- 根目录:
- fs
- xfs
- xfs_dir2_data.c
/*
* 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_log.h"
#include "xfs_inum.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_dir2.h"
#include "xfs_mount.h"
#include "xfs_da_btree.h"
#include "xfs_bmap_btree.h"
#include "xfs_dir2_sf.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
#include "xfs_dir2_data.h"
#include "xfs_dir2_leaf.h"
#include "xfs_dir2_block.h"
#include "xfs_error.h"
#ifdef DEBUG
/*
* Check the consistency of the data block.
* The input can also be a block-format directory.
* Pop an assert if we find anything bad.
*/
void
xfs_dir2_data_check(
xfs_inode_t *dp, /* incore inode pointer */
xfs_dabuf_t *bp) /* data block's buffer */
{
xfs_dir2_dataptr_t addr; /* addr for leaf lookup */
xfs_dir2_data_free_t *bf; /* bestfree table */
xfs_dir2_block_tail_t *btp=NULL; /* block tail */
int count; /* count of entries found */
xfs_dir2_data_t *d; /* data block pointer */
xfs_dir2_data_entry_t *dep; /* data entry */
xfs_dir2_data_free_t *dfp; /* bestfree entry */
xfs_dir2_data_unused_t *dup; /* unused entry */
char *endp; /* end of useful data */
int freeseen; /* mask of bestfrees seen */
xfs_dahash_t hash; /* hash of current name */
int i; /* leaf index */
int lastfree; /* last entry was unused */
xfs_dir2_leaf_entry_t *lep=NULL; /* block leaf entries */
xfs_mount_t *mp; /* filesystem mount point */
char *p; /* current data position */
int stale; /* count of stale leaves */
struct xfs_name name;
mp = dp->i_mount;
d = bp->data;
ASSERT(be32_to_cpu(d->hdr.magic) == XFS_DIR2_DATA_MAGIC ||
be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC);
bf = d->hdr.bestfree;
p = (char *)d->u;
if (be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC) {
btp = xfs_dir2_block_tail_p(mp, (xfs_dir2_block_t *)d);
lep = xfs_dir2_block_leaf_p(btp);
endp = (char *)lep;
} else
endp = (char *)d + mp->m_dirblksize;
count = lastfree = freeseen = 0;
/*
* Account for zero bestfree entries.
*/
if (!bf[0].length) {
ASSERT(!bf[0].offset);
freeseen |= 1 << 0;
}
if (!bf[1].length) {
ASSERT(!bf[1].offset);
freeseen |= 1 << 1;
}
if (!bf[2].length) {
ASSERT(!bf[2].offset);
freeseen |= 1 << 2;
}
ASSERT(be16_to_cpu(bf[0].length) >= be16_to_cpu(bf[1].length));
ASSERT(be16_to_cpu(bf[1].length) >= be16_to_cpu(bf[2].length));
/*
* Loop over the data/unused entries.
*/
while (p < endp) {
dup = (xfs_dir2_data_unused_t *)p;
/*
* If it's unused, look for the space in the bestfree table.
* If we find it, account for that, else make sure it
* doesn't need to be there.
*/
if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
ASSERT(lastfree == 0);
ASSERT(be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup)) ==
(char *)dup - (char *)d);
dfp = xfs_dir2_data_freefind(d, dup);
if (dfp) {
i = (int)(dfp - bf);
ASSERT((freeseen & (1 << i)) == 0);
freeseen |= 1 << i;
} else {
ASSERT(be16_to_cpu(dup->length) <=
be16_to_cpu(bf[2].length));
}
p += be16_to_cpu(dup->length);
lastfree = 1;
continue;
}
/*
* It's a real entry. Validate the fields.
* If this is a block directory then make sure it's
* in the leaf section of the block.
* The linear search is crude but this is DEBUG code.
*/
dep = (xfs_dir2_data_entry_t *)p;
ASSERT(dep->namelen != 0);
ASSERT(xfs_dir_ino_validate(mp, be64_to_cpu(dep->inumber)) == 0);
ASSERT(be16_to_cpu(*xfs_dir2_data_entry_tag_p(dep)) ==
(char *)dep - (char *)d);
count++;
lastfree = 0;
if (be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC) {
addr = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk,
(xfs_dir2_data_aoff_t)
((char *)dep - (char *)d));
name.name = dep->name;
name.len = dep->namelen;
hash = mp->m_dirnameops->hashname(&name);
for (i = 0; i < be32_to_cpu(btp->count); i++) {
if (be32_to_cpu(lep[i].address) == addr &&
be32_to_cpu(lep[i].hashval) == hash)
break;
}
ASSERT(i < be32_to_cpu(btp->count));
}
p += xfs_dir2_data_entsize(dep->namelen);
}
/*
* Need to have seen all the entries and all the bestfree slots.
*/
ASSERT(freeseen == 7);
if (be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC) {
for (i = stale = 0; i < be32_to_cpu(btp->count); i++) {
if (be32_to_cpu(lep[i].address) == XFS_DIR2_NULL_DATAPTR)
stale++;
if (i > 0)
ASSERT(be32_to_cpu(lep[i].hashval) >= be32_to_cpu(lep[i - 1].hashval));
}
ASSERT(count == be32_to_cpu(btp->count) - be32_to_cpu(btp->stale));
ASSERT(stale == be32_to_cpu(btp->stale));
}
}
#endif
/*
* Given a data block and an unused entry from that block,
* return the bestfree entry if any that corresponds to it.
*/
xfs_dir2_data_free_t *
xfs_dir2_data_freefind(
xfs_dir2_data_t *d, /* data block */
xfs_dir2_data_unused_t *dup) /* data unused entry */
{
xfs_dir2_data_free_t *dfp; /* bestfree entry */
xfs_dir2_data_aoff_t off; /* offset value needed */
#if defined(DEBUG) && defined(__KERNEL__)
int matched; /* matched the value */
int seenzero; /* saw a 0 bestfree entry */
#endif
off = (xfs_dir2_data_aoff_t)((char *)dup - (char *)d);
#if defined(DEBUG) && defined(__KERNEL__)
/*
* Validate some consistency in the bestfree table.
* Check order, non-overlapping entries, and if we find the
* one we're looking for it has to be exact.
*/
ASSERT(be32_to_cpu(d->hdr.magic) == XFS_DIR2_DATA_MAGIC ||
be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC);
for (dfp = &d->hdr.bestfree[0], seenzero = matched = 0;
dfp < &d->hdr.bestfree[XFS_DIR2_DATA_FD_COUNT];
dfp++) {
if (!dfp->offset) {
ASSERT(!dfp->length);
seenzero = 1;
continue;
}
ASSERT(seenzero == 0);
if (be16_to_cpu(dfp->offset) == off) {
matched = 1;
ASSERT(dfp->length == dup->length);
} else if (off < be16_to_cpu(dfp->offset))
ASSERT(off + be16_to_cpu(dup->length) <= be16_to_cpu(dfp->offset));
else
ASSERT(be16_to_cpu(dfp->offset) + be16_to_cpu(dfp->length) <= off);
ASSERT(matched || be16_to_cpu(dfp->length) >= be16_to_cpu(dup->length));
if (dfp > &d->hdr.bestfree[0])
ASSERT(be16_to_cpu(dfp[-1].length) >= be16_to_cpu(dfp[0].length));
}
#endif
/*
* If this is smaller than the smallest bestfree entry,
* it can't be there since they're sorted.
*/
if (be16_to_cpu(dup->length) <
be16_to_cpu(d->hdr.bestfree[XFS_DIR2_DATA_FD_COUNT - 1].length))
return NULL;
/*
* Look at the three bestfree entries for our guy.
*/
for (dfp = &d->hdr.bestfree[0];
dfp < &d->hdr.bestfree[XFS_DIR2_DATA_FD_COUNT];
dfp++) {
if (!dfp->offset)
return NULL;
if (be16_to_cpu(dfp->offset) == off)
return dfp;
}
/*
* Didn't find it. This only happens if there are duplicate lengths.
*/
return NULL;
}
/*
* Insert an unused-space entry into the bestfree table.
*/
xfs_dir2_data_free_t * /* entry inserted */
xfs_dir2_data_freeinsert(
xfs_dir2_data_t *d, /* data block pointer */
xfs_dir2_data_unused_t *dup, /* unused space */
int *loghead) /* log the data header (out) */
{
xfs_dir2_data_free_t *dfp; /* bestfree table pointer */
xfs_dir2_data_free_t new; /* new bestfree entry */
#ifdef __KERNEL__
ASSERT(be32_to_cpu(d->hdr.magic) == XFS_DIR2_DATA_MAGIC ||
be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC);
#endif
dfp = d->hdr.bestfree;
new.length = dup->length;
new.offset = cpu_to_be16((char *)dup - (char *)d);
/*
* Insert at position 0, 1, or 2; or not at all.
*/
if (be16_to_cpu(new.length) > be16_to_cpu(dfp[0].length)) {
dfp[2] = dfp[1];
dfp[1] = dfp[0];
dfp[0] = new;
*loghead = 1;
return &dfp[0];
}
if (be16_to_cpu(new.length) > be16_to_cpu(dfp[1].length)) {
dfp[2] = dfp[1];
dfp[1] = new;
*loghead = 1;
return &dfp[1];
}
if (be16_to_cpu(new.length) > be16_to_cpu(dfp[2].length)) {
dfp[2] = new;
*loghead = 1;
return &dfp[2];
}
return NULL;
}
/*
* Remove a bestfree entry from the table.
*/
STATIC void
xfs_dir2_data_freeremove(
xfs_dir2_data_t *d, /* data block pointer */
xfs_dir2_data_free_t *dfp, /* bestfree entry pointer */
int *loghead) /* out: log data header */
{
#ifdef __KERNEL__
ASSERT(be32_to_cpu(d->hdr.magic) == XFS_DIR2_DATA_MAGIC ||
be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC);
#endif
/*
* It's the first entry, slide the next 2 up.
*/
if (dfp == &d->hdr.bestfree[0]) {
d->hdr.bestfree[0] = d->hdr.bestfree[1];
d->hdr.bestfree[1] = d->hdr.bestfree[2];
}
/*
* It's the second entry, slide the 3rd entry up.
*/
else if (dfp == &d->hdr.bestfree[1])
d->hdr.bestfree[1] = d->hdr.bestfree[2];
/*
* Must be the last entry.
*/
else
ASSERT(dfp == &d->hdr.bestfree[2]);
/*
* Clear the 3rd entry, must be zero now.
*/
d->hdr.bestfree[2].length = 0;
d->hdr.bestfree[2].offset = 0;
*loghead = 1;
}
/*
* Given a data block, reconstruct its bestfree map.
*/
void
xfs_dir2_data_freescan(
xfs_mount_t *mp, /* filesystem mount point */
xfs_dir2_data_t *d, /* data block pointer */
int *loghead) /* out: log data header */
{
xfs_dir2_block_tail_t *btp; /* block tail */
xfs_dir2_data_entry_t *dep; /* active data entry */
xfs_dir2_data_unused_t *dup; /* unused data entry */
char *endp; /* end of block's data */
char *p; /* current entry pointer */
#ifdef __KERNEL__
ASSERT(be32_to_cpu(d->hdr.magic) == XFS_DIR2_DATA_MAGIC ||
be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC);
#endif
/*
* Start by clearing the table.
*/
memset(d->hdr.bestfree, 0, sizeof(d->hdr.bestfree));
*loghead = 1;
/*
* Set up pointers.
*/
p = (char *)d->u;
if (be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC) {
btp = xfs_dir2_block_tail_p(mp, (xfs_dir2_block_t *)d);
endp = (char *)xfs_dir2_block_leaf_p(btp);
} else
endp = (char *)d + mp->m_dirblksize;
/*
* Loop over the block's entries.
*/
while (p < endp) {
dup = (xfs_dir2_data_unused_t *)p;
/*
* If it's a free entry, insert it.
*/
if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
ASSERT((char *)dup - (char *)d ==
be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup)));
xfs_dir2_data_freeinsert(d, dup, loghead);
p += be16_to_cpu(dup->length);
}
/*
* For active entries, check their tags and skip them.
*/
else {
dep = (xfs_dir2_data_entry_t *)p;
ASSERT((char *)dep - (char *)d ==
be16_to_cpu(*xfs_dir2_data_entry_tag_p(dep)));
p += xfs_dir2_data_entsize(dep->namelen);
}
}
}
/*
* Initialize a data block at the given block number in the directory.
* Give back the buffer for the created block.
*/
int /* error */
xfs_dir2_data_init(
xfs_da_args_t *args, /* directory operation args */
xfs_dir2_db_t blkno, /* logical dir block number */
xfs_dabuf_t **bpp) /* output block buffer */
{
xfs_dabuf_t *bp; /* block buffer */
xfs_dir2_data_t *d; /* pointer to block */
xfs_inode_t *dp; /* incore directory inode */
xfs_dir2_data_unused_t *dup; /* unused entry pointer */
int error; /* error return value */
int i; /* bestfree index */
xfs_mount_t *mp; /* filesystem mount point */
xfs_trans_t *tp; /* transaction pointer */
int t; /* temp */
dp = args->dp;
mp = dp->i_mount;
tp = args->trans;
/*
* Get the buffer set up for the block.
*/
error = xfs_da_get_buf(tp, dp, xfs_dir2_db_to_da(mp, blkno), -1, &bp,
XFS_DATA_FORK);
if (error) {
return error;
}
ASSERT(bp != NULL);
/*
* Initialize the header.
*/
d = bp->data;
d->hdr.magic = cpu_to_be32(XFS_DIR2_DATA_MAGIC);
d->hdr.bestfree[0].offset = cpu_to_be16(sizeof(d->hdr));
for (i = 1; i < XFS_DIR2_DATA_FD_COUNT; i++) {
d->hdr.bestfree[i].length = 0;
d->hdr.bestfree[i].offset = 0;
}
/*
* Set up an unused entry for the block's body.
*/
dup = &d->u[0].unused;
dup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
t=mp->m_dirblksize - (uint)sizeof(d->hdr);
d->hdr.bestfree[0].length = cpu_to_be16(t);
dup->length = cpu_to_be16(t);
*xfs_dir2_data_unused_tag_p(dup) = cpu_to_be16((char *)dup - (char *)d);
/*
* Log it and return it.
*/
xfs_dir2_data_log_header(tp, bp);
xfs_dir2_data_log_unused(tp, bp, dup);
*bpp = bp;
return 0;
}
/*
* Log an active data entry from the block.
*/
void
xfs_dir2_data_log_entry(
xfs_trans_t *tp, /* transaction pointer */
xfs_dabuf_t *bp, /* block buffer */
xfs_dir2_data_entry_t *dep) /* data entry pointer */
{
xfs_dir2_data_t *d; /* data block pointer */
d = bp->data;
ASSERT(be32_to_cpu(d->hdr.magic) == XFS_DIR2_DATA_MAGIC ||
be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC);
xfs_da_log_buf(tp, bp, (uint)((char *)dep - (char *)d),
(uint)((char *)(xfs_dir2_data_entry_tag_p(dep) + 1) -
(char *)d - 1));
}
/*
* Log a data block header.
*/
void
xfs_dir2_data_log_header(
xfs_trans_t *tp, /* transaction pointer */
xfs_dabuf_t *bp) /* block buffer */
{
xfs_dir2_data_t *d; /* data block pointer */
d = bp->data;
ASSERT(be32_to_cpu(d->hdr.magic) == XFS_DIR2_DATA_MAGIC ||
be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC);
xfs_da_log_buf(tp, bp, (uint)((char *)&d->hdr - (char *)d),
(uint)(sizeof(d->hdr) - 1));
}
/*
* Log a data unused entry.
*/
void
xfs_dir2_data_log_unused(
xfs_trans_t *tp, /* transaction pointer */
xfs_dabuf_t *bp, /* block buffer */
xfs_dir2_data_unused_t *dup) /* data unused pointer */
{
xfs_dir2_data_t *d; /* data block pointer */
d = bp->data;
ASSERT(be32_to_cpu(d->hdr.magic) == XFS_DIR2_DATA_MAGIC ||
be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC);
/*
* Log the first part of the unused entry.
*/
xfs_da_log_buf(tp, bp, (uint)((char *)dup - (char *)d),
(uint)((char *)&dup->length + sizeof(dup->length) -
1 - (char *)d));
/*
* Log the end (tag) of the unused entry.
*/
xfs_da_log_buf(tp, bp,
(uint)((char *)xfs_dir2_data_unused_tag_p(dup) - (char *)d),
(uint)((char *)xfs_dir2_data_unused_tag_p(dup) - (char *)d +
sizeof(xfs_dir2_data_off_t) - 1));
}
/*
* Make a byte range in the data block unused.
* Its current contents are unimportant.
*/
void
xfs_dir2_data_make_free(
xfs_trans_t *tp, /* transaction pointer */
xfs_dabuf_t *bp, /* block buffer */
xfs_dir2_data_aoff_t offset, /* starting byte offset */
xfs_dir2_data_aoff_t len, /* length in bytes */
int *needlogp, /* out: log header */
int *needscanp) /* out: regen bestfree */
{
xfs_dir2_data_t *d; /* data block pointer */
xfs_dir2_data_free_t *dfp; /* bestfree pointer */
char *endptr; /* end of data area */
xfs_mount_t *mp; /* filesystem mount point */
int needscan; /* need to regen bestfree */
xfs_dir2_data_unused_t *newdup; /* new unused entry */
xfs_dir2_data_unused_t *postdup; /* unused entry after us */
xfs_dir2_data_unused_t *prevdup; /* unused entry before us */
mp = tp->t_mountp;
d = bp->data;
/*
* Figure out where the end of the data area is.
*/
if (be32_to_cpu(d->hdr.magic) == XFS_DIR2_DATA_MAGIC)
endptr = (char *)d + mp->m_dirblksize;
else {
xfs_dir2_block_tail_t *btp; /* block tail */
ASSERT(be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC);
btp = xfs_dir2_block_tail_p(mp, (xfs_dir2_block_t *)d);
endptr = (char *)xfs_dir2_block_leaf_p(btp);
}
/*
* If this isn't the start of the block, then back up to
* the previous entry and see if it's free.
*/
if (offset > sizeof(d->hdr)) {
__be16 *tagp; /* tag just before us */
tagp = (__be16 *)((char *)d + offset) - 1;
prevdup = (xfs_dir2_data_unused_t *)((char *)d + be16_to_cpu(*tagp));
if (be16_to_cpu(prevdup->freetag) != XFS_DIR2_DATA_FREE_TAG)
prevdup = NULL;
} else
prevdup = NULL;
/*
* If this isn't the end of the block, see if the entry after
* us is free.
*/
if ((char *)d + offset + len < endptr) {
postdup =
(xfs_dir2_data_unused_t *)((char *)d + offset + len);
if (be16_to_cpu(postdup->freetag) != XFS_DIR2_DATA_FREE_TAG)
postdup = NULL;
} else
postdup = NULL;
ASSERT(*needscanp == 0);
needscan = 0;
/*
* Previous and following entries are both free,
* merge everything into a single free entry.
*/
if (prevdup && postdup) {
xfs_dir2_data_free_t *dfp2; /* another bestfree pointer */
/*
* See if prevdup and/or postdup are in bestfree table.
*/
dfp = xfs_dir2_data_freefind(d, prevdup);
dfp2 = xfs_dir2_data_freefind(d, postdup);
/*
* We need a rescan unless there are exactly 2 free entries
* namely our two. Then we know what's happening, otherwise
* since the third bestfree is there, there might be more
* entries.
*/
needscan = (d->hdr.bestfree[2].length != 0);
/*
* Fix up the new big freespace.
*/
be16_add_cpu(&prevdup->length, len + be16_to_cpu(postdup->length));
*xfs_dir2_data_unused_tag_p(prevdup) =
cpu_to_be16((char *)prevdup - (char *)d);
xfs_dir2_data_log_unused(tp, bp, prevdup);
if (!needscan) {
/*
* Has to be the case that entries 0 and 1 are
* dfp and dfp2 (don't know which is which), and
* entry 2 is empty.
* Remove entry 1 first then entry 0.
*/
ASSERT(dfp && dfp2);
if (dfp == &d->hdr.bestfree[1]) {
dfp = &d->hdr.bestfree[0];
ASSERT(dfp2 == dfp);
dfp2 = &d->hdr.bestfree[1];
}
xfs_dir2_data_freeremove(d, dfp2, needlogp);
xfs_dir2_data_freeremove(d, dfp, needlogp);
/*
* Now insert the new entry.
*/
dfp = xfs_dir2_data_freeinsert(d, prevdup, needlogp);
ASSERT(dfp == &d->hdr.bestfree[0]);
ASSERT(dfp->length == prevdup->length);
ASSERT(!dfp[1].length);
ASSERT(!dfp[2].length);
}
}
/*
* The entry before us is free, merge with it.
*/
else if (prevdup) {
dfp = xfs_dir2_data_freefind(d, prevdup);
be16_add_cpu(&prevdup->length, len);
*xfs_dir2_data_unused_tag_p(prevdup) =
cpu_to_be16((char *)prevdup - (char *)d);
xfs_dir2_data_log_unused(tp, bp, prevdup);
/*
* If the previous entry was in the table, the new entry
* is longer, so it will be in the table too. Remove
* the old one and add the new one.
*/
if (dfp) {
xfs_dir2_data_freeremove(d, dfp, needlogp);
(void)xfs_dir2_data_freeinsert(d, prevdup, needlogp);
}
/*
* Otherwise we need a scan if the new entry is big enough.
*/
else {
needscan = be16_to_cpu(prevdup->length) >
be16_to_cpu(d->hdr.bestfree[2].length);
}
}
/*
* The following entry is free, merge with it.
*/
else if (postdup) {
dfp = xfs_dir2_data_freefind(d, postdup);
newdup = (xfs_dir2_data_unused_t *)((char *)d + offset);
newdup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
newdup->length = cpu_to_be16(len + be16_to_cpu(postdup->length));
*xfs_dir2_data_unused_tag_p(newdup) =
cpu_to_be16((char *)newdup - (char *)d);
xfs_dir2_data_log_unused(tp, bp, newdup);
/*
* If the following entry was in the table, the new entry
* is longer, so it will be in the table too. Remove
* the old one and add the new one.
*/
if (dfp) {
xfs_dir2_data_freeremove(d, dfp, needlogp);
(void)xfs_dir2_data_freeinsert(d, newdup, needlogp);
}
/*
* Otherwise we need a scan if the new entry is big enough.
*/
else {
needscan = be16_to_cpu(newdup->length) >
be16_to_cpu(d->hdr.bestfree[2].length);
}
}
/*
* Neither neighbor is free. Make a new entry.
*/
else {
newdup = (xfs_dir2_data_unused_t *)((char *)d + offset);
newdup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
newdup->length = cpu_to_be16(len);
*xfs_dir2_data_unused_tag_p(newdup) =
cpu_to_be16((char *)newdup - (char *)d);
xfs_dir2_data_log_unused(tp, bp, newdup);
(void)xfs_dir2_data_freeinsert(d, newdup, needlogp);
}
*needscanp = needscan;
}
/*
* Take a byte range out of an existing unused space and make it un-free.
*/
void
xfs_dir2_data_use_free(
xfs_trans_t *tp, /* transaction pointer */
xfs_dabuf_t *bp, /* data block buffer */
xfs_dir2_data_unused_t *dup, /* unused entry */
xfs_dir2_data_aoff_t offset, /* starting offset to use */
xfs_dir2_data_aoff_t len, /* length to use */
int *needlogp, /* out: need to log header */
int *needscanp) /* out: need regen bestfree */
{
xfs_dir2_data_t *d; /* data block */
xfs_dir2_data_free_t *dfp; /* bestfree pointer */
int matchback; /* matches end of freespace */
int matchfront; /* matches start of freespace */
int needscan; /* need to regen bestfree */
xfs_dir2_data_unused_t *newdup; /* new unused entry */
xfs_dir2_data_unused_t *newdup2; /* another new unused entry */
int oldlen; /* old unused entry's length */
d = bp->data;
ASSERT(be32_to_cpu(d->hdr.magic) == XFS_DIR2_DATA_MAGIC ||
be32_to_cpu(d->hdr.magic) == XFS_DIR2_BLOCK_MAGIC);
ASSERT(be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG);
ASSERT(offset >= (char *)dup - (char *)d);
ASSERT(offset + len <= (char *)dup + be16_to_cpu(dup->length) - (char *)d);
ASSERT((char *)dup - (char *)d == be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup)));
/*
* Look up the entry in the bestfree table.
*/
dfp = xfs_dir2_data_freefind(d, dup);
oldlen = be16_to_cpu(dup->length);
ASSERT(dfp || oldlen <= be16_to_cpu(d->hdr.bestfree[2].length));
/*
* Check for alignment with front and back of the entry.
*/
matchfront = (char *)dup - (char *)d == offset;
matchback = (char *)dup + oldlen - (char *)d == offset + len;
ASSERT(*needscanp == 0);
needscan = 0;
/*
* If we matched it exactly we just need to get rid of it from
* the bestfree table.
*/
if (matchfront && matchback) {
if (dfp) {
needscan = (d->hdr.bestfree[2].offset != 0);
if (!needscan)
xfs_dir2_data_freeremove(d, dfp, needlogp);
}
}
/*
* We match the first part of the entry.
* Make a new entry with the remaining freespace.
*/
else if (matchfront) {
newdup = (xfs_dir2_data_unused_t *)((char *)d + offset + len);
newdup->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
newdup->length = cpu_to_be16(oldlen - len);
*xfs_dir2_data_unused_tag_p(newdup) =
cpu_to_be16((char *)newdup - (char *)d);
xfs_dir2_data_log_unused(tp, bp, newdup);
/*
* If it was in the table, remove it and add the new one.
*/
if (dfp) {
xfs_dir2_data_freeremove(d, dfp, needlogp);
dfp = xfs_dir2_data_freeinsert(d, newdup, needlogp);
ASSERT(dfp != NULL);
ASSERT(dfp->length == newdup->length);
ASSERT(be16_to_cpu(dfp->offset) == (char *)newdup - (char *)d);
/*
* If we got inserted at the last slot,
* that means we don't know if there was a better
* choice for the last slot, or not. Rescan.
*/
needscan = dfp == &d->hdr.bestfree[2];
}
}
/*
* We match the last part of the entry.
* Trim the allocated space off the tail of the entry.
*/
else if (matchback) {
newdup = dup;
newdup->length = cpu_to_be16(((char *)d + offset) - (char *)newdup);
*xfs_dir2_data_unused_tag_p(newdup) =
cpu_to_be16((char *)newdup - (char *)d);
xfs_dir2_data_log_unused(tp, bp, newdup);
/*
* If it was in the table, remove it and add the new one.
*/
if (dfp) {
xfs_dir2_data_freeremove(d, dfp, needlogp);
dfp = xfs_dir2_data_freeinsert(d, newdup, needlogp);
ASSERT(dfp != NULL);
ASSERT(dfp->length == newdup->length);
ASSERT(be16_to_cpu(dfp->offset) == (char *)newdup - (char *)d);
/*
* If we got inserted at the last slot,
* that means we don't know if there was a better
* choice for the last slot, or not. Rescan.
*/
needscan = dfp == &d->hdr.bestfree[2];
}
}
/*
* Poking out the middle of an entry.
* Make two new entries.
*/
else {
newdup = dup;
newdup->length = cpu_to_be16(((char *)d + offset) - (char *)newdup);
*xfs_dir2_data_unused_tag_p(newdup) =
cpu_to_be16((char *)newdup - (char *)d);
xfs_dir2_data_log_unused(tp, bp, newdup);
newdup2 = (xfs_dir2_data_unused_t *)((char *)d + offset + len);
newdup2->freetag = cpu_to_be16(XFS_DIR2_DATA_FREE_TAG);
newdup2->length = cpu_to_be16(oldlen - len - be16_to_cpu(newdup->length));
*xfs_dir2_data_unused_tag_p(newdup2) =
cpu_to_be16((char *)newdup2 - (char *)d);
xfs_dir2_data_log_unused(tp, bp, newdup2);
/*
* If the old entry was in the table, we need to scan
* if the 3rd entry was valid, since these entries
* are smaller than the old one.
* If we don't need to scan that means there were 1 or 2
* entries in the table, and removing the old and adding
* the 2 new will work.
*/
if (dfp) {
needscan = (d->hdr.bestfree[2].length != 0);
if (!needscan) {
xfs_dir2_data_freeremove(d, dfp, needlogp);
(void)xfs_dir2_data_freeinsert(d, newdup,
needlogp);
(void)xfs_dir2_data_freeinsert(d, newdup2,
needlogp);
}
}
}
*needscanp = needscan;
}