#include <linux/buffer_head.h>
#include <linux/fs.h>
#include <linux/gfs2_ondisk.h>
-#include <linux/lm_interface.h>
#include <linux/prefetch.h>
+#include <linux/blkdev.h>
#include "gfs2.h"
#include "incore.h"
}
/**
+ * gfs2_bit_search
+ * @ptr: Pointer to bitmap data
+ * @mask: Mask to use (normally 0x55555.... but adjusted for search start)
+ * @state: The state we are searching for
+ *
+ * We xor the bitmap data with a patter which is the bitwise opposite
+ * of what we are looking for, this gives rise to a pattern of ones
+ * wherever there is a match. Since we have two bits per entry, we
+ * take this pattern, shift it down by one place and then and it with
+ * the original. All the even bit positions (0,2,4, etc) then represent
+ * successful matches, so we mask with 0x55555..... to remove the unwanted
+ * odd bit positions.
+ *
+ * This allows searching of a whole u64 at once (32 blocks) with a
+ * single test (on 64 bit arches).
+ */
+
+static inline u64 gfs2_bit_search(const __le64 *ptr, u64 mask, u8 state)
+{
+ u64 tmp;
+ static const u64 search[] = {
+ [0] = 0xffffffffffffffffULL,
+ [1] = 0xaaaaaaaaaaaaaaaaULL,
+ [2] = 0x5555555555555555ULL,
+ [3] = 0x0000000000000000ULL,
+ };
+ tmp = le64_to_cpu(*ptr) ^ search[state];
+ tmp &= (tmp >> 1);
+ tmp &= mask;
+ return tmp;
+}
+
+/**
* gfs2_bitfit - Search an rgrp's bitmap buffer to find a bit-pair representing
* a block in a given allocation state.
* @buffer: the buffer that holds the bitmaps
- * @buflen: the length (in bytes) of the buffer
+ * @len: the length (in bytes) of the buffer
* @goal: start search at this block's bit-pair (within @buffer)
- * @old_state: GFS2_BLKST_XXX the state of the block we're looking for.
+ * @state: GFS2_BLKST_XXX the state of the block we're looking for.
*
* Scope of @goal and returned block number is only within this bitmap buffer,
* not entire rgrp or filesystem. @buffer will be offset from the actual
- * beginning of a bitmap block buffer, skipping any header structures.
+ * beginning of a bitmap block buffer, skipping any header structures, but
+ * headers are always a multiple of 64 bits long so that the buffer is
+ * always aligned to a 64 bit boundary.
+ *
+ * The size of the buffer is in bytes, but is it assumed that it is
+ * always ok to to read a complete multiple of 64 bits at the end
+ * of the block in case the end is no aligned to a natural boundary.
*
* Return: the block number (bitmap buffer scope) that was found
*/
-static u32 gfs2_bitfit(const u8 *buffer, unsigned int buflen, u32 goal,
- u8 old_state)
+static u32 gfs2_bitfit(const u8 *buf, const unsigned int len,
+ u32 goal, u8 state)
{
- const u8 *byte, *start, *end;
- int bit, startbit;
- u32 g1, g2, misaligned;
- unsigned long *plong;
- unsigned long lskipval;
-
- lskipval = (old_state & GFS2_BLKST_USED) ? LBITSKIP00 : LBITSKIP55;
- g1 = (goal / GFS2_NBBY);
- start = buffer + g1;
- byte = start;
- end = buffer + buflen;
- g2 = ALIGN(g1, sizeof(unsigned long));
- plong = (unsigned long *)(buffer + g2);
- startbit = bit = (goal % GFS2_NBBY) * GFS2_BIT_SIZE;
- misaligned = g2 - g1;
- if (!misaligned)
- goto ulong_aligned;
-/* parse the bitmap a byte at a time */
-misaligned:
- while (byte < end) {
- if (((*byte >> bit) & GFS2_BIT_MASK) == old_state) {
- return goal +
- (((byte - start) * GFS2_NBBY) +
- ((bit - startbit) >> 1));
- }
- bit += GFS2_BIT_SIZE;
- if (bit >= GFS2_NBBY * GFS2_BIT_SIZE) {
- bit = 0;
- byte++;
- misaligned--;
- if (!misaligned) {
- plong = (unsigned long *)byte;
- goto ulong_aligned;
- }
- }
- }
- return BFITNOENT;
-
-/* parse the bitmap a unsigned long at a time */
-ulong_aligned:
- /* Stop at "end - 1" or else prefetch can go past the end and segfault.
- We could "if" it but we'd lose some of the performance gained.
- This way will only slow down searching the very last 4/8 bytes
- depending on architecture. I've experimented with several ways
- of writing this section such as using an else before the goto
- but this one seems to be the fastest. */
- while ((unsigned char *)plong < end - sizeof(unsigned long)) {
- prefetch(plong + 1);
- if (((*plong) & LBITMASK) != lskipval)
- break;
- plong++;
- }
- if ((unsigned char *)plong < end) {
- byte = (const u8 *)plong;
- misaligned += sizeof(unsigned long) - 1;
- goto misaligned;
+ u32 spoint = (goal << 1) & ((8*sizeof(u64)) - 1);
+ const __le64 *ptr = ((__le64 *)buf) + (goal >> 5);
+ const __le64 *end = (__le64 *)(buf + ALIGN(len, sizeof(u64)));
+ u64 tmp;
+ u64 mask = 0x5555555555555555ULL;
+ u32 bit;
+
+ BUG_ON(state > 3);
+
+ /* Mask off bits we don't care about at the start of the search */
+ mask <<= spoint;
+ tmp = gfs2_bit_search(ptr, mask, state);
+ ptr++;
+ while(tmp == 0 && ptr < end) {
+ tmp = gfs2_bit_search(ptr, 0x5555555555555555ULL, state);
+ ptr++;
}
- return BFITNOENT;
+ /* Mask off any bits which are more than len bytes from the start */
+ if (ptr == end && (len & (sizeof(u64) - 1)))
+ tmp &= (((u64)~0) >> (64 - 8*(len & (sizeof(u64) - 1))));
+ /* Didn't find anything, so return */
+ if (tmp == 0)
+ return BFITNOENT;
+ ptr--;
+ bit = __ffs64(tmp);
+ bit /= 2; /* two bits per entry in the bitmap */
+ return (((const unsigned char *)ptr - buf) * GFS2_NBBY) + bit;
}
/**
return;
}
- tmp = rgd->rd_data -
- rgd->rd_free -
- rgd->rd_rg.rg_dinodes;
+ tmp = rgd->rd_data - rgd->rd_free - rgd->rd_dinodes;
if (count[1] + count[2] != tmp) {
if (gfs2_consist_rgrpd(rgd))
fs_err(sdp, "used data mismatch: %u != %u\n",
return;
}
- if (count[3] != rgd->rd_rg.rg_dinodes) {
+ if (count[3] != rgd->rd_dinodes) {
if (gfs2_consist_rgrpd(rgd))
fs_err(sdp, "used metadata mismatch: %u != %u\n",
- count[3], rgd->rd_rg.rg_dinodes);
+ count[3], rgd->rd_dinodes);
return;
}
static void gfs2_rgrp_in(struct gfs2_rgrpd *rgd, const void *buf)
{
const struct gfs2_rgrp *str = buf;
- struct gfs2_rgrp_host *rg = &rgd->rd_rg;
u32 rg_flags;
rg_flags = be32_to_cpu(str->rg_flags);
else
rgd->rd_flags &= ~GFS2_RDF_NOALLOC;
rgd->rd_free = be32_to_cpu(str->rg_free);
- rg->rg_dinodes = be32_to_cpu(str->rg_dinodes);
+ rgd->rd_dinodes = be32_to_cpu(str->rg_dinodes);
rgd->rd_igeneration = be64_to_cpu(str->rg_igeneration);
}
static void gfs2_rgrp_out(struct gfs2_rgrpd *rgd, void *buf)
{
struct gfs2_rgrp *str = buf;
- struct gfs2_rgrp_host *rg = &rgd->rd_rg;
u32 rg_flags = 0;
if (rgd->rd_flags & GFS2_RDF_NOALLOC)
rg_flags |= GFS2_RGF_NOALLOC;
str->rg_flags = cpu_to_be32(rg_flags);
str->rg_free = cpu_to_be32(rgd->rd_free);
- str->rg_dinodes = cpu_to_be32(rg->rg_dinodes);
+ str->rg_dinodes = cpu_to_be32(rgd->rd_dinodes);
str->__pad = cpu_to_be32(0);
str->rg_igeneration = cpu_to_be64(rgd->rd_igeneration);
memset(&str->rg_reserved, 0, sizeof(str->rg_reserved));
spin_unlock(&sdp->sd_rindex_spin);
}
+static void gfs2_rgrp_send_discards(struct gfs2_sbd *sdp, u64 offset,
+ const struct gfs2_bitmap *bi)
+{
+ struct super_block *sb = sdp->sd_vfs;
+ struct block_device *bdev = sb->s_bdev;
+ const unsigned int sects_per_blk = sdp->sd_sb.sb_bsize /
+ bdev_hardsect_size(sb->s_bdev);
+ u64 blk;
+ sector_t start = 0;
+ sector_t nr_sects = 0;
+ int rv;
+ unsigned int x;
+
+ for (x = 0; x < bi->bi_len; x++) {
+ const u8 *orig = bi->bi_bh->b_data + bi->bi_offset + x;
+ const u8 *clone = bi->bi_clone + bi->bi_offset + x;
+ u8 diff = ~(*orig | (*orig >> 1)) & (*clone | (*clone >> 1));
+ diff &= 0x55;
+ if (diff == 0)
+ continue;
+ blk = offset + ((bi->bi_start + x) * GFS2_NBBY);
+ blk *= sects_per_blk; /* convert to sectors */
+ while(diff) {
+ if (diff & 1) {
+ if (nr_sects == 0)
+ goto start_new_extent;
+ if ((start + nr_sects) != blk) {
+ rv = blkdev_issue_discard(bdev, start,
+ nr_sects, GFP_NOFS);
+ if (rv)
+ goto fail;
+ nr_sects = 0;
+start_new_extent:
+ start = blk;
+ }
+ nr_sects += sects_per_blk;
+ }
+ diff >>= 2;
+ blk += sects_per_blk;
+ }
+ }
+ if (nr_sects) {
+ rv = blkdev_issue_discard(bdev, start, nr_sects, GFP_NOFS);
+ if (rv)
+ goto fail;
+ }
+ return;
+fail:
+ fs_warn(sdp, "error %d on discard request, turning discards off for this filesystem", rv);
+ sdp->sd_args.ar_discard = 0;
+}
+
void gfs2_rgrp_repolish_clones(struct gfs2_rgrpd *rgd)
{
struct gfs2_sbd *sdp = rgd->rd_sbd;
struct gfs2_bitmap *bi = rgd->rd_bits + x;
if (!bi->bi_clone)
continue;
+ if (sdp->sd_args.ar_discard)
+ gfs2_rgrp_send_discards(sdp, rgd->rd_data0, bi);
memcpy(bi->bi_clone + bi->bi_offset,
bi->bi_bh->b_data + bi->bi_offset, bi->bi_len);
}
u64 gfs2_alloc_block(struct gfs2_inode *ip, unsigned int *n)
{
struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
+ struct buffer_head *dibh;
struct gfs2_alloc *al = ip->i_alloc;
struct gfs2_rgrpd *rgd = al->al_rgd;
u32 goal, blk;
u64 block;
+ int error;
if (rgrp_contains_block(rgd, ip->i_goal))
goal = ip->i_goal - rgd->rd_data0;
rgd->rd_last_alloc = blk;
block = rgd->rd_data0 + blk;
ip->i_goal = block;
-
+ error = gfs2_meta_inode_buffer(ip, &dibh);
+ if (error == 0) {
+ struct gfs2_dinode *di = (struct gfs2_dinode *)dibh->b_data;
+ gfs2_trans_add_bh(ip->i_gl, dibh, 1);
+ di->di_goal_meta = di->di_goal_data = cpu_to_be64(ip->i_goal);
+ brelse(dibh);
+ }
gfs2_assert_withdraw(sdp, rgd->rd_free >= *n);
rgd->rd_free -= *n;
gfs2_assert_withdraw(sdp, rgd->rd_free);
rgd->rd_free--;
- rgd->rd_rg.rg_dinodes++;
+ rgd->rd_dinodes++;
*generation = rgd->rd_igeneration++;
gfs2_trans_add_bh(rgd->rd_gl, rgd->rd_bits[0].bi_bh, 1);
gfs2_rgrp_out(rgd, rgd->rd_bits[0].bi_bh->b_data);
return;
gfs2_assert_withdraw(sdp, rgd == tmp_rgd);
- if (!rgd->rd_rg.rg_dinodes)
+ if (!rgd->rd_dinodes)
gfs2_consist_rgrpd(rgd);
- rgd->rd_rg.rg_dinodes--;
+ rgd->rd_dinodes--;
rgd->rd_free++;
gfs2_trans_add_bh(rgd->rd_gl, rgd->rd_bits[0].bi_bh, 1);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff