/*
* Mark an extent specified by start and len freed.
* Updates all the summary information as well as the bitmap.
*/
int
xfs_rtfree_range(
xfs_mount_t *mp, /* file system mount point */
xfs_trans_t *tp, /* transaction pointer */
xfs_rtblock_t start, /* starting block to free */
xfs_extlen_t len, /* length to free */
xfs_buf_t **rbpp, /* in/out: summary block buffer */
xfs_fsblock_t *rsb) /* in/out: summary block number */
{
xfs_rtblock_t end; /* end of the freed extent */
int error; /* error value */
xfs_rtblock_t postblock; /* first block freed > end */
xfs_rtblock_t preblock; /* first block freed < start */
end = start + len - 1;
/*
* Modify the bitmap to mark this extent freed.
*/
error = xfs_rtmodify_range(mp, tp, start, len, 1);
if (error) {
return error;
}
/*
* Assume we're freeing out of the middle of an allocated extent.
* We need to find the beginning and end of the extent so we can
* properly update the summary.
*/
error = xfs_rtfind_back(mp, tp, start, 0, &preblock);
if (error) {
return error;
}
/*
* Find the next allocated block (end of allocated extent).
*/
error = xfs_rtfind_forw(mp, tp, end, mp->m_sb.sb_rextents - 1,
&postblock);
if (error)
return error;
/*
* If there are blocks not being freed at the front of the
* old extent, add summary data for them to be allocated.
*/
if (preblock < start) {
error = xfs_rtmodify_summary(mp, tp,
XFS_RTBLOCKLOG(start - preblock),
XFS_BITTOBLOCK(mp, preblock), -1, rbpp, rsb);
if (error) {
return error;
}
}
/*
* If there are blocks not being freed at the end of the
* old extent, add summary data for them to be allocated.
*/
if (postblock > end) {
error = xfs_rtmodify_summary(mp, tp,
XFS_RTBLOCKLOG(postblock - end),
XFS_BITTOBLOCK(mp, end + 1), -1, rbpp, rsb);
if (error) {
return error;
}
}
/*
* Increment the summary information corresponding to the entire
* (new) free extent.
*/
error = xfs_rtmodify_summary(mp, tp,
XFS_RTBLOCKLOG(postblock + 1 - preblock),
XFS_BITTOBLOCK(mp, preblock), 1, rbpp, rsb);
return error;
}
/*
* Set the given range of bitmap bits to the given value.
* Do whatever I/O and logging is required.
*/
int
xfs_rtmodify_range(
xfs_mount_t *mp, /* file system mount point */
xfs_trans_t *tp, /* transaction pointer */
xfs_rtblock_t start, /* starting block to modify */
xfs_extlen_t len, /* length of extent to modify */
int val) /* 1 for free, 0 for allocated */
{
xfs_rtword_t *b; /* current word in buffer */
int bit; /* bit number in the word */
xfs_rtblock_t block; /* bitmap block number */
xfs_buf_t *bp; /* buf for the block */
xfs_rtword_t *bufp; /* starting word in buffer */
int error; /* error value */
xfs_rtword_t *first; /* first used word in the buffer */
int i; /* current bit number rel. to start */
int lastbit; /* last useful bit in word */
xfs_rtword_t mask; /* mask o frelevant bits for value */
int word; /* word number in the buffer */
/*
* Compute starting bitmap block number.
*/
block = XFS_BITTOBLOCK(mp, start);
/*
* Read the bitmap block, and point to its data.
*/
error = xfs_rtbuf_get(mp, tp, block, 0, &bp);
if (error) {
return error;
}
bufp = bp->b_addr;
/*
* Compute the starting word's address, and starting bit.
*/
word = XFS_BITTOWORD(mp, start);
first = b = &bufp[word];
bit = (int)(start & (XFS_NBWORD - 1));
/*
* 0 (allocated) => all zeroes; 1 (free) => all ones.
*/
val = -val;
/*
* If not starting on a word boundary, deal with the first
* (partial) word.
*/
if (bit) {
/*
* Compute first bit not changed and mask of relevant bits.
*/
lastbit = XFS_RTMIN(bit + len, XFS_NBWORD);
mask = (((xfs_rtword_t)1 << (lastbit - bit)) - 1) << bit;
/*
* Set/clear the active bits.
*/
if (val)
*b |= mask;
else
*b &= ~mask;
i = lastbit - bit;
/*
* Go on to the next block if that's where the next word is
* and we need the next word.
*/
if (++word == XFS_BLOCKWSIZE(mp) && i < len) {
/*
* Log the changed part of this block.
* Get the next one.
*/
xfs_trans_log_buf(tp, bp,
(uint)((char *)first - (char *)bufp),
(uint)((char *)b - (char *)bufp));
error = xfs_rtbuf_get(mp, tp, ++block, 0, &bp);
if (error) {
return error;
}
first = b = bufp = bp->b_addr;
word = 0;
} else {
/*
* Go on to the next word in the buffer
*/
b++;
}
} else {
/*
* Starting on a word boundary, no partial word.
*/
i = 0;
}
/*
* Loop over whole words in buffers. When we use up one buffer
* we move on to the next one.
*/
while (len - i >= XFS_NBWORD) {
/*
* Set the word value correctly.
*/
*b = val;
i += XFS_NBWORD;
/*
* Go on to the next block if that's where the next word is
* and we need the next word.
*/
if (++word == XFS_BLOCKWSIZE(mp) && i < len) {
/*
* Log the changed part of this block.
* Get the next one.
*/
xfs_trans_log_buf(tp, bp,
(uint)((char *)first - (char *)bufp),
(uint)((char *)b - (char *)bufp));
error = xfs_rtbuf_get(mp, tp, ++block, 0, &bp);
if (error) {
return error;
}
first = b = bufp = bp->b_addr;
word = 0;
} else {
/*
* Go on to the next word in the buffer
*/
b++;
}
}
/*
* If not ending on a word boundary, deal with the last
* (partial) word.
*/
if ((lastbit = len - i)) {
/*
* Compute a mask of relevant bits.
*/
mask = ((xfs_rtword_t)1 << lastbit) - 1;
/*
* Set/clear the active bits.
*/
if (val)
*b |= mask;
else
*b &= ~mask;
b++;
}
/*
* Log any remaining changed bytes.
*/
if (b > first)
xfs_trans_log_buf(tp, bp, (uint)((char *)first - (char *)bufp),
(uint)((char *)b - (char *)bufp - 1));
return 0;
}
/*
* Searching forward from start to limit, find the first block whose
* allocated/free state is different from start's.
*/
int
xfs_rtfind_forw(
xfs_mount_t *mp, /* file system mount point */
xfs_trans_t *tp, /* transaction pointer */
xfs_rtblock_t start, /* starting block to look at */
xfs_rtblock_t limit, /* last block to look at */
xfs_rtblock_t *rtblock) /* out: start block found */
{
xfs_rtword_t *b; /* current word in buffer */
int bit; /* bit number in the word */
xfs_rtblock_t block; /* bitmap block number */
xfs_buf_t *bp; /* buf for the block */
xfs_rtword_t *bufp; /* starting word in buffer */
int error; /* error value */
xfs_rtblock_t i; /* current bit number rel. to start */
xfs_rtblock_t lastbit; /* last useful bit in the word */
xfs_rtblock_t len; /* length of inspected area */
xfs_rtword_t mask; /* mask of relevant bits for value */
xfs_rtword_t want; /* mask for "good" values */
xfs_rtword_t wdiff; /* difference from wanted value */
int word; /* word number in the buffer */
/*
* Compute and read in starting bitmap block for starting block.
*/
block = XFS_BITTOBLOCK(mp, start);
error = xfs_rtbuf_get(mp, tp, block, 0, &bp);
if (error) {
return error;
}
bufp = bp->b_addr;
/*
* Get the first word's index & point to it.
*/
word = XFS_BITTOWORD(mp, start);
b = &bufp[word];
bit = (int)(start & (XFS_NBWORD - 1));
len = limit - start + 1;
/*
* Compute match value, based on the bit at start: if 1 (free)
* then all-ones, else all-zeroes.
*/
want = (*b & ((xfs_rtword_t)1 << bit)) ? -1 : 0;
/*
* If the starting position is not word-aligned, deal with the
* partial word.
*/
if (bit) {
/*
* Calculate last (rightmost) bit number to look at,
* and mask for all the relevant bits in this word.
*/
lastbit = XFS_RTMIN(bit + len, XFS_NBWORD);
mask = (((xfs_rtword_t)1 << (lastbit - bit)) - 1) << bit;
/*
* Calculate the difference between the value there
* and what we're looking for.
*/
if ((wdiff = (*b ^ want) & mask)) {
/*
* Different. Mark where we are and return.
*/
xfs_trans_brelse(tp, bp);
i = XFS_RTLOBIT(wdiff) - bit;
*rtblock = start + i - 1;
return 0;
}
i = lastbit - bit;
/*
* Go on to next block if that's where the next word is
* and we need the next word.
*/
if (++word == XFS_BLOCKWSIZE(mp) && i < len) {
/*
* If done with this block, get the previous one.
*/
xfs_trans_brelse(tp, bp);
error = xfs_rtbuf_get(mp, tp, ++block, 0, &bp);
if (error) {
return error;
}
b = bufp = bp->b_addr;
word = 0;
} else {
/*
* Go on to the previous word in the buffer.
*/
b++;
}
} else {
/*
* Starting on a word boundary, no partial word.
*/
i = 0;
}
/*
* Loop over whole words in buffers. When we use up one buffer
* we move on to the next one.
*/
while (len - i >= XFS_NBWORD) {
/*
* Compute difference between actual and desired value.
*/
if ((wdiff = *b ^ want)) {
/*
* Different, mark where we are and return.
*/
xfs_trans_brelse(tp, bp);
i += XFS_RTLOBIT(wdiff);
*rtblock = start + i - 1;
return 0;
}
i += XFS_NBWORD;
/*
* Go on to next block if that's where the next word is
* and we need the next word.
*/
if (++word == XFS_BLOCKWSIZE(mp) && i < len) {
/*
* If done with this block, get the next one.
*/
xfs_trans_brelse(tp, bp);
error = xfs_rtbuf_get(mp, tp, ++block, 0, &bp);
if (error) {
return error;
}
b = bufp = bp->b_addr;
word = 0;
} else {
/*
* Go on to the next word in the buffer.
*/
b++;
}
}
/*
* If not ending on a word boundary, deal with the last
* (partial) word.
*/
if ((lastbit = len - i)) {
/*
* Calculate mask for all the relevant bits in this word.
*/
mask = ((xfs_rtword_t)1 << lastbit) - 1;
/*
* Compute difference between actual and desired value.
*/
if ((wdiff = (*b ^ want) & mask)) {
/*
* Different, mark where we are and return.
*/
xfs_trans_brelse(tp, bp);
i += XFS_RTLOBIT(wdiff);
*rtblock = start + i - 1;
return 0;
} else
i = len;
}
/*
* No match, return that we scanned the whole area.
*/
xfs_trans_brelse(tp, bp);
*rtblock = start + i - 1;
return 0;
}
xfs_rtword_t *b; /* current word in buffer */
int bit; /* bit number in the word */
xfs_rtblock_t block; /* bitmap block number */
xfs_buf_t *bp; /* buf for the block */
xfs_rtword_t *bufp; /* starting word in buffer */
int error; /* error value */
xfs_rtblock_t i; /* current bit number rel. to start */
xfs_rtblock_t lastbit; /* last useful bit in word */
xfs_rtword_t mask; /* mask of relevant bits for value */
xfs_rtword_t wdiff; /* difference from wanted value */
int word; /* word number in the buffer */
/*
* Compute starting bitmap block number
*/
block = XFS_BITTOBLOCK(mp, start);
/*
* Read the bitmap block.
*/
error = xfs_rtbuf_get(mp, tp, block, 0, &bp);
if (error) {
return error;
}
bufp = bp->b_addr;
/*
* Compute the starting word's address, and starting bit.
*/
word = XFS_BITTOWORD(mp, start);
b = &bufp[word];
bit = (int)(start & (XFS_NBWORD - 1));
/*
/*
* Allocate an extent of length minlen<=len<=maxlen, with no position
* specified. If we don't get maxlen then use prod to trim
* the length, if given. The lengths are all in rtextents.
*/
STATIC int /* error */
xfs_rtallocate_extent_size(
xfs_mount_t *mp, /* file system mount point */
xfs_trans_t *tp, /* transaction pointer */
xfs_extlen_t minlen, /* minimum length to allocate */
xfs_extlen_t maxlen, /* maximum length to allocate */
xfs_extlen_t *len, /* out: actual length allocated */
xfs_buf_t **rbpp, /* in/out: summary block buffer */
xfs_fsblock_t *rsb, /* in/out: summary block number */
xfs_extlen_t prod, /* extent product factor */
xfs_rtblock_t *rtblock) /* out: start block allocated */
{
int error; /* error value */
int i; /* bitmap block number */
int l; /* level number (loop control) */
xfs_rtblock_t n; /* next block to be tried */
xfs_rtblock_t r; /* result block number */
xfs_suminfo_t sum; /* summary information for extents */
ASSERT(minlen % prod == 0 && maxlen % prod == 0);
ASSERT(maxlen != 0);
/*
* Loop over all the levels starting with maxlen.
* At each level, look at all the bitmap blocks, to see if there
* are extents starting there that are long enough (>= maxlen).
* Note, only on the initial level can the allocation fail if
* the summary says there's an extent.
*/
for (l = xfs_highbit32(maxlen); l < mp->m_rsumlevels; l++) {
/*
* Loop over all the bitmap blocks.
*/
for (i = 0; i < mp->m_sb.sb_rbmblocks; i++) {
/*
* Get the summary for this level/block.
*/
error = xfs_rtget_summary(mp, tp, l, i, rbpp, rsb,
&sum);
if (error) {
return error;
}
/*
* Nothing there, on to the next block.
*/
if (!sum)
continue;
/*
* Try allocating the extent.
*/
error = xfs_rtallocate_extent_block(mp, tp, i, maxlen,
maxlen, len, &n, rbpp, rsb, prod, &r);
if (error) {
return error;
}
/*
* If it worked, return that.
*/
if (r != NULLRTBLOCK) {
*rtblock = r;
return 0;
}
/*
* If the "next block to try" returned from the
* allocator is beyond the next bitmap block,
* skip to that bitmap block.
*/
if (XFS_BITTOBLOCK(mp, n) > i + 1)
i = XFS_BITTOBLOCK(mp, n) - 1;
}
}
/*
* Didn't find any maxlen blocks. Try smaller ones, unless
* we're asking for a fixed size extent.
*/
if (minlen > --maxlen) {
*rtblock = NULLRTBLOCK;
return 0;
}
ASSERT(minlen != 0);
ASSERT(maxlen != 0);
/*
* Loop over sizes, from maxlen down to minlen.
* This time, when we do the allocations, allow smaller ones
* to succeed.
*/
for (l = xfs_highbit32(maxlen); l >= xfs_highbit32(minlen); l--) {
/*
* Loop over all the bitmap blocks, try an allocation
* starting in that block.
*/
for (i = 0; i < mp->m_sb.sb_rbmblocks; i++) {
/*
* Get the summary information for this level/block.
*/
error = xfs_rtget_summary(mp, tp, l, i, rbpp, rsb,
&sum);
if (error) {
return error;
}
/*
* If nothing there, go on to next.
*/
if (!sum)
continue;
/*
* Try the allocation. Make sure the specified
* minlen/maxlen are in the possible range for
* this summary level.
*/
error = xfs_rtallocate_extent_block(mp, tp, i,
XFS_RTMAX(minlen, 1 << l),
XFS_RTMIN(maxlen, (1 << (l + 1)) - 1),
len, &n, rbpp, rsb, prod, &r);
if (error) {
return error;
}
/*
* If it worked, return that extent.
*/
if (r != NULLRTBLOCK) {
*rtblock = r;
return 0;
}
/*
* If the "next block to try" returned from the
* allocator is beyond the next bitmap block,
* skip to that bitmap block.
*/
if (XFS_BITTOBLOCK(mp, n) > i + 1)
i = XFS_BITTOBLOCK(mp, n) - 1;
}
}
/*
* Got nothing, return failure.
*/
*rtblock = NULLRTBLOCK;
return 0;
}
/*
* Allocate an extent of length minlen<=len<=maxlen, starting as near
* to bno as possible. If we don't get maxlen then use prod to trim
* the length, if given. The lengths are all in rtextents.
*/
STATIC int /* error */
xfs_rtallocate_extent_near(
xfs_mount_t *mp, /* file system mount point */
xfs_trans_t *tp, /* transaction pointer */
xfs_rtblock_t bno, /* starting block number to allocate */
xfs_extlen_t minlen, /* minimum length to allocate */
xfs_extlen_t maxlen, /* maximum length to allocate */
xfs_extlen_t *len, /* out: actual length allocated */
xfs_buf_t **rbpp, /* in/out: summary block buffer */
xfs_fsblock_t *rsb, /* in/out: summary block number */
xfs_extlen_t prod, /* extent product factor */
xfs_rtblock_t *rtblock) /* out: start block allocated */
{
int any; /* any useful extents from summary */
xfs_rtblock_t bbno; /* bitmap block number */
int error; /* error value */
int i; /* bitmap block offset (loop control) */
int j; /* secondary loop control */
int log2len; /* log2 of minlen */
xfs_rtblock_t n; /* next block to try */
xfs_rtblock_t r; /* result block */
ASSERT(minlen % prod == 0 && maxlen % prod == 0);
/*
* If the block number given is off the end, silently set it to
* the last block.
*/
if (bno >= mp->m_sb.sb_rextents)
bno = mp->m_sb.sb_rextents - 1;
/*
* Try the exact allocation first.
*/
error = xfs_rtallocate_extent_exact(mp, tp, bno, minlen, maxlen, len,
rbpp, rsb, prod, &r);
if (error) {
return error;
}
/*
* If the exact allocation worked, return that.
*/
if (r != NULLRTBLOCK) {
*rtblock = r;
return 0;
}
bbno = XFS_BITTOBLOCK(mp, bno);
i = 0;
ASSERT(minlen != 0);
log2len = xfs_highbit32(minlen);
/*
* Loop over all bitmap blocks (bbno + i is current block).
*/
for (;;) {
/*
* Get summary information of extents of all useful levels
* starting in this bitmap block.
*/
error = xfs_rtany_summary(mp, tp, log2len, mp->m_rsumlevels - 1,
bbno + i, rbpp, rsb, &any);
if (error) {
return error;
}
/*
* If there are any useful extents starting here, try
* allocating one.
*/
if (any) {
/*
* On the positive side of the starting location.
*/
if (i >= 0) {
/*
* Try to allocate an extent starting in
* this block.
*/
error = xfs_rtallocate_extent_block(mp, tp,
bbno + i, minlen, maxlen, len, &n, rbpp,
rsb, prod, &r);
if (error) {
return error;
}
/*
* If it worked, return it.
*/
if (r != NULLRTBLOCK) {
*rtblock = r;
return 0;
}
}
/*
* On the negative side of the starting location.
*/
else { /* i < 0 */
/*
* Loop backwards through the bitmap blocks from
* the starting point-1 up to where we are now.
* There should be an extent which ends in this
* bitmap block and is long enough.
*/
for (j = -1; j > i; j--) {
/*
* Grab the summary information for
* this bitmap block.
*/
error = xfs_rtany_summary(mp, tp,
log2len, mp->m_rsumlevels - 1,
bbno + j, rbpp, rsb, &any);
if (error) {
return error;
}
/*
* If there's no extent given in the
* summary that means the extent we
* found must carry over from an
* earlier block. If there is an
* extent given, we've already tried
* that allocation, don't do it again.
*/
if (any)
continue;
error = xfs_rtallocate_extent_block(mp,
tp, bbno + j, minlen, maxlen,
len, &n, rbpp, rsb, prod, &r);
if (error) {
return error;
}
/*
* If it works, return the extent.
*/
if (r != NULLRTBLOCK) {
*rtblock = r;
return 0;
}
}
/*
* There weren't intervening bitmap blocks
* with a long enough extent, or the
* allocation didn't work for some reason
* (i.e. it's a little * too short).
* Try to allocate from the summary block
* that we found.
*/
error = xfs_rtallocate_extent_block(mp, tp,
bbno + i, minlen, maxlen, len, &n, rbpp,
rsb, prod, &r);
if (error) {
return error;
}
/*
* If it works, return the extent.
*/
if (r != NULLRTBLOCK) {
*rtblock = r;
return 0;
}
}
}
/*
* Loop control. If we were on the positive side, and there's
* still more blocks on the negative side, go there.
*/
if (i > 0 && (int)bbno - i >= 0)
i = -i;
/*
* If positive, and no more negative, but there are more
* positive, go there.
*/
else if (i > 0 && (int)bbno + i < mp->m_sb.sb_rbmblocks - 1)
i++;
/*
* If negative or 0 (just started), and there are positive
* blocks to go, go there. The 0 case moves to block 1.
*/
else if (i <= 0 && (int)bbno - i < mp->m_sb.sb_rbmblocks - 1)
i = 1 - i;
/*
* If negative or 0 and there are more negative blocks,
* go there.
*/
else if (i <= 0 && (int)bbno + i > 0)
i--;
/*
* Must be done. Return failure.
*/
else
break;
}
*rtblock = NULLRTBLOCK;
return 0;
}