[PATCH] ufs: not usual amounts of fragments per block
The writing to UFS file system with block/fragment!=8 may cause bogus behaviour. The problem in "ufs_bitmap_search" function, which doesn't work correctly in "block/fragment!=8" case. The idea is stolen from BSD code. Signed-off-by: Evgeniy Dushistov <dushistov@mail.ru> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Evgeniy Dushistov
Linus Torvalds
parent
9695ef16ed
commit
3e41f597b1
130
fs/ufs/balloc.c
130
fs/ufs/balloc.c
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@ -726,18 +726,63 @@ gotit:
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return result;
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}
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static unsigned ufs_bitmap_search (struct super_block * sb,
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struct ufs_cg_private_info * ucpi, unsigned goal, unsigned count)
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static unsigned ubh_scanc(struct ufs_sb_private_info *uspi,
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struct ufs_buffer_head *ubh,
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unsigned begin, unsigned size,
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unsigned char *table, unsigned char mask)
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{
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struct ufs_sb_private_info * uspi;
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struct ufs_super_block_first * usb1;
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struct ufs_cylinder_group * ucg;
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unsigned start, length, location, result;
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unsigned possition, fragsize, blockmap, mask;
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unsigned rest, offset;
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unsigned char *cp;
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UFSD(("ENTER, cg %u, goal %u, count %u\n", ucpi->c_cgx, goal, count))
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uspi = UFS_SB(sb)->s_uspi;
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offset = begin & ~uspi->s_fmask;
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begin >>= uspi->s_fshift;
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for (;;) {
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if ((offset + size) < uspi->s_fsize)
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rest = size;
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else
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rest = uspi->s_fsize - offset;
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size -= rest;
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cp = ubh->bh[begin]->b_data + offset;
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while ((table[*cp++] & mask) == 0 && --rest)
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;
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if (rest || !size)
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break;
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begin++;
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offset = 0;
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}
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return (size + rest);
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}
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/*
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* Find a block of the specified size in the specified cylinder group.
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* @sp: pointer to super block
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* @ucpi: pointer to cylinder group info
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* @goal: near which block we want find new one
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* @count: specified size
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*/
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static unsigned ufs_bitmap_search(struct super_block *sb,
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struct ufs_cg_private_info *ucpi,
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unsigned goal, unsigned count)
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{
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/*
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* Bit patterns for identifying fragments in the block map
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* used as ((map & mask_arr) == want_arr)
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*/
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static const int mask_arr[9] = {
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0x3, 0x7, 0xf, 0x1f, 0x3f, 0x7f, 0xff, 0x1ff, 0x3ff
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};
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static const int want_arr[9] = {
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0x0, 0x2, 0x6, 0xe, 0x1e, 0x3e, 0x7e, 0xfe, 0x1fe
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};
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struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
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struct ufs_super_block_first *usb1;
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struct ufs_cylinder_group *ucg;
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unsigned start, length, loc, result;
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unsigned pos, want, blockmap, mask, end;
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UFSD(("ENTER, cg %u, goal %u, count %u\n", ucpi->c_cgx, goal, count));
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usb1 = ubh_get_usb_first (uspi);
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ucg = ubh_get_ucg(UCPI_UBH(ucpi));
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@ -747,53 +792,50 @@ static unsigned ufs_bitmap_search (struct super_block * sb,
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start = ucpi->c_frotor >> 3;
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length = ((uspi->s_fpg + 7) >> 3) - start;
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location = ubh_scanc(UCPI_UBH(ucpi), ucpi->c_freeoff + start, length,
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loc = ubh_scanc(uspi, UCPI_UBH(ucpi), ucpi->c_freeoff + start, length,
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(uspi->s_fpb == 8) ? ufs_fragtable_8fpb : ufs_fragtable_other,
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1 << (count - 1 + (uspi->s_fpb & 7)));
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if (location == 0) {
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if (loc == 0) {
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length = start + 1;
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location = ubh_scanc(UCPI_UBH(ucpi), ucpi->c_freeoff, length,
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(uspi->s_fpb == 8) ? ufs_fragtable_8fpb : ufs_fragtable_other,
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1 << (count - 1 + (uspi->s_fpb & 7)));
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if (location == 0) {
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ufs_error (sb, "ufs_bitmap_search",
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"bitmap corrupted on cg %u, start %u, length %u, count %u, freeoff %u\n",
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ucpi->c_cgx, start, length, count, ucpi->c_freeoff);
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loc = ubh_scanc(uspi, UCPI_UBH(ucpi), ucpi->c_freeoff, length,
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(uspi->s_fpb == 8) ? ufs_fragtable_8fpb :
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ufs_fragtable_other,
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1 << (count - 1 + (uspi->s_fpb & 7)));
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if (loc == 0) {
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ufs_error(sb, "ufs_bitmap_search",
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"bitmap corrupted on cg %u, start %u,"
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" length %u, count %u, freeoff %u\n",
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ucpi->c_cgx, start, length, count,
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ucpi->c_freeoff);
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return (unsigned)-1;
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}
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start = 0;
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}
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result = (start + length - location) << 3;
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result = (start + length - loc) << 3;
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ucpi->c_frotor = result;
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/*
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* found the byte in the map
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*/
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blockmap = ubh_blkmap(UCPI_UBH(ucpi), ucpi->c_freeoff, result);
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fragsize = 0;
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for (possition = 0, mask = 1; possition < 8; possition++, mask <<= 1) {
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if (blockmap & mask) {
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if (!(possition & uspi->s_fpbmask))
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fragsize = 1;
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else
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fragsize++;
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}
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else {
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if (fragsize == count) {
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result += possition - count;
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UFSD(("EXIT, result %u\n", result))
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return result;
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}
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fragsize = 0;
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}
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}
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if (fragsize == count) {
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result += possition - count;
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UFSD(("EXIT, result %u\n", result))
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return result;
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}
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ufs_error (sb, "ufs_bitmap_search", "block not in map on cg %u\n", ucpi->c_cgx);
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UFSD(("EXIT (FAILED)\n"))
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for (end = result + 8; result < end; result += uspi->s_fpb) {
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blockmap = ubh_blkmap(UCPI_UBH(ucpi), ucpi->c_freeoff, result);
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blockmap <<= 1;
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mask = mask_arr[count];
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want = want_arr[count];
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for (pos = 0; pos <= uspi->s_fpb - count; pos++) {
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if ((blockmap & mask) == want) {
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UFSD(("EXIT, result %u\n", result));
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return result + pos;
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}
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mask <<= 1;
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want <<= 1;
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}
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}
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ufs_error(sb, "ufs_bitmap_search", "block not in map on cg %u\n",
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ucpi->c_cgx);
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UFSD(("EXIT (FAILED)\n"));
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return (unsigned)-1;
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}
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@ -513,29 +513,3 @@ static inline void ufs_fragacct (struct super_block * sb, unsigned blockmap,
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if (fragsize > 0 && fragsize < uspi->s_fpb)
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fs32_add(sb, &fraglist[fragsize], cnt);
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}
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#define ubh_scanc(ubh,begin,size,table,mask) _ubh_scanc_(uspi,ubh,begin,size,table,mask)
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static inline unsigned _ubh_scanc_(struct ufs_sb_private_info * uspi, struct ufs_buffer_head * ubh,
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unsigned begin, unsigned size, unsigned char * table, unsigned char mask)
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{
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unsigned rest, offset;
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unsigned char * cp;
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offset = begin & ~uspi->s_fmask;
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begin >>= uspi->s_fshift;
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for (;;) {
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if ((offset + size) < uspi->s_fsize)
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rest = size;
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else
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rest = uspi->s_fsize - offset;
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size -= rest;
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cp = ubh->bh[begin]->b_data + offset;
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while ((table[*cp++] & mask) == 0 && --rest);
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if (rest || !size)
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break;
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begin++;
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offset = 0;
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}
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return (size + rest);
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}
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