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/*
* linux/fs/ext3/balloc.c
*
* Copyright (C) 1992, 1993, 1994, 1995
* Remy Card (card@masi.ibp.fr)
* Laboratoire MASI - Institut Blaise Pascal
* Universite Pierre et Marie Curie (Paris VI)
*
* Enhanced block allocation by Stephen Tweedie (sct@redhat.com), 1993
* Big-endian to little-endian byte-swapping/bitmaps by
* David S. Miller (davem@caip.rutgers.edu), 1995
*/
#include <linux/config.h>
#include <linux/sched.h>
#include <linux/fs.h>
#include <linux/jbd.h>
#include <linux/ext3_fs.h>
#include <linux/ext3_jbd.h>
#include <linux/locks.h>
#include <linux/quotaops.h>
/*
* balloc.c contains the blocks allocation and deallocation routines
*/
/*
* The free blocks are managed by bitmaps. A file system contains several
* blocks groups. Each group contains 1 bitmap block for blocks, 1 bitmap
* block for inodes, N blocks for the inode table and data blocks.
*
* The file system contains group descriptors which are located after the
* super block. Each descriptor contains the number of the bitmap block and
* the free blocks count in the block. The descriptors are loaded in memory
* when a file system is mounted (see ext3_read_super).
*/
#define in_range(b, first, len) ((b) >= (first) && (b) <= (first) + (len) - 1)
struct ext3_group_desc * ext3_get_group_desc(struct super_block * sb,
unsigned int block_group,
struct buffer_head ** bh)
{
unsigned long group_desc;
unsigned long desc;
struct ext3_group_desc * gdp;
if (block_group >= sb->u.ext3_sb.s_groups_count) {
ext3_error (sb, "ext3_get_group_desc",
"block_group >= groups_count - "
"block_group = %d, groups_count = %lu",
block_group, sb->u.ext3_sb.s_groups_count);
return NULL;
}
group_desc = block_group / EXT3_DESC_PER_BLOCK(sb);
desc = block_group % EXT3_DESC_PER_BLOCK(sb);
if (!sb->u.ext3_sb.s_group_desc[group_desc]) {
ext3_error (sb, "ext3_get_group_desc",
"Group descriptor not loaded - "
"block_group = %d, group_desc = %lu, desc = %lu",
block_group, group_desc, desc);
return NULL;
}
gdp = (struct ext3_group_desc *)
sb->u.ext3_sb.s_group_desc[group_desc]->b_data;
if (bh)
*bh = sb->u.ext3_sb.s_group_desc[group_desc];
return gdp + desc;
}
/*
* Read the bitmap for a given block_group, reading into the specified
* slot in the superblock's bitmap cache.
*
* Return >=0 on success or a -ve error code.
*/
static int read_block_bitmap (struct super_block * sb,
unsigned int block_group,
unsigned long bitmap_nr)
{
struct ext3_group_desc * gdp;
struct buffer_head * bh = NULL;
int retval = -EIO;
gdp = ext3_get_group_desc (sb, block_group, NULL);
if (!gdp)
goto error_out;
retval = 0;
bh = sb_bread(sb, le32_to_cpu(gdp->bg_block_bitmap));
if (!bh) {
ext3_error (sb, "read_block_bitmap",
"Cannot read block bitmap - "
"block_group = %d, block_bitmap = %lu",
block_group, (unsigned long) gdp->bg_block_bitmap);
retval = -EIO;
}
/*
* On IO error, just leave a zero in the superblock's block pointer for
* this group. The IO will be retried next time.
*/
error_out:
sb->u.ext3_sb.s_block_bitmap_number[bitmap_nr] = block_group;
sb->u.ext3_sb.s_block_bitmap[bitmap_nr] = bh;
return retval;
}
/*
* load_block_bitmap loads the block bitmap for a blocks group
*
* It maintains a cache for the last bitmaps loaded. This cache is managed
* with a LRU algorithm.
*
* Notes:
* 1/ There is one cache per mounted file system.
* 2/ If the file system contains less than EXT3_MAX_GROUP_LOADED groups,
* this function reads the bitmap without maintaining a LRU cache.
*
* Return the slot used to store the bitmap, or a -ve error code.
*/
static int __load_block_bitmap (struct super_block * sb,
unsigned int block_group)
{
int i, j, retval = 0;
unsigned long block_bitmap_number;
struct buffer_head * block_bitmap;
if (block_group >= sb->u.ext3_sb.s_groups_count)
ext3_panic (sb, "load_block_bitmap",
"block_group >= groups_count - "
"block_group = %d, groups_count = %lu",
block_group, sb->u.ext3_sb.s_groups_count);
if (sb->u.ext3_sb.s_groups_count <= EXT3_MAX_GROUP_LOADED) {
if (sb->u.ext3_sb.s_block_bitmap[block_group]) {
if (sb->u.ext3_sb.s_block_bitmap_number[block_group] ==
block_group)
return block_group;
ext3_error (sb, "__load_block_bitmap",
"block_group != block_bitmap_number");
}
retval = read_block_bitmap (sb, block_group, block_group);
if (retval < 0)
return retval;
return block_group;
}
for (i = 0; i < sb->u.ext3_sb.s_loaded_block_bitmaps &&
sb->u.ext3_sb.s_block_bitmap_number[i] != block_group; i++)
;
if (i < sb->u.ext3_sb.s_loaded_block_bitmaps &&
sb->u.ext3_sb.s_block_bitmap_number[i] == block_group) {
block_bitmap_number = sb->u.ext3_sb.s_block_bitmap_number[i];
block_bitmap = sb->u.ext3_sb.s_block_bitmap[i];
for (j = i; j > 0; j--) {
sb->u.ext3_sb.s_block_bitmap_number[j] =
sb->u.ext3_sb.s_block_bitmap_number[j - 1];
sb->u.ext3_sb.s_block_bitmap[j] =
sb->u.ext3_sb.s_block_bitmap[j - 1];
}
sb->u.ext3_sb.s_block_bitmap_number[0] = block_bitmap_number;
sb->u.ext3_sb.s_block_bitmap[0] = block_bitmap;
/*
* There's still one special case here --- if block_bitmap == 0
* then our last attempt to read the bitmap failed and we have
* just ended up caching that failure. Try again to read it.
*/
if (!block_bitmap)
retval = read_block_bitmap (sb, block_group, 0);
} else {
if (sb->u.ext3_sb.s_loaded_block_bitmaps<EXT3_MAX_GROUP_LOADED)
sb->u.ext3_sb.s_loaded_block_bitmaps++;
else
brelse (sb->u.ext3_sb.s_block_bitmap
[EXT3_MAX_GROUP_LOADED - 1]);
for (j = sb->u.ext3_sb.s_loaded_block_bitmaps - 1;
j > 0; j--) {
sb->u.ext3_sb.s_block_bitmap_number[j] =
sb->u.ext3_sb.s_block_bitmap_number[j - 1];
sb->u.ext3_sb.s_block_bitmap[j] =
sb->u.ext3_sb.s_block_bitmap[j - 1];
}
retval = read_block_bitmap (sb, block_group, 0);
}
return retval;
}
/*
* Load the block bitmap for a given block group. First of all do a couple
* of fast lookups for common cases and then pass the request onto the guts
* of the bitmap loader.
*
* Return the slot number of the group in the superblock bitmap cache's on
* success, or a -ve error code.
*
* There is still one inconsistency here --- if the number of groups in this
* filesystems is <= EXT3_MAX_GROUP_LOADED, then we have no way of
* differentiating between a group for which we have never performed a bitmap
* IO request, and a group for which the last bitmap read request failed.
*/
static inline int load_block_bitmap (struct super_block * sb,
unsigned int block_group)
{
int slot;
/*
* Do the lookup for the slot. First of all, check if we're asking
* for the same slot as last time, and did we succeed that last time?
*/
if (sb->u.ext3_sb.s_loaded_block_bitmaps > 0 &&
sb->u.ext3_sb.s_block_bitmap_number[0] == block_group &&
sb->u.ext3_sb.s_block_bitmap[0]) {
return 0;
}
/*
* Or can we do a fast lookup based on a loaded group on a filesystem
* small enough to be mapped directly into the superblock?
*/
else if (sb->u.ext3_sb.s_groups_count <= EXT3_MAX_GROUP_LOADED &&
sb->u.ext3_sb.s_block_bitmap_number[block_group]==block_group
&& sb->u.ext3_sb.s_block_bitmap[block_group]) {
slot = block_group;
}
/*
* If not, then do a full lookup for this block group.
*/
else {
slot = __load_block_bitmap (sb, block_group);
}
/*
* <0 means we just got an error
*/
if (slot < 0)
return slot;
/*
* If it's a valid slot, we may still have cached a previous IO error,
* in which case the bh in the superblock cache will be zero.
*/
if (!sb->u.ext3_sb.s_block_bitmap[slot])
return -EIO;
/*
* Must have been read in OK to get this far.
*/
return slot;
}
/* Free given blocks, update quota and i_blocks field */
void ext3_free_blocks (handle_t *handle, struct inode * inode,
unsigned long block, unsigned long count)
{
struct buffer_head *bitmap_bh;
struct buffer_head *gd_bh;
unsigned long block_group;
unsigned long bit;
unsigned long i;
int bitmap_nr;
unsigned long overflow;
struct super_block * sb;
struct ext3_group_desc * gdp;
struct ext3_super_block * es;
int err = 0, ret;
int dquot_freed_blocks = 0;
sb = inode->i_sb;
if (!sb) {
printk ("ext3_free_blocks: nonexistent device");
return;
}
lock_super (sb);
es = sb->u.ext3_sb.s_es;
if (block < le32_to_cpu(es->s_first_data_block) ||
(block + count) > le32_to_cpu(es->s_blocks_count)) {
ext3_error (sb, "ext3_free_blocks",
"Freeing blocks not in datazone - "
"block = %lu, count = %lu", block, count);
goto error_return;
}
ext3_debug ("freeing block %lu\n", block);
do_more:
overflow = 0;
block_group = (block - le32_to_cpu(es->s_first_data_block)) /
EXT3_BLOCKS_PER_GROUP(sb);
bit = (block - le32_to_cpu(es->s_first_data_block)) %
EXT3_BLOCKS_PER_GROUP(sb);
/*
* Check to see if we are freeing blocks across a group
* boundary.
*/
if (bit + count > EXT3_BLOCKS_PER_GROUP(sb)) {
overflow = bit + count - EXT3_BLOCKS_PER_GROUP(sb);
count -= overflow;
}
bitmap_nr = load_block_bitmap (sb, block_group);
if (bitmap_nr < 0)
goto error_return;
bitmap_bh = sb->u.ext3_sb.s_block_bitmap[bitmap_nr];
gdp = ext3_get_group_desc (sb, block_group, &gd_bh);
if (!gdp)
goto error_return;
if (in_range (le32_to_cpu(gdp->bg_block_bitmap), block, count) ||
in_range (le32_to_cpu(gdp->bg_inode_bitmap), block, count) ||
in_range (block, le32_to_cpu(gdp->bg_inode_table),
sb->u.ext3_sb.s_itb_per_group) ||
in_range (block + count - 1, le32_to_cpu(gdp->bg_inode_table),
sb->u.ext3_sb.s_itb_per_group))
ext3_error (sb, "ext3_free_blocks",
"Freeing blocks in system zones - "
"Block = %lu, count = %lu",
block, count);
/*
* We are about to start releasing blocks in the bitmap,
* so we need undo access.
*/
/* @@@ check errors */
BUFFER_TRACE(bitmap_bh, "getting undo access");
err = ext3_journal_get_undo_access(handle, bitmap_bh);
if (err)
goto error_return;
/*
* We are about to modify some metadata. Call the journal APIs
* to unshare ->b_data if a currently-committing transaction is
* using it
*/
BUFFER_TRACE(gd_bh, "get_write_access");
err = ext3_journal_get_write_access(handle, gd_bh);
if (err)
goto error_return;
BUFFER_TRACE(sb->u.ext3_sb.s_sbh, "get_write_access");
err = ext3_journal_get_write_access(handle, sb->u.ext3_sb.s_sbh);
if (err)
goto error_return;
for (i = 0; i < count; i++) {
/*
* An HJ special. This is expensive...
*/
#ifdef CONFIG_JBD_DEBUG
{
struct buffer_head *debug_bh;
debug_bh = sb_get_hash_table(sb, block + i);
if (debug_bh) {
BUFFER_TRACE(debug_bh, "Deleted!");
if (!bh2jh(bitmap_bh)->b_committed_data)
BUFFER_TRACE(debug_bh,
"No commited data in bitmap");
BUFFER_TRACE2(debug_bh, bitmap_bh, "bitmap");
__brelse(debug_bh);
}
}
#endif
BUFFER_TRACE(bitmap_bh, "clear bit");
if (!ext3_clear_bit (bit + i, bitmap_bh->b_data)) {
ext3_error (sb, __FUNCTION__,
"bit already cleared for block %lu",
block + i);
BUFFER_TRACE(bitmap_bh, "bit already cleared");
} else {
dquot_freed_blocks++;
gdp->bg_free_blocks_count =
cpu_to_le16(le16_to_cpu(gdp->bg_free_blocks_count)+1);
es->s_free_blocks_count =
cpu_to_le32(le32_to_cpu(es->s_free_blocks_count)+1);
}
/* @@@ This prevents newly-allocated data from being
* freed and then reallocated within the same
* transaction.
*
* Ideally we would want to allow that to happen, but to
* do so requires making journal_forget() capable of
* revoking the queued write of a data block, which
* implies blocking on the journal lock. *forget()
* cannot block due to truncate races.
*
* Eventually we can fix this by making journal_forget()
* return a status indicating whether or not it was able
* to revoke the buffer. On successful revoke, it is
* safe not to set the allocation bit in the committed
* bitmap, because we know that there is no outstanding
* activity on the buffer any more and so it is safe to
* reallocate it.
*/
BUFFER_TRACE(bitmap_bh, "clear in b_committed_data");
J_ASSERT_BH(bitmap_bh,
bh2jh(bitmap_bh)->b_committed_data != NULL);
ext3_set_bit(bit + i, bh2jh(bitmap_bh)->b_committed_data);
}
/* We dirtied the bitmap block */
BUFFER_TRACE(bitmap_bh, "dirtied bitmap block");
err = ext3_journal_dirty_metadata(handle, bitmap_bh);
/* And the group descriptor block */
BUFFER_TRACE(gd_bh, "dirtied group descriptor block");
ret = ext3_journal_dirty_metadata(handle, gd_bh);
if (!err) err = ret;
/* And the superblock */
BUFFER_TRACE(sb->u.ext3_sb.s_sbh, "dirtied superblock");
ret = ext3_journal_dirty_metadata(handle, sb->u.ext3_sb.s_sbh);
if (!err) err = ret;
if (overflow && !err) {
block += count;
count = overflow;
goto do_more;
}
sb->s_dirt = 1;
error_return:
ext3_std_error(sb, err);
unlock_super(sb);
if (dquot_freed_blocks)
DQUOT_FREE_BLOCK(inode, dquot_freed_blocks);
return;
}
/* For ext3 allocations, we must not reuse any blocks which are
* allocated in the bitmap buffer's "last committed data" copy. This
* prevents deletes from freeing up the page for reuse until we have
* committed the delete transaction.
*
* If we didn't do this, then deleting something and reallocating it as
* data would allow the old block to be overwritten before the
* transaction committed (because we force data to disk before commit).
* This would lead to corruption if we crashed between overwriting the
* data and committing the delete.
*
* @@@ We may want to make this allocation behaviour conditional on
* data-writes at some point, and disable it for metadata allocations or
* sync-data inodes.
*/
static int ext3_test_allocatable(int nr, struct buffer_head *bh)
{
if (ext3_test_bit(nr, bh->b_data))
return 0;
if (!buffer_jbd(bh) || !bh2jh(bh)->b_committed_data)
return 1;
return !ext3_test_bit(nr, bh2jh(bh)->b_committed_data);
}
/*
* Find an allocatable block in a bitmap. We honour both the bitmap and
* its last-committed copy (if that exists), and perform the "most
* appropriate allocation" algorithm of looking for a free block near
* the initial goal; then for a free byte somewhere in the bitmap; then
* for any free bit in the bitmap.
*/
static int find_next_usable_block(int start,
struct buffer_head *bh, int maxblocks)
{
int here, next;
char *p, *r;
if (start > 0) {
/*
* The goal was occupied; search forward for a free
* block within the next XX blocks.
*
* end_goal is more or less random, but it has to be
* less than EXT3_BLOCKS_PER_GROUP. Aligning up to the
* next 64-bit boundary is simple..
*/
int end_goal = (start + 63) & ~63;
here = ext3_find_next_zero_bit(bh->b_data, end_goal, start);
if (here < end_goal && ext3_test_allocatable(here, bh))
return here;
ext3_debug ("Bit not found near goal\n");
}
here = start;
if (here < 0)
here = 0;
/*
* There has been no free block found in the near vicinity of
* the goal: do a search forward through the block groups,
* searching in each group first for an entire free byte in the
* bitmap and then for any free bit.
*
* Search first in the remainder of the current group
*/
p = ((char *) bh->b_data) + (here >> 3);
r = memscan(p, 0, (maxblocks - here + 7) >> 3);
next = (r - ((char *) bh->b_data)) << 3;
if (next < maxblocks && ext3_test_allocatable(next, bh))
return next;
/* The bitmap search --- search forward alternately
* through the actual bitmap and the last-committed copy
* until we find a bit free in both. */
while (here < maxblocks) {
next = ext3_find_next_zero_bit ((unsigned long *) bh->b_data,
maxblocks, here);
if (next >= maxblocks)
return -1;
if (ext3_test_allocatable(next, bh))
return next;
J_ASSERT_BH(bh, bh2jh(bh)->b_committed_data);
here = ext3_find_next_zero_bit
((unsigned long *) bh2jh(bh)->b_committed_data,
maxblocks, next);
}
return -1;
}
/*
* ext3_new_block uses a goal block to assist allocation. If the goal is
* free, or there is a free block within 32 blocks of the goal, that block
* is allocated. Otherwise a forward search is made for a free block; within
* each block group the search first looks for an entire free byte in the block
* bitmap, and then for any free bit if that fails.
* This function also updates quota and i_blocks field.
*/
int ext3_new_block (handle_t *handle, struct inode * inode,
unsigned long goal, u32 * prealloc_count,
u32 * prealloc_block, int * errp)
{
struct buffer_head * bh, *bhtmp;
struct buffer_head * bh2;
#if 0
char * p, * r;
#endif
int i, j, k, tmp, alloctmp;
int bitmap_nr;
int fatal = 0, err;
struct super_block * sb;
struct ext3_group_desc * gdp;
struct ext3_super_block * es;
#ifdef EXT3FS_DEBUG
static int goal_hits = 0, goal_attempts = 0;
#endif
*errp = -ENOSPC;
sb = inode->i_sb;
if (!sb) {
printk ("ext3_new_block: nonexistent device");
return 0;
}
/*
* Check quota for allocation of this block.
*/
if (DQUOT_ALLOC_BLOCK(inode, 1)) {
*errp = -EDQUOT;
return 0;
}
lock_super (sb);
es = sb->u.ext3_sb.s_es;
if (le32_to_cpu(es->s_free_blocks_count) <=
le32_to_cpu(es->s_r_blocks_count) &&
((sb->u.ext3_sb.s_resuid != current->fsuid) &&
(sb->u.ext3_sb.s_resgid == 0 ||
!in_group_p (sb->u.ext3_sb.s_resgid)) &&
!capable(CAP_SYS_RESOURCE)))
goto out;
ext3_debug ("goal=%lu.\n", goal);
/*
* First, test whether the goal block is free.
*/
if (goal < le32_to_cpu(es->s_first_data_block) ||
goal >= le32_to_cpu(es->s_blocks_count))
goal = le32_to_cpu(es->s_first_data_block);
i = (goal - le32_to_cpu(es->s_first_data_block)) /
EXT3_BLOCKS_PER_GROUP(sb);
gdp = ext3_get_group_desc (sb, i, &bh2);
if (!gdp)
goto io_error;
if (le16_to_cpu(gdp->bg_free_blocks_count) > 0) {
j = ((goal - le32_to_cpu(es->s_first_data_block)) %
EXT3_BLOCKS_PER_GROUP(sb));
#ifdef EXT3FS_DEBUG
if (j)
goal_attempts++;
#endif
bitmap_nr = load_block_bitmap (sb, i);
if (bitmap_nr < 0)
goto io_error;
bh = sb->u.ext3_sb.s_block_bitmap[bitmap_nr];
ext3_debug ("goal is at %d:%d.\n", i, j);
if (ext3_test_allocatable(j, bh)) {
#ifdef EXT3FS_DEBUG
goal_hits++;
ext3_debug ("goal bit allocated.\n");
#endif
goto got_block;
}
j = find_next_usable_block(j, bh, EXT3_BLOCKS_PER_GROUP(sb));
if (j >= 0)
goto search_back;
}
ext3_debug ("Bit not found in block group %d.\n", i);
/*
* Now search the rest of the groups. We assume that
* i and gdp correctly point to the last group visited.
*/
for (k = 0; k < sb->u.ext3_sb.s_groups_count; k++) {
i++;
if (i >= sb->u.ext3_sb.s_groups_count)
i = 0;
gdp = ext3_get_group_desc (sb, i, &bh2);
if (!gdp) {
*errp = -EIO;
goto out;
}
if (le16_to_cpu(gdp->bg_free_blocks_count) > 0) {
bitmap_nr = load_block_bitmap (sb, i);
if (bitmap_nr < 0)
goto io_error;
bh = sb->u.ext3_sb.s_block_bitmap[bitmap_nr];
j = find_next_usable_block(-1, bh,
EXT3_BLOCKS_PER_GROUP(sb));
if (j >= 0)
goto search_back;
}
}
/* No space left on the device */
unlock_super (sb);
return 0;
search_back:
/*
* We have succeeded in finding a free byte in the block
* bitmap. Now search backwards up to 7 bits to find the
* start of this group of free blocks.
*/
for ( k = 0;
k < 7 && j > 0 && ext3_test_allocatable(j - 1, bh);
k++, j--)
;
got_block:
ext3_debug ("using block group %d(%d)\n", i, gdp->bg_free_blocks_count);
/* Make sure we use undo access for the bitmap, because it is
critical that we do the frozen_data COW on bitmap buffers in
all cases even if the buffer is in BJ_Forget state in the
committing transaction. */
BUFFER_TRACE(bh, "get undo access for marking new block");
fatal = ext3_journal_get_undo_access(handle, bh);
if (fatal) goto out;
BUFFER_TRACE(bh2, "get_write_access");
fatal = ext3_journal_get_write_access(handle, bh2);
if (fatal) goto out;
BUFFER_TRACE(sb->u.ext3_sb.s_sbh, "get_write_access");
fatal = ext3_journal_get_write_access(handle, sb->u.ext3_sb.s_sbh);
if (fatal) goto out;
tmp = j + i * EXT3_BLOCKS_PER_GROUP(sb)
+ le32_to_cpu(es->s_first_data_block);
if (tmp == le32_to_cpu(gdp->bg_block_bitmap) ||
tmp == le32_to_cpu(gdp->bg_inode_bitmap) ||
in_range (tmp, le32_to_cpu(gdp->bg_inode_table),
sb->u.ext3_sb.s_itb_per_group))
ext3_error (sb, "ext3_new_block",
"Allocating block in system zone - "
"block = %u", tmp);
/* The superblock lock should guard against anybody else beating
* us to this point! */
J_ASSERT_BH(bh, !ext3_test_bit(j, bh->b_data));
BUFFER_TRACE(bh, "setting bitmap bit");
ext3_set_bit(j, bh->b_data);
#ifdef CONFIG_JBD_DEBUG
{
struct buffer_head *debug_bh;
/* Record bitmap buffer state in the newly allocated block */
debug_bh = sb_get_hash_table(sb, tmp);
if (debug_bh) {
BUFFER_TRACE(debug_bh, "state when allocated");
BUFFER_TRACE2(debug_bh, bh, "bitmap state");
brelse(debug_bh);
}
}
#endif
if (buffer_jbd(bh) && bh2jh(bh)->b_committed_data)
J_ASSERT_BH(bh, !ext3_test_bit(j, bh2jh(bh)->b_committed_data));
bhtmp = bh;
alloctmp = j;
ext3_debug ("found bit %d\n", j);
/*
* Do block preallocation now if required.
*/
#ifdef EXT3_PREALLOCATE
/*
* akpm: this is not enabled for ext3. Need to use
* ext3_test_allocatable()
*/
/* Writer: ->i_prealloc* */
if (prealloc_count && !*prealloc_count) {
int prealloc_goal;
unsigned long next_block = tmp + 1;
prealloc_goal = es->s_prealloc_blocks ?
es->s_prealloc_blocks : EXT3_DEFAULT_PREALLOC_BLOCKS;
*prealloc_block = next_block;
/* Writer: end */
for (k = 1;
k < prealloc_goal && (j + k) < EXT3_BLOCKS_PER_GROUP(sb);
k++, next_block++) {
if (DQUOT_PREALLOC_BLOCK(inode, 1))
break;
/* Writer: ->i_prealloc* */
if (*prealloc_block + *prealloc_count != next_block ||
ext3_set_bit (j + k, bh->b_data)) {
/* Writer: end */
DQUOT_FREE_BLOCK(inode, 1);
break;
}
(*prealloc_count)++;
/* Writer: end */
}
/*
* As soon as we go for per-group spinlocks we'll need these
* done inside the loop above.
*/
gdp->bg_free_blocks_count =
cpu_to_le16(le16_to_cpu(gdp->bg_free_blocks_count) -
(k - 1));
es->s_free_blocks_count =
cpu_to_le32(le32_to_cpu(es->s_free_blocks_count) -
(k - 1));
ext3_debug ("Preallocated a further %lu bits.\n",
(k - 1));
}
#endif
j = tmp;
BUFFER_TRACE(bh, "journal_dirty_metadata for bitmap block");
err = ext3_journal_dirty_metadata(handle, bh);
if (!fatal) fatal = err;
if (j >= le32_to_cpu(es->s_blocks_count)) {
ext3_error (sb, "ext3_new_block",
"block(%d) >= blocks count(%d) - "
"block_group = %d, es == %p ",j,
le32_to_cpu(es->s_blocks_count), i, es);
goto out;
}
/*
* It is up to the caller to add the new buffer to a journal
* list of some description. We don't know in advance whether
* the caller wants to use it as metadata or data.
*/
ext3_debug ("allocating block %d. "
"Goal hits %d of %d.\n", j, goal_hits, goal_attempts);
gdp->bg_free_blocks_count =
cpu_to_le16(le16_to_cpu(gdp->bg_free_blocks_count) - 1);
es->s_free_blocks_count =
cpu_to_le32(le32_to_cpu(es->s_free_blocks_count) - 1);
BUFFER_TRACE(bh2, "journal_dirty_metadata for group descriptor");
err = ext3_journal_dirty_metadata(handle, bh2);
if (!fatal) fatal = err;
BUFFER_TRACE(bh, "journal_dirty_metadata for superblock");
err = ext3_journal_dirty_metadata(handle, sb->u.ext3_sb.s_sbh);
if (!fatal) fatal = err;
sb->s_dirt = 1;
if (fatal)
goto out;
unlock_super (sb);
*errp = 0;
return j;
io_error:
*errp = -EIO;
out:
if (fatal) {
*errp = fatal;
ext3_std_error(sb, fatal);
}
unlock_super (sb);
return 0;
}
unsigned long ext3_count_free_blocks (struct super_block * sb)
{
#ifdef EXT3FS_DEBUG
struct ext3_super_block * es;
unsigned long desc_count, bitmap_count, x;
int bitmap_nr;
struct ext3_group_desc * gdp;
int i;
lock_super (sb);
es = sb->u.ext3_sb.s_es;
desc_count = 0;
bitmap_count = 0;
gdp = NULL;
for (i = 0; i < sb->u.ext3_sb.s_groups_count; i++) {
gdp = ext3_get_group_desc (sb, i, NULL);
if (!gdp)
continue;
desc_count += le16_to_cpu(gdp->bg_free_blocks_count);
bitmap_nr = load_block_bitmap (sb, i);
if (bitmap_nr < 0)
continue;
x = ext3_count_free (sb->u.ext3_sb.s_block_bitmap[bitmap_nr],
sb->s_blocksize);
printk ("group %d: stored = %d, counted = %lu\n",
i, le16_to_cpu(gdp->bg_free_blocks_count), x);
bitmap_count += x;
}
printk("ext3_count_free_blocks: stored = %lu, computed = %lu, %lu\n",
le32_to_cpu(es->s_free_blocks_count), desc_count, bitmap_count);
unlock_super (sb);
return bitmap_count;
#else
return le32_to_cpu(sb->u.ext3_sb.s_es->s_free_blocks_count);
#endif
}
static inline int block_in_use (unsigned long block,
struct super_block * sb,
unsigned char * map)
{
return ext3_test_bit ((block -
le32_to_cpu(sb->u.ext3_sb.s_es->s_first_data_block)) %
EXT3_BLOCKS_PER_GROUP(sb), map);
}
static inline int test_root(int a, int b)
{
if (a == 0)
return 1;
while (1) {
if (a == 1)
return 1;
if (a % b)
return 0;
a = a / b;
}
}
int ext3_group_sparse(int group)
{
return (test_root(group, 3) || test_root(group, 5) ||
test_root(group, 7));
}
/**
* ext3_bg_has_super - number of blocks used by the superblock in group
* @sb: superblock for filesystem
* @group: group number to check
*
* Return the number of blocks used by the superblock (primary or backup)
* in this group. Currently this will be only 0 or 1.
*/
int ext3_bg_has_super(struct super_block *sb, int group)
{
if (EXT3_HAS_RO_COMPAT_FEATURE(sb,EXT3_FEATURE_RO_COMPAT_SPARSE_SUPER)&&
!ext3_group_sparse(group))
return 0;
return 1;
}
/**
* ext3_bg_num_gdb - number of blocks used by the group table in group
* @sb: superblock for filesystem
* @group: group number to check
*
* Return the number of blocks used by the group descriptor table
* (primary or backup) in this group. In the future there may be a
* different number of descriptor blocks in each group.
*/
unsigned long ext3_bg_num_gdb(struct super_block *sb, int group)
{
if (EXT3_HAS_RO_COMPAT_FEATURE(sb,EXT3_FEATURE_RO_COMPAT_SPARSE_SUPER)&&
!ext3_group_sparse(group))
return 0;
return EXT3_SB(sb)->s_gdb_count;
}
#ifdef CONFIG_EXT3_CHECK
/* Called at mount-time, super-block is locked */
void ext3_check_blocks_bitmap (struct super_block * sb)
{
struct buffer_head * bh;
struct ext3_super_block * es;
unsigned long desc_count, bitmap_count, x, j;
unsigned long desc_blocks;
int bitmap_nr;
struct ext3_group_desc * gdp;
int i;
es = sb->u.ext3_sb.s_es;
desc_count = 0;
bitmap_count = 0;
gdp = NULL;
for (i = 0; i < sb->u.ext3_sb.s_groups_count; i++) {
gdp = ext3_get_group_desc (sb, i, NULL);
if (!gdp)
continue;
desc_count += le16_to_cpu(gdp->bg_free_blocks_count);
bitmap_nr = load_block_bitmap (sb, i);
if (bitmap_nr < 0)
continue;
bh = EXT3_SB(sb)->s_block_bitmap[bitmap_nr];
if (ext3_bg_has_super(sb, i) && !ext3_test_bit(0, bh->b_data))
ext3_error(sb, __FUNCTION__,
"Superblock in group %d is marked free", i);
desc_blocks = ext3_bg_num_gdb(sb, i);
for (j = 0; j < desc_blocks; j++)
if (!ext3_test_bit(j + 1, bh->b_data))
ext3_error(sb, __FUNCTION__,
"Descriptor block #%ld in group "
"%d is marked free", j, i);
if (!block_in_use (le32_to_cpu(gdp->bg_block_bitmap),
sb, bh->b_data))
ext3_error (sb, "ext3_check_blocks_bitmap",
"Block bitmap for group %d is marked free",
i);
if (!block_in_use (le32_to_cpu(gdp->bg_inode_bitmap),
sb, bh->b_data))
ext3_error (sb, "ext3_check_blocks_bitmap",
"Inode bitmap for group %d is marked free",
i);
for (j = 0; j < sb->u.ext3_sb.s_itb_per_group; j++)
if (!block_in_use (le32_to_cpu(gdp->bg_inode_table) + j,
sb, bh->b_data))
ext3_error (sb, "ext3_check_blocks_bitmap",
"Block #%d of the inode table in "
"group %d is marked free", j, i);
x = ext3_count_free (bh, sb->s_blocksize);
if (le16_to_cpu(gdp->bg_free_blocks_count) != x)
ext3_error (sb, "ext3_check_blocks_bitmap",
"Wrong free blocks count for group %d, "
"stored = %d, counted = %lu", i,
le16_to_cpu(gdp->bg_free_blocks_count), x);
bitmap_count += x;
}
if (le32_to_cpu(es->s_free_blocks_count) != bitmap_count)
ext3_error (sb, "ext3_check_blocks_bitmap",
"Wrong free blocks count in super block, "
"stored = %lu, counted = %lu",
(unsigned long)le32_to_cpu(es->s_free_blocks_count),
bitmap_count);
}
#endif
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