original development tree for Linux kernel GTP module; now long in mainline.
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/*
* linux/fs/affs/bitmap.c
*
* (c) 1996 Hans-Joachim Widmaier
*
* bitmap.c contains the code that handles all bitmap related stuff -
* block allocation, deallocation, calculation of free space.
*/
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
12 years ago
#include <linux/slab.h>
#include "affs.h"
u32
affs_count_free_blocks(struct super_block *sb)
{
struct affs_bm_info *bm;
u32 free;
int i;
pr_debug("AFFS: count_free_blocks()\n");
if (sb->s_flags & MS_RDONLY)
return 0;
mutex_lock(&AFFS_SB(sb)->s_bmlock);
bm = AFFS_SB(sb)->s_bitmap;
free = 0;
for (i = AFFS_SB(sb)->s_bmap_count; i > 0; bm++, i--)
free += bm->bm_free;
mutex_unlock(&AFFS_SB(sb)->s_bmlock);
return free;
}
void
affs_free_block(struct super_block *sb, u32 block)
{
struct affs_sb_info *sbi = AFFS_SB(sb);
struct affs_bm_info *bm;
struct buffer_head *bh;
u32 blk, bmap, bit, mask, tmp;
__be32 *data;
pr_debug("AFFS: free_block(%u)\n", block);
if (block > sbi->s_partition_size)
goto err_range;
blk = block - sbi->s_reserved;
bmap = blk / sbi->s_bmap_bits;
bit = blk % sbi->s_bmap_bits;
bm = &sbi->s_bitmap[bmap];
mutex_lock(&sbi->s_bmlock);
bh = sbi->s_bmap_bh;
if (sbi->s_last_bmap != bmap) {
affs_brelse(bh);
bh = affs_bread(sb, bm->bm_key);
if (!bh)
goto err_bh_read;
sbi->s_bmap_bh = bh;
sbi->s_last_bmap = bmap;
}
mask = 1 << (bit & 31);
data = (__be32 *)bh->b_data + bit / 32 + 1;
/* mark block free */
tmp = be32_to_cpu(*data);
if (tmp & mask)
goto err_free;
*data = cpu_to_be32(tmp | mask);
/* fix checksum */
tmp = be32_to_cpu(*(__be32 *)bh->b_data);
*(__be32 *)bh->b_data = cpu_to_be32(tmp - mask);
mark_buffer_dirty(bh);
affs_mark_sb_dirty(sb);
bm->bm_free++;
mutex_unlock(&sbi->s_bmlock);
return;
err_free:
affs_warning(sb,"affs_free_block","Trying to free block %u which is already free", block);
mutex_unlock(&sbi->s_bmlock);
return;
err_bh_read:
affs_error(sb,"affs_free_block","Cannot read bitmap block %u", bm->bm_key);
sbi->s_bmap_bh = NULL;
sbi->s_last_bmap = ~0;
mutex_unlock(&sbi->s_bmlock);
return;
err_range:
affs_error(sb, "affs_free_block","Block %u outside partition", block);
return;
}
/*
* Allocate a block in the given allocation zone.
* Since we have to byte-swap the bitmap on little-endian
* machines, this is rather expensive. Therefore we will
* preallocate up to 16 blocks from the same word, if
* possible. We are not doing preallocations in the
* header zone, though.
*/
u32
affs_alloc_block(struct inode *inode, u32 goal)
{
struct super_block *sb;
struct affs_sb_info *sbi;
struct affs_bm_info *bm;
struct buffer_head *bh;
__be32 *data, *enddata;
u32 blk, bmap, bit, mask, mask2, tmp;
int i;
sb = inode->i_sb;
sbi = AFFS_SB(sb);
pr_debug("AFFS: balloc(inode=%lu,goal=%u): ", inode->i_ino, goal);
if (AFFS_I(inode)->i_pa_cnt) {
pr_debug("%d\n", AFFS_I(inode)->i_lastalloc+1);
AFFS_I(inode)->i_pa_cnt--;
return ++AFFS_I(inode)->i_lastalloc;
}
if (!goal || goal > sbi->s_partition_size) {
if (goal)
affs_warning(sb, "affs_balloc", "invalid goal %d", goal);
//if (!AFFS_I(inode)->i_last_block)
// affs_warning(sb, "affs_balloc", "no last alloc block");
goal = sbi->s_reserved;
}
blk = goal - sbi->s_reserved;
bmap = blk / sbi->s_bmap_bits;
bm = &sbi->s_bitmap[bmap];
mutex_lock(&sbi->s_bmlock);
if (bm->bm_free)
goto find_bmap_bit;
find_bmap:
/* search for the next bmap buffer with free bits */
i = sbi->s_bmap_count;
do {
if (--i < 0)
goto err_full;
bmap++;
bm++;
if (bmap < sbi->s_bmap_count)
continue;
/* restart search at zero */
bmap = 0;
bm = sbi->s_bitmap;
} while (!bm->bm_free);
blk = bmap * sbi->s_bmap_bits;
find_bmap_bit:
bh = sbi->s_bmap_bh;
if (sbi->s_last_bmap != bmap) {
affs_brelse(bh);
bh = affs_bread(sb, bm->bm_key);
if (!bh)
goto err_bh_read;
sbi->s_bmap_bh = bh;
sbi->s_last_bmap = bmap;
}
/* find an unused block in this bitmap block */
bit = blk % sbi->s_bmap_bits;
data = (__be32 *)bh->b_data + bit / 32 + 1;
enddata = (__be32 *)((u8 *)bh->b_data + sb->s_blocksize);
mask = ~0UL << (bit & 31);
blk &= ~31UL;
tmp = be32_to_cpu(*data);
if (tmp & mask)
goto find_bit;
/* scan the rest of the buffer */
do {
blk += 32;
if (++data >= enddata)
/* didn't find something, can only happen
* if scan didn't start at 0, try next bmap
*/
goto find_bmap;
} while (!*data);
tmp = be32_to_cpu(*data);
mask = ~0;
find_bit:
/* finally look for a free bit in the word */
bit = ffs(tmp & mask) - 1;
blk += bit + sbi->s_reserved;
mask2 = mask = 1 << (bit & 31);
AFFS_I(inode)->i_lastalloc = blk;
/* prealloc as much as possible within this word */
while ((mask2 <<= 1)) {
if (!(tmp & mask2))
break;
AFFS_I(inode)->i_pa_cnt++;
mask |= mask2;
}
bm->bm_free -= AFFS_I(inode)->i_pa_cnt + 1;
*data = cpu_to_be32(tmp & ~mask);
/* fix checksum */
tmp = be32_to_cpu(*(__be32 *)bh->b_data);
*(__be32 *)bh->b_data = cpu_to_be32(tmp + mask);
mark_buffer_dirty(bh);
affs_mark_sb_dirty(sb);
mutex_unlock(&sbi->s_bmlock);
pr_debug("%d\n", blk);
return blk;
err_bh_read:
affs_error(sb,"affs_read_block","Cannot read bitmap block %u", bm->bm_key);
sbi->s_bmap_bh = NULL;
sbi->s_last_bmap = ~0;
err_full:
mutex_unlock(&sbi->s_bmlock);
pr_debug("failed\n");
return 0;
}
int affs_init_bitmap(struct super_block *sb, int *flags)
{
struct affs_bm_info *bm;
struct buffer_head *bmap_bh = NULL, *bh = NULL;
__be32 *bmap_blk;
u32 size, blk, end, offset, mask;
int i, res = 0;
struct affs_sb_info *sbi = AFFS_SB(sb);
if (*flags & MS_RDONLY)
return 0;
if (!AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->bm_flag) {
printk(KERN_NOTICE "AFFS: Bitmap invalid - mounting %s read only\n",
sb->s_id);
*flags |= MS_RDONLY;
return 0;
}
sbi->s_last_bmap = ~0;
sbi->s_bmap_bh = NULL;
sbi->s_bmap_bits = sb->s_blocksize * 8 - 32;
sbi->s_bmap_count = (sbi->s_partition_size - sbi->s_reserved +
sbi->s_bmap_bits - 1) / sbi->s_bmap_bits;
size = sbi->s_bmap_count * sizeof(*bm);
bm = sbi->s_bitmap = kzalloc(size, GFP_KERNEL);
if (!sbi->s_bitmap) {
printk(KERN_ERR "AFFS: Bitmap allocation failed\n");
return -ENOMEM;
}
bmap_blk = (__be32 *)sbi->s_root_bh->b_data;
blk = sb->s_blocksize / 4 - 49;
end = blk + 25;
for (i = sbi->s_bmap_count; i > 0; bm++, i--) {
affs_brelse(bh);
bm->bm_key = be32_to_cpu(bmap_blk[blk]);
bh = affs_bread(sb, bm->bm_key);
if (!bh) {
printk(KERN_ERR "AFFS: Cannot read bitmap\n");
res = -EIO;
goto out;
}
if (affs_checksum_block(sb, bh)) {
printk(KERN_WARNING "AFFS: Bitmap %u invalid - mounting %s read only.\n",
bm->bm_key, sb->s_id);
*flags |= MS_RDONLY;
goto out;
}
pr_debug("AFFS: read bitmap block %d: %d\n", blk, bm->bm_key);
bm->bm_free = memweight(bh->b_data + 4, sb->s_blocksize - 4);
/* Don't try read the extension if this is the last block,
* but we also need the right bm pointer below
*/
if (++blk < end || i == 1)
continue;
if (bmap_bh)
affs_brelse(bmap_bh);
bmap_bh = affs_bread(sb, be32_to_cpu(bmap_blk[blk]));
if (!bmap_bh) {
printk(KERN_ERR "AFFS: Cannot read bitmap extension\n");
res = -EIO;
goto out;
}
bmap_blk = (__be32 *)bmap_bh->b_data;
blk = 0;
end = sb->s_blocksize / 4 - 1;
}
offset = (sbi->s_partition_size - sbi->s_reserved) % sbi->s_bmap_bits;
mask = ~(0xFFFFFFFFU << (offset & 31));
pr_debug("last word: %d %d %d\n", offset, offset / 32 + 1, mask);
offset = offset / 32 + 1;
if (mask) {
u32 old, new;
/* Mark unused bits in the last word as allocated */
old = be32_to_cpu(((__be32 *)bh->b_data)[offset]);
new = old & mask;
//if (old != new) {
((__be32 *)bh->b_data)[offset] = cpu_to_be32(new);
/* fix checksum */
//new -= old;
//old = be32_to_cpu(*(__be32 *)bh->b_data);
//*(__be32 *)bh->b_data = cpu_to_be32(old - new);
//mark_buffer_dirty(bh);
//}
/* correct offset for the bitmap count below */
//offset++;
}
while (++offset < sb->s_blocksize / 4)
((__be32 *)bh->b_data)[offset] = 0;
((__be32 *)bh->b_data)[0] = 0;
((__be32 *)bh->b_data)[0] = cpu_to_be32(-affs_checksum_block(sb, bh));
mark_buffer_dirty(bh);
/* recalculate bitmap count for last block */
bm--;
bm->bm_free = memweight(bh->b_data + 4, sb->s_blocksize - 4);
out:
affs_brelse(bh);
affs_brelse(bmap_bh);
return res;
}
void affs_free_bitmap(struct super_block *sb)
{
struct affs_sb_info *sbi = AFFS_SB(sb);
if (!sbi->s_bitmap)
return;
affs_brelse(sbi->s_bmap_bh);
sbi->s_bmap_bh = NULL;
sbi->s_last_bmap = ~0;
kfree(sbi->s_bitmap);
sbi->s_bitmap = NULL;
}