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linux/fs/xfs/libxfs/xfs_ialloc.c
Darrick J. Wong c94613feef xfs: fix maxicount division by zero error 
In xfs_ialloc_setup_geometry, it's possible for a malicious/corrupt fs
image to set an unreasonably large value for sb_inopblog which will
cause ialloc_blks to be zero.  If sb_imax_pct is also set, this results
in a division by zero error in the second do_div call.  Therefore, force
maxicount to zero if ialloc_blks is zero.

Note that the kernel metadata verifiers will catch the garbage inopblog
value and abort the fs mount long before it tries to set up the inode
geometry; this is needed to avoid a crash in xfs_db while setting up the
xfs_mount structure.

Found by fuzzing sb_inopblog to 122 in xfs/350.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
2019-08-28 08:31:01 -07:00

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// 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_shared.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_bit.h"
#include "xfs_sb.h"
#include "xfs_mount.h"
#include "xfs_inode.h"
#include "xfs_btree.h"
#include "xfs_ialloc.h"
#include "xfs_ialloc_btree.h"
#include "xfs_alloc.h"
#include "xfs_errortag.h"
#include "xfs_error.h"
#include "xfs_bmap.h"
#include "xfs_trans.h"
#include "xfs_buf_item.h"
#include "xfs_icreate_item.h"
#include "xfs_icache.h"
#include "xfs_trace.h"
#include "xfs_log.h"
#include "xfs_rmap.h"
/*
* Lookup a record by ino in the btree given by cur.
*/
int /* error */
xfs_inobt_lookup(
struct xfs_btree_cur *cur, /* btree cursor */
xfs_agino_t ino, /* starting inode of chunk */
xfs_lookup_t dir, /* <=, >=, == */
int *stat) /* success/failure */
{
cur->bc_rec.i.ir_startino = ino;
cur->bc_rec.i.ir_holemask = 0;
cur->bc_rec.i.ir_count = 0;
cur->bc_rec.i.ir_freecount = 0;
cur->bc_rec.i.ir_free = 0;
return xfs_btree_lookup(cur, dir, stat);
}
/*
* Update the record referred to by cur to the value given.
* This either works (return 0) or gets an EFSCORRUPTED error.
*/
STATIC int /* error */
xfs_inobt_update(
struct xfs_btree_cur *cur, /* btree cursor */
xfs_inobt_rec_incore_t *irec) /* btree record */
{
union xfs_btree_rec rec;
rec.inobt.ir_startino = cpu_to_be32(irec->ir_startino);
if (xfs_sb_version_hassparseinodes(&cur->bc_mp->m_sb)) {
rec.inobt.ir_u.sp.ir_holemask = cpu_to_be16(irec->ir_holemask);
rec.inobt.ir_u.sp.ir_count = irec->ir_count;
rec.inobt.ir_u.sp.ir_freecount = irec->ir_freecount;
} else {
/* ir_holemask/ir_count not supported on-disk */
rec.inobt.ir_u.f.ir_freecount = cpu_to_be32(irec->ir_freecount);
}
rec.inobt.ir_free = cpu_to_be64(irec->ir_free);
return xfs_btree_update(cur, &rec);
}
/* Convert on-disk btree record to incore inobt record. */
void
xfs_inobt_btrec_to_irec(
struct xfs_mount *mp,
union xfs_btree_rec *rec,
struct xfs_inobt_rec_incore *irec)
{
irec->ir_startino = be32_to_cpu(rec->inobt.ir_startino);
if (xfs_sb_version_hassparseinodes(&mp->m_sb)) {
irec->ir_holemask = be16_to_cpu(rec->inobt.ir_u.sp.ir_holemask);
irec->ir_count = rec->inobt.ir_u.sp.ir_count;
irec->ir_freecount = rec->inobt.ir_u.sp.ir_freecount;
} else {
/*
* ir_holemask/ir_count not supported on-disk. Fill in hardcoded
* values for full inode chunks.
*/
irec->ir_holemask = XFS_INOBT_HOLEMASK_FULL;
irec->ir_count = XFS_INODES_PER_CHUNK;
irec->ir_freecount =
be32_to_cpu(rec->inobt.ir_u.f.ir_freecount);
}
irec->ir_free = be64_to_cpu(rec->inobt.ir_free);
}
/*
* Get the data from the pointed-to record.
*/
int
xfs_inobt_get_rec(
struct xfs_btree_cur *cur,
struct xfs_inobt_rec_incore *irec,
int *stat)
{
struct xfs_mount *mp = cur->bc_mp;
xfs_agnumber_t agno = cur->bc_private.a.agno;
union xfs_btree_rec *rec;
int error;
uint64_t realfree;
error = xfs_btree_get_rec(cur, &rec, stat);
if (error || *stat == 0)
return error;
xfs_inobt_btrec_to_irec(mp, rec, irec);
if (!xfs_verify_agino(mp, agno, irec->ir_startino))
goto out_bad_rec;
if (irec->ir_count < XFS_INODES_PER_HOLEMASK_BIT ||
irec->ir_count > XFS_INODES_PER_CHUNK)
goto out_bad_rec;
if (irec->ir_freecount > XFS_INODES_PER_CHUNK)
goto out_bad_rec;
/* if there are no holes, return the first available offset */
if (!xfs_inobt_issparse(irec->ir_holemask))
realfree = irec->ir_free;
else
realfree = irec->ir_free & xfs_inobt_irec_to_allocmask(irec);
if (hweight64(realfree) != irec->ir_freecount)
goto out_bad_rec;
return 0;
out_bad_rec:
xfs_warn(mp,
"%s Inode BTree record corruption in AG %d detected!",
cur->bc_btnum == XFS_BTNUM_INO ? "Used" : "Free", agno);
xfs_warn(mp,
"start inode 0x%x, count 0x%x, free 0x%x freemask 0x%llx, holemask 0x%x",
irec->ir_startino, irec->ir_count, irec->ir_freecount,
irec->ir_free, irec->ir_holemask);
return -EFSCORRUPTED;
}
/*
* Insert a single inobt record. Cursor must already point to desired location.
*/
int
xfs_inobt_insert_rec(
struct xfs_btree_cur *cur,
uint16_t holemask,
uint8_t count,
int32_t freecount,
xfs_inofree_t free,
int *stat)
{
cur->bc_rec.i.ir_holemask = holemask;
cur->bc_rec.i.ir_count = count;
cur->bc_rec.i.ir_freecount = freecount;
cur->bc_rec.i.ir_free = free;
return xfs_btree_insert(cur, stat);
}
/*
* Insert records describing a newly allocated inode chunk into the inobt.
*/
STATIC int
xfs_inobt_insert(
struct xfs_mount *mp,
struct xfs_trans *tp,
struct xfs_buf *agbp,
xfs_agino_t newino,
xfs_agino_t newlen,
xfs_btnum_t btnum)
{
struct xfs_btree_cur *cur;
struct xfs_agi *agi = XFS_BUF_TO_AGI(agbp);
xfs_agnumber_t agno = be32_to_cpu(agi->agi_seqno);
xfs_agino_t thisino;
int i;
int error;
cur = xfs_inobt_init_cursor(mp, tp, agbp, agno, btnum);
for (thisino = newino;
thisino < newino + newlen;
thisino += XFS_INODES_PER_CHUNK) {
error = xfs_inobt_lookup(cur, thisino, XFS_LOOKUP_EQ, &i);
if (error) {
xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
return error;
}
ASSERT(i == 0);
error = xfs_inobt_insert_rec(cur, XFS_INOBT_HOLEMASK_FULL,
XFS_INODES_PER_CHUNK,
XFS_INODES_PER_CHUNK,
XFS_INOBT_ALL_FREE, &i);
if (error) {
xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
return error;
}
ASSERT(i == 1);
}
xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
return 0;
}
/*
* Verify that the number of free inodes in the AGI is correct.
*/
#ifdef DEBUG
STATIC int
xfs_check_agi_freecount(
struct xfs_btree_cur *cur,
struct xfs_agi *agi)
{
if (cur->bc_nlevels == 1) {
xfs_inobt_rec_incore_t rec;
int freecount = 0;
int error;
int i;
error = xfs_inobt_lookup(cur, 0, XFS_LOOKUP_GE, &i);
if (error)
return error;
do {
error = xfs_inobt_get_rec(cur, &rec, &i);
if (error)
return error;
if (i) {
freecount += rec.ir_freecount;
error = xfs_btree_increment(cur, 0, &i);
if (error)
return error;
}
} while (i == 1);
if (!XFS_FORCED_SHUTDOWN(cur->bc_mp))
ASSERT(freecount == be32_to_cpu(agi->agi_freecount));
}
return 0;
}
#else
#define xfs_check_agi_freecount(cur, agi) 0
#endif
/*
* Initialise a new set of inodes. When called without a transaction context
* (e.g. from recovery) we initiate a delayed write of the inode buffers rather
* than logging them (which in a transaction context puts them into the AIL
* for writeback rather than the xfsbufd queue).
*/
int
xfs_ialloc_inode_init(
struct xfs_mount *mp,
struct xfs_trans *tp,
struct list_head *buffer_list,
int icount,
xfs_agnumber_t agno,
xfs_agblock_t agbno,
xfs_agblock_t length,
unsigned int gen)
{
struct xfs_buf *fbuf;
struct xfs_dinode *free;
int nbufs;
int version;
int i, j;
xfs_daddr_t d;
xfs_ino_t ino = 0;
/*
* Loop over the new block(s), filling in the inodes. For small block
* sizes, manipulate the inodes in buffers which are multiples of the
* blocks size.
*/
nbufs = length / M_IGEO(mp)->blocks_per_cluster;
/*
* Figure out what version number to use in the inodes we create. If
* the superblock version has caught up to the one that supports the new
* inode format, then use the new inode version. Otherwise use the old
* version so that old kernels will continue to be able to use the file
* system.
*
* For v3 inodes, we also need to write the inode number into the inode,
* so calculate the first inode number of the chunk here as
* XFS_AGB_TO_AGINO() only works within a filesystem block, not
* across multiple filesystem blocks (such as a cluster) and so cannot
* be used in the cluster buffer loop below.
*
* Further, because we are writing the inode directly into the buffer
* and calculating a CRC on the entire inode, we have ot log the entire
* inode so that the entire range the CRC covers is present in the log.
* That means for v3 inode we log the entire buffer rather than just the
* inode cores.
*/
if (xfs_sb_version_hascrc(&mp->m_sb)) {
version = 3;
ino = XFS_AGINO_TO_INO(mp, agno, XFS_AGB_TO_AGINO(mp, agbno));
/*
* log the initialisation that is about to take place as an
* logical operation. This means the transaction does not
* need to log the physical changes to the inode buffers as log
* recovery will know what initialisation is actually needed.
* Hence we only need to log the buffers as "ordered" buffers so
* they track in the AIL as if they were physically logged.
*/
if (tp)
xfs_icreate_log(tp, agno, agbno, icount,
mp->m_sb.sb_inodesize, length, gen);
} else
version = 2;
for (j = 0; j < nbufs; j++) {
/*
* Get the block.
*/
d = XFS_AGB_TO_DADDR(mp, agno, agbno +
(j * M_IGEO(mp)->blocks_per_cluster));
fbuf = xfs_trans_get_buf(tp, mp->m_ddev_targp, d,
mp->m_bsize *
M_IGEO(mp)->blocks_per_cluster,
XBF_UNMAPPED);
if (!fbuf)
return -ENOMEM;
/* Initialize the inode buffers and log them appropriately. */
fbuf->b_ops = &xfs_inode_buf_ops;
xfs_buf_zero(fbuf, 0, BBTOB(fbuf->b_length));
for (i = 0; i < M_IGEO(mp)->inodes_per_cluster; i++) {
int ioffset = i << mp->m_sb.sb_inodelog;
uint isize = xfs_dinode_size(version);
free = xfs_make_iptr(mp, fbuf, i);
free->di_magic = cpu_to_be16(XFS_DINODE_MAGIC);
free->di_version = version;
free->di_gen = cpu_to_be32(gen);
free->di_next_unlinked = cpu_to_be32(NULLAGINO);
if (version == 3) {
free->di_ino = cpu_to_be64(ino);
ino++;
uuid_copy(&free->di_uuid,
&mp->m_sb.sb_meta_uuid);
xfs_dinode_calc_crc(mp, free);
} else if (tp) {
/* just log the inode core */
xfs_trans_log_buf(tp, fbuf, ioffset,
ioffset + isize - 1);
}
}
if (tp) {
/*
* Mark the buffer as an inode allocation buffer so it
* sticks in AIL at the point of this allocation
* transaction. This ensures the they are on disk before
* the tail of the log can be moved past this
* transaction (i.e. by preventing relogging from moving
* it forward in the log).
*/
xfs_trans_inode_alloc_buf(tp, fbuf);
if (version == 3) {
/*
* Mark the buffer as ordered so that they are
* not physically logged in the transaction but
* still tracked in the AIL as part of the
* transaction and pin the log appropriately.
*/
xfs_trans_ordered_buf(tp, fbuf);
}
} else {
fbuf->b_flags |= XBF_DONE;
xfs_buf_delwri_queue(fbuf, buffer_list);
xfs_buf_relse(fbuf);
}
}
return 0;
}
/*
* Align startino and allocmask for a recently allocated sparse chunk such that
* they are fit for insertion (or merge) into the on-disk inode btrees.
*
* Background:
*
* When enabled, sparse inode support increases the inode alignment from cluster
* size to inode chunk size. This means that the minimum range between two
* non-adjacent inode records in the inobt is large enough for a full inode
* record. This allows for cluster sized, cluster aligned block allocation
* without need to worry about whether the resulting inode record overlaps with
* another record in the tree. Without this basic rule, we would have to deal
* with the consequences of overlap by potentially undoing recent allocations in
* the inode allocation codepath.
*
* Because of this alignment rule (which is enforced on mount), there are two
* inobt possibilities for newly allocated sparse chunks. One is that the
* aligned inode record for the chunk covers a range of inodes not already
* covered in the inobt (i.e., it is safe to insert a new sparse record). The
* other is that a record already exists at the aligned startino that considers
* the newly allocated range as sparse. In the latter case, record content is
* merged in hope that sparse inode chunks fill to full chunks over time.
*/
STATIC void
xfs_align_sparse_ino(
struct xfs_mount *mp,
xfs_agino_t *startino,
uint16_t *allocmask)
{
xfs_agblock_t agbno;
xfs_agblock_t mod;
int offset;
agbno = XFS_AGINO_TO_AGBNO(mp, *startino);
mod = agbno % mp->m_sb.sb_inoalignmt;
if (!mod)
return;
/* calculate the inode offset and align startino */
offset = XFS_AGB_TO_AGINO(mp, mod);
*startino -= offset;
/*
* Since startino has been aligned down, left shift allocmask such that
* it continues to represent the same physical inodes relative to the
* new startino.
*/
*allocmask <<= offset / XFS_INODES_PER_HOLEMASK_BIT;
}
/*
* Determine whether the source inode record can merge into the target. Both
* records must be sparse, the inode ranges must match and there must be no
* allocation overlap between the records.
*/
STATIC bool
__xfs_inobt_can_merge(
struct xfs_inobt_rec_incore *trec, /* tgt record */
struct xfs_inobt_rec_incore *srec) /* src record */
{
uint64_t talloc;
uint64_t salloc;
/* records must cover the same inode range */
if (trec->ir_startino != srec->ir_startino)
return false;
/* both records must be sparse */
if (!xfs_inobt_issparse(trec->ir_holemask) ||
!xfs_inobt_issparse(srec->ir_holemask))
return false;
/* both records must track some inodes */
if (!trec->ir_count || !srec->ir_count)
return false;
/* can't exceed capacity of a full record */
if (trec->ir_count + srec->ir_count > XFS_INODES_PER_CHUNK)
return false;
/* verify there is no allocation overlap */
talloc = xfs_inobt_irec_to_allocmask(trec);
salloc = xfs_inobt_irec_to_allocmask(srec);
if (talloc & salloc)
return false;
return true;
}
/*
* Merge the source inode record into the target. The caller must call
* __xfs_inobt_can_merge() to ensure the merge is valid.
*/
STATIC void
__xfs_inobt_rec_merge(
struct xfs_inobt_rec_incore *trec, /* target */
struct xfs_inobt_rec_incore *srec) /* src */
{
ASSERT(trec->ir_startino == srec->ir_startino);
/* combine the counts */
trec->ir_count += srec->ir_count;
trec->ir_freecount += srec->ir_freecount;
/*
* Merge the holemask and free mask. For both fields, 0 bits refer to
* allocated inodes. We combine the allocated ranges with bitwise AND.
*/
trec->ir_holemask &= srec->ir_holemask;
trec->ir_free &= srec->ir_free;
}
/*
* Insert a new sparse inode chunk into the associated inode btree. The inode
* record for the sparse chunk is pre-aligned to a startino that should match
* any pre-existing sparse inode record in the tree. This allows sparse chunks
* to fill over time.
*
* This function supports two modes of handling preexisting records depending on
* the merge flag. If merge is true, the provided record is merged with the
* existing record and updated in place. The merged record is returned in nrec.
* If merge is false, an existing record is replaced with the provided record.
* If no preexisting record exists, the provided record is always inserted.
*
* It is considered corruption if a merge is requested and not possible. Given
* the sparse inode alignment constraints, this should never happen.
*/
STATIC int
xfs_inobt_insert_sprec(
struct xfs_mount *mp,
struct xfs_trans *tp,
struct xfs_buf *agbp,
int btnum,
struct xfs_inobt_rec_incore *nrec, /* in/out: new/merged rec. */
bool merge) /* merge or replace */
{
struct xfs_btree_cur *cur;
struct xfs_agi *agi = XFS_BUF_TO_AGI(agbp);
xfs_agnumber_t agno = be32_to_cpu(agi->agi_seqno);
int error;
int i;
struct xfs_inobt_rec_incore rec;
cur = xfs_inobt_init_cursor(mp, tp, agbp, agno, btnum);
/* the new record is pre-aligned so we know where to look */
error = xfs_inobt_lookup(cur, nrec->ir_startino, XFS_LOOKUP_EQ, &i);
if (error)
goto error;
/* if nothing there, insert a new record and return */
if (i == 0) {
error = xfs_inobt_insert_rec(cur, nrec->ir_holemask,
nrec->ir_count, nrec->ir_freecount,
nrec->ir_free, &i);
if (error)
goto error;
XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error);
goto out;
}
/*
* A record exists at this startino. Merge or replace the record
* depending on what we've been asked to do.
*/
if (merge) {
error = xfs_inobt_get_rec(cur, &rec, &i);
if (error)
goto error;
XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error);
XFS_WANT_CORRUPTED_GOTO(mp,
rec.ir_startino == nrec->ir_startino,
error);
/*
* This should never fail. If we have coexisting records that
* cannot merge, something is seriously wrong.
*/
XFS_WANT_CORRUPTED_GOTO(mp, __xfs_inobt_can_merge(nrec, &rec),
error);
trace_xfs_irec_merge_pre(mp, agno, rec.ir_startino,
rec.ir_holemask, nrec->ir_startino,
nrec->ir_holemask);
/* merge to nrec to output the updated record */
__xfs_inobt_rec_merge(nrec, &rec);
trace_xfs_irec_merge_post(mp, agno, nrec->ir_startino,
nrec->ir_holemask);
error = xfs_inobt_rec_check_count(mp, nrec);
if (error)
goto error;
}
error = xfs_inobt_update(cur, nrec);
if (error)
goto error;
out:
xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
return 0;
error:
xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
return error;
}
/*
* Allocate new inodes in the allocation group specified by agbp.
* Return 0 for success, else error code.
*/
STATIC int
xfs_ialloc_ag_alloc(
struct xfs_trans *tp,
struct xfs_buf *agbp,
int *alloc)
{
struct xfs_agi *agi;
struct xfs_alloc_arg args;
xfs_agnumber_t agno;
int error;
xfs_agino_t newino; /* new first inode's number */
xfs_agino_t newlen; /* new number of inodes */
int isaligned = 0; /* inode allocation at stripe */
/* unit boundary */
/* init. to full chunk */
uint16_t allocmask = (uint16_t) -1;
struct xfs_inobt_rec_incore rec;
struct xfs_perag *pag;
struct xfs_ino_geometry *igeo = M_IGEO(tp->t_mountp);
int do_sparse = 0;
memset(&args, 0, sizeof(args));
args.tp = tp;
args.mp = tp->t_mountp;
args.fsbno = NULLFSBLOCK;
args.oinfo = XFS_RMAP_OINFO_INODES;
#ifdef DEBUG
/* randomly do sparse inode allocations */
if (xfs_sb_version_hassparseinodes(&tp->t_mountp->m_sb) &&
igeo->ialloc_min_blks < igeo->ialloc_blks)
do_sparse = prandom_u32() & 1;
#endif
/*
* Locking will ensure that we don't have two callers in here
* at one time.
*/
newlen = igeo->ialloc_inos;
if (igeo->maxicount &&
percpu_counter_read_positive(&args.mp->m_icount) + newlen >
igeo->maxicount)
return -ENOSPC;
args.minlen = args.maxlen = igeo->ialloc_blks;
/*
* First try to allocate inodes contiguous with the last-allocated
* chunk of inodes. If the filesystem is striped, this will fill
* an entire stripe unit with inodes.
*/
agi = XFS_BUF_TO_AGI(agbp);
newino = be32_to_cpu(agi->agi_newino);
agno = be32_to_cpu(agi->agi_seqno);
args.agbno = XFS_AGINO_TO_AGBNO(args.mp, newino) +
igeo->ialloc_blks;
if (do_sparse)
goto sparse_alloc;
if (likely(newino != NULLAGINO &&
(args.agbno < be32_to_cpu(agi->agi_length)))) {
args.fsbno = XFS_AGB_TO_FSB(args.mp, agno, args.agbno);
args.type = XFS_ALLOCTYPE_THIS_BNO;
args.prod = 1;
/*
* We need to take into account alignment here to ensure that
* we don't modify the free list if we fail to have an exact
* block. If we don't have an exact match, and every oher
* attempt allocation attempt fails, we'll end up cancelling
* a dirty transaction and shutting down.
*
* For an exact allocation, alignment must be 1,
* however we need to take cluster alignment into account when
* fixing up the freelist. Use the minalignslop field to
* indicate that extra blocks might be required for alignment,
* but not to use them in the actual exact allocation.
*/
args.alignment = 1;
args.minalignslop = igeo->cluster_align - 1;
/* Allow space for the inode btree to split. */
args.minleft = igeo->inobt_maxlevels - 1;
if ((error = xfs_alloc_vextent(&args)))
return error;
/*
* This request might have dirtied the transaction if the AG can
* satisfy the request, but the exact block was not available.
* If the allocation did fail, subsequent requests will relax
* the exact agbno requirement and increase the alignment
* instead. It is critical that the total size of the request
* (len + alignment + slop) does not increase from this point
* on, so reset minalignslop to ensure it is not included in
* subsequent requests.
*/
args.minalignslop = 0;
}
if (unlikely(args.fsbno == NULLFSBLOCK)) {
/*
* Set the alignment for the allocation.
* If stripe alignment is turned on then align at stripe unit
* boundary.
* If the cluster size is smaller than a filesystem block
* then we're doing I/O for inodes in filesystem block size
* pieces, so don't need alignment anyway.
*/
isaligned = 0;
if (igeo->ialloc_align) {
ASSERT(!(args.mp->m_flags & XFS_MOUNT_NOALIGN));
args.alignment = args.mp->m_dalign;
isaligned = 1;
} else
args.alignment = igeo->cluster_align;
/*
* Need to figure out where to allocate the inode blocks.
* Ideally they should be spaced out through the a.g.
* For now, just allocate blocks up front.
*/
args.agbno = be32_to_cpu(agi->agi_root);
args.fsbno = XFS_AGB_TO_FSB(args.mp, agno, args.agbno);
/*
* Allocate a fixed-size extent of inodes.
*/
args.type = XFS_ALLOCTYPE_NEAR_BNO;
args.prod = 1;
/*
* Allow space for the inode btree to split.
*/
args.minleft = igeo->inobt_maxlevels - 1;
if ((error = xfs_alloc_vextent(&args)))
return error;
}
/*
* If stripe alignment is turned on, then try again with cluster
* alignment.
*/
if (isaligned && args.fsbno == NULLFSBLOCK) {
args.type = XFS_ALLOCTYPE_NEAR_BNO;
args.agbno = be32_to_cpu(agi->agi_root);
args.fsbno = XFS_AGB_TO_FSB(args.mp, agno, args.agbno);
args.alignment = igeo->cluster_align;
if ((error = xfs_alloc_vextent(&args)))
return error;
}
/*
* Finally, try a sparse allocation if the filesystem supports it and
* the sparse allocation length is smaller than a full chunk.
*/
if (xfs_sb_version_hassparseinodes(&args.mp->m_sb) &&
igeo->ialloc_min_blks < igeo->ialloc_blks &&
args.fsbno == NULLFSBLOCK) {
sparse_alloc:
args.type = XFS_ALLOCTYPE_NEAR_BNO;
args.agbno = be32_to_cpu(agi->agi_root);
args.fsbno = XFS_AGB_TO_FSB(args.mp, agno, args.agbno);
args.alignment = args.mp->m_sb.sb_spino_align;
args.prod = 1;
args.minlen = igeo->ialloc_min_blks;
args.maxlen = args.minlen;
/*
* The inode record will be aligned to full chunk size. We must
* prevent sparse allocation from AG boundaries that result in
* invalid inode records, such as records that start at agbno 0
* or extend beyond the AG.
*
* Set min agbno to the first aligned, non-zero agbno and max to
* the last aligned agbno that is at least one full chunk from
* the end of the AG.
*/
args.min_agbno = args.mp->m_sb.sb_inoalignmt;
args.max_agbno = round_down(args.mp->m_sb.sb_agblocks,
args.mp->m_sb.sb_inoalignmt) -
igeo->ialloc_blks;
error = xfs_alloc_vextent(&args);
if (error)
return error;
newlen = XFS_AGB_TO_AGINO(args.mp, args.len);
ASSERT(newlen <= XFS_INODES_PER_CHUNK);
allocmask = (1 << (newlen / XFS_INODES_PER_HOLEMASK_BIT)) - 1;
}
if (args.fsbno == NULLFSBLOCK) {
*alloc = 0;
return 0;
}
ASSERT(args.len == args.minlen);
/*
* Stamp and write the inode buffers.
*
* Seed the new inode cluster with a random generation number. This
* prevents short-term reuse of generation numbers if a chunk is
* freed and then immediately reallocated. We use random numbers
* rather than a linear progression to prevent the next generation
* number from being easily guessable.
*/
error = xfs_ialloc_inode_init(args.mp, tp, NULL, newlen, agno,
args.agbno, args.len, prandom_u32());
if (error)
return error;
/*
* Convert the results.
*/
newino = XFS_AGB_TO_AGINO(args.mp, args.agbno);
if (xfs_inobt_issparse(~allocmask)) {
/*
* We've allocated a sparse chunk. Align the startino and mask.
*/
xfs_align_sparse_ino(args.mp, &newino, &allocmask);
rec.ir_startino = newino;
rec.ir_holemask = ~allocmask;
rec.ir_count = newlen;
rec.ir_freecount = newlen;
rec.ir_free = XFS_INOBT_ALL_FREE;
/*
* Insert the sparse record into the inobt and allow for a merge
* if necessary. If a merge does occur, rec is updated to the
* merged record.
*/
error = xfs_inobt_insert_sprec(args.mp, tp, agbp, XFS_BTNUM_INO,
&rec, true);
if (error == -EFSCORRUPTED) {
xfs_alert(args.mp,
"invalid sparse inode record: ino 0x%llx holemask 0x%x count %u",
XFS_AGINO_TO_INO(args.mp, agno,
rec.ir_startino),
rec.ir_holemask, rec.ir_count);
xfs_force_shutdown(args.mp, SHUTDOWN_CORRUPT_INCORE);
}
if (error)
return error;
/*
* We can't merge the part we've just allocated as for the inobt
* due to finobt semantics. The original record may or may not
* exist independent of whether physical inodes exist in this
* sparse chunk.
*
* We must update the finobt record based on the inobt record.
* rec contains the fully merged and up to date inobt record
* from the previous call. Set merge false to replace any
* existing record with this one.
*/
if (xfs_sb_version_hasfinobt(&args.mp->m_sb)) {
error = xfs_inobt_insert_sprec(args.mp, tp, agbp,
XFS_BTNUM_FINO, &rec,
false);
if (error)
return error;
}
} else {
/* full chunk - insert new records to both btrees */
error = xfs_inobt_insert(args.mp, tp, agbp, newino, newlen,
XFS_BTNUM_INO);
if (error)
return error;
if (xfs_sb_version_hasfinobt(&args.mp->m_sb)) {
error = xfs_inobt_insert(args.mp, tp, agbp, newino,
newlen, XFS_BTNUM_FINO);
if (error)
return error;
}
}
/*
* Update AGI counts and newino.
*/
be32_add_cpu(&agi->agi_count, newlen);
be32_add_cpu(&agi->agi_freecount, newlen);
pag = xfs_perag_get(args.mp, agno);
pag->pagi_freecount += newlen;
pag->pagi_count += newlen;
xfs_perag_put(pag);
agi->agi_newino = cpu_to_be32(newino);
/*
* Log allocation group header fields
*/
xfs_ialloc_log_agi(tp, agbp,
XFS_AGI_COUNT | XFS_AGI_FREECOUNT | XFS_AGI_NEWINO);
/*
* Modify/log superblock values for inode count and inode free count.
*/
xfs_trans_mod_sb(tp, XFS_TRANS_SB_ICOUNT, (long)newlen);
xfs_trans_mod_sb(tp, XFS_TRANS_SB_IFREE, (long)newlen);
*alloc = 1;
return 0;
}
STATIC xfs_agnumber_t
xfs_ialloc_next_ag(
xfs_mount_t *mp)
{
xfs_agnumber_t agno;
spin_lock(&mp->m_agirotor_lock);
agno = mp->m_agirotor;
if (++mp->m_agirotor >= mp->m_maxagi)
mp->m_agirotor = 0;
spin_unlock(&mp->m_agirotor_lock);
return agno;
}
/*
* Select an allocation group to look for a free inode in, based on the parent
* inode and the mode. Return the allocation group buffer.
*/
STATIC xfs_agnumber_t
xfs_ialloc_ag_select(
xfs_trans_t *tp, /* transaction pointer */
xfs_ino_t parent, /* parent directory inode number */
umode_t mode) /* bits set to indicate file type */
{
xfs_agnumber_t agcount; /* number of ag's in the filesystem */
xfs_agnumber_t agno; /* current ag number */
int flags; /* alloc buffer locking flags */
xfs_extlen_t ineed; /* blocks needed for inode allocation */
xfs_extlen_t longest = 0; /* longest extent available */
xfs_mount_t *mp; /* mount point structure */
int needspace; /* file mode implies space allocated */
xfs_perag_t *pag; /* per allocation group data */
xfs_agnumber_t pagno; /* parent (starting) ag number */
int error;
/*
* Files of these types need at least one block if length > 0
* (and they won't fit in the inode, but that's hard to figure out).
*/
needspace = S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode);
mp = tp->t_mountp;
agcount = mp->m_maxagi;
if (S_ISDIR(mode))
pagno = xfs_ialloc_next_ag(mp);
else {
pagno = XFS_INO_TO_AGNO(mp, parent);
if (pagno >= agcount)
pagno = 0;
}
ASSERT(pagno < agcount);
/*
* Loop through allocation groups, looking for one with a little
* free space in it. Note we don't look for free inodes, exactly.
* Instead, we include whether there is a need to allocate inodes
* to mean that blocks must be allocated for them,
* if none are currently free.
*/
agno = pagno;
flags = XFS_ALLOC_FLAG_TRYLOCK;
for (;;) {
pag = xfs_perag_get(mp, agno);
if (!pag->pagi_inodeok) {
xfs_ialloc_next_ag(mp);
goto nextag;
}
if (!pag->pagi_init) {
error = xfs_ialloc_pagi_init(mp, tp, agno);
if (error)
goto nextag;
}
if (pag->pagi_freecount) {
xfs_perag_put(pag);
return agno;
}
if (!pag->pagf_init) {
error = xfs_alloc_pagf_init(mp, tp, agno, flags);
if (error)
goto nextag;
}
/*
* Check that there is enough free space for the file plus a
* chunk of inodes if we need to allocate some. If this is the
* first pass across the AGs, take into account the potential
* space needed for alignment of inode chunks when checking the
* longest contiguous free space in the AG - this prevents us
* from getting ENOSPC because we have free space larger than
* ialloc_blks but alignment constraints prevent us from using
* it.
*
* If we can't find an AG with space for full alignment slack to
* be taken into account, we must be near ENOSPC in all AGs.
* Hence we don't include alignment for the second pass and so
* if we fail allocation due to alignment issues then it is most
* likely a real ENOSPC condition.
*/
ineed = M_IGEO(mp)->ialloc_min_blks;
if (flags && ineed > 1)
ineed += M_IGEO(mp)->cluster_align;
longest = pag->pagf_longest;
if (!longest)
longest = pag->pagf_flcount > 0;
if (pag->pagf_freeblks >= needspace + ineed &&
longest >= ineed) {
xfs_perag_put(pag);
return agno;
}
nextag:
xfs_perag_put(pag);
/*
* No point in iterating over the rest, if we're shutting
* down.
*/
if (XFS_FORCED_SHUTDOWN(mp))
return NULLAGNUMBER;
agno++;
if (agno >= agcount)
agno = 0;
if (agno == pagno) {
if (flags == 0)
return NULLAGNUMBER;
flags = 0;
}
}
}
/*
* Try to retrieve the next record to the left/right from the current one.
*/
STATIC int
xfs_ialloc_next_rec(
struct xfs_btree_cur *cur,
xfs_inobt_rec_incore_t *rec,
int *done,
int left)
{
int error;
int i;
if (left)
error = xfs_btree_decrement(cur, 0, &i);
else
error = xfs_btree_increment(cur, 0, &i);
if (error)
return error;
*done = !i;
if (i) {
error = xfs_inobt_get_rec(cur, rec, &i);
if (error)
return error;
XFS_WANT_CORRUPTED_RETURN(cur->bc_mp, i == 1);
}
return 0;
}
STATIC int
xfs_ialloc_get_rec(
struct xfs_btree_cur *cur,
xfs_agino_t agino,
xfs_inobt_rec_incore_t *rec,
int *done)
{
int error;
int i;
error = xfs_inobt_lookup(cur, agino, XFS_LOOKUP_EQ, &i);
if (error)
return error;
*done = !i;
if (i) {
error = xfs_inobt_get_rec(cur, rec, &i);
if (error)
return error;
XFS_WANT_CORRUPTED_RETURN(cur->bc_mp, i == 1);
}
return 0;
}
/*
* Return the offset of the first free inode in the record. If the inode chunk
* is sparsely allocated, we convert the record holemask to inode granularity
* and mask off the unallocated regions from the inode free mask.
*/
STATIC int
xfs_inobt_first_free_inode(
struct xfs_inobt_rec_incore *rec)
{
xfs_inofree_t realfree;
/* if there are no holes, return the first available offset */
if (!xfs_inobt_issparse(rec->ir_holemask))
return xfs_lowbit64(rec->ir_free);
realfree = xfs_inobt_irec_to_allocmask(rec);
realfree &= rec->ir_free;
return xfs_lowbit64(realfree);
}
/*
* Allocate an inode using the inobt-only algorithm.
*/
STATIC int
xfs_dialloc_ag_inobt(
struct xfs_trans *tp,
struct xfs_buf *agbp,
xfs_ino_t parent,
xfs_ino_t *inop)
{
struct xfs_mount *mp = tp->t_mountp;
struct xfs_agi *agi = XFS_BUF_TO_AGI(agbp);
xfs_agnumber_t agno = be32_to_cpu(agi->agi_seqno);
xfs_agnumber_t pagno = XFS_INO_TO_AGNO(mp, parent);
xfs_agino_t pagino = XFS_INO_TO_AGINO(mp, parent);
struct xfs_perag *pag;
struct xfs_btree_cur *cur, *tcur;
struct xfs_inobt_rec_incore rec, trec;
xfs_ino_t ino;
int error;
int offset;
int i, j;
int searchdistance = 10;
pag = xfs_perag_get(mp, agno);
ASSERT(pag->pagi_init);
ASSERT(pag->pagi_inodeok);
ASSERT(pag->pagi_freecount > 0);
restart_pagno:
cur = xfs_inobt_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_INO);
/*
* If pagino is 0 (this is the root inode allocation) use newino.
* This must work because we've just allocated some.
*/
if (!pagino)
pagino = be32_to_cpu(agi->agi_newino);
error = xfs_check_agi_freecount(cur, agi);
if (error)
goto error0;
/*
* If in the same AG as the parent, try to get near the parent.
*/
if (pagno == agno) {
int doneleft; /* done, to the left */
int doneright; /* done, to the right */
error = xfs_inobt_lookup(cur, pagino, XFS_LOOKUP_LE, &i);
if (error)
goto error0;
XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
error = xfs_inobt_get_rec(cur, &rec, &j);
if (error)
goto error0;
XFS_WANT_CORRUPTED_GOTO(mp, j == 1, error0);
if (rec.ir_freecount > 0) {
/*
* Found a free inode in the same chunk
* as the parent, done.
*/
goto alloc_inode;
}
/*
* In the same AG as parent, but parent's chunk is full.
*/
/* duplicate the cursor, search left & right simultaneously */
error = xfs_btree_dup_cursor(cur, &tcur);
if (error)
goto error0;
/*
* Skip to last blocks looked up if same parent inode.
*/
if (pagino != NULLAGINO &&
pag->pagl_pagino == pagino &&
pag->pagl_leftrec != NULLAGINO &&
pag->pagl_rightrec != NULLAGINO) {
error = xfs_ialloc_get_rec(tcur, pag->pagl_leftrec,
&trec, &doneleft);
if (error)
goto error1;
error = xfs_ialloc_get_rec(cur, pag->pagl_rightrec,
&rec, &doneright);
if (error)
goto error1;
} else {
/* search left with tcur, back up 1 record */
error = xfs_ialloc_next_rec(tcur, &trec, &doneleft, 1);
if (error)
goto error1;
/* search right with cur, go forward 1 record. */
error = xfs_ialloc_next_rec(cur, &rec, &doneright, 0);
if (error)
goto error1;
}
/*
* Loop until we find an inode chunk with a free inode.
*/
while (--searchdistance > 0 && (!doneleft || !doneright)) {
int useleft; /* using left inode chunk this time */
/* figure out the closer block if both are valid. */
if (!doneleft && !doneright) {
useleft = pagino -
(trec.ir_startino + XFS_INODES_PER_CHUNK - 1) <
rec.ir_startino - pagino;
} else {
useleft = !doneleft;
}
/* free inodes to the left? */
if (useleft && trec.ir_freecount) {
xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
cur = tcur;
pag->pagl_leftrec = trec.ir_startino;
pag->pagl_rightrec = rec.ir_startino;
pag->pagl_pagino = pagino;
rec = trec;
goto alloc_inode;
}
/* free inodes to the right? */
if (!useleft && rec.ir_freecount) {
xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
pag->pagl_leftrec = trec.ir_startino;
pag->pagl_rightrec = rec.ir_startino;
pag->pagl_pagino = pagino;
goto alloc_inode;
}
/* get next record to check */
if (useleft) {
error = xfs_ialloc_next_rec(tcur, &trec,
&doneleft, 1);
} else {
error = xfs_ialloc_next_rec(cur, &rec,
&doneright, 0);
}
if (error)
goto error1;
}
if (searchdistance <= 0) {
/*
* Not in range - save last search
* location and allocate a new inode
*/
xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
pag->pagl_leftrec = trec.ir_startino;
pag->pagl_rightrec = rec.ir_startino;
pag->pagl_pagino = pagino;
} else {
/*
* We've reached the end of the btree. because
* we are only searching a small chunk of the
* btree each search, there is obviously free
* inodes closer to the parent inode than we
* are now. restart the search again.
*/
pag->pagl_pagino = NULLAGINO;
pag->pagl_leftrec = NULLAGINO;
pag->pagl_rightrec = NULLAGINO;
xfs_btree_del_cursor(tcur, XFS_BTREE_NOERROR);
xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
goto restart_pagno;
}
}
/*
* In a different AG from the parent.
* See if the most recently allocated block has any free.
*/
if (agi->agi_newino != cpu_to_be32(NULLAGINO)) {
error = xfs_inobt_lookup(cur, be32_to_cpu(agi->agi_newino),
XFS_LOOKUP_EQ, &i);
if (error)
goto error0;
if (i == 1) {
error = xfs_inobt_get_rec(cur, &rec, &j);
if (error)
goto error0;
if (j == 1 && rec.ir_freecount > 0) {
/*
* The last chunk allocated in the group
* still has a free inode.
*/
goto alloc_inode;
}
}
}
/*
* None left in the last group, search the whole AG
*/
error = xfs_inobt_lookup(cur, 0, XFS_LOOKUP_GE, &i);
if (error)
goto error0;
XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
for (;;) {
error = xfs_inobt_get_rec(cur, &rec, &i);
if (error)
goto error0;
XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
if (rec.ir_freecount > 0)
break;
error = xfs_btree_increment(cur, 0, &i);
if (error)
goto error0;
XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
}
alloc_inode:
offset = xfs_inobt_first_free_inode(&rec);
ASSERT(offset >= 0);
ASSERT(offset < XFS_INODES_PER_CHUNK);
ASSERT((XFS_AGINO_TO_OFFSET(mp, rec.ir_startino) %
XFS_INODES_PER_CHUNK) == 0);
ino = XFS_AGINO_TO_INO(mp, agno, rec.ir_startino + offset);
rec.ir_free &= ~XFS_INOBT_MASK(offset);
rec.ir_freecount--;
error = xfs_inobt_update(cur, &rec);
if (error)
goto error0;
be32_add_cpu(&agi->agi_freecount, -1);
xfs_ialloc_log_agi(tp, agbp, XFS_AGI_FREECOUNT);
pag->pagi_freecount--;
error = xfs_check_agi_freecount(cur, agi);
if (error)
goto error0;
xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
xfs_trans_mod_sb(tp, XFS_TRANS_SB_IFREE, -1);
xfs_perag_put(pag);
*inop = ino;
return 0;
error1:
xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
error0:
xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
xfs_perag_put(pag);
return error;
}
/*
* Use the free inode btree to allocate an inode based on distance from the
* parent. Note that the provided cursor may be deleted and replaced.
*/
STATIC int
xfs_dialloc_ag_finobt_near(
xfs_agino_t pagino,
struct xfs_btree_cur **ocur,
struct xfs_inobt_rec_incore *rec)
{
struct xfs_btree_cur *lcur = *ocur; /* left search cursor */
struct xfs_btree_cur *rcur; /* right search cursor */
struct xfs_inobt_rec_incore rrec;
int error;
int i, j;
error = xfs_inobt_lookup(lcur, pagino, XFS_LOOKUP_LE, &i);
if (error)
return error;
if (i == 1) {
error = xfs_inobt_get_rec(lcur, rec, &i);
if (error)
return error;
XFS_WANT_CORRUPTED_RETURN(lcur->bc_mp, i == 1);
/*
* See if we've landed in the parent inode record. The finobt
* only tracks chunks with at least one free inode, so record
* existence is enough.
*/
if (pagino >= rec->ir_startino &&
pagino < (rec->ir_startino + XFS_INODES_PER_CHUNK))
return 0;
}
error = xfs_btree_dup_cursor(lcur, &rcur);
if (error)
return error;
error = xfs_inobt_lookup(rcur, pagino, XFS_LOOKUP_GE, &j);
if (error)
goto error_rcur;
if (j == 1) {
error = xfs_inobt_get_rec(rcur, &rrec, &j);
if (error)
goto error_rcur;
XFS_WANT_CORRUPTED_GOTO(lcur->bc_mp, j == 1, error_rcur);
}
XFS_WANT_CORRUPTED_GOTO(lcur->bc_mp, i == 1 || j == 1, error_rcur);
if (i == 1 && j == 1) {
/*
* Both the left and right records are valid. Choose the closer
* inode chunk to the target.
*/
if ((pagino - rec->ir_startino + XFS_INODES_PER_CHUNK - 1) >
(rrec.ir_startino - pagino)) {
*rec = rrec;
xfs_btree_del_cursor(lcur, XFS_BTREE_NOERROR);
*ocur = rcur;
} else {
xfs_btree_del_cursor(rcur, XFS_BTREE_NOERROR);
}
} else if (j == 1) {
/* only the right record is valid */
*rec = rrec;
xfs_btree_del_cursor(lcur, XFS_BTREE_NOERROR);
*ocur = rcur;
} else if (i == 1) {
/* only the left record is valid */
xfs_btree_del_cursor(rcur, XFS_BTREE_NOERROR);
}
return 0;
error_rcur:
xfs_btree_del_cursor(rcur, XFS_BTREE_ERROR);
return error;
}
/*
* Use the free inode btree to find a free inode based on a newino hint. If
* the hint is NULL, find the first free inode in the AG.
*/
STATIC int
xfs_dialloc_ag_finobt_newino(
struct xfs_agi *agi,
struct xfs_btree_cur *cur,
struct xfs_inobt_rec_incore *rec)
{
int error;
int i;
if (agi->agi_newino != cpu_to_be32(NULLAGINO)) {
error = xfs_inobt_lookup(cur, be32_to_cpu(agi->agi_newino),
XFS_LOOKUP_EQ, &i);
if (error)
return error;
if (i == 1) {
error = xfs_inobt_get_rec(cur, rec, &i);
if (error)
return error;
XFS_WANT_CORRUPTED_RETURN(cur->bc_mp, i == 1);
return 0;
}
}
/*
* Find the first inode available in the AG.
*/
error = xfs_inobt_lookup(cur, 0, XFS_LOOKUP_GE, &i);
if (error)
return error;
XFS_WANT_CORRUPTED_RETURN(cur->bc_mp, i == 1);
error = xfs_inobt_get_rec(cur, rec, &i);
if (error)
return error;
XFS_WANT_CORRUPTED_RETURN(cur->bc_mp, i == 1);
return 0;
}
/*
* Update the inobt based on a modification made to the finobt. Also ensure that
* the records from both trees are equivalent post-modification.
*/
STATIC int
xfs_dialloc_ag_update_inobt(
struct xfs_btree_cur *cur, /* inobt cursor */
struct xfs_inobt_rec_incore *frec, /* finobt record */
int offset) /* inode offset */
{
struct xfs_inobt_rec_incore rec;
int error;
int i;
error = xfs_inobt_lookup(cur, frec->ir_startino, XFS_LOOKUP_EQ, &i);
if (error)
return error;
XFS_WANT_CORRUPTED_RETURN(cur->bc_mp, i == 1);
error = xfs_inobt_get_rec(cur, &rec, &i);
if (error)
return error;
XFS_WANT_CORRUPTED_RETURN(cur->bc_mp, i == 1);
ASSERT((XFS_AGINO_TO_OFFSET(cur->bc_mp, rec.ir_startino) %
XFS_INODES_PER_CHUNK) == 0);
rec.ir_free &= ~XFS_INOBT_MASK(offset);
rec.ir_freecount--;
XFS_WANT_CORRUPTED_RETURN(cur->bc_mp, (rec.ir_free == frec->ir_free) &&
(rec.ir_freecount == frec->ir_freecount));
return xfs_inobt_update(cur, &rec);
}
/*
* Allocate an inode using the free inode btree, if available. Otherwise, fall
* back to the inobt search algorithm.
*
* The caller selected an AG for us, and made sure that free inodes are
* available.
*/
STATIC int
xfs_dialloc_ag(
struct xfs_trans *tp,
struct xfs_buf *agbp,
xfs_ino_t parent,
xfs_ino_t *inop)
{
struct xfs_mount *mp = tp->t_mountp;
struct xfs_agi *agi = XFS_BUF_TO_AGI(agbp);
xfs_agnumber_t agno = be32_to_cpu(agi->agi_seqno);
xfs_agnumber_t pagno = XFS_INO_TO_AGNO(mp, parent);
xfs_agino_t pagino = XFS_INO_TO_AGINO(mp, parent);
struct xfs_perag *pag;
struct xfs_btree_cur *cur; /* finobt cursor */
struct xfs_btree_cur *icur; /* inobt cursor */
struct xfs_inobt_rec_incore rec;
xfs_ino_t ino;
int error;
int offset;
int i;
if (!xfs_sb_version_hasfinobt(&mp->m_sb))
return xfs_dialloc_ag_inobt(tp, agbp, parent, inop);
pag = xfs_perag_get(mp, agno);
/*
* If pagino is 0 (this is the root inode allocation) use newino.
* This must work because we've just allocated some.
*/
if (!pagino)
pagino = be32_to_cpu(agi->agi_newino);
cur = xfs_inobt_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_FINO);
error = xfs_check_agi_freecount(cur, agi);
if (error)
goto error_cur;
/*
* The search algorithm depends on whether we're in the same AG as the
* parent. If so, find the closest available inode to the parent. If
* not, consider the agi hint or find the first free inode in the AG.
*/
if (agno == pagno)
error = xfs_dialloc_ag_finobt_near(pagino, &cur, &rec);
else
error = xfs_dialloc_ag_finobt_newino(agi, cur, &rec);
if (error)
goto error_cur;
offset = xfs_inobt_first_free_inode(&rec);
ASSERT(offset >= 0);
ASSERT(offset < XFS_INODES_PER_CHUNK);
ASSERT((XFS_AGINO_TO_OFFSET(mp, rec.ir_startino) %
XFS_INODES_PER_CHUNK) == 0);
ino = XFS_AGINO_TO_INO(mp, agno, rec.ir_startino + offset);
/*
* Modify or remove the finobt record.
*/
rec.ir_free &= ~XFS_INOBT_MASK(offset);
rec.ir_freecount--;
if (rec.ir_freecount)
error = xfs_inobt_update(cur, &rec);
else
error = xfs_btree_delete(cur, &i);
if (error)
goto error_cur;
/*
* The finobt has now been updated appropriately. We haven't updated the
* agi and superblock yet, so we can create an inobt cursor and validate
* the original freecount. If all is well, make the equivalent update to
* the inobt using the finobt record and offset information.
*/
icur = xfs_inobt_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_INO);
error = xfs_check_agi_freecount(icur, agi);
if (error)
goto error_icur;
error = xfs_dialloc_ag_update_inobt(icur, &rec, offset);
if (error)
goto error_icur;
/*
* Both trees have now been updated. We must update the perag and
* superblock before we can check the freecount for each btree.
*/
be32_add_cpu(&agi->agi_freecount, -1);
xfs_ialloc_log_agi(tp, agbp, XFS_AGI_FREECOUNT);
pag->pagi_freecount--;
xfs_trans_mod_sb(tp, XFS_TRANS_SB_IFREE, -1);
error = xfs_check_agi_freecount(icur, agi);
if (error)
goto error_icur;
error = xfs_check_agi_freecount(cur, agi);
if (error)
goto error_icur;
xfs_btree_del_cursor(icur, XFS_BTREE_NOERROR);
xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
xfs_perag_put(pag);
*inop = ino;
return 0;
error_icur:
xfs_btree_del_cursor(icur, XFS_BTREE_ERROR);
error_cur:
xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
xfs_perag_put(pag);
return error;
}
/*
* Allocate an inode on disk.
*
* Mode is used to tell whether the new inode will need space, and whether it
* is a directory.
*
* This function is designed to be called twice if it has to do an allocation
* to make more free inodes. On the first call, *IO_agbp should be set to NULL.
* If an inode is available without having to performn an allocation, an inode
* number is returned. In this case, *IO_agbp is set to NULL. If an allocation
* needs to be done, xfs_dialloc returns the current AGI buffer in *IO_agbp.
* The caller should then commit the current transaction, allocate a
* new transaction, and call xfs_dialloc() again, passing in the previous value
* of *IO_agbp. IO_agbp should be held across the transactions. Since the AGI
* buffer is locked across the two calls, the second call is guaranteed to have
* a free inode available.
*
* Once we successfully pick an inode its number is returned and the on-disk
* data structures are updated. The inode itself is not read in, since doing so
* would break ordering constraints with xfs_reclaim.
*/
int
xfs_dialloc(
struct xfs_trans *tp,
xfs_ino_t parent,
umode_t mode,
struct xfs_buf **IO_agbp,
xfs_ino_t *inop)
{
struct xfs_mount *mp = tp->t_mountp;
struct xfs_buf *agbp;
xfs_agnumber_t agno;
int error;
int ialloced;
int noroom = 0;
xfs_agnumber_t start_agno;
struct xfs_perag *pag;
struct xfs_ino_geometry *igeo = M_IGEO(mp);
int okalloc = 1;
if (*IO_agbp) {
/*
* If the caller passes in a pointer to the AGI buffer,
* continue where we left off before. In this case, we
* know that the allocation group has free inodes.
*/
agbp = *IO_agbp;
goto out_alloc;
}
/*
* We do not have an agbp, so select an initial allocation
* group for inode allocation.
*/
start_agno = xfs_ialloc_ag_select(tp, parent, mode);
if (start_agno == NULLAGNUMBER) {
*inop = NULLFSINO;
return 0;
}
/*
* If we have already hit the ceiling of inode blocks then clear
* okalloc so we scan all available agi structures for a free
* inode.
*
* Read rough value of mp->m_icount by percpu_counter_read_positive,
* which will sacrifice the preciseness but improve the performance.
*/
if (igeo->maxicount &&
percpu_counter_read_positive(&mp->m_icount) + igeo->ialloc_inos
> igeo->maxicount) {
noroom = 1;
okalloc = 0;
}
/*
* Loop until we find an allocation group that either has free inodes
* or in which we can allocate some inodes. Iterate through the
* allocation groups upward, wrapping at the end.
*/
agno = start_agno;
for (;;) {
pag = xfs_perag_get(mp, agno);
if (!pag->pagi_inodeok) {
xfs_ialloc_next_ag(mp);
goto nextag;
}
if (!pag->pagi_init) {
error = xfs_ialloc_pagi_init(mp, tp, agno);
if (error)
goto out_error;
}
/*
* Do a first racy fast path check if this AG is usable.
*/
if (!pag->pagi_freecount && !okalloc)
goto nextag;
/*
* Then read in the AGI buffer and recheck with the AGI buffer
* lock held.
*/
error = xfs_ialloc_read_agi(mp, tp, agno, &agbp);
if (error)
goto out_error;
if (pag->pagi_freecount) {
xfs_perag_put(pag);
goto out_alloc;
}
if (!okalloc)
goto nextag_relse_buffer;
error = xfs_ialloc_ag_alloc(tp, agbp, &ialloced);
if (error) {
xfs_trans_brelse(tp, agbp);
if (error != -ENOSPC)
goto out_error;
xfs_perag_put(pag);
*inop = NULLFSINO;
return 0;
}
if (ialloced) {
/*
* We successfully allocated some inodes, return
* the current context to the caller so that it
* can commit the current transaction and call
* us again where we left off.
*/
ASSERT(pag->pagi_freecount > 0);
xfs_perag_put(pag);
*IO_agbp = agbp;
*inop = NULLFSINO;
return 0;
}
nextag_relse_buffer:
xfs_trans_brelse(tp, agbp);
nextag:
xfs_perag_put(pag);
if (++agno == mp->m_sb.sb_agcount)
agno = 0;
if (agno == start_agno) {
*inop = NULLFSINO;
return noroom ? -ENOSPC : 0;
}
}
out_alloc:
*IO_agbp = NULL;
return xfs_dialloc_ag(tp, agbp, parent, inop);
out_error:
xfs_perag_put(pag);
return error;
}
/*
* Free the blocks of an inode chunk. We must consider that the inode chunk
* might be sparse and only free the regions that are allocated as part of the
* chunk.
*/
STATIC void
xfs_difree_inode_chunk(
struct xfs_trans *tp,
xfs_agnumber_t agno,
struct xfs_inobt_rec_incore *rec)
{
struct xfs_mount *mp = tp->t_mountp;
xfs_agblock_t sagbno = XFS_AGINO_TO_AGBNO(mp,
rec->ir_startino);
int startidx, endidx;
int nextbit;
xfs_agblock_t agbno;
int contigblk;
DECLARE_BITMAP(holemask, XFS_INOBT_HOLEMASK_BITS);
if (!xfs_inobt_issparse(rec->ir_holemask)) {
/* not sparse, calculate extent info directly */
xfs_bmap_add_free(tp, XFS_AGB_TO_FSB(mp, agno, sagbno),
M_IGEO(mp)->ialloc_blks,
&XFS_RMAP_OINFO_INODES);
return;
}
/* holemask is only 16-bits (fits in an unsigned long) */
ASSERT(sizeof(rec->ir_holemask) <= sizeof(holemask[0]));
holemask[0] = rec->ir_holemask;
/*
* Find contiguous ranges of zeroes (i.e., allocated regions) in the
* holemask and convert the start/end index of each range to an extent.
* We start with the start and end index both pointing at the first 0 in
* the mask.
*/
startidx = endidx = find_first_zero_bit(holemask,
XFS_INOBT_HOLEMASK_BITS);
nextbit = startidx + 1;
while (startidx < XFS_INOBT_HOLEMASK_BITS) {
nextbit = find_next_zero_bit(holemask, XFS_INOBT_HOLEMASK_BITS,
nextbit);
/*
* If the next zero bit is contiguous, update the end index of
* the current range and continue.
*/
if (nextbit != XFS_INOBT_HOLEMASK_BITS &&
nextbit == endidx + 1) {
endidx = nextbit;
goto next;
}
/*
* nextbit is not contiguous with the current end index. Convert
* the current start/end to an extent and add it to the free
* list.
*/
agbno = sagbno + (startidx * XFS_INODES_PER_HOLEMASK_BIT) /
mp->m_sb.sb_inopblock;
contigblk = ((endidx - startidx + 1) *
XFS_INODES_PER_HOLEMASK_BIT) /
mp->m_sb.sb_inopblock;
ASSERT(agbno % mp->m_sb.sb_spino_align == 0);
ASSERT(contigblk % mp->m_sb.sb_spino_align == 0);
xfs_bmap_add_free(tp, XFS_AGB_TO_FSB(mp, agno, agbno),
contigblk, &XFS_RMAP_OINFO_INODES);
/* reset range to current bit and carry on... */
startidx = endidx = nextbit;
next:
nextbit++;
}
}
STATIC int
xfs_difree_inobt(
struct xfs_mount *mp,
struct xfs_trans *tp,
struct xfs_buf *agbp,
xfs_agino_t agino,
struct xfs_icluster *xic,
struct xfs_inobt_rec_incore *orec)
{
struct xfs_agi *agi = XFS_BUF_TO_AGI(agbp);
xfs_agnumber_t agno = be32_to_cpu(agi->agi_seqno);
struct xfs_perag *pag;
struct xfs_btree_cur *cur;
struct xfs_inobt_rec_incore rec;
int ilen;
int error;
int i;
int off;
ASSERT(agi->agi_magicnum == cpu_to_be32(XFS_AGI_MAGIC));
ASSERT(XFS_AGINO_TO_AGBNO(mp, agino) < be32_to_cpu(agi->agi_length));
/*
* Initialize the cursor.
*/
cur = xfs_inobt_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_INO);
error = xfs_check_agi_freecount(cur, agi);
if (error)
goto error0;
/*
* Look for the entry describing this inode.
*/
if ((error = xfs_inobt_lookup(cur, agino, XFS_LOOKUP_LE, &i))) {
xfs_warn(mp, "%s: xfs_inobt_lookup() returned error %d.",
__func__, error);
goto error0;
}
XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
error = xfs_inobt_get_rec(cur, &rec, &i);
if (error) {
xfs_warn(mp, "%s: xfs_inobt_get_rec() returned error %d.",
__func__, error);
goto error0;
}
XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
/*
* Get the offset in the inode chunk.
*/
off = agino - rec.ir_startino;
ASSERT(off >= 0 && off < XFS_INODES_PER_CHUNK);
ASSERT(!(rec.ir_free & XFS_INOBT_MASK(off)));
/*
* Mark the inode free & increment the count.
*/
rec.ir_free |= XFS_INOBT_MASK(off);
rec.ir_freecount++;
/*
* When an inode chunk is free, it becomes eligible for removal. Don't
* remove the chunk if the block size is large enough for multiple inode
* chunks (that might not be free).
*/
if (!(mp->m_flags & XFS_MOUNT_IKEEP) &&
rec.ir_free == XFS_INOBT_ALL_FREE &&
mp->m_sb.sb_inopblock <= XFS_INODES_PER_CHUNK) {
xic->deleted = true;
xic->first_ino = XFS_AGINO_TO_INO(mp, agno, rec.ir_startino);
xic->alloc = xfs_inobt_irec_to_allocmask(&rec);
/*
* Remove the inode cluster from the AGI B+Tree, adjust the
* AGI and Superblock inode counts, and mark the disk space
* to be freed when the transaction is committed.
*/
ilen = rec.ir_freecount;
be32_add_cpu(&agi->agi_count, -ilen);
be32_add_cpu(&agi->agi_freecount, -(ilen - 1));
xfs_ialloc_log_agi(tp, agbp, XFS_AGI_COUNT | XFS_AGI_FREECOUNT);
pag = xfs_perag_get(mp, agno);
pag->pagi_freecount -= ilen - 1;
pag->pagi_count -= ilen;
xfs_perag_put(pag);
xfs_trans_mod_sb(tp, XFS_TRANS_SB_ICOUNT, -ilen);
xfs_trans_mod_sb(tp, XFS_TRANS_SB_IFREE, -(ilen - 1));
if ((error = xfs_btree_delete(cur, &i))) {
xfs_warn(mp, "%s: xfs_btree_delete returned error %d.",
__func__, error);
goto error0;
}
xfs_difree_inode_chunk(tp, agno, &rec);
} else {
xic->deleted = false;
error = xfs_inobt_update(cur, &rec);
if (error) {
xfs_warn(mp, "%s: xfs_inobt_update returned error %d.",
__func__, error);
goto error0;
}
/*
* Change the inode free counts and log the ag/sb changes.
*/
be32_add_cpu(&agi->agi_freecount, 1);
xfs_ialloc_log_agi(tp, agbp, XFS_AGI_FREECOUNT);
pag = xfs_perag_get(mp, agno);
pag->pagi_freecount++;
xfs_perag_put(pag);
xfs_trans_mod_sb(tp, XFS_TRANS_SB_IFREE, 1);
}
error = xfs_check_agi_freecount(cur, agi);
if (error)
goto error0;
*orec = rec;
xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
return 0;
error0:
xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
return error;
}
/*
* Free an inode in the free inode btree.
*/
STATIC int
xfs_difree_finobt(
struct xfs_mount *mp,
struct xfs_trans *tp,
struct xfs_buf *agbp,
xfs_agino_t agino,
struct xfs_inobt_rec_incore *ibtrec) /* inobt record */
{
struct xfs_agi *agi = XFS_BUF_TO_AGI(agbp);
xfs_agnumber_t agno = be32_to_cpu(agi->agi_seqno);
struct xfs_btree_cur *cur;
struct xfs_inobt_rec_incore rec;
int offset = agino - ibtrec->ir_startino;
int error;
int i;
cur = xfs_inobt_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_FINO);
error = xfs_inobt_lookup(cur, ibtrec->ir_startino, XFS_LOOKUP_EQ, &i);
if (error)
goto error;
if (i == 0) {
/*
* If the record does not exist in the finobt, we must have just
* freed an inode in a previously fully allocated chunk. If not,
* something is out of sync.
*/
XFS_WANT_CORRUPTED_GOTO(mp, ibtrec->ir_freecount == 1, error);
error = xfs_inobt_insert_rec(cur, ibtrec->ir_holemask,
ibtrec->ir_count,
ibtrec->ir_freecount,
ibtrec->ir_free, &i);
if (error)
goto error;
ASSERT(i == 1);
goto out;
}
/*
* Read and update the existing record. We could just copy the ibtrec
* across here, but that would defeat the purpose of having redundant
* metadata. By making the modifications independently, we can catch
* corruptions that we wouldn't see if we just copied from one record
* to another.
*/
error = xfs_inobt_get_rec(cur, &rec, &i);
if (error)
goto error;
XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error);
rec.ir_free |= XFS_INOBT_MASK(offset);
rec.ir_freecount++;
XFS_WANT_CORRUPTED_GOTO(mp, (rec.ir_free == ibtrec->ir_free) &&
(rec.ir_freecount == ibtrec->ir_freecount),
error);
/*
* The content of inobt records should always match between the inobt
* and finobt. The lifecycle of records in the finobt is different from
* the inobt in that the finobt only tracks records with at least one
* free inode. Hence, if all of the inodes are free and we aren't
* keeping inode chunks permanently on disk, remove the record.
* Otherwise, update the record with the new information.
*
* Note that we currently can't free chunks when the block size is large
* enough for multiple chunks. Leave the finobt record to remain in sync
* with the inobt.
*/
if (rec.ir_free == XFS_INOBT_ALL_FREE &&
mp->m_sb.sb_inopblock <= XFS_INODES_PER_CHUNK &&
!(mp->m_flags & XFS_MOUNT_IKEEP)) {
error = xfs_btree_delete(cur, &i);
if (error)
goto error;
ASSERT(i == 1);
} else {
error = xfs_inobt_update(cur, &rec);
if (error)
goto error;
}
out:
error = xfs_check_agi_freecount(cur, agi);
if (error)
goto error;
xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
return 0;
error:
xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
return error;
}
/*
* Free disk inode. Carefully avoids touching the incore inode, all
* manipulations incore are the caller's responsibility.
* The on-disk inode is not changed by this operation, only the
* btree (free inode mask) is changed.
*/
int
xfs_difree(
struct xfs_trans *tp, /* transaction pointer */
xfs_ino_t inode, /* inode to be freed */
struct xfs_icluster *xic) /* cluster info if deleted */
{
/* REFERENCED */
xfs_agblock_t agbno; /* block number containing inode */
struct xfs_buf *agbp; /* buffer for allocation group header */
xfs_agino_t agino; /* allocation group inode number */
xfs_agnumber_t agno; /* allocation group number */
int error; /* error return value */
struct xfs_mount *mp; /* mount structure for filesystem */
struct xfs_inobt_rec_incore rec;/* btree record */
mp = tp->t_mountp;
/*
* Break up inode number into its components.
*/
agno = XFS_INO_TO_AGNO(mp, inode);
if (agno >= mp->m_sb.sb_agcount) {
xfs_warn(mp, "%s: agno >= mp->m_sb.sb_agcount (%d >= %d).",
__func__, agno, mp->m_sb.sb_agcount);
ASSERT(0);
return -EINVAL;
}
agino = XFS_INO_TO_AGINO(mp, inode);
if (inode != XFS_AGINO_TO_INO(mp, agno, agino)) {
xfs_warn(mp, "%s: inode != XFS_AGINO_TO_INO() (%llu != %llu).",
__func__, (unsigned long long)inode,
(unsigned long long)XFS_AGINO_TO_INO(mp, agno, agino));
ASSERT(0);
return -EINVAL;
}
agbno = XFS_AGINO_TO_AGBNO(mp, agino);
if (agbno >= mp->m_sb.sb_agblocks) {
xfs_warn(mp, "%s: agbno >= mp->m_sb.sb_agblocks (%d >= %d).",
__func__, agbno, mp->m_sb.sb_agblocks);
ASSERT(0);
return -EINVAL;
}
/*
* Get the allocation group header.
*/
error = xfs_ialloc_read_agi(mp, tp, agno, &agbp);
if (error) {
xfs_warn(mp, "%s: xfs_ialloc_read_agi() returned error %d.",
__func__, error);
return error;
}
/*
* Fix up the inode allocation btree.
*/
error = xfs_difree_inobt(mp, tp, agbp, agino, xic, &rec);
if (error)
goto error0;
/*
* Fix up the free inode btree.
*/
if (xfs_sb_version_hasfinobt(&mp->m_sb)) {
error = xfs_difree_finobt(mp, tp, agbp, agino, &rec);
if (error)
goto error0;
}
return 0;
error0:
return error;
}
STATIC int
xfs_imap_lookup(
struct xfs_mount *mp,
struct xfs_trans *tp,
xfs_agnumber_t agno,
xfs_agino_t agino,
xfs_agblock_t agbno,
xfs_agblock_t *chunk_agbno,
xfs_agblock_t *offset_agbno,
int flags)
{
struct xfs_inobt_rec_incore rec;
struct xfs_btree_cur *cur;
struct xfs_buf *agbp;
int error;
int i;
error = xfs_ialloc_read_agi(mp, tp, agno, &agbp);
if (error) {
xfs_alert(mp,
"%s: xfs_ialloc_read_agi() returned error %d, agno %d",
__func__, error, agno);
return error;
}
/*
* Lookup the inode record for the given agino. If the record cannot be
* found, then it's an invalid inode number and we should abort. Once
* we have a record, we need to ensure it contains the inode number
* we are looking up.
*/
cur = xfs_inobt_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_INO);
error = xfs_inobt_lookup(cur, agino, XFS_LOOKUP_LE, &i);
if (!error) {
if (i)
error = xfs_inobt_get_rec(cur, &rec, &i);
if (!error && i == 0)
error = -EINVAL;
}
xfs_trans_brelse(tp, agbp);
xfs_btree_del_cursor(cur, error);
if (error)
return error;
/* check that the returned record contains the required inode */
if (rec.ir_startino > agino ||
rec.ir_startino + M_IGEO(mp)->ialloc_inos <= agino)
return -EINVAL;
/* for untrusted inodes check it is allocated first */
if ((flags & XFS_IGET_UNTRUSTED) &&
(rec.ir_free & XFS_INOBT_MASK(agino - rec.ir_startino)))
return -EINVAL;
*chunk_agbno = XFS_AGINO_TO_AGBNO(mp, rec.ir_startino);
*offset_agbno = agbno - *chunk_agbno;
return 0;
}
/*
* Return the location of the inode in imap, for mapping it into a buffer.
*/
int
xfs_imap(
xfs_mount_t *mp, /* file system mount structure */
xfs_trans_t *tp, /* transaction pointer */
xfs_ino_t ino, /* inode to locate */
struct xfs_imap *imap, /* location map structure */
uint flags) /* flags for inode btree lookup */
{
xfs_agblock_t agbno; /* block number of inode in the alloc group */
xfs_agino_t agino; /* inode number within alloc group */
xfs_agnumber_t agno; /* allocation group number */
xfs_agblock_t chunk_agbno; /* first block in inode chunk */
xfs_agblock_t cluster_agbno; /* first block in inode cluster */
int error; /* error code */
int offset; /* index of inode in its buffer */
xfs_agblock_t offset_agbno; /* blks from chunk start to inode */
ASSERT(ino != NULLFSINO);
/*
* Split up the inode number into its parts.
*/
agno = XFS_INO_TO_AGNO(mp, ino);
agino = XFS_INO_TO_AGINO(mp, ino);
agbno = XFS_AGINO_TO_AGBNO(mp, agino);
if (agno >= mp->m_sb.sb_agcount || agbno >= mp->m_sb.sb_agblocks ||
ino != XFS_AGINO_TO_INO(mp, agno, agino)) {
#ifdef DEBUG
/*
* Don't output diagnostic information for untrusted inodes
* as they can be invalid without implying corruption.
*/
if (flags & XFS_IGET_UNTRUSTED)
return -EINVAL;
if (agno >= mp->m_sb.sb_agcount) {
xfs_alert(mp,
"%s: agno (%d) >= mp->m_sb.sb_agcount (%d)",
__func__, agno, mp->m_sb.sb_agcount);
}
if (agbno >= mp->m_sb.sb_agblocks) {
xfs_alert(mp,
"%s: agbno (0x%llx) >= mp->m_sb.sb_agblocks (0x%lx)",
__func__, (unsigned long long)agbno,
(unsigned long)mp->m_sb.sb_agblocks);
}
if (ino != XFS_AGINO_TO_INO(mp, agno, agino)) {
xfs_alert(mp,
"%s: ino (0x%llx) != XFS_AGINO_TO_INO() (0x%llx)",
__func__, ino,
XFS_AGINO_TO_INO(mp, agno, agino));
}
xfs_stack_trace();
#endif /* DEBUG */
return -EINVAL;
}
/*
* For bulkstat and handle lookups, we have an untrusted inode number
* that we have to verify is valid. We cannot do this just by reading
* the inode buffer as it may have been unlinked and removed leaving
* inodes in stale state on disk. Hence we have to do a btree lookup
* in all cases where an untrusted inode number is passed.
*/
if (flags & XFS_IGET_UNTRUSTED) {
error = xfs_imap_lookup(mp, tp, agno, agino, agbno,
&chunk_agbno, &offset_agbno, flags);
if (error)
return error;
goto out_map;
}
/*
* If the inode cluster size is the same as the blocksize or
* smaller we get to the buffer by simple arithmetics.
*/
if (M_IGEO(mp)->blocks_per_cluster == 1) {
offset = XFS_INO_TO_OFFSET(mp, ino);
ASSERT(offset < mp->m_sb.sb_inopblock);
imap->im_blkno = XFS_AGB_TO_DADDR(mp, agno, agbno);
imap->im_len = XFS_FSB_TO_BB(mp, 1);
imap->im_boffset = (unsigned short)(offset <<
mp->m_sb.sb_inodelog);
return 0;
}
/*
* If the inode chunks are aligned then use simple maths to
* find the location. Otherwise we have to do a btree
* lookup to find the location.
*/
if (M_IGEO(mp)->inoalign_mask) {
offset_agbno = agbno & M_IGEO(mp)->inoalign_mask;
chunk_agbno = agbno - offset_agbno;
} else {
error = xfs_imap_lookup(mp, tp, agno, agino, agbno,
&chunk_agbno, &offset_agbno, flags);
if (error)
return error;
}
out_map:
ASSERT(agbno >= chunk_agbno);
cluster_agbno = chunk_agbno +
((offset_agbno / M_IGEO(mp)->blocks_per_cluster) *
M_IGEO(mp)->blocks_per_cluster);
offset = ((agbno - cluster_agbno) * mp->m_sb.sb_inopblock) +
XFS_INO_TO_OFFSET(mp, ino);
imap->im_blkno = XFS_AGB_TO_DADDR(mp, agno, cluster_agbno);
imap->im_len = XFS_FSB_TO_BB(mp, M_IGEO(mp)->blocks_per_cluster);
imap->im_boffset = (unsigned short)(offset << mp->m_sb.sb_inodelog);
/*
* If the inode number maps to a block outside the bounds
* of the file system then return NULL rather than calling
* read_buf and panicing when we get an error from the
* driver.
*/
if ((imap->im_blkno + imap->im_len) >
XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks)) {
xfs_alert(mp,
"%s: (im_blkno (0x%llx) + im_len (0x%llx)) > sb_dblocks (0x%llx)",
__func__, (unsigned long long) imap->im_blkno,
(unsigned long long) imap->im_len,
XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks));
return -EINVAL;
}
return 0;
}
/*
* Log specified fields for the ag hdr (inode section). The growth of the agi
* structure over time requires that we interpret the buffer as two logical
* regions delineated by the end of the unlinked list. This is due to the size
* of the hash table and its location in the middle of the agi.
*
* For example, a request to log a field before agi_unlinked and a field after
* agi_unlinked could cause us to log the entire hash table and use an excessive
* amount of log space. To avoid this behavior, log the region up through
* agi_unlinked in one call and the region after agi_unlinked through the end of
* the structure in another.
*/
void
xfs_ialloc_log_agi(
xfs_trans_t *tp, /* transaction pointer */
xfs_buf_t *bp, /* allocation group header buffer */
int fields) /* bitmask of fields to log */
{
int first; /* first byte number */
int last; /* last byte number */
static const short offsets[] = { /* field starting offsets */
/* keep in sync with bit definitions */
offsetof(xfs_agi_t, agi_magicnum),
offsetof(xfs_agi_t, agi_versionnum),
offsetof(xfs_agi_t, agi_seqno),
offsetof(xfs_agi_t, agi_length),
offsetof(xfs_agi_t, agi_count),
offsetof(xfs_agi_t, agi_root),
offsetof(xfs_agi_t, agi_level),
offsetof(xfs_agi_t, agi_freecount),
offsetof(xfs_agi_t, agi_newino),
offsetof(xfs_agi_t, agi_dirino),
offsetof(xfs_agi_t, agi_unlinked),
offsetof(xfs_agi_t, agi_free_root),
offsetof(xfs_agi_t, agi_free_level),
sizeof(xfs_agi_t)
};
#ifdef DEBUG
xfs_agi_t *agi; /* allocation group header */
agi = XFS_BUF_TO_AGI(bp);
ASSERT(agi->agi_magicnum == cpu_to_be32(XFS_AGI_MAGIC));
#endif
/*
* Compute byte offsets for the first and last fields in the first
* region and log the agi buffer. This only logs up through
* agi_unlinked.
*/
if (fields & XFS_AGI_ALL_BITS_R1) {
xfs_btree_offsets(fields, offsets, XFS_AGI_NUM_BITS_R1,
&first, &last);
xfs_trans_log_buf(tp, bp, first, last);
}
/*
* Mask off the bits in the first region and calculate the first and
* last field offsets for any bits in the second region.
*/
fields &= ~XFS_AGI_ALL_BITS_R1;
if (fields) {
xfs_btree_offsets(fields, offsets, XFS_AGI_NUM_BITS_R2,
&first, &last);
xfs_trans_log_buf(tp, bp, first, last);
}
}
static xfs_failaddr_t
xfs_agi_verify(
struct xfs_buf *bp)
{
struct xfs_mount *mp = bp->b_mount;
struct xfs_agi *agi = XFS_BUF_TO_AGI(bp);
int i;
if (xfs_sb_version_hascrc(&mp->m_sb)) {
if (!uuid_equal(&agi->agi_uuid, &mp->m_sb.sb_meta_uuid))
return __this_address;
if (!xfs_log_check_lsn(mp,
be64_to_cpu(XFS_BUF_TO_AGI(bp)->agi_lsn)))
return __this_address;
}
/*
* Validate the magic number of the agi block.
*/
if (!xfs_verify_magic(bp, agi->agi_magicnum))
return __this_address;
if (!XFS_AGI_GOOD_VERSION(be32_to_cpu(agi->agi_versionnum)))
return __this_address;
if (be32_to_cpu(agi->agi_level) < 1 ||
be32_to_cpu(agi->agi_level) > XFS_BTREE_MAXLEVELS)
return __this_address;
if (xfs_sb_version_hasfinobt(&mp->m_sb) &&
(be32_to_cpu(agi->agi_free_level) < 1 ||
be32_to_cpu(agi->agi_free_level) > XFS_BTREE_MAXLEVELS))
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(agi->agi_seqno) != bp->b_pag->pag_agno)
return __this_address;
for (i = 0; i < XFS_AGI_UNLINKED_BUCKETS; i++) {
if (agi->agi_unlinked[i] == cpu_to_be32(NULLAGINO))
continue;
if (!xfs_verify_ino(mp, be32_to_cpu(agi->agi_unlinked[i])))
return __this_address;
}
return NULL;
}
static void
xfs_agi_read_verify(
struct xfs_buf *bp)
{
struct xfs_mount *mp = bp->b_mount;
xfs_failaddr_t fa;
if (xfs_sb_version_hascrc(&mp->m_sb) &&
!xfs_buf_verify_cksum(bp, XFS_AGI_CRC_OFF))
xfs_verifier_error(bp, -EFSBADCRC, __this_address);
else {
fa = xfs_agi_verify(bp);
if (XFS_TEST_ERROR(fa, mp, XFS_ERRTAG_IALLOC_READ_AGI))
xfs_verifier_error(bp, -EFSCORRUPTED, fa);
}
}
static void
xfs_agi_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;
fa = xfs_agi_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_AGI(bp)->agi_lsn = cpu_to_be64(bip->bli_item.li_lsn);
xfs_buf_update_cksum(bp, XFS_AGI_CRC_OFF);
}
const struct xfs_buf_ops xfs_agi_buf_ops = {
.name = "xfs_agi",
.magic = { cpu_to_be32(XFS_AGI_MAGIC), cpu_to_be32(XFS_AGI_MAGIC) },
.verify_read = xfs_agi_read_verify,
.verify_write = xfs_agi_write_verify,
.verify_struct = xfs_agi_verify,
};
/*
* Read in the allocation group header (inode allocation section)
*/
int
xfs_read_agi(
struct xfs_mount *mp, /* file system mount structure */
struct xfs_trans *tp, /* transaction pointer */
xfs_agnumber_t agno, /* allocation group number */
struct xfs_buf **bpp) /* allocation group hdr buf */
{
int error;
trace_xfs_read_agi(mp, agno);
ASSERT(agno != NULLAGNUMBER);
error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
XFS_AG_DADDR(mp, agno, XFS_AGI_DADDR(mp)),
XFS_FSS_TO_BB(mp, 1), 0, bpp, &xfs_agi_buf_ops);
if (error)
return error;
if (tp)
xfs_trans_buf_set_type(tp, *bpp, XFS_BLFT_AGI_BUF);
xfs_buf_set_ref(*bpp, XFS_AGI_REF);
return 0;
}
int
xfs_ialloc_read_agi(
struct xfs_mount *mp, /* file system mount structure */
struct xfs_trans *tp, /* transaction pointer */
xfs_agnumber_t agno, /* allocation group number */
struct xfs_buf **bpp) /* allocation group hdr buf */
{
struct xfs_agi *agi; /* allocation group header */
struct xfs_perag *pag; /* per allocation group data */
int error;
trace_xfs_ialloc_read_agi(mp, agno);
error = xfs_read_agi(mp, tp, agno, bpp);
if (error)
return error;
agi = XFS_BUF_TO_AGI(*bpp);
pag = xfs_perag_get(mp, agno);
if (!pag->pagi_init) {
pag->pagi_freecount = be32_to_cpu(agi->agi_freecount);
pag->pagi_count = be32_to_cpu(agi->agi_count);
pag->pagi_init = 1;
}
/*
* It's possible for these to be out of sync if
* we are in the middle of a forced shutdown.
*/
ASSERT(pag->pagi_freecount == be32_to_cpu(agi->agi_freecount) ||
XFS_FORCED_SHUTDOWN(mp));
xfs_perag_put(pag);
return 0;
}
/*
* Read in the agi to initialise the per-ag data in the mount structure
*/
int
xfs_ialloc_pagi_init(
xfs_mount_t *mp, /* file system mount structure */
xfs_trans_t *tp, /* transaction pointer */
xfs_agnumber_t agno) /* allocation group number */
{
xfs_buf_t *bp = NULL;
int error;
error = xfs_ialloc_read_agi(mp, tp, agno, &bp);
if (error)
return error;
if (bp)
xfs_trans_brelse(tp, bp);
return 0;
}
/* Is there an inode record covering a given range of inode numbers? */
int
xfs_ialloc_has_inode_record(
struct xfs_btree_cur *cur,
xfs_agino_t low,
xfs_agino_t high,
bool *exists)
{
struct xfs_inobt_rec_incore irec;
xfs_agino_t agino;
uint16_t holemask;
int has_record;
int i;
int error;
*exists = false;
error = xfs_inobt_lookup(cur, low, XFS_LOOKUP_LE, &has_record);
while (error == 0 && has_record) {
error = xfs_inobt_get_rec(cur, &irec, &has_record);
if (error || irec.ir_startino > high)
break;
agino = irec.ir_startino;
holemask = irec.ir_holemask;
for (i = 0; i < XFS_INOBT_HOLEMASK_BITS; holemask >>= 1,
i++, agino += XFS_INODES_PER_HOLEMASK_BIT) {
if (holemask & 1)
continue;
if (agino + XFS_INODES_PER_HOLEMASK_BIT > low &&
agino <= high) {
*exists = true;
return 0;
}
}
error = xfs_btree_increment(cur, 0, &has_record);
}
return error;
}
/* Is there an inode record covering a given extent? */
int
xfs_ialloc_has_inodes_at_extent(
struct xfs_btree_cur *cur,
xfs_agblock_t bno,
xfs_extlen_t len,
bool *exists)
{
xfs_agino_t low;
xfs_agino_t high;
low = XFS_AGB_TO_AGINO(cur->bc_mp, bno);
high = XFS_AGB_TO_AGINO(cur->bc_mp, bno + len) - 1;
return xfs_ialloc_has_inode_record(cur, low, high, exists);
}
struct xfs_ialloc_count_inodes {
xfs_agino_t count;
xfs_agino_t freecount;
};
/* Record inode counts across all inobt records. */
STATIC int
xfs_ialloc_count_inodes_rec(
struct xfs_btree_cur *cur,
union xfs_btree_rec *rec,
void *priv)
{
struct xfs_inobt_rec_incore irec;
struct xfs_ialloc_count_inodes *ci = priv;
xfs_inobt_btrec_to_irec(cur->bc_mp, rec, &irec);
ci->count += irec.ir_count;
ci->freecount += irec.ir_freecount;
return 0;
}
/* Count allocated and free inodes under an inobt. */
int
xfs_ialloc_count_inodes(
struct xfs_btree_cur *cur,
xfs_agino_t *count,
xfs_agino_t *freecount)
{
struct xfs_ialloc_count_inodes ci = {0};
int error;
ASSERT(cur->bc_btnum == XFS_BTNUM_INO);
error = xfs_btree_query_all(cur, xfs_ialloc_count_inodes_rec, &ci);
if (error)
return error;
*count = ci.count;
*freecount = ci.freecount;
return 0;
}
/*
* Initialize inode-related geometry information.
*
* Compute the inode btree min and max levels and set maxicount.
*
* Set the inode cluster size. This may still be overridden by the file
* system block size if it is larger than the chosen cluster size.
*
* For v5 filesystems, scale the cluster size with the inode size to keep a
* constant ratio of inode per cluster buffer, but only if mkfs has set the
* inode alignment value appropriately for larger cluster sizes.
*
* Then compute the inode cluster alignment information.
*/
void
xfs_ialloc_setup_geometry(
struct xfs_mount *mp)
{
struct xfs_sb *sbp = &mp->m_sb;
struct xfs_ino_geometry *igeo = M_IGEO(mp);
uint64_t icount;
uint inodes;
/* Compute inode btree geometry. */
igeo->agino_log = sbp->sb_inopblog + sbp->sb_agblklog;
igeo->inobt_mxr[0] = xfs_inobt_maxrecs(mp, sbp->sb_blocksize, 1);
igeo->inobt_mxr[1] = xfs_inobt_maxrecs(mp, sbp->sb_blocksize, 0);
igeo->inobt_mnr[0] = igeo->inobt_mxr[0] / 2;
igeo->inobt_mnr[1] = igeo->inobt_mxr[1] / 2;
igeo->ialloc_inos = max_t(uint16_t, XFS_INODES_PER_CHUNK,
sbp->sb_inopblock);
igeo->ialloc_blks = igeo->ialloc_inos >> sbp->sb_inopblog;
if (sbp->sb_spino_align)
igeo->ialloc_min_blks = sbp->sb_spino_align;
else
igeo->ialloc_min_blks = igeo->ialloc_blks;
/* Compute and fill in value of m_ino_geo.inobt_maxlevels. */
inodes = (1LL << XFS_INO_AGINO_BITS(mp)) >> XFS_INODES_PER_CHUNK_LOG;
igeo->inobt_maxlevels = xfs_btree_compute_maxlevels(igeo->inobt_mnr,
inodes);
/*
* Set the maximum inode count for this filesystem, being careful not
* to use obviously garbage sb_inopblog/sb_inopblock values. Regular
* users should never get here due to failing sb verification, but
* certain users (xfs_db) need to be usable even with corrupt metadata.
*/
if (sbp->sb_imax_pct && igeo->ialloc_blks) {
/*
* Make sure the maximum inode count is a multiple
* of the units we allocate inodes in.
*/
icount = sbp->sb_dblocks * sbp->sb_imax_pct;
do_div(icount, 100);
do_div(icount, igeo->ialloc_blks);
igeo->maxicount = XFS_FSB_TO_INO(mp,
icount * igeo->ialloc_blks);
} else {
igeo->maxicount = 0;
}
/*
* Compute the desired size of an inode cluster buffer size, which
* starts at 8K and (on v5 filesystems) scales up with larger inode
* sizes.
*
* Preserve the desired inode cluster size because the sparse inodes
* feature uses that desired size (not the actual size) to compute the
* sparse inode alignment. The mount code validates this value, so we
* cannot change the behavior.
*/
igeo->inode_cluster_size_raw = XFS_INODE_BIG_CLUSTER_SIZE;
if (xfs_sb_version_hascrc(&mp->m_sb)) {
int new_size = igeo->inode_cluster_size_raw;
new_size *= mp->m_sb.sb_inodesize / XFS_DINODE_MIN_SIZE;
if (mp->m_sb.sb_inoalignmt >= XFS_B_TO_FSBT(mp, new_size))
igeo->inode_cluster_size_raw = new_size;
}
/* Calculate inode cluster ratios. */
if (igeo->inode_cluster_size_raw > mp->m_sb.sb_blocksize)
igeo->blocks_per_cluster = XFS_B_TO_FSBT(mp,
igeo->inode_cluster_size_raw);
else
igeo->blocks_per_cluster = 1;
igeo->inode_cluster_size = XFS_FSB_TO_B(mp, igeo->blocks_per_cluster);
igeo->inodes_per_cluster = XFS_FSB_TO_INO(mp, igeo->blocks_per_cluster);
/* Calculate inode cluster alignment. */
if (xfs_sb_version_hasalign(&mp->m_sb) &&
mp->m_sb.sb_inoalignmt >= igeo->blocks_per_cluster)
igeo->cluster_align = mp->m_sb.sb_inoalignmt;
else
igeo->cluster_align = 1;
igeo->inoalign_mask = igeo->cluster_align - 1;
igeo->cluster_align_inodes = XFS_FSB_TO_INO(mp, igeo->cluster_align);
/*
* If we are using stripe alignment, check whether
* the stripe unit is a multiple of the inode alignment
*/
if (mp->m_dalign && igeo->inoalign_mask &&
!(mp->m_dalign & igeo->inoalign_mask))
igeo->ialloc_align = mp->m_dalign;
else
igeo->ialloc_align = 0;
}
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