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3ccb8b5f65
linux/fs/xfs/xfs_ialloc.c
Glen Overby 3ccb8b5f65 [XFS] A change to inode chunk allocation to try allocating the new chunk 
contiguous with the most recently allocated chunk.  On a striped
filesystem, this will fill a stripe unit with inodes before allocating new
inodes in another stripe unit.

SGI-PV: 951416
SGI-Modid: xfs-linux-melb:xfs-kern:208488a

Signed-off-by: Glen Overby <overby@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>
2006-03-29 09:52:28 +10:00

1410 lines
41 KiB
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/*
* Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
* All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it would be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_types.h"
#include "xfs_bit.h"
#include "xfs_log.h"
#include "xfs_inum.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_dir.h"
#include "xfs_dir2.h"
#include "xfs_dmapi.h"
#include "xfs_mount.h"
#include "xfs_bmap_btree.h"
#include "xfs_alloc_btree.h"
#include "xfs_ialloc_btree.h"
#include "xfs_dir_sf.h"
#include "xfs_dir2_sf.h"
#include "xfs_attr_sf.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
#include "xfs_btree.h"
#include "xfs_ialloc.h"
#include "xfs_alloc.h"
#include "xfs_rtalloc.h"
#include "xfs_error.h"
#include "xfs_bmap.h"
/*
* Log specified fields for the inode given by bp and off.
*/
STATIC void
xfs_ialloc_log_di(
xfs_trans_t *tp, /* transaction pointer */
xfs_buf_t *bp, /* inode buffer */
int off, /* index of inode in buffer */
int fields) /* bitmask of fields to log */
{
int first; /* first byte number */
int ioffset; /* off in bytes */
int last; /* last byte number */
xfs_mount_t *mp; /* mount point structure */
static const short offsets[] = { /* field offsets */
/* keep in sync with bits */
offsetof(xfs_dinode_core_t, di_magic),
offsetof(xfs_dinode_core_t, di_mode),
offsetof(xfs_dinode_core_t, di_version),
offsetof(xfs_dinode_core_t, di_format),
offsetof(xfs_dinode_core_t, di_onlink),
offsetof(xfs_dinode_core_t, di_uid),
offsetof(xfs_dinode_core_t, di_gid),
offsetof(xfs_dinode_core_t, di_nlink),
offsetof(xfs_dinode_core_t, di_projid),
offsetof(xfs_dinode_core_t, di_pad),
offsetof(xfs_dinode_core_t, di_atime),
offsetof(xfs_dinode_core_t, di_mtime),
offsetof(xfs_dinode_core_t, di_ctime),
offsetof(xfs_dinode_core_t, di_size),
offsetof(xfs_dinode_core_t, di_nblocks),
offsetof(xfs_dinode_core_t, di_extsize),
offsetof(xfs_dinode_core_t, di_nextents),
offsetof(xfs_dinode_core_t, di_anextents),
offsetof(xfs_dinode_core_t, di_forkoff),
offsetof(xfs_dinode_core_t, di_aformat),
offsetof(xfs_dinode_core_t, di_dmevmask),
offsetof(xfs_dinode_core_t, di_dmstate),
offsetof(xfs_dinode_core_t, di_flags),
offsetof(xfs_dinode_core_t, di_gen),
offsetof(xfs_dinode_t, di_next_unlinked),
offsetof(xfs_dinode_t, di_u),
offsetof(xfs_dinode_t, di_a),
sizeof(xfs_dinode_t)
};
ASSERT(offsetof(xfs_dinode_t, di_core) == 0);
ASSERT((fields & (XFS_DI_U|XFS_DI_A)) == 0);
mp = tp->t_mountp;
/*
* Get the inode-relative first and last bytes for these fields
*/
xfs_btree_offsets(fields, offsets, XFS_DI_NUM_BITS, &first, &last);
/*
* Convert to buffer offsets and log it.
*/
ioffset = off << mp->m_sb.sb_inodelog;
first += ioffset;
last += ioffset;
xfs_trans_log_buf(tp, bp, first, last);
}
/*
* Allocation group level functions.
*/
/*
* Allocate new inodes in the allocation group specified by agbp.
* Return 0 for success, else error code.
*/
STATIC int /* error code or 0 */
xfs_ialloc_ag_alloc(
xfs_trans_t *tp, /* transaction pointer */
xfs_buf_t *agbp, /* alloc group buffer */
int *alloc)
{
xfs_agi_t *agi; /* allocation group header */
xfs_alloc_arg_t args; /* allocation argument structure */
int blks_per_cluster; /* fs blocks per inode cluster */
xfs_btree_cur_t *cur; /* inode btree cursor */
xfs_daddr_t d; /* disk addr of buffer */
int error;
xfs_buf_t *fbuf; /* new free inodes' buffer */
xfs_dinode_t *free; /* new free inode structure */
int i; /* inode counter */
int j; /* block counter */
int nbufs; /* num bufs of new inodes */
xfs_agino_t newino; /* new first inode's number */
xfs_agino_t newlen; /* new number of inodes */
int ninodes; /* num inodes per buf */
xfs_agino_t thisino; /* current inode number, for loop */
int version; /* inode version number to use */
int isaligned = 0; /* inode allocation at stripe unit */
/* boundary */
args.tp = tp;
args.mp = tp->t_mountp;
/*
* Locking will ensure that we don't have two callers in here
* at one time.
*/
newlen = XFS_IALLOC_INODES(args.mp);
if (args.mp->m_maxicount &&
args.mp->m_sb.sb_icount + newlen > args.mp->m_maxicount)
return XFS_ERROR(ENOSPC);
args.minlen = args.maxlen = XFS_IALLOC_BLOCKS(args.mp);
/*
* 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);
if(likely(newino != NULLAGINO)) {
args.agbno = XFS_AGINO_TO_AGBNO(args.mp, newino) +
XFS_IALLOC_BLOCKS(args.mp);
args.fsbno = XFS_AGB_TO_FSB(args.mp,
be32_to_cpu(agi->agi_seqno), args.agbno);
args.type = XFS_ALLOCTYPE_THIS_BNO;
args.mod = args.total = args.wasdel = args.isfl =
args.userdata = args.minalignslop = 0;
args.prod = 1;
args.alignment = 1;
/*
* Allow space for the inode btree to split.
*/
args.minleft = XFS_IN_MAXLEVELS(args.mp) - 1;
if ((error = xfs_alloc_vextent(&args)))
return error;
} else
args.fsbno = NULLFSBLOCK;
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 (args.mp->m_sinoalign) {
ASSERT(!(args.mp->m_flags & XFS_MOUNT_NOALIGN));
args.alignment = args.mp->m_dalign;
isaligned = 1;
} else if (XFS_SB_VERSION_HASALIGN(&args.mp->m_sb) &&
args.mp->m_sb.sb_inoalignmt >=
XFS_B_TO_FSBT(args.mp,
XFS_INODE_CLUSTER_SIZE(args.mp)))
args.alignment = args.mp->m_sb.sb_inoalignmt;
else
args.alignment = 1;
/*
* 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,
be32_to_cpu(agi->agi_seqno), args.agbno);
/*
* Allocate a fixed-size extent of inodes.
*/
args.type = XFS_ALLOCTYPE_NEAR_BNO;
args.mod = args.total = args.wasdel = args.isfl =
args.userdata = args.minalignslop = 0;
args.prod = 1;
/*
* Allow space for the inode btree to split.
*/
args.minleft = XFS_IN_MAXLEVELS(args.mp) - 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,
be32_to_cpu(agi->agi_seqno), args.agbno);
if (XFS_SB_VERSION_HASALIGN(&args.mp->m_sb) &&
args.mp->m_sb.sb_inoalignmt >=
XFS_B_TO_FSBT(args.mp, XFS_INODE_CLUSTER_SIZE(args.mp)))
args.alignment = args.mp->m_sb.sb_inoalignmt;
else
args.alignment = 1;
if ((error = xfs_alloc_vextent(&args)))
return error;
}
if (args.fsbno == NULLFSBLOCK) {
*alloc = 0;
return 0;
}
ASSERT(args.len == args.minlen);
/*
* Convert the results.
*/
newino = XFS_OFFBNO_TO_AGINO(args.mp, args.agbno, 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.
*/
if (args.mp->m_sb.sb_blocksize >= XFS_INODE_CLUSTER_SIZE(args.mp)) {
blks_per_cluster = 1;
nbufs = (int)args.len;
ninodes = args.mp->m_sb.sb_inopblock;
} else {
blks_per_cluster = XFS_INODE_CLUSTER_SIZE(args.mp) /
args.mp->m_sb.sb_blocksize;
nbufs = (int)args.len / blks_per_cluster;
ninodes = blks_per_cluster * args.mp->m_sb.sb_inopblock;
}
/*
* 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.
*/
if (XFS_SB_VERSION_HASNLINK(&args.mp->m_sb))
version = XFS_DINODE_VERSION_2;
else
version = XFS_DINODE_VERSION_1;
for (j = 0; j < nbufs; j++) {
/*
* Get the block.
*/
d = XFS_AGB_TO_DADDR(args.mp, be32_to_cpu(agi->agi_seqno),
args.agbno + (j * blks_per_cluster));
fbuf = xfs_trans_get_buf(tp, args.mp->m_ddev_targp, d,
args.mp->m_bsize * blks_per_cluster,
XFS_BUF_LOCK);
ASSERT(fbuf);
ASSERT(!XFS_BUF_GETERROR(fbuf));
/*
* Set initial values for the inodes in this buffer.
*/
xfs_biozero(fbuf, 0, ninodes << args.mp->m_sb.sb_inodelog);
for (i = 0; i < ninodes; i++) {
free = XFS_MAKE_IPTR(args.mp, fbuf, i);
INT_SET(free->di_core.di_magic, ARCH_CONVERT, XFS_DINODE_MAGIC);
INT_SET(free->di_core.di_version, ARCH_CONVERT, version);
INT_SET(free->di_next_unlinked, ARCH_CONVERT, NULLAGINO);
xfs_ialloc_log_di(tp, fbuf, i,
XFS_DI_CORE_BITS | XFS_DI_NEXT_UNLINKED);
}
xfs_trans_inode_alloc_buf(tp, fbuf);
}
be32_add(&agi->agi_count, newlen);
be32_add(&agi->agi_freecount, newlen);
down_read(&args.mp->m_peraglock);
args.mp->m_perag[be32_to_cpu(agi->agi_seqno)].pagi_freecount += newlen;
up_read(&args.mp->m_peraglock);
agi->agi_newino = cpu_to_be32(newino);
/*
* Insert records describing the new inode chunk into the btree.
*/
cur = xfs_btree_init_cursor(args.mp, tp, agbp,
be32_to_cpu(agi->agi_seqno),
XFS_BTNUM_INO, (xfs_inode_t *)0, 0);
for (thisino = newino;
thisino < newino + newlen;
thisino += XFS_INODES_PER_CHUNK) {
if ((error = xfs_inobt_lookup_eq(cur, thisino,
XFS_INODES_PER_CHUNK, XFS_INOBT_ALL_FREE, &i))) {
xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
return error;
}
ASSERT(i == 0);
if ((error = xfs_inobt_insert(cur, &i))) {
xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
return error;
}
ASSERT(i == 1);
}
xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
/*
* 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 __inline 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 then mode. Return the allocation group buffer.
*/
STATIC xfs_buf_t * /* allocation group buffer */
xfs_ialloc_ag_select(
xfs_trans_t *tp, /* transaction pointer */
xfs_ino_t parent, /* parent directory inode number */
mode_t mode, /* bits set to indicate file type */
int okalloc) /* ok to allocate more space */
{
xfs_buf_t *agbp; /* allocation group header buffer */
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 */
/*
* 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;
down_read(&mp->m_peraglock);
for (;;) {
pag = &mp->m_perag[agno];
if (!pag->pagi_init) {
if (xfs_ialloc_read_agi(mp, tp, agno, &agbp)) {
agbp = NULL;
goto nextag;
}
} else
agbp = NULL;
if (!pag->pagi_inodeok) {
xfs_ialloc_next_ag(mp);
goto unlock_nextag;
}
/*
* Is there enough free space for the file plus a block
* of inodes (if we need to allocate some)?
*/
ineed = pag->pagi_freecount ? 0 : XFS_IALLOC_BLOCKS(mp);
if (ineed && !pag->pagf_init) {
if (agbp == NULL &&
xfs_ialloc_read_agi(mp, tp, agno, &agbp)) {
agbp = NULL;
goto nextag;
}
(void)xfs_alloc_pagf_init(mp, tp, agno, flags);
}
if (!ineed || pag->pagf_init) {
if (ineed && !(longest = pag->pagf_longest))
longest = pag->pagf_flcount > 0;
if (!ineed ||
(pag->pagf_freeblks >= needspace + ineed &&
longest >= ineed &&
okalloc)) {
if (agbp == NULL &&
xfs_ialloc_read_agi(mp, tp, agno, &agbp)) {
agbp = NULL;
goto nextag;
}
up_read(&mp->m_peraglock);
return agbp;
}
}
unlock_nextag:
if (agbp)
xfs_trans_brelse(tp, agbp);
nextag:
/*
* No point in iterating over the rest, if we're shutting
* down.
*/
if (XFS_FORCED_SHUTDOWN(mp)) {
up_read(&mp->m_peraglock);
return (xfs_buf_t *)0;
}
agno++;
if (agno >= agcount)
agno = 0;
if (agno == pagno) {
if (flags == 0) {
up_read(&mp->m_peraglock);
return (xfs_buf_t *)0;
}
flags = 0;
}
}
}
/*
* Visible inode allocation functions.
*/
/*
* Allocate an inode on disk.
* Mode is used to tell whether the new inode will need space, and whether
* it is a directory.
*
* The arguments IO_agbp and alloc_done are defined to work within
* the constraint of one allocation per transaction.
* xfs_dialloc() 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,
* i.e., xfs_dialloc() did not need to do an allocation, an inode
* number is returned. In this case, IO_agbp would be set to the
* current ag_buf and alloc_done set to false.
* If an allocation needed to be done, xfs_dialloc would return
* the current ag_buf in IO_agbp and set alloc_done to true.
* 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 agbp 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(
xfs_trans_t *tp, /* transaction pointer */
xfs_ino_t parent, /* parent inode (directory) */
mode_t mode, /* mode bits for new inode */
int okalloc, /* ok to allocate more space */
xfs_buf_t **IO_agbp, /* in/out ag header's buffer */
boolean_t *alloc_done, /* true if we needed to replenish
inode freelist */
xfs_ino_t *inop) /* inode number allocated */
{
xfs_agnumber_t agcount; /* number of allocation groups */
xfs_buf_t *agbp; /* allocation group header's buffer */
xfs_agnumber_t agno; /* allocation group number */
xfs_agi_t *agi; /* allocation group header structure */
xfs_btree_cur_t *cur; /* inode allocation btree cursor */
int error; /* error return value */
int i; /* result code */
int ialloced; /* inode allocation status */
int noroom = 0; /* no space for inode blk allocation */
xfs_ino_t ino; /* fs-relative inode to be returned */
/* REFERENCED */
int j; /* result code */
xfs_mount_t *mp; /* file system mount structure */
int offset; /* index of inode in chunk */
xfs_agino_t pagino; /* parent's a.g. relative inode # */
xfs_agnumber_t pagno; /* parent's allocation group number */
xfs_inobt_rec_t rec; /* inode allocation record */
xfs_agnumber_t tagno; /* testing allocation group number */
xfs_btree_cur_t *tcur; /* temp cursor */
xfs_inobt_rec_t trec; /* temp inode allocation record */
if (*IO_agbp == NULL) {
/*
* We do not have an agbp, so select an initial allocation
* group for inode allocation.
*/
agbp = xfs_ialloc_ag_select(tp, parent, mode, okalloc);
/*
* Couldn't find an allocation group satisfying the
* criteria, give up.
*/
if (!agbp) {
*inop = NULLFSINO;
return 0;
}
agi = XFS_BUF_TO_AGI(agbp);
ASSERT(be32_to_cpu(agi->agi_magicnum) == XFS_AGI_MAGIC);
} else {
/*
* Continue where we left off before. In this case, we
* know that the allocation group has free inodes.
*/
agbp = *IO_agbp;
agi = XFS_BUF_TO_AGI(agbp);
ASSERT(be32_to_cpu(agi->agi_magicnum) == XFS_AGI_MAGIC);
ASSERT(be32_to_cpu(agi->agi_freecount) > 0);
}
mp = tp->t_mountp;
agcount = mp->m_sb.sb_agcount;
agno = be32_to_cpu(agi->agi_seqno);
tagno = agno;
pagno = XFS_INO_TO_AGNO(mp, parent);
pagino = XFS_INO_TO_AGINO(mp, parent);
/*
* If we have already hit the ceiling of inode blocks then clear
* okalloc so we scan all available agi structures for a free
* inode.
*/
if (mp->m_maxicount &&
mp->m_sb.sb_icount + XFS_IALLOC_INODES(mp) > mp->m_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.
*/
*alloc_done = B_FALSE;
while (!agi->agi_freecount) {
/*
* Don't do anything if we're not supposed to allocate
* any blocks, just go on to the next ag.
*/
if (okalloc) {
/*
* Try to allocate some new inodes in the allocation
* group.
*/
if ((error = xfs_ialloc_ag_alloc(tp, agbp, &ialloced))) {
xfs_trans_brelse(tp, agbp);
if (error == ENOSPC) {
*inop = NULLFSINO;
return 0;
} else
return error;
}
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(be32_to_cpu(agi->agi_freecount) > 0);
*alloc_done = B_TRUE;
*IO_agbp = agbp;
*inop = NULLFSINO;
return 0;
}
}
/*
* If it failed, give up on this ag.
*/
xfs_trans_brelse(tp, agbp);
/*
* Go on to the next ag: get its ag header.
*/
nextag:
if (++tagno == agcount)
tagno = 0;
if (tagno == agno) {
*inop = NULLFSINO;
return noroom ? ENOSPC : 0;
}
down_read(&mp->m_peraglock);
if (mp->m_perag[tagno].pagi_inodeok == 0) {
up_read(&mp->m_peraglock);
goto nextag;
}
error = xfs_ialloc_read_agi(mp, tp, tagno, &agbp);
up_read(&mp->m_peraglock);
if (error)
goto nextag;
agi = XFS_BUF_TO_AGI(agbp);
ASSERT(be32_to_cpu(agi->agi_magicnum) == XFS_AGI_MAGIC);
}
/*
* Here with an allocation group that has a free inode.
* Reset agno since we may have chosen a new ag in the
* loop above.
*/
agno = tagno;
*IO_agbp = NULL;
cur = xfs_btree_init_cursor(mp, tp, agbp, be32_to_cpu(agi->agi_seqno),
XFS_BTNUM_INO, (xfs_inode_t *)0, 0);
/*
* 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);
#ifdef DEBUG
if (cur->bc_nlevels == 1) {
int freecount = 0;
if ((error = xfs_inobt_lookup_ge(cur, 0, 0, 0, &i)))
goto error0;
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
do {
if ((error = xfs_inobt_get_rec(cur, &rec.ir_startino,
&rec.ir_freecount, &rec.ir_free, &i)))
goto error0;
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
freecount += rec.ir_freecount;
if ((error = xfs_inobt_increment(cur, 0, &i)))
goto error0;
} while (i == 1);
ASSERT(freecount == be32_to_cpu(agi->agi_freecount) ||
XFS_FORCED_SHUTDOWN(mp));
}
#endif
/*
* If in the same a.g. as the parent, try to get near the parent.
*/
if (pagno == agno) {
if ((error = xfs_inobt_lookup_le(cur, pagino, 0, 0, &i)))
goto error0;
if (i != 0 &&
(error = xfs_inobt_get_rec(cur, &rec.ir_startino,
&rec.ir_freecount, &rec.ir_free, &j)) == 0 &&
j == 1 &&
rec.ir_freecount > 0) {
/*
* Found a free inode in the same chunk
* as parent, done.
*/
}
/*
* In the same a.g. as parent, but parent's chunk is full.
*/
else {
int doneleft; /* done, to the left */
int doneright; /* done, to the right */
if (error)
goto error0;
ASSERT(i == 1);
ASSERT(j == 1);
/*
* Duplicate the cursor, search left & right
* simultaneously.
*/
if ((error = xfs_btree_dup_cursor(cur, &tcur)))
goto error0;
/*
* Search left with tcur, back up 1 record.
*/
if ((error = xfs_inobt_decrement(tcur, 0, &i)))
goto error1;
doneleft = !i;
if (!doneleft) {
if ((error = xfs_inobt_get_rec(tcur,
&trec.ir_startino,
&trec.ir_freecount,
&trec.ir_free, &i)))
goto error1;
XFS_WANT_CORRUPTED_GOTO(i == 1, error1);
}
/*
* Search right with cur, go forward 1 record.
*/
if ((error = xfs_inobt_increment(cur, 0, &i)))
goto error1;
doneright = !i;
if (!doneright) {
if ((error = xfs_inobt_get_rec(cur,
&rec.ir_startino,
&rec.ir_freecount,
&rec.ir_free, &i)))
goto error1;
XFS_WANT_CORRUPTED_GOTO(i == 1, error1);
}
/*
* Loop until we find the closest inode chunk
* with a free one.
*/
while (!doneleft || !doneright) {
int useleft; /* using left inode
chunk this time */
/*
* Figure out which block is closer,
* if both are valid.
*/
if (!doneleft && !doneright)
useleft =
pagino -
(trec.ir_startino +
XFS_INODES_PER_CHUNK - 1) <
rec.ir_startino - pagino;
else
useleft = !doneleft;
/*
* If checking the left, does it have
* free inodes?
*/
if (useleft && trec.ir_freecount) {
/*
* Yes, set it up as the chunk to use.
*/
rec = trec;
xfs_btree_del_cursor(cur,
XFS_BTREE_NOERROR);
cur = tcur;
break;
}
/*
* If checking the right, does it have
* free inodes?
*/
if (!useleft && rec.ir_freecount) {
/*
* Yes, it's already set up.
*/
xfs_btree_del_cursor(tcur,
XFS_BTREE_NOERROR);
break;
}
/*
* If used the left, get another one
* further left.
*/
if (useleft) {
if ((error = xfs_inobt_decrement(tcur, 0,
&i)))
goto error1;
doneleft = !i;
if (!doneleft) {
if ((error = xfs_inobt_get_rec(
tcur,
&trec.ir_startino,
&trec.ir_freecount,
&trec.ir_free, &i)))
goto error1;
XFS_WANT_CORRUPTED_GOTO(i == 1,
error1);
}
}
/*
* If used the right, get another one
* further right.
*/
else {
if ((error = xfs_inobt_increment(cur, 0,
&i)))
goto error1;
doneright = !i;
if (!doneright) {
if ((error = xfs_inobt_get_rec(
cur,
&rec.ir_startino,
&rec.ir_freecount,
&rec.ir_free, &i)))
goto error1;
XFS_WANT_CORRUPTED_GOTO(i == 1,
error1);
}
}
}
ASSERT(!doneleft || !doneright);
}
}
/*
* In a different a.g. from the parent.
* See if the most recently allocated block has any free.
*/
else if (be32_to_cpu(agi->agi_newino) != NULLAGINO) {
if ((error = xfs_inobt_lookup_eq(cur,
be32_to_cpu(agi->agi_newino), 0, 0, &i)))
goto error0;
if (i == 1 &&
(error = xfs_inobt_get_rec(cur, &rec.ir_startino,
&rec.ir_freecount, &rec.ir_free, &j)) == 0 &&
j == 1 &&
rec.ir_freecount > 0) {
/*
* The last chunk allocated in the group still has
* a free inode.
*/
}
/*
* None left in the last group, search the whole a.g.
*/
else {
if (error)
goto error0;
if ((error = xfs_inobt_lookup_ge(cur, 0, 0, 0, &i)))
goto error0;
ASSERT(i == 1);
for (;;) {
if ((error = xfs_inobt_get_rec(cur,
&rec.ir_startino,
&rec.ir_freecount, &rec.ir_free,
&i)))
goto error0;
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
if (rec.ir_freecount > 0)
break;
if ((error = xfs_inobt_increment(cur, 0, &i)))
goto error0;
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
}
}
}
offset = XFS_IALLOC_FIND_FREE(&rec.ir_free);
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);
XFS_INOBT_CLR_FREE(&rec, offset);
rec.ir_freecount--;
if ((error = xfs_inobt_update(cur, rec.ir_startino, rec.ir_freecount,
rec.ir_free)))
goto error0;
be32_add(&agi->agi_freecount, -1);
xfs_ialloc_log_agi(tp, agbp, XFS_AGI_FREECOUNT);
down_read(&mp->m_peraglock);
mp->m_perag[tagno].pagi_freecount--;
up_read(&mp->m_peraglock);
#ifdef DEBUG
if (cur->bc_nlevels == 1) {
int freecount = 0;
if ((error = xfs_inobt_lookup_ge(cur, 0, 0, 0, &i)))
goto error0;
do {
if ((error = xfs_inobt_get_rec(cur, &rec.ir_startino,
&rec.ir_freecount, &rec.ir_free, &i)))
goto error0;
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
freecount += rec.ir_freecount;
if ((error = xfs_inobt_increment(cur, 0, &i)))
goto error0;
} while (i == 1);
ASSERT(freecount == be32_to_cpu(agi->agi_freecount) ||
XFS_FORCED_SHUTDOWN(mp));
}
#endif
xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
xfs_trans_mod_sb(tp, XFS_TRANS_SB_IFREE, -1);
*inop = ino;
return 0;
error1:
xfs_btree_del_cursor(tcur, XFS_BTREE_ERROR);
error0:
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(
xfs_trans_t *tp, /* transaction pointer */
xfs_ino_t inode, /* inode to be freed */
xfs_bmap_free_t *flist, /* extents to free */
int *delete, /* set if inode cluster was deleted */
xfs_ino_t *first_ino) /* first inode in deleted cluster */
{
/* REFERENCED */
xfs_agblock_t agbno; /* block number containing inode */
xfs_buf_t *agbp; /* buffer containing allocation group header */
xfs_agino_t agino; /* inode number relative to allocation group */
xfs_agnumber_t agno; /* allocation group number */
xfs_agi_t *agi; /* allocation group header */
xfs_btree_cur_t *cur; /* inode btree cursor */
int error; /* error return value */
int i; /* result code */
int ilen; /* inodes in an inode cluster */
xfs_mount_t *mp; /* mount structure for filesystem */
int off; /* offset of inode in inode chunk */
xfs_inobt_rec_t 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) {
cmn_err(CE_WARN,
"xfs_difree: agno >= mp->m_sb.sb_agcount (%d >= %d) on %s. Returning EINVAL.",
agno, mp->m_sb.sb_agcount, mp->m_fsname);
ASSERT(0);
return XFS_ERROR(EINVAL);
}
agino = XFS_INO_TO_AGINO(mp, inode);
if (inode != XFS_AGINO_TO_INO(mp, agno, agino)) {
cmn_err(CE_WARN,
"xfs_difree: inode != XFS_AGINO_TO_INO() "
"(%llu != %llu) on %s. Returning EINVAL.",
(unsigned long long)inode,
(unsigned long long)XFS_AGINO_TO_INO(mp, agno, agino),
mp->m_fsname);
ASSERT(0);
return XFS_ERROR(EINVAL);
}
agbno = XFS_AGINO_TO_AGBNO(mp, agino);
if (agbno >= mp->m_sb.sb_agblocks) {
cmn_err(CE_WARN,
"xfs_difree: agbno >= mp->m_sb.sb_agblocks (%d >= %d) on %s. Returning EINVAL.",
agbno, mp->m_sb.sb_agblocks, mp->m_fsname);
ASSERT(0);
return XFS_ERROR(EINVAL);
}
/*
* Get the allocation group header.
*/
down_read(&mp->m_peraglock);
error = xfs_ialloc_read_agi(mp, tp, agno, &agbp);
up_read(&mp->m_peraglock);
if (error) {
cmn_err(CE_WARN,
"xfs_difree: xfs_ialloc_read_agi() returned an error %d on %s. Returning error.",
error, mp->m_fsname);
return error;
}
agi = XFS_BUF_TO_AGI(agbp);
ASSERT(be32_to_cpu(agi->agi_magicnum) == XFS_AGI_MAGIC);
ASSERT(agbno < be32_to_cpu(agi->agi_length));
/*
* Initialize the cursor.
*/
cur = xfs_btree_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_INO,
(xfs_inode_t *)0, 0);
#ifdef DEBUG
if (cur->bc_nlevels == 1) {
int freecount = 0;
if ((error = xfs_inobt_lookup_ge(cur, 0, 0, 0, &i)))
goto error0;
do {
if ((error = xfs_inobt_get_rec(cur, &rec.ir_startino,
&rec.ir_freecount, &rec.ir_free, &i)))
goto error0;
if (i) {
freecount += rec.ir_freecount;
if ((error = xfs_inobt_increment(cur, 0, &i)))
goto error0;
}
} while (i == 1);
ASSERT(freecount == be32_to_cpu(agi->agi_freecount) ||
XFS_FORCED_SHUTDOWN(mp));
}
#endif
/*
* Look for the entry describing this inode.
*/
if ((error = xfs_inobt_lookup_le(cur, agino, 0, 0, &i))) {
cmn_err(CE_WARN,
"xfs_difree: xfs_inobt_lookup_le returned() an error %d on %s. Returning error.",
error, mp->m_fsname);
goto error0;
}
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
if ((error = xfs_inobt_get_rec(cur, &rec.ir_startino, &rec.ir_freecount,
&rec.ir_free, &i))) {
cmn_err(CE_WARN,
"xfs_difree: xfs_inobt_get_rec() returned an error %d on %s. Returning error.",
error, mp->m_fsname);
goto error0;
}
XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
/*
* Get the offset in the inode chunk.
*/
off = agino - rec.ir_startino;
ASSERT(off >= 0 && off < XFS_INODES_PER_CHUNK);
ASSERT(!XFS_INOBT_IS_FREE(&rec, off));
/*
* Mark the inode free & increment the count.
*/
XFS_INOBT_SET_FREE(&rec, off);
rec.ir_freecount++;
/*
* When an inode cluster is free, it becomes eligible for removal
*/
if ((mp->m_flags & XFS_MOUNT_IDELETE) &&
(rec.ir_freecount == XFS_IALLOC_INODES(mp))) {
*delete = 1;
*first_ino = XFS_AGINO_TO_INO(mp, agno, rec.ir_startino);
/*
* 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 = XFS_IALLOC_INODES(mp);
be32_add(&agi->agi_count, -ilen);
be32_add(&agi->agi_freecount, -(ilen - 1));
xfs_ialloc_log_agi(tp, agbp, XFS_AGI_COUNT | XFS_AGI_FREECOUNT);
down_read(&mp->m_peraglock);
mp->m_perag[agno].pagi_freecount -= ilen - 1;
up_read(&mp->m_peraglock);
xfs_trans_mod_sb(tp, XFS_TRANS_SB_ICOUNT, -ilen);
xfs_trans_mod_sb(tp, XFS_TRANS_SB_IFREE, -(ilen - 1));
if ((error = xfs_inobt_delete(cur, &i))) {
cmn_err(CE_WARN, "xfs_difree: xfs_inobt_delete returned an error %d on %s.\n",
error, mp->m_fsname);
goto error0;
}
xfs_bmap_add_free(XFS_AGB_TO_FSB(mp,
agno, XFS_INO_TO_AGBNO(mp,rec.ir_startino)),
XFS_IALLOC_BLOCKS(mp), flist, mp);
} else {
*delete = 0;
if ((error = xfs_inobt_update(cur, rec.ir_startino, rec.ir_freecount, rec.ir_free))) {
cmn_err(CE_WARN,
"xfs_difree: xfs_inobt_update() returned an error %d on %s. Returning error.",
error, mp->m_fsname);
goto error0;
}
/*
* Change the inode free counts and log the ag/sb changes.
*/
be32_add(&agi->agi_freecount, 1);
xfs_ialloc_log_agi(tp, agbp, XFS_AGI_FREECOUNT);
down_read(&mp->m_peraglock);
mp->m_perag[agno].pagi_freecount++;
up_read(&mp->m_peraglock);
xfs_trans_mod_sb(tp, XFS_TRANS_SB_IFREE, 1);
}
#ifdef DEBUG
if (cur->bc_nlevels == 1) {
int freecount = 0;
if ((error = xfs_inobt_lookup_ge(cur, 0, 0, 0, &i)))
goto error0;
do {
if ((error = xfs_inobt_get_rec(cur,
&rec.ir_startino,
&rec.ir_freecount,
&rec.ir_free, &i)))
goto error0;
if (i) {
freecount += rec.ir_freecount;
if ((error = xfs_inobt_increment(cur, 0, &i)))
goto error0;
}
} while (i == 1);
ASSERT(freecount == be32_to_cpu(agi->agi_freecount) ||
XFS_FORCED_SHUTDOWN(mp));
}
#endif
xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
return 0;
error0:
xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
return error;
}
/*
* Return the location of the inode in bno/off, for mapping it into a buffer.
*/
/*ARGSUSED*/
int
xfs_dilocate(
xfs_mount_t *mp, /* file system mount structure */
xfs_trans_t *tp, /* transaction pointer */
xfs_ino_t ino, /* inode to locate */
xfs_fsblock_t *bno, /* output: block containing inode */
int *len, /* output: num blocks in inode cluster */
int *off, /* output: index in block of inode */
uint flags) /* flags concerning inode lookup */
{
xfs_agblock_t agbno; /* block number of inode in the alloc group */
xfs_buf_t *agbp; /* agi buffer */
xfs_agino_t agino; /* inode number within alloc group */
xfs_agnumber_t agno; /* allocation group number */
int blks_per_cluster; /* num blocks per inode cluster */
xfs_agblock_t chunk_agbno; /* first block in inode chunk */
xfs_agino_t chunk_agino; /* first agino in inode chunk */
__int32_t chunk_cnt; /* count of free inodes in chunk */
xfs_inofree_t chunk_free; /* mask of free inodes in chunk */
xfs_agblock_t cluster_agbno; /* first block in inode cluster */
xfs_btree_cur_t *cur; /* inode btree cursor */
int error; /* error code */
int i; /* temp state */
int offset; /* index of inode in its buffer */
int 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
if (agno >= mp->m_sb.sb_agcount) {
xfs_fs_cmn_err(CE_ALERT, mp,
"xfs_dilocate: agno (%d) >= "
"mp->m_sb.sb_agcount (%d)",
agno, mp->m_sb.sb_agcount);
}
if (agbno >= mp->m_sb.sb_agblocks) {
xfs_fs_cmn_err(CE_ALERT, mp,
"xfs_dilocate: agbno (0x%llx) >= "
"mp->m_sb.sb_agblocks (0x%lx)",
(unsigned long long) agbno,
(unsigned long) mp->m_sb.sb_agblocks);
}
if (ino != XFS_AGINO_TO_INO(mp, agno, agino)) {
xfs_fs_cmn_err(CE_ALERT, mp,
"xfs_dilocate: ino (0x%llx) != "
"XFS_AGINO_TO_INO(mp, agno, agino) "
"(0x%llx)",
ino, XFS_AGINO_TO_INO(mp, agno, agino));
}
#endif /* DEBUG */
return XFS_ERROR(EINVAL);
}
if ((mp->m_sb.sb_blocksize >= XFS_INODE_CLUSTER_SIZE(mp)) ||
!(flags & XFS_IMAP_LOOKUP)) {
offset = XFS_INO_TO_OFFSET(mp, ino);
ASSERT(offset < mp->m_sb.sb_inopblock);
*bno = XFS_AGB_TO_FSB(mp, agno, agbno);
*off = offset;
*len = 1;
return 0;
}
blks_per_cluster = XFS_INODE_CLUSTER_SIZE(mp) >> mp->m_sb.sb_blocklog;
if (*bno != NULLFSBLOCK) {
offset = XFS_INO_TO_OFFSET(mp, ino);
ASSERT(offset < mp->m_sb.sb_inopblock);
cluster_agbno = XFS_FSB_TO_AGBNO(mp, *bno);
*off = ((agbno - cluster_agbno) * mp->m_sb.sb_inopblock) +
offset;
*len = blks_per_cluster;
return 0;
}
if (mp->m_inoalign_mask) {
offset_agbno = agbno & mp->m_inoalign_mask;
chunk_agbno = agbno - offset_agbno;
} else {
down_read(&mp->m_peraglock);
error = xfs_ialloc_read_agi(mp, tp, agno, &agbp);
up_read(&mp->m_peraglock);
if (error) {
#ifdef DEBUG
xfs_fs_cmn_err(CE_ALERT, mp, "xfs_dilocate: "
"xfs_ialloc_read_agi() returned "
"error %d, agno %d",
error, agno);
#endif /* DEBUG */
return error;
}
cur = xfs_btree_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_INO,
(xfs_inode_t *)0, 0);
if ((error = xfs_inobt_lookup_le(cur, agino, 0, 0, &i))) {
#ifdef DEBUG
xfs_fs_cmn_err(CE_ALERT, mp, "xfs_dilocate: "
"xfs_inobt_lookup_le() failed");
#endif /* DEBUG */
goto error0;
}
if ((error = xfs_inobt_get_rec(cur, &chunk_agino, &chunk_cnt,
&chunk_free, &i))) {
#ifdef DEBUG
xfs_fs_cmn_err(CE_ALERT, mp, "xfs_dilocate: "
"xfs_inobt_get_rec() failed");
#endif /* DEBUG */
goto error0;
}
if (i == 0) {
#ifdef DEBUG
xfs_fs_cmn_err(CE_ALERT, mp, "xfs_dilocate: "
"xfs_inobt_get_rec() failed");
#endif /* DEBUG */
error = XFS_ERROR(EINVAL);
}
xfs_trans_brelse(tp, agbp);
xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
if (error)
return error;
chunk_agbno = XFS_AGINO_TO_AGBNO(mp, chunk_agino);
offset_agbno = agbno - chunk_agbno;
}
ASSERT(agbno >= chunk_agbno);
cluster_agbno = chunk_agbno +
((offset_agbno / blks_per_cluster) * blks_per_cluster);
offset = ((agbno - cluster_agbno) * mp->m_sb.sb_inopblock) +
XFS_INO_TO_OFFSET(mp, ino);
*bno = XFS_AGB_TO_FSB(mp, agno, cluster_agbno);
*off = offset;
*len = blks_per_cluster;
return 0;
error0:
xfs_trans_brelse(tp, agbp);
xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
return error;
}
/*
* Compute and fill in value of m_in_maxlevels.
*/
void
xfs_ialloc_compute_maxlevels(
xfs_mount_t *mp) /* file system mount structure */
{
int level;
uint maxblocks;
uint maxleafents;
int minleafrecs;
int minnoderecs;
maxleafents = (1LL << XFS_INO_AGINO_BITS(mp)) >>
XFS_INODES_PER_CHUNK_LOG;
minleafrecs = mp->m_alloc_mnr[0];
minnoderecs = mp->m_alloc_mnr[1];
maxblocks = (maxleafents + minleafrecs - 1) / minleafrecs;
for (level = 1; maxblocks > 1; level++)
maxblocks = (maxblocks + minnoderecs - 1) / minnoderecs;
mp->m_in_maxlevels = level;
}
/*
* Log specified fields for the ag hdr (inode section)
*/
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),
sizeof(xfs_agi_t)
};
#ifdef DEBUG
xfs_agi_t *agi; /* allocation group header */
agi = XFS_BUF_TO_AGI(bp);
ASSERT(be32_to_cpu(agi->agi_magicnum) == XFS_AGI_MAGIC);
#endif
/*
* Compute byte offsets for the first and last fields.
*/
xfs_btree_offsets(fields, offsets, XFS_AGI_NUM_BITS, &first, &last);
/*
* Log the allocation group inode header buffer.
*/
xfs_trans_log_buf(tp, bp, first, last);
}
/*
* Read in the allocation group header (inode allocation section)
*/
int
xfs_ialloc_read_agi(
xfs_mount_t *mp, /* file system mount structure */
xfs_trans_t *tp, /* transaction pointer */
xfs_agnumber_t agno, /* allocation group number */
xfs_buf_t **bpp) /* allocation group hdr buf */
{
xfs_agi_t *agi; /* allocation group header */
int agi_ok; /* agi is consistent */
xfs_buf_t *bp; /* allocation group hdr buf */
xfs_perag_t *pag; /* per allocation group data */
int error;
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, &bp);
if (error)
return error;
ASSERT(bp && !XFS_BUF_GETERROR(bp));
/*
* Validate the magic number of the agi block.
*/
agi = XFS_BUF_TO_AGI(bp);
agi_ok =
be32_to_cpu(agi->agi_magicnum) == XFS_AGI_MAGIC &&
XFS_AGI_GOOD_VERSION(be32_to_cpu(agi->agi_versionnum));
if (unlikely(XFS_TEST_ERROR(!agi_ok, mp, XFS_ERRTAG_IALLOC_READ_AGI,
XFS_RANDOM_IALLOC_READ_AGI))) {
XFS_CORRUPTION_ERROR("xfs_ialloc_read_agi", XFS_ERRLEVEL_LOW,
mp, agi);
xfs_trans_brelse(tp, bp);
return XFS_ERROR(EFSCORRUPTED);
}
pag = &mp->m_perag[agno];
if (!pag->pagi_init) {
pag->pagi_freecount = be32_to_cpu(agi->agi_freecount);
pag->pagi_init = 1;
} else {
/*
* 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));
}
#ifdef DEBUG
{
int i;
for (i = 0; i < XFS_AGI_UNLINKED_BUCKETS; i++)
ASSERT(agi->agi_unlinked[i]);
}
#endif
XFS_BUF_SET_VTYPE_REF(bp, B_FS_AGI, XFS_AGI_REF);
*bpp = bp;
return 0;
}
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