp, + args->agno, 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; + XFS_WANT_CORRUPTED_GOTO(args->mp, + args->agbno + args->len <= + be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length), + 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; +} + +/* + * 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( + xfs_alloc_arg_t *args, /* allocation argument structure */ + xfs_btree_cur_t *ccur, /* 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_owner_info oinfo; + int error; + xfs_agblock_t fbno; + xfs_extlen_t flen; + int i; + + if ((error = xfs_btree_decrement(ccur, 0, &i))) + goto error0; + if (i) { + if ((error = xfs_alloc_get_rec(ccur, &fbno, &flen, &i))) + goto error0; + XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0); + } + /* + * Nothing in the btree, try the freelist. Make sure + * to respect minleft even when pulling from the + * freelist. + */ + else if (args->minlen == 1 && args->alignment == 1 && + args->resv != XFS_AG_RESV_AGFL && + (be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_flcount) + > args->minleft)) { + error = xfs_alloc_get_freelist(args->tp, args->agbp, &fbno, 0); + if (error) + goto error0; + if (fbno != NULLAGBLOCK) { + xfs_extent_busy_reuse(args->mp, args->agno, fbno, 1, + xfs_alloc_allow_busy_reuse(args->datatype)); + + if (xfs_alloc_is_userdata(args->datatype)) { + xfs_buf_t *bp; + + bp = xfs_btree_get_bufs(args->mp, args->tp, + args->agno, fbno, 0); + if (!bp) { + error = -EFSCORRUPTED; + goto error0; + } + xfs_trans_binval(args->tp, bp); + } + args->len = 1; + args->agbno = fbno; + XFS_WANT_CORRUPTED_GOTO(args->mp, + args->agbno + args->len <= + be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length), + error0); + 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. + */ + xfs_rmap_ag_owner(&oinfo, XFS_RMAP_OWN_AG); + error = xfs_rmap_free(args->tp, args->agbp, args->agno, + fbno, 1, &oinfo); + if (error) + goto error0; + + *stat = 0; + return 0; + } + /* + * Nothing in the freelist. + */ + else + flen = 0; + } + /* + * Can't allocate from the freelist for some reason. + */ + else { + fbno = NULLAGBLOCK; + flen = 0; + } + /* + * 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; + +error0: + trace_xfs_alloc_small_error(args); + return error; +} + +/* + * Free the extent starting at agno/bno for length. + */ +STATIC int +xfs_free_ag_extent( + xfs_trans_t *tp, + xfs_buf_t *agbp, + xfs_agnumber_t agno, + xfs_agblock_t bno, + xfs_extlen_t len, + struct xfs_owner_info *oinfo, + enum xfs_ag_resv_type type) +{ + xfs_btree_cur_t *bno_cur; /* cursor for by-block btree */ + xfs_btree_cur_t *cnt_cur; /* cursor for by-size btree */ + int error; /* error return value */ + xfs_agblock_t gtbno; /* start of right neighbor block */ + xfs_extlen_t gtlen; /* length of right neighbor block */ + int haveleft; /* have a left neighbor block */ + int haveright; /* have a right neighbor block */ + int i; /* temp, result code */ + xfs_agblock_t ltbno; /* start of left neighbor block */ + xfs_extlen_t ltlen; /* length of left neighbor block */ + xfs_mount_t *mp; /* mount point struct for filesystem */ + xfs_agblock_t nbno; /* new starting block of freespace */ + xfs_extlen_t nlen; /* new length of freespace */ + xfs_perag_t *pag; /* per allocation group data */ + + bno_cur = cnt_cur = NULL; + mp = tp->t_mountp; + + if (!xfs_rmap_should_skip_owner_update(oinfo)) { + error = xfs_rmap_free(tp, agbp, agno, 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, agno, 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; + XFS_WANT_CORRUPTED_GOTO(mp, i == 1, 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. + */ + XFS_WANT_CORRUPTED_GOTO(mp, + ltbno + ltlen <= bno, 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; + XFS_WANT_CORRUPTED_GOTO(mp, i == 1, 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. + */ + XFS_WANT_CORRUPTED_GOTO(mp, gtbno >= bno + len, error0); + } + } + /* + * Now allocate and initialize a cursor for the by-size tree. + */ + cnt_cur = xfs_allocbt_init_cursor(mp, tp, agbp, agno, 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; + XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0); + if ((error = xfs_btree_delete(cnt_cur, &i))) + goto error0; + XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0); + /* + * Delete the old by-size entry on the right. + */ + if ((error = xfs_alloc_lookup_eq(cnt_cur, gtbno, gtlen, &i))) + goto error0; + XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0); + if ((error = xfs_btree_delete(cnt_cur, &i))) + goto error0; + XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0); + /* + * Delete the old by-block entry for the right block. + */ + if ((error = xfs_btree_delete(bno_cur, &i))) + goto error0; + XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0); + /* + * Move the by-block cursor back to the left neighbor. + */ + if ((error = xfs_btree_decrement(bno_cur, 0, &i))) + goto error0; + XFS_WANT_CORRUPTED_GOTO(mp, i == 1, 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; + XFS_WANT_CORRUPTED_GOTO(mp, + i == 1 && xxbno == ltbno && xxlen == ltlen, + 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; + XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0); + if ((error = xfs_btree_delete(cnt_cur, &i))) + goto error0; + XFS_WANT_CORRUPTED_GOTO(mp, i == 1, 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; + XFS_WANT_CORRUPTED_GOTO(mp, i == 1, 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; + XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0); + if ((error = xfs_btree_delete(cnt_cur, &i))) + goto error0; + XFS_WANT_CORRUPTED_GOTO(mp, i == 1, 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; + XFS_WANT_CORRUPTED_GOTO(mp, i == 1, 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; + XFS_WANT_CORRUPTED_GOTO(mp, i == 0, error0); + if ((error = xfs_btree_insert(cnt_cur, &i))) + goto error0; + XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0); + xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR); + cnt_cur = NULL; + + /* + * Update the freespace totals in the ag and superblock. + */ + pag = xfs_perag_get(mp, agno); + error = xfs_alloc_update_counters(tp, pag, agbp, len); + xfs_ag_resv_free_extent(pag, type, tp, len); + xfs_perag_put(pag); + 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_ag_maxlevels. + */ +void +xfs_alloc_compute_maxlevels( + xfs_mount_t *mp) /* file system mount structure */ +{ + mp->m_ag_maxlevels = xfs_btree_compute_maxlevels(mp->m_alloc_mnr, + (mp->m_sb.sb_agblocks + 1) / 2); +} + +/* + * 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 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; +} + +unsigned int +xfs_alloc_min_freelist( + struct xfs_mount *mp, + struct xfs_perag *pag) +{ + unsigned int min_free; + + /* space needed by-bno freespace btree */ + min_free = min_t(unsigned int, pag->pagf_levels[XFS_BTNUM_BNOi] + 1, + mp->m_ag_maxlevels); + /* space needed by-size freespace btree */ + min_free += min_t(unsigned int, pag->pagf_levels[XFS_BTNUM_CNTi] + 1, + mp->m_ag_maxlevels); + /* space needed reverse mapping used space btree */ + if (xfs_sb_version_hasrmapbt(&mp->m_sb)) + min_free += min_t(unsigned int, + pag->pagf_levels[XFS_BTNUM_RMAPi] + 1, + mp->m_rmap_maxlevels); + + 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; + + 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? */ + available = (int)(pag->pagf_freeblks + pag->pagf_flcount - + 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; + + bp = xfs_btree_get_bufs(tp->t_mountp, tp, agno, agbno, 0); + if (!bp) + return -EFSCORRUPTED; + xfs_trans_binval(tp, bp); + + return 0; +} + +/* + * Check the agfl fields of the agf for inconsistency or corruption. The purpose + * is 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. This + * may also catch variants of agfl count corruption unrelated to padding. Either + * way, we'll 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; + + /* no agfl header on v4 supers */ + if (!xfs_sb_version_hascrc(&mp->m_sb)) + return false; + + /* + * 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 = XFS_BUF_TO_AGF(agbp); + + ASSERT(pag->pagf_agflreset); + 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; + pag->pagf_agflreset = false; +} + +/* + * Defer an AGFL block free. This is effectively equivalent to + * xfs_bmap_add_free() 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 void +xfs_defer_agfl_block( + struct xfs_trans *tp, + xfs_agnumber_t agno, + xfs_fsblock_t agbno, + struct xfs_owner_info *oinfo) +{ + struct xfs_mount *mp = tp->t_mountp; + struct xfs_extent_free_item *new; /* new element */ + + ASSERT(xfs_bmap_free_item_zone != NULL); + ASSERT(oinfo != NULL); + + new = kmem_zone_alloc(xfs_bmap_free_item_zone, KM_SLEEP); + new->xefi_startblock = XFS_AGB_TO_FSB(mp, agno, agbno); + new->xefi_blockcount = 1; + new->xefi_oinfo = *oinfo; + new->xefi_skip_discard = false; + + trace_xfs_agfl_free_defer(mp, agno, 0, agbno, 1); + + xfs_defer_add(tp, XFS_DEFER_OPS_TYPE_AGFL_FREE, &new->xefi_list); +} + +/* + * 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 */ + int flags) /* XFS_ALLOC_FLAG_... */ +{ + 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; + + if (!pag->pagf_init) { + error = xfs_alloc_read_agf(mp, tp, args->agno, flags, &agbp); + if (error) + goto out_no_agbp; + if (!pag->pagf_init) { + ASSERT(flags & XFS_ALLOC_FLAG_TRYLOCK); + ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING)); + goto out_agbp_relse; + } + } + + /* + * 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 (pag->pagf_metadata && xfs_alloc_is_userdata(args->datatype) && + (flags & XFS_ALLOC_FLAG_TRYLOCK)) { + ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING)); + goto out_agbp_relse; + } + + need = xfs_alloc_min_freelist(mp, pag); + if (!xfs_alloc_space_available(args, need, 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(mp, tp, args->agno, flags, &agbp); + if (error) + goto out_no_agbp; + if (!agbp) { + ASSERT(flags & XFS_ALLOC_FLAG_TRYLOCK); + ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING)); + goto out_no_agbp; + } + } + + /* reset a padding mismatched agfl before final free space check */ + if (pag->pagf_agflreset) + 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, flags)) + goto out_agbp_relse; + + /* + * 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)); + if (flags & XFS_ALLOC_FLAG_NORMAP) + xfs_rmap_skip_owner_update(&targs.oinfo); + else + xfs_rmap_ag_owner(&targs.oinfo, XFS_RMAP_OWN_AG); + while (!(flags & XFS_ALLOC_FLAG_NOSHRINK) && pag->pagf_flcount > need) { + error = xfs_alloc_get_freelist(tp, agbp, &bno, 0); + if (error) + goto out_agbp_relse; + + /* defer agfl frees */ + xfs_defer_agfl_block(tp, args->agno, bno, &targs.oinfo); + } + + targs.tp = tp; + targs.mp = mp; + targs.agbp = agbp; + targs.agno = args->agno; + targs.alignment = targs.minlen = targs.prod = 1; + targs.type = XFS_ALLOCTYPE_THIS_AG; + targs.pag = pag; + error = xfs_alloc_read_agfl(mp, tp, targs.agno, &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(&targs); + 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 (flags & XFS_ALLOC_FLAG_FREEING) + break; + 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(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 /* error */ +xfs_alloc_get_freelist( + xfs_trans_t *tp, /* transaction pointer */ + xfs_buf_t *agbp, /* buffer containing the agf structure */ + xfs_agblock_t *bnop, /* block address retrieved from freelist */ + int btreeblk) /* destination is a AGF btree */ +{ + xfs_agf_t *agf; /* a.g. freespace structure */ + xfs_buf_t *agflbp;/* buffer for a.g. freelist structure */ + xfs_agblock_t bno; /* block number returned */ + __be32 *agfl_bno; + int error; + int logflags; + xfs_mount_t *mp = tp->t_mountp; + xfs_perag_t *pag; /* per allocation group data */ + + /* + * Freelist is empty, give up. + */ + agf = XFS_BUF_TO_AGF(agbp); + if (!agf->agf_flcount) { + *bnop = NULLAGBLOCK; + return 0; + } + /* + * Read the array of free blocks. + */ + error = xfs_alloc_read_agfl(mp, tp, be32_to_cpu(agf->agf_seqno), + &agflbp); + if (error) + return error; + + + /* + * Get the block number and update the data structures. + */ + agfl_bno = XFS_BUF_TO_AGFL_BNO(mp, agflbp); + bno = be32_to_cpu(agfl_bno[be32_to_cpu(agf->agf_flfirst)]); + 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; + + pag = xfs_perag_get(mp, be32_to_cpu(agf->agf_seqno)); + ASSERT(!pag->pagf_agflreset); + be32_add_cpu(&agf->agf_flcount, -1); + xfs_trans_agflist_delta(tp, -1); + pag->pagf_flcount--; + xfs_perag_put(pag); + + 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( + xfs_trans_t *tp, /* transaction pointer */ + xfs_buf_t *bp, /* buffer for a.g. freelist header */ + int fields) /* mask of fields to be logged (XFS_AGF_...) */ +{ + 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, XFS_BUF_TO_AGF(bp), 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); +} + +/* + * Interface for inode allocation to force the pag data to be initialized. + */ +int /* error */ +xfs_alloc_pagf_init( + xfs_mount_t *mp, /* file system mount structure */ + xfs_trans_t *tp, /* transaction pointer */ + xfs_agnumber_t agno, /* allocation group number */ + int flags) /* XFS_ALLOC_FLAGS_... */ +{ + xfs_buf_t *bp; + int error; + + if ((error = xfs_alloc_read_agf(mp, tp, agno, flags, &bp))) + return error; + if (bp) + xfs_trans_brelse(tp, bp); + return 0; +} + +/* + * Put the block on the freelist for the allocation group. + */ +int /* error */ +xfs_alloc_put_freelist( + xfs_trans_t *tp, /* transaction pointer */ + xfs_buf_t *agbp, /* buffer for a.g. freelist header */ + xfs_buf_t *agflbp,/* buffer for a.g. free block array */ + xfs_agblock_t bno, /* block being freed */ + int btreeblk) /* block came from a AGF btree */ +{ + xfs_agf_t *agf; /* a.g. freespace structure */ + __be32 *blockp;/* pointer to array entry */ + int error; + int logflags; + xfs_mount_t *mp; /* mount structure */ + xfs_perag_t *pag; /* per allocation group data */ + __be32 *agfl_bno; + int startoff; + + agf = XFS_BUF_TO_AGF(agbp); + mp = tp->t_mountp; + + if (!agflbp && (error = xfs_alloc_read_agfl(mp, tp, + be32_to_cpu(agf->agf_seqno), &agflbp))) + return error; + be32_add_cpu(&agf->agf_fllast, 1); + if (be32_to_cpu(agf->agf_fllast) == xfs_agfl_size(mp)) + agf->agf_fllast = 0; + + pag = xfs_perag_get(mp, be32_to_cpu(agf->agf_seqno)); + ASSERT(!pag->pagf_agflreset); + be32_add_cpu(&agf->agf_flcount, 1); + xfs_trans_agflist_delta(tp, 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_perag_put(pag); + + 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(mp, 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; +} + +static xfs_failaddr_t +xfs_agf_verify( + struct xfs_buf *bp) +{ + struct xfs_mount *mp = bp->b_target->bt_mount; + struct xfs_agf *agf = XFS_BUF_TO_AGF(bp); + + if (xfs_sb_version_hascrc(&mp->m_sb)) { + if (!uuid_equal(&agf->agf_uuid, &mp->m_sb.sb_meta_uuid)) + return __this_address; + if (!xfs_log_check_lsn(mp, + be64_to_cpu(XFS_BUF_TO_AGF(bp)->agf_lsn))) + return __this_address; + } + + if (!(agf->agf_magicnum == cpu_to_be32(XFS_AGF_MAGIC) && + XFS_AGF_GOOD_VERSION(be32_to_cpu(agf->agf_versionnum)) && + be32_to_cpu(agf->agf_freeblks) <= be32_to_cpu(agf->agf_length) && + be32_to_cpu(agf->agf_flfirst) < xfs_agfl_size(mp) && + be32_to_cpu(agf->agf_fllast) < xfs_agfl_size(mp) && + be32_to_cpu(agf->agf_flcount) <= xfs_agfl_size(mp))) + return __this_address; + + if (be32_to_cpu(agf->agf_length) > mp->m_sb.sb_dblocks) + return __this_address; + + if (be32_to_cpu(agf->agf_freeblks) < be32_to_cpu(agf->agf_longest) || + be32_to_cpu(agf->agf_freeblks) > be32_to_cpu(agf->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]) > XFS_BTREE_MAXLEVELS || + be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNT]) > XFS_BTREE_MAXLEVELS) + return __this_address; + + if (xfs_sb_version_hasrmapbt(&mp->m_sb) && + (be32_to_cpu(agf->agf_levels[XFS_BTNUM_RMAP]) < 1 || + be32_to_cpu(agf->agf_levels[XFS_BTNUM_RMAP]) > XFS_BTREE_MAXLEVELS)) + return __this_address; + + if (xfs_sb_version_hasrmapbt(&mp->m_sb) && + be32_to_cpu(agf->agf_rmap_blocks) > be32_to_cpu(agf->agf_length)) + 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(agf->agf_seqno) != bp->b_pag->pag_agno) + return __this_address; + + if (xfs_sb_version_haslazysbcount(&mp->m_sb) && + be32_to_cpu(agf->agf_btreeblks) > be32_to_cpu(agf->agf_length)) + return __this_address; + + if (xfs_sb_version_hasreflink(&mp->m_sb) && + be32_to_cpu(agf->agf_refcount_blocks) > + be32_to_cpu(agf->agf_length)) + return __this_address; + + if (xfs_sb_version_hasreflink(&mp->m_sb) && + (be32_to_cpu(agf->agf_refcount_level) < 1 || + be32_to_cpu(agf->agf_refcount_level) > XFS_BTREE_MAXLEVELS)) + return __this_address; + + return NULL; + +} + +static void +xfs_agf_read_verify( + struct xfs_buf *bp) +{ + struct xfs_mount *mp = bp->b_target->bt_mount; + xfs_failaddr_t fa; + + if (xfs_sb_version_hascrc(&mp->m_sb) && + !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_target->bt_mount; + struct xfs_buf_log_item *bip = bp->b_log_item; + xfs_failaddr_t fa; + + fa = xfs_agf_verify(bp); + if (fa) { + xfs_verifier_error(bp, -EFSCORRUPTED, fa); + return; + } + + if (!xfs_sb_version_hascrc(&mp->m_sb)) + return; + + if (bip) + XFS_BUF_TO_AGF(bp)->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", + .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 /* error */ +xfs_read_agf( + struct xfs_mount *mp, /* mount point structure */ + struct xfs_trans *tp, /* transaction pointer */ + xfs_agnumber_t agno, /* allocation group number */ + int flags, /* XFS_BUF_ */ + struct xfs_buf **bpp) /* buffer for the ag freelist header */ +{ + int error; + + trace_xfs_read_agf(mp, agno); + + ASSERT(agno != NULLAGNUMBER); + error = xfs_trans_read_buf( + mp, tp, mp->m_ddev_targp, + XFS_AG_DADDR(mp, agno, XFS_AGF_DADDR(mp)), + XFS_FSS_TO_BB(mp, 1), flags, bpp, &xfs_agf_buf_ops); + if (error) + return error; + if (!*bpp) + return 0; + + ASSERT(!(*bpp)->b_error); + xfs_buf_set_ref(*bpp, XFS_AGF_REF); + return 0; +} + +/* + * Read in the allocation group header (free/alloc section). + */ +int /* error */ +xfs_alloc_read_agf( + struct xfs_mount *mp, /* mount point structure */ + struct xfs_trans *tp, /* transaction pointer */ + xfs_agnumber_t agno, /* allocation group number */ + int flags, /* XFS_ALLOC_FLAG_... */ + struct xfs_buf **bpp) /* buffer for the ag freelist header */ +{ + struct xfs_agf *agf; /* ag freelist header */ + struct xfs_perag *pag; /* per allocation group data */ + int error; + + trace_xfs_alloc_read_agf(mp, agno); + + ASSERT(agno != NULLAGNUMBER); + error = xfs_read_agf(mp, tp, agno, + (flags & XFS_ALLOC_FLAG_TRYLOCK) ? XBF_TRYLOCK : 0, + bpp); + if (error) + return error; + if (!*bpp) + return 0; + ASSERT(!(*bpp)->b_error); + + agf = XFS_BUF_TO_AGF(*bpp); + pag = xfs_perag_get(mp, agno); + if (!pag->pagf_init) { + 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); + pag->pagf_init = 1; + pag->pagf_agflreset = xfs_agfl_needs_reset(mp, agf); + } +#ifdef DEBUG + else if (!XFS_FORCED_SHUTDOWN(mp)) { + 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 + xfs_perag_put(pag); + return 0; +} + +/* + * Allocate an extent (variable-size). + * Depending on the allocation type, we either look in a single allocation + * group or loop over the allocation groups to find the result. + */ +int /* error */ +xfs_alloc_vextent( + struct xfs_alloc_arg *args) /* allocation argument structure */ +{ + xfs_agblock_t agsize; /* allocation group size */ + int error; + int flags; /* XFS_ALLOC_FLAG_... locking flags */ + struct xfs_mount *mp; /* mount structure pointer */ + xfs_agnumber_t sagno; /* starting allocation group number */ + xfs_alloctype_t type; /* input allocation type */ + int bump_rotor = 0; + xfs_agnumber_t rotorstep = xfs_rotorstep; /* inode32 agf stepper */ + + mp = args->mp; + type = args->otype = args->type; + args->agbno = NULLAGBLOCK; + /* + * 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(XFS_FSB_TO_AGNO(mp, args->fsbno) < mp->m_sb.sb_agcount); + ASSERT(XFS_FSB_TO_AGBNO(mp, args->fsbno) < agsize); + ASSERT(args->minlen <= args->maxlen); + ASSERT(args->minlen <= agsize); + ASSERT(args->mod < args->prod); + if (XFS_FSB_TO_AGNO(mp, args->fsbno) >= mp->m_sb.sb_agcount || + XFS_FSB_TO_AGBNO(mp, args->fsbno) >= agsize || + args->minlen > args->maxlen || args->minlen > agsize || + args->mod >= args->prod) { + args->fsbno = NULLFSBLOCK; + trace_xfs_alloc_vextent_badargs(args); + return 0; + } + + switch (type) { + case XFS_ALLOCTYPE_THIS_AG: + case XFS_ALLOCTYPE_NEAR_BNO: + case XFS_ALLOCTYPE_THIS_BNO: + /* + * These three force us into a single a.g. + */ + args->agno = XFS_FSB_TO_AGNO(mp, args->fsbno); + args->pag = xfs_perag_get(mp, args->agno); + error = xfs_alloc_fix_freelist(args, 0); + if (error) { + trace_xfs_alloc_vextent_nofix(args); + goto error0; + } + if (!args->agbp) { + trace_xfs_alloc_vextent_noagbp(args); + break; + } + args->agbno = XFS_FSB_TO_AGBNO(mp, args->fsbno); + if ((error = xfs_alloc_ag_vextent(args))) + goto error0; + break; + case XFS_ALLOCTYPE_START_BNO: + /* + * Try near allocation first, then anywhere-in-ag after + * the first a.g. fails. + */ + if ((args->datatype & XFS_ALLOC_INITIAL_USER_DATA) && + (mp->m_flags & XFS_MOUNT_32BITINODES)) { + args->fsbno = XFS_AGB_TO_FSB(mp, + ((mp->m_agfrotor / rotorstep) % + mp->m_sb.sb_agcount), 0); + bump_rotor = 1; + } + args->agbno = XFS_FSB_TO_AGBNO(mp, args->fsbno); + args->type = XFS_ALLOCTYPE_NEAR_BNO; + /* FALLTHROUGH */ + case XFS_ALLOCTYPE_FIRST_AG: + /* + * Rotate through the allocation groups looking for a winner. + */ + if (type == XFS_ALLOCTYPE_FIRST_AG) { + /* + * Start with allocation group given by bno. + */ + args->agno = XFS_FSB_TO_AGNO(mp, args->fsbno); + args->type = XFS_ALLOCTYPE_THIS_AG; + sagno = 0; + flags = 0; + } else { + /* + * Start with the given allocation group. + */ + args->agno = sagno = XFS_FSB_TO_AGNO(mp, args->fsbno); + flags = XFS_ALLOC_FLAG_TRYLOCK; + } + /* + * Loop over allocation groups twice; first time with + * trylock set, second time without. + */ + for (;;) { + args->pag = xfs_perag_get(mp, args->agno); + error = xfs_alloc_fix_freelist(args, flags); + if (error) { + trace_xfs_alloc_vextent_nofix(args); + goto error0; + } + /* + * If we get a buffer back then the allocation will fly. + */ + if (args->agbp) { + if ((error = xfs_alloc_ag_vextent(args))) + goto error0; + break; + } + + trace_xfs_alloc_vextent_loopfailed(args); + + /* + * Didn't work, figure out the next iteration. + */ + if (args->agno == sagno && + type == XFS_ALLOCTYPE_START_BNO) + args->type = XFS_ALLOCTYPE_THIS_AG; + /* + * For the first allocation, we can try any AG to get + * space. However, if we already have allocated a + * block, we don't want to try AGs whose number is below + * sagno. Otherwise, we may end up with out-of-order + * locking of AGF, which might cause deadlock. + */ + if (++(args->agno) == mp->m_sb.sb_agcount) { + if (args->tp->t_firstblock != NULLFSBLOCK) + args->agno = sagno; + else + args->agno = 0; + } + /* + * Reached the starting a.g., must either be done + * or switch to non-trylock mode. + */ + if (args->agno == sagno) { + if (flags == 0) { + args->agbno = NULLAGBLOCK; + trace_xfs_alloc_vextent_allfailed(args); + break; + } + + flags = 0; + if (type == XFS_ALLOCTYPE_START_BNO) { + args->agbno = XFS_FSB_TO_AGBNO(mp, + args->fsbno); + args->type = XFS_ALLOCTYPE_NEAR_BNO; + } + } + xfs_perag_put(args->pag); + } + if (bump_rotor) { + if (args->agno == sagno) + 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); + } + break; + default: + ASSERT(0); + /* NOTREACHED */ + } + if (args->agbno == NULLAGBLOCK) + args->fsbno = NULLFSBLOCK; + else { + args->fsbno = XFS_AGB_TO_FSB(mp, args->agno, args->agbno); +#ifdef DEBUG + 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); +#endif + + /* Zero the extent if we were asked to do so */ + if (args->datatype & XFS_ALLOC_USERDATA_ZERO) { + error = xfs_zero_extent(args->ip, args->fsbno, args->len); + if (error) + goto error0; + } + + } + xfs_perag_put(args->pag); + return 0; +error0: + xfs_perag_put(args->pag); + return error; +} + +/* Ensure that the freelist is at full capacity. */ +int +xfs_free_extent_fix_freelist( + struct xfs_trans *tp, + xfs_agnumber_t agno, + 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 = agno; + + /* + * 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; + + args.pag = xfs_perag_get(args.mp, args.agno); + ASSERT(args.pag); + + error = xfs_alloc_fix_freelist(&args, XFS_ALLOC_FLAG_FREEING); + if (error) + goto out; + + *agbp = args.agbp; +out: + xfs_perag_put(args.pag); + return error; +} + +/* + * Free an extent. + * Just break up the extent address and hand off to xfs_free_ag_extent + * after fixing up the freelist. + */ +int /* error */ +__xfs_free_extent( + struct xfs_trans *tp, /* transaction pointer */ + xfs_fsblock_t bno, /* starting block number of extent */ + xfs_extlen_t len, /* length of extent */ + struct xfs_owner_info *oinfo, /* extent owner */ + enum xfs_ag_resv_type type, /* block reservation type */ + bool skip_discard) +{ + struct xfs_mount *mp = tp->t_mountp; + struct xfs_buf *agbp; + xfs_agnumber_t agno = XFS_FSB_TO_AGNO(mp, bno); + xfs_agblock_t agbno = XFS_FSB_TO_AGBNO(mp, bno); + 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, agno, &agbp); + if (error) + return error; + + XFS_WANT_CORRUPTED_GOTO(mp, agbno < mp->m_sb.sb_agblocks, err); + + /* validate the extent size is legal now we have the agf locked */ + XFS_WANT_CORRUPTED_GOTO(mp, + agbno + len <= be32_to_cpu(XFS_BUF_TO_AGF(agbp)->agf_length), + err); + + error = xfs_free_ag_extent(tp, agbp, agno, agbno, len, oinfo, type); + if (error) + goto err; + + if (skip_discard) + busy_flags |= XFS_EXTENT_BUSY_SKIP_DISCARD; + xfs_extent_busy_insert(tp, agno, agbno, len, busy_flags); + return 0; + +err: + 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, + union xfs_btree_rec *rec, + void *priv) +{ + struct xfs_alloc_query_range_info *query = priv; + 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); + 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, + struct xfs_alloc_rec_incore *low_rec, + struct xfs_alloc_rec_incore *high_rec, + xfs_alloc_query_range_fn fn, + void *priv) +{ + union xfs_btree_irec low_brec; + union xfs_btree_irec high_brec; + struct xfs_alloc_query_range_info query; + + ASSERT(cur->bc_btnum == XFS_BTNUM_BNO); + low_brec.a = *low_rec; + high_brec.a = *high_rec; + query.priv = priv; + query.fn = fn; + 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); +} + +/* Is there a record covering a given extent? */ +int +xfs_alloc_has_record( + struct xfs_btree_cur *cur, + xfs_agblock_t bno, + xfs_extlen_t len, + bool *exists) +{ + 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_record(cur, &low, &high, exists); +} + +/* + * Walk all the blocks in the AGFL. The @walk_fn can return any negative + * error code or XFS_BTREE_QUERY_RANGE_ABORT. + */ +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(mp, 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; +} |