android_kernel_xiaomi_sm8350/fs/xfs/xfs_dir2_data.c
David Chinner da353b0d64 [XFS] Radix tree based inode caching
One of the perpetual scaling problems XFS has is indexing it's incore
inodes. We currently uses hashes and the default hash sizes chosen can
only ever be a tradeoff between memory consumption and the maximum
realistic size of the cache.

As a result, anyone who has millions of inodes cached on a filesystem
needs to tunes the size of the cache via the ihashsize mount option to
allow decent scalability with inode cache operations.

A further problem is the separate inode cluster hash, whose size is based
on the ihashsize but is smaller, and so under certain conditions (sparse
cluster cache population) this can become a limitation long before the
inode hash is causing issues.

The following patchset removes the inode hash and cluster hash and
replaces them with radix trees to avoid the scalability limitations of the
hashes. It also reduces the size of the inodes by 3 pointers....

SGI-PV: 969561
SGI-Modid: xfs-linux-melb:xfs-kern:29481a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Tim Shimmin <tes@sgi.com>
2007-10-15 16:50:50 +10:00

833 lines
25 KiB
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_dmapi.h"
#include "xfs_mount.h"
#include "xfs_da_btree.h"
#include "xfs_bmap_btree.h"
#include "xfs_dir2_sf.h"
#include "xfs_attr_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 */
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));
hash = xfs_da_hashname((char *)dep->name, dep->namelen);
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(&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(&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;
}