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linux-zen-server/fs/reiserfs/bitmap.c

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Initial commit
2023-08-30 17:53:23 +02:00
/*
* Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
*/
/* Reiserfs block (de)allocator, bitmap-based. */
#include <linux/time.h>
#include "reiserfs.h"
#include <linux/errno.h>
#include <linux/buffer_head.h>
#include <linux/kernel.h>
#include <linux/pagemap.h>
#include <linux/vmalloc.h>
#include <linux/quotaops.h>
#include <linux/seq_file.h>
#define PREALLOCATION_SIZE 9
/* different reiserfs block allocator options */
#define SB_ALLOC_OPTS(s) (REISERFS_SB(s)->s_alloc_options.bits)
#define _ALLOC_concentrating_formatted_nodes 0
#define _ALLOC_displacing_large_files 1
#define _ALLOC_displacing_new_packing_localities 2
#define _ALLOC_old_hashed_relocation 3
#define _ALLOC_new_hashed_relocation 4
#define _ALLOC_skip_busy 5
#define _ALLOC_displace_based_on_dirid 6
#define _ALLOC_hashed_formatted_nodes 7
#define _ALLOC_old_way 8
#define _ALLOC_hundredth_slices 9
#define _ALLOC_dirid_groups 10
#define _ALLOC_oid_groups 11
#define _ALLOC_packing_groups 12
#define concentrating_formatted_nodes(s) test_bit(_ALLOC_concentrating_formatted_nodes, &SB_ALLOC_OPTS(s))
#define displacing_large_files(s) test_bit(_ALLOC_displacing_large_files, &SB_ALLOC_OPTS(s))
#define displacing_new_packing_localities(s) test_bit(_ALLOC_displacing_new_packing_localities, &SB_ALLOC_OPTS(s))
#define SET_OPTION(optname) \
do { \
reiserfs_info(s, "block allocator option \"%s\" is set", #optname); \
set_bit(_ALLOC_ ## optname , &SB_ALLOC_OPTS(s)); \
} while(0)
#define TEST_OPTION(optname, s) \
test_bit(_ALLOC_ ## optname , &SB_ALLOC_OPTS(s))
static inline void get_bit_address(struct super_block *s,
b_blocknr_t block,
unsigned int *bmap_nr,
unsigned int *offset)
{
/*
* It is in the bitmap block number equal to the block
* number divided by the number of bits in a block.
*/
*bmap_nr = block >> (s->s_blocksize_bits + 3);
/* Within that bitmap block it is located at bit offset *offset. */
*offset = block & ((s->s_blocksize << 3) - 1);
}
int is_reusable(struct super_block *s, b_blocknr_t block, int bit_value)
{
unsigned int bmap, offset;
unsigned int bmap_count = reiserfs_bmap_count(s);
if (block == 0 || block >= SB_BLOCK_COUNT(s)) {
reiserfs_error(s, "vs-4010",
"block number is out of range %lu (%u)",
block, SB_BLOCK_COUNT(s));
return 0;
}
get_bit_address(s, block, &bmap, &offset);
/*
* Old format filesystem? Unlikely, but the bitmaps are all
* up front so we need to account for it.
*/
if (unlikely(test_bit(REISERFS_OLD_FORMAT,
&REISERFS_SB(s)->s_properties))) {
b_blocknr_t bmap1 = REISERFS_SB(s)->s_sbh->b_blocknr + 1;
if (block >= bmap1 &&
block <= bmap1 + bmap_count) {
reiserfs_error(s, "vs-4019", "bitmap block %lu(%u) "
"can't be freed or reused",
block, bmap_count);
return 0;
}
} else {
if (offset == 0) {
reiserfs_error(s, "vs-4020", "bitmap block %lu(%u) "
"can't be freed or reused",
block, bmap_count);
return 0;
}
}
if (bmap >= bmap_count) {
reiserfs_error(s, "vs-4030", "bitmap for requested block "
"is out of range: block=%lu, bitmap_nr=%u",
block, bmap);
return 0;
}
if (bit_value == 0 && block == SB_ROOT_BLOCK(s)) {
reiserfs_error(s, "vs-4050", "this is root block (%u), "
"it must be busy", SB_ROOT_BLOCK(s));
return 0;
}
return 1;
}
/*
* Searches in journal structures for a given block number (bmap, off).
* If block is found in reiserfs journal it suggests next free block
* candidate to test.
*/
static inline int is_block_in_journal(struct super_block *s, unsigned int bmap,
int off, int *next)
{
b_blocknr_t tmp;
if (reiserfs_in_journal(s, bmap, off, 1, &tmp)) {
if (tmp) { /* hint supplied */
*next = tmp;
PROC_INFO_INC(s, scan_bitmap.in_journal_hint);
} else {
(*next) = off + 1; /* inc offset to avoid looping. */
PROC_INFO_INC(s, scan_bitmap.in_journal_nohint);
}
PROC_INFO_INC(s, scan_bitmap.retry);
return 1;
}
return 0;
}
/*
* Searches for a window of zero bits with given minimum and maximum
* lengths in one bitmap block
*/
static int scan_bitmap_block(struct reiserfs_transaction_handle *th,
unsigned int bmap_n, int *beg, int boundary,
int min, int max, int unfm)
{
struct super_block *s = th->t_super;
struct reiserfs_bitmap_info *bi = &SB_AP_BITMAP(s)[bmap_n];
struct buffer_head *bh;
int end, next;
int org = *beg;
BUG_ON(!th->t_trans_id);
RFALSE(bmap_n >= reiserfs_bmap_count(s), "Bitmap %u is out of "
"range (0..%u)", bmap_n, reiserfs_bmap_count(s) - 1);
PROC_INFO_INC(s, scan_bitmap.bmap);
if (!bi) {
reiserfs_error(s, "jdm-4055", "NULL bitmap info pointer "
"for bitmap %d", bmap_n);
return 0;
}
bh = reiserfs_read_bitmap_block(s, bmap_n);
if (bh == NULL)
return 0;
while (1) {
cont:
if (bi->free_count < min) {
brelse(bh);
return 0; /* No free blocks in this bitmap */
}
/* search for a first zero bit -- beginning of a window */
*beg = reiserfs_find_next_zero_le_bit
((unsigned long *)(bh->b_data), boundary, *beg);
/*
* search for a zero bit fails or the rest of bitmap block
* cannot contain a zero window of minimum size
*/
if (*beg + min > boundary) {
brelse(bh);
return 0;
}
if (unfm && is_block_in_journal(s, bmap_n, *beg, beg))
continue;
/* first zero bit found; we check next bits */
for (end = *beg + 1;; end++) {
if (end >= *beg + max || end >= boundary
|| reiserfs_test_le_bit(end, bh->b_data)) {
next = end;
break;
}
/*
* finding the other end of zero bit window requires
* looking into journal structures (in case of
* searching for free blocks for unformatted nodes)
*/
if (unfm && is_block_in_journal(s, bmap_n, end, &next))
break;
}
/*
* now (*beg) points to beginning of zero bits window,
* (end) points to one bit after the window end
*/
/* found window of proper size */
if (end - *beg >= min) {
int i;
reiserfs_prepare_for_journal(s, bh, 1);
/*
* try to set all blocks used checking are
* they still free
*/
for (i = *beg; i < end; i++) {
/* Don't check in journal again. */
if (reiserfs_test_and_set_le_bit
(i, bh->b_data)) {
/*
* bit was set by another process while
* we slept in prepare_for_journal()
*/
PROC_INFO_INC(s, scan_bitmap.stolen);
/*
* we can continue with smaller set
* of allocated blocks, if length of
* this set is more or equal to `min'
*/
if (i >= *beg + min) {
end = i;
break;
}
/*
* otherwise we clear all bit
* were set ...
*/
while (--i >= *beg)
reiserfs_clear_le_bit
(i, bh->b_data);
reiserfs_restore_prepared_buffer(s, bh);
*beg = org;
/*
* Search again in current block
* from beginning
*/
goto cont;
}
}
bi->free_count -= (end - *beg);
journal_mark_dirty(th, bh);
brelse(bh);
/* free block count calculation */
reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s),
1);
PUT_SB_FREE_BLOCKS(s, SB_FREE_BLOCKS(s) - (end - *beg));
journal_mark_dirty(th, SB_BUFFER_WITH_SB(s));
return end - (*beg);
} else {
*beg = next;
}
}
}
static int bmap_hash_id(struct super_block *s, u32 id)
{
char *hash_in = NULL;
unsigned long hash;
unsigned bm;
if (id <= 2) {
bm = 1;
} else {
hash_in = (char *)(&id);
hash = keyed_hash(hash_in, 4);
bm = hash % reiserfs_bmap_count(s);
if (!bm)
bm = 1;
}
/* this can only be true when SB_BMAP_NR = 1 */
if (bm >= reiserfs_bmap_count(s))
bm = 0;
return bm;
}
/*
* hashes the id and then returns > 0 if the block group for the
* corresponding hash is full
*/
static inline int block_group_used(struct super_block *s, u32 id)
{
int bm = bmap_hash_id(s, id);
struct reiserfs_bitmap_info *info = &SB_AP_BITMAP(s)[bm];
/*
* If we don't have cached information on this bitmap block, we're
* going to have to load it later anyway. Loading it here allows us
* to make a better decision. This favors long-term performance gain
* with a better on-disk layout vs. a short term gain of skipping the
* read and potentially having a bad placement.
*/
if (info->free_count == UINT_MAX) {
struct buffer_head *bh = reiserfs_read_bitmap_block(s, bm);
brelse(bh);
}
if (info->free_count > ((s->s_blocksize << 3) * 60 / 100)) {
return 0;
}
return 1;
}
/*
* the packing is returned in disk byte order
*/
__le32 reiserfs_choose_packing(struct inode * dir)
{
__le32 packing;
if (TEST_OPTION(packing_groups, dir->i_sb)) {
u32 parent_dir = le32_to_cpu(INODE_PKEY(dir)->k_dir_id);
/*
* some versions of reiserfsck expect packing locality 1 to be
* special
*/
if (parent_dir == 1 || block_group_used(dir->i_sb, parent_dir))
packing = INODE_PKEY(dir)->k_objectid;
else
packing = INODE_PKEY(dir)->k_dir_id;
} else
packing = INODE_PKEY(dir)->k_objectid;
return packing;
}
/*
* Tries to find contiguous zero bit window (given size) in given region of
* bitmap and place new blocks there. Returns number of allocated blocks.
*/
static int scan_bitmap(struct reiserfs_transaction_handle *th,
b_blocknr_t * start, b_blocknr_t finish,
int min, int max, int unfm, sector_t file_block)
{
int nr_allocated = 0;
struct super_block *s = th->t_super;
unsigned int bm, off;
unsigned int end_bm, end_off;
unsigned int off_max = s->s_blocksize << 3;
BUG_ON(!th->t_trans_id);
PROC_INFO_INC(s, scan_bitmap.call);
/* No point in looking for more free blocks */
if (SB_FREE_BLOCKS(s) <= 0)
return 0;
get_bit_address(s, *start, &bm, &off);
get_bit_address(s, finish, &end_bm, &end_off);
if (bm > reiserfs_bmap_count(s))
return 0;
if (end_bm > reiserfs_bmap_count(s))
end_bm = reiserfs_bmap_count(s);
/*
* When the bitmap is more than 10% free, anyone can allocate.
* When it's less than 10% free, only files that already use the
* bitmap are allowed. Once we pass 80% full, this restriction
* is lifted.
*
* We do this so that files that grow later still have space close to
* their original allocation. This improves locality, and presumably
* performance as a result.
*
* This is only an allocation policy and does not make up for getting a
* bad hint. Decent hinting must be implemented for this to work well.
*/
if (TEST_OPTION(skip_busy, s)
&& SB_FREE_BLOCKS(s) > SB_BLOCK_COUNT(s) / 20) {
for (; bm < end_bm; bm++, off = 0) {
if ((off && (!unfm || (file_block != 0)))
|| SB_AP_BITMAP(s)[bm].free_count >
(s->s_blocksize << 3) / 10)
nr_allocated =
scan_bitmap_block(th, bm, &off, off_max,
min, max, unfm);
if (nr_allocated)
goto ret;
}
/* we know from above that start is a reasonable number */
get_bit_address(s, *start, &bm, &off);
}
for (; bm < end_bm; bm++, off = 0) {
nr_allocated =
scan_bitmap_block(th, bm, &off, off_max, min, max, unfm);
if (nr_allocated)
goto ret;
}
nr_allocated =
scan_bitmap_block(th, bm, &off, end_off + 1, min, max, unfm);
ret:
*start = bm * off_max + off;
return nr_allocated;
}
static void _reiserfs_free_block(struct reiserfs_transaction_handle *th,
struct inode *inode, b_blocknr_t block,
int for_unformatted)
{
struct super_block *s = th->t_super;
struct reiserfs_super_block *rs;
struct buffer_head *sbh, *bmbh;
struct reiserfs_bitmap_info *apbi;
unsigned int nr, offset;
BUG_ON(!th->t_trans_id);
PROC_INFO_INC(s, free_block);
rs = SB_DISK_SUPER_BLOCK(s);
sbh = SB_BUFFER_WITH_SB(s);
apbi = SB_AP_BITMAP(s);
get_bit_address(s, block, &nr, &offset);
if (nr >= reiserfs_bmap_count(s)) {
reiserfs_error(s, "vs-4075", "block %lu is out of range",
block);
return;
}
bmbh = reiserfs_read_bitmap_block(s, nr);
if (!bmbh)
return;
reiserfs_prepare_for_journal(s, bmbh, 1);
/* clear bit for the given block in bit map */
if (!reiserfs_test_and_clear_le_bit(offset, bmbh->b_data)) {
reiserfs_error(s, "vs-4080",
"block %lu: bit already cleared", block);
}
apbi[nr].free_count++;
journal_mark_dirty(th, bmbh);
brelse(bmbh);
reiserfs_prepare_for_journal(s, sbh, 1);
/* update super block */
set_sb_free_blocks(rs, sb_free_blocks(rs) + 1);
journal_mark_dirty(th, sbh);
if (for_unformatted) {
int depth = reiserfs_write_unlock_nested(s);
dquot_free_block_nodirty(inode, 1);
reiserfs_write_lock_nested(s, depth);
}
}
void reiserfs_free_block(struct reiserfs_transaction_handle *th,
struct inode *inode, b_blocknr_t block,
int for_unformatted)
{
struct super_block *s = th->t_super;
BUG_ON(!th->t_trans_id);
RFALSE(!s, "vs-4061: trying to free block on nonexistent device");
if (!is_reusable(s, block, 1))
return;
if (block > sb_block_count(REISERFS_SB(s)->s_rs)) {
reiserfs_error(th->t_super, "bitmap-4072",
"Trying to free block outside file system "
"boundaries (%lu > %lu)",
block, sb_block_count(REISERFS_SB(s)->s_rs));
return;
}
/* mark it before we clear it, just in case */
journal_mark_freed(th, s, block);
_reiserfs_free_block(th, inode, block, for_unformatted);
}
/* preallocated blocks don't need to be run through journal_mark_freed */
static void reiserfs_free_prealloc_block(struct reiserfs_transaction_handle *th,
struct inode *inode, b_blocknr_t block)
{
BUG_ON(!th->t_trans_id);
RFALSE(!th->t_super,
"vs-4060: trying to free block on nonexistent device");
if (!is_reusable(th->t_super, block, 1))
return;
_reiserfs_free_block(th, inode, block, 1);
}
static void __discard_prealloc(struct reiserfs_transaction_handle *th,
struct reiserfs_inode_info *ei)
{
unsigned long save = ei->i_prealloc_block;
int dirty = 0;
struct inode *inode = &ei->vfs_inode;
BUG_ON(!th->t_trans_id);
#ifdef CONFIG_REISERFS_CHECK
if (ei->i_prealloc_count < 0)
reiserfs_error(th->t_super, "zam-4001",
"inode has negative prealloc blocks count.");
#endif
while (ei->i_prealloc_count > 0) {
b_blocknr_t block_to_free;
/*
* reiserfs_free_prealloc_block can drop the write lock,
* which could allow another caller to free the same block.
* We can protect against it by modifying the prealloc
* state before calling it.
*/
block_to_free = ei->i_prealloc_block++;
ei->i_prealloc_count--;
reiserfs_free_prealloc_block(th, inode, block_to_free);
dirty = 1;
}
if (dirty)
reiserfs_update_sd(th, inode);
ei->i_prealloc_block = save;
list_del_init(&ei->i_prealloc_list);
}
/* FIXME: It should be inline function */
void reiserfs_discard_prealloc(struct reiserfs_transaction_handle *th,
struct inode *inode)
{
struct reiserfs_inode_info *ei = REISERFS_I(inode);
BUG_ON(!th->t_trans_id);
if (ei->i_prealloc_count)
__discard_prealloc(th, ei);
}
void reiserfs_discard_all_prealloc(struct reiserfs_transaction_handle *th)
{
struct list_head *plist = &SB_JOURNAL(th->t_super)->j_prealloc_list;
BUG_ON(!th->t_trans_id);
while (!list_empty(plist)) {
struct reiserfs_inode_info *ei;
ei = list_entry(plist->next, struct reiserfs_inode_info,
i_prealloc_list);
#ifdef CONFIG_REISERFS_CHECK
if (!ei->i_prealloc_count) {
reiserfs_error(th->t_super, "zam-4001",
"inode is in prealloc list but has "
"no preallocated blocks.");
}
#endif
__discard_prealloc(th, ei);
}
}
void reiserfs_init_alloc_options(struct super_block *s)
{
set_bit(_ALLOC_skip_busy, &SB_ALLOC_OPTS(s));
set_bit(_ALLOC_dirid_groups, &SB_ALLOC_OPTS(s));
set_bit(_ALLOC_packing_groups, &SB_ALLOC_OPTS(s));
}
/* block allocator related options are parsed here */
int reiserfs_parse_alloc_options(struct super_block *s, char *options)
{
char *this_char, *value;
/* clear default settings */
REISERFS_SB(s)->s_alloc_options.bits = 0;
while ((this_char = strsep(&options, ":")) != NULL) {
if ((value = strchr(this_char, '=')) != NULL)
*value++ = 0;
if (!strcmp(this_char, "concentrating_formatted_nodes")) {
int temp;
SET_OPTION(concentrating_formatted_nodes);
temp = (value
&& *value) ? simple_strtoul(value, &value,
0) : 10;
if (temp <= 0 || temp > 100) {
REISERFS_SB(s)->s_alloc_options.border = 10;
} else {
REISERFS_SB(s)->s_alloc_options.border =
100 / temp;
}
continue;
}
if (!strcmp(this_char, "displacing_large_files")) {
SET_OPTION(displacing_large_files);
REISERFS_SB(s)->s_alloc_options.large_file_size =
(value
&& *value) ? simple_strtoul(value, &value, 0) : 16;
continue;
}
if (!strcmp(this_char, "displacing_new_packing_localities")) {
SET_OPTION(displacing_new_packing_localities);
continue;
}
if (!strcmp(this_char, "old_hashed_relocation")) {
SET_OPTION(old_hashed_relocation);
continue;
}
if (!strcmp(this_char, "new_hashed_relocation")) {
SET_OPTION(new_hashed_relocation);
continue;
}
if (!strcmp(this_char, "dirid_groups")) {
SET_OPTION(dirid_groups);
continue;
}
if (!strcmp(this_char, "oid_groups")) {
SET_OPTION(oid_groups);
continue;
}
if (!strcmp(this_char, "packing_groups")) {
SET_OPTION(packing_groups);
continue;
}
if (!strcmp(this_char, "hashed_formatted_nodes")) {
SET_OPTION(hashed_formatted_nodes);
continue;
}
if (!strcmp(this_char, "skip_busy")) {
SET_OPTION(skip_busy);
continue;
}
if (!strcmp(this_char, "hundredth_slices")) {
SET_OPTION(hundredth_slices);
continue;
}
if (!strcmp(this_char, "old_way")) {
SET_OPTION(old_way);
continue;
}
if (!strcmp(this_char, "displace_based_on_dirid")) {
SET_OPTION(displace_based_on_dirid);
continue;
}
if (!strcmp(this_char, "preallocmin")) {
REISERFS_SB(s)->s_alloc_options.preallocmin =
(value
&& *value) ? simple_strtoul(value, &value, 0) : 4;
continue;
}
if (!strcmp(this_char, "preallocsize")) {
REISERFS_SB(s)->s_alloc_options.preallocsize =
(value
&& *value) ? simple_strtoul(value, &value,
0) :
PREALLOCATION_SIZE;
continue;
}
reiserfs_warning(s, "zam-4001", "unknown option - %s",
this_char);
return 1;
}
reiserfs_info(s, "allocator options = [%08x]\n", SB_ALLOC_OPTS(s));
return 0;
}
static void print_sep(struct seq_file *seq, int *first)
{
if (!*first)
seq_puts(seq, ":");
else
*first = 0;
}
void show_alloc_options(struct seq_file *seq, struct super_block *s)
{
int first = 1;
if (SB_ALLOC_OPTS(s) == ((1 << _ALLOC_skip_busy) |
(1 << _ALLOC_dirid_groups) | (1 << _ALLOC_packing_groups)))
return;
seq_puts(seq, ",alloc=");
if (TEST_OPTION(concentrating_formatted_nodes, s)) {
print_sep(seq, &first);
if (REISERFS_SB(s)->s_alloc_options.border != 10) {
seq_printf(seq, "concentrating_formatted_nodes=%d",
100 / REISERFS_SB(s)->s_alloc_options.border);
} else
seq_puts(seq, "concentrating_formatted_nodes");
}
if (TEST_OPTION(displacing_large_files, s)) {
print_sep(seq, &first);
if (REISERFS_SB(s)->s_alloc_options.large_file_size != 16) {
seq_printf(seq, "displacing_large_files=%lu",
REISERFS_SB(s)->s_alloc_options.large_file_size);
} else
seq_puts(seq, "displacing_large_files");
}
if (TEST_OPTION(displacing_new_packing_localities, s)) {
print_sep(seq, &first);
seq_puts(seq, "displacing_new_packing_localities");
}
if (TEST_OPTION(old_hashed_relocation, s)) {
print_sep(seq, &first);
seq_puts(seq, "old_hashed_relocation");
}
if (TEST_OPTION(new_hashed_relocation, s)) {
print_sep(seq, &first);
seq_puts(seq, "new_hashed_relocation");
}
if (TEST_OPTION(dirid_groups, s)) {
print_sep(seq, &first);
seq_puts(seq, "dirid_groups");
}
if (TEST_OPTION(oid_groups, s)) {
print_sep(seq, &first);
seq_puts(seq, "oid_groups");
}
if (TEST_OPTION(packing_groups, s)) {
print_sep(seq, &first);
seq_puts(seq, "packing_groups");
}
if (TEST_OPTION(hashed_formatted_nodes, s)) {
print_sep(seq, &first);
seq_puts(seq, "hashed_formatted_nodes");
}
if (TEST_OPTION(skip_busy, s)) {
print_sep(seq, &first);
seq_puts(seq, "skip_busy");
}
if (TEST_OPTION(hundredth_slices, s)) {
print_sep(seq, &first);
seq_puts(seq, "hundredth_slices");
}
if (TEST_OPTION(old_way, s)) {
print_sep(seq, &first);
seq_puts(seq, "old_way");
}
if (TEST_OPTION(displace_based_on_dirid, s)) {
print_sep(seq, &first);
seq_puts(seq, "displace_based_on_dirid");
}
if (REISERFS_SB(s)->s_alloc_options.preallocmin != 0) {
print_sep(seq, &first);
seq_printf(seq, "preallocmin=%d",
REISERFS_SB(s)->s_alloc_options.preallocmin);
}
if (REISERFS_SB(s)->s_alloc_options.preallocsize != 17) {
print_sep(seq, &first);
seq_printf(seq, "preallocsize=%d",
REISERFS_SB(s)->s_alloc_options.preallocsize);
}
}
static inline void new_hashed_relocation(reiserfs_blocknr_hint_t * hint)
{
char *hash_in;
if (hint->formatted_node) {
hash_in = (char *)&hint->key.k_dir_id;
} else {
if (!hint->inode) {
/*hint->search_start = hint->beg;*/
hash_in = (char *)&hint->key.k_dir_id;
} else
if (TEST_OPTION(displace_based_on_dirid, hint->th->t_super))
hash_in = (char *)(&INODE_PKEY(hint->inode)->k_dir_id);
else
hash_in =
(char *)(&INODE_PKEY(hint->inode)->k_objectid);
}
hint->search_start =
hint->beg + keyed_hash(hash_in, 4) % (hint->end - hint->beg);
}
/*
* Relocation based on dirid, hashing them into a given bitmap block
* files. Formatted nodes are unaffected, a separate policy covers them
*/
static void dirid_groups(reiserfs_blocknr_hint_t * hint)
{
unsigned long hash;
__u32 dirid = 0;
int bm = 0;
struct super_block *sb = hint->th->t_super;
if (hint->inode)
dirid = le32_to_cpu(INODE_PKEY(hint->inode)->k_dir_id);
else if (hint->formatted_node)
dirid = hint->key.k_dir_id;
if (dirid) {
bm = bmap_hash_id(sb, dirid);
hash = bm * (sb->s_blocksize << 3);
/* give a portion of the block group to metadata */
if (hint->inode)
hash += sb->s_blocksize / 2;
hint->search_start = hash;
}
}
/*
* Relocation based on oid, hashing them into a given bitmap block
* files. Formatted nodes are unaffected, a separate policy covers them
*/
static void oid_groups(reiserfs_blocknr_hint_t * hint)
{
if (hint->inode) {
unsigned long hash;
__u32 oid;
__u32 dirid;
int bm;
dirid = le32_to_cpu(INODE_PKEY(hint->inode)->k_dir_id);
/*
* keep the root dir and it's first set of subdirs close to
* the start of the disk
*/
if (dirid <= 2)
hash = (hint->inode->i_sb->s_blocksize << 3);
else {
oid = le32_to_cpu(INODE_PKEY(hint->inode)->k_objectid);
bm = bmap_hash_id(hint->inode->i_sb, oid);
hash = bm * (hint->inode->i_sb->s_blocksize << 3);
}
hint->search_start = hash;
}
}
/*
* returns 1 if it finds an indirect item and gets valid hint info
* from it, otherwise 0
*/
static int get_left_neighbor(reiserfs_blocknr_hint_t * hint)
{
struct treepath *path;
struct buffer_head *bh;
struct item_head *ih;
int pos_in_item;
__le32 *item;
int ret = 0;
/*
* reiserfs code can call this function w/o pointer to path
* structure supplied; then we rely on supplied search_start
*/
if (!hint->path)
return 0;
path = hint->path;
bh = get_last_bh(path);
RFALSE(!bh, "green-4002: Illegal path specified to get_left_neighbor");
ih = tp_item_head(path);
pos_in_item = path->pos_in_item;
item = tp_item_body(path);
hint->search_start = bh->b_blocknr;
/*
* for indirect item: go to left and look for the first non-hole entry
* in the indirect item
*/
if (!hint->formatted_node && is_indirect_le_ih(ih)) {
if (pos_in_item == I_UNFM_NUM(ih))
pos_in_item--;
while (pos_in_item >= 0) {
int t = get_block_num(item, pos_in_item);
if (t) {
hint->search_start = t;
ret = 1;
break;
}
pos_in_item--;
}
}
/* does result value fit into specified region? */
return ret;
}
/*
* should be, if formatted node, then try to put on first part of the device
* specified as number of percent with mount option device, else try to put
* on last of device. This is not to say it is good code to do so,
* but the effect should be measured.
*/
static inline void set_border_in_hint(struct super_block *s,
reiserfs_blocknr_hint_t * hint)
{
b_blocknr_t border =
SB_BLOCK_COUNT(s) / REISERFS_SB(s)->s_alloc_options.border;
if (hint->formatted_node)
hint->end = border - 1;
else
hint->beg = border;
}
static inline void displace_large_file(reiserfs_blocknr_hint_t * hint)
{
if (TEST_OPTION(displace_based_on_dirid, hint->th->t_super))
hint->search_start =
hint->beg +
keyed_hash((char *)(&INODE_PKEY(hint->inode)->k_dir_id),
4) % (hint->end - hint->beg);
else
hint->search_start =
hint->beg +
keyed_hash((char *)(&INODE_PKEY(hint->inode)->k_objectid),
4) % (hint->end - hint->beg);
}
static inline void hash_formatted_node(reiserfs_blocknr_hint_t * hint)
{
char *hash_in;
if (!hint->inode)
hash_in = (char *)&hint->key.k_dir_id;
else if (TEST_OPTION(displace_based_on_dirid, hint->th->t_super))
hash_in = (char *)(&INODE_PKEY(hint->inode)->k_dir_id);
else
hash_in = (char *)(&INODE_PKEY(hint->inode)->k_objectid);
hint->search_start =
hint->beg + keyed_hash(hash_in, 4) % (hint->end - hint->beg);
}
static inline int
this_blocknr_allocation_would_make_it_a_large_file(reiserfs_blocknr_hint_t *
hint)
{
return hint->block ==
REISERFS_SB(hint->th->t_super)->s_alloc_options.large_file_size;
}
#ifdef DISPLACE_NEW_PACKING_LOCALITIES
static inline void displace_new_packing_locality(reiserfs_blocknr_hint_t * hint)
{
struct in_core_key *key = &hint->key;
hint->th->displace_new_blocks = 0;
hint->search_start =
hint->beg + keyed_hash((char *)(&key->k_objectid),
4) % (hint->end - hint->beg);
}
#endif
static inline int old_hashed_relocation(reiserfs_blocknr_hint_t * hint)
{
b_blocknr_t border;
u32 hash_in;
if (hint->formatted_node || hint->inode == NULL) {
return 0;
}
hash_in = le32_to_cpu((INODE_PKEY(hint->inode))->k_dir_id);
border =
hint->beg + (u32) keyed_hash(((char *)(&hash_in)),
4) % (hint->end - hint->beg - 1);
if (border > hint->search_start)
hint->search_start = border;
return 1;
}
static inline int old_way(reiserfs_blocknr_hint_t * hint)
{
b_blocknr_t border;
if (hint->formatted_node || hint->inode == NULL) {
return 0;
}
border =
hint->beg +
le32_to_cpu(INODE_PKEY(hint->inode)->k_dir_id) % (hint->end -
hint->beg);
if (border > hint->search_start)
hint->search_start = border;
return 1;
}
static inline void hundredth_slices(reiserfs_blocknr_hint_t * hint)
{
struct in_core_key *key = &hint->key;
b_blocknr_t slice_start;
slice_start =
(keyed_hash((char *)(&key->k_dir_id), 4) % 100) * (hint->end / 100);
if (slice_start > hint->search_start
|| slice_start + (hint->end / 100) <= hint->search_start) {
hint->search_start = slice_start;
}
}
static void determine_search_start(reiserfs_blocknr_hint_t * hint,
int amount_needed)
{
struct super_block *s = hint->th->t_super;
int unfm_hint;
hint->beg = 0;
hint->end = SB_BLOCK_COUNT(s) - 1;
/* This is former border algorithm. Now with tunable border offset */
if (concentrating_formatted_nodes(s))
set_border_in_hint(s, hint);
#ifdef DISPLACE_NEW_PACKING_LOCALITIES
/*
* whenever we create a new directory, we displace it. At first
* we will hash for location, later we might look for a moderately
* empty place for it
*/
if (displacing_new_packing_localities(s)
&& hint->th->displace_new_blocks) {
displace_new_packing_locality(hint);
/*
* we do not continue determine_search_start,
* if new packing locality is being displaced
*/
return;
}
#endif
/*
* all persons should feel encouraged to add more special cases
* here and test them
*/
if (displacing_large_files(s) && !hint->formatted_node
&& this_blocknr_allocation_would_make_it_a_large_file(hint)) {
displace_large_file(hint);
return;
}
/*
* if none of our special cases is relevant, use the left
* neighbor in the tree order of the new node we are allocating for
*/
if (hint->formatted_node && TEST_OPTION(hashed_formatted_nodes, s)) {
hash_formatted_node(hint);
return;
}
unfm_hint = get_left_neighbor(hint);
/*
* Mimic old block allocator behaviour, that is if VFS allowed for
* preallocation, new blocks are displaced based on directory ID.
* Also, if suggested search_start is less than last preallocated
* block, we start searching from it, assuming that HDD dataflow
* is faster in forward direction
*/
if (TEST_OPTION(old_way, s)) {
if (!hint->formatted_node) {
if (!reiserfs_hashed_relocation(s))
old_way(hint);
else if (!reiserfs_no_unhashed_relocation(s))
old_hashed_relocation(hint);
if (hint->inode
&& hint->search_start <
REISERFS_I(hint->inode)->i_prealloc_block)
hint->search_start =
REISERFS_I(hint->inode)->i_prealloc_block;
}
return;
}
/* This is an approach proposed by Hans */
if (TEST_OPTION(hundredth_slices, s)
&& !(displacing_large_files(s) && !hint->formatted_node)) {
hundredth_slices(hint);
return;
}
/* old_hashed_relocation only works on unformatted */
if (!unfm_hint && !hint->formatted_node &&
TEST_OPTION(old_hashed_relocation, s)) {
old_hashed_relocation(hint);
}
/* new_hashed_relocation works with both formatted/unformatted nodes */
if ((!unfm_hint || hint->formatted_node) &&
TEST_OPTION(new_hashed_relocation, s)) {
new_hashed_relocation(hint);
}
/* dirid grouping works only on unformatted nodes */
if (!unfm_hint && !hint->formatted_node && TEST_OPTION(dirid_groups, s)) {
dirid_groups(hint);
}
#ifdef DISPLACE_NEW_PACKING_LOCALITIES
if (hint->formatted_node && TEST_OPTION(dirid_groups, s)) {
dirid_groups(hint);
}
#endif
/* oid grouping works only on unformatted nodes */
if (!unfm_hint && !hint->formatted_node && TEST_OPTION(oid_groups, s)) {
oid_groups(hint);
}
return;
}
static int determine_prealloc_size(reiserfs_blocknr_hint_t * hint)
{
/* make minimum size a mount option and benchmark both ways */
/* we preallocate blocks only for regular files, specific size */
/* benchmark preallocating always and see what happens */
hint->prealloc_size = 0;
if (!hint->formatted_node && hint->preallocate) {
if (S_ISREG(hint->inode->i_mode) && !IS_PRIVATE(hint->inode)
&& hint->inode->i_size >=
REISERFS_SB(hint->th->t_super)->s_alloc_options.
preallocmin * hint->inode->i_sb->s_blocksize)
hint->prealloc_size =
REISERFS_SB(hint->th->t_super)->s_alloc_options.
preallocsize - 1;
}
return CARRY_ON;
}
static inline int allocate_without_wrapping_disk(reiserfs_blocknr_hint_t * hint,
b_blocknr_t * new_blocknrs,
b_blocknr_t start,
b_blocknr_t finish, int min,
int amount_needed,
int prealloc_size)
{
int rest = amount_needed;
int nr_allocated;
while (rest > 0 && start <= finish) {
nr_allocated = scan_bitmap(hint->th, &start, finish, min,
rest + prealloc_size,
!hint->formatted_node, hint->block);
if (nr_allocated == 0) /* no new blocks allocated, return */
break;
/* fill free_blocknrs array first */
while (rest > 0 && nr_allocated > 0) {
*new_blocknrs++ = start++;
rest--;
nr_allocated--;
}
/* do we have something to fill prealloc. array also ? */
if (nr_allocated > 0) {
/*
* it means prealloc_size was greater that 0 and
* we do preallocation
*/
list_add(&REISERFS_I(hint->inode)->i_prealloc_list,
&SB_JOURNAL(hint->th->t_super)->
j_prealloc_list);
REISERFS_I(hint->inode)->i_prealloc_block = start;
REISERFS_I(hint->inode)->i_prealloc_count =
nr_allocated;
break;
}
}
return (amount_needed - rest);
}
static inline int blocknrs_and_prealloc_arrays_from_search_start
(reiserfs_blocknr_hint_t * hint, b_blocknr_t * new_blocknrs,
int amount_needed) {
struct super_block *s = hint->th->t_super;
b_blocknr_t start = hint->search_start;
b_blocknr_t finish = SB_BLOCK_COUNT(s) - 1;
int passno = 0;
int nr_allocated = 0;
int depth;
determine_prealloc_size(hint);
if (!hint->formatted_node) {
int quota_ret;
#ifdef REISERQUOTA_DEBUG
reiserfs_debug(s, REISERFS_DEBUG_CODE,
"reiserquota: allocating %d blocks id=%u",
amount_needed, hint->inode->i_uid);
#endif
depth = reiserfs_write_unlock_nested(s);
quota_ret =
dquot_alloc_block_nodirty(hint->inode, amount_needed);
if (quota_ret) { /* Quota exceeded? */
reiserfs_write_lock_nested(s, depth);
return QUOTA_EXCEEDED;
}
if (hint->preallocate && hint->prealloc_size) {
#ifdef REISERQUOTA_DEBUG
reiserfs_debug(s, REISERFS_DEBUG_CODE,
"reiserquota: allocating (prealloc) %d blocks id=%u",
hint->prealloc_size, hint->inode->i_uid);
#endif
quota_ret = dquot_prealloc_block_nodirty(hint->inode,
hint->prealloc_size);
if (quota_ret)
hint->preallocate = hint->prealloc_size = 0;
}
/* for unformatted nodes, force large allocations */
reiserfs_write_lock_nested(s, depth);
}
do {
switch (passno++) {
case 0: /* Search from hint->search_start to end of disk */
start = hint->search_start;
finish = SB_BLOCK_COUNT(s) - 1;
break;
case 1: /* Search from hint->beg to hint->search_start */
start = hint->beg;
finish = hint->search_start;
break;
case 2: /* Last chance: Search from 0 to hint->beg */
start = 0;
finish = hint->beg;
break;
default:
/* We've tried searching everywhere, not enough space */
/* Free the blocks */
if (!hint->formatted_node) {
#ifdef REISERQUOTA_DEBUG
reiserfs_debug(s, REISERFS_DEBUG_CODE,
"reiserquota: freeing (nospace) %d blocks id=%u",
amount_needed +
hint->prealloc_size -
nr_allocated,
hint->inode->i_uid);
#endif
/* Free not allocated blocks */
depth = reiserfs_write_unlock_nested(s);
dquot_free_block_nodirty(hint->inode,
amount_needed + hint->prealloc_size -
nr_allocated);
reiserfs_write_lock_nested(s, depth);
}
while (nr_allocated--)
reiserfs_free_block(hint->th, hint->inode,
new_blocknrs[nr_allocated],
!hint->formatted_node);
return NO_DISK_SPACE;
}
} while ((nr_allocated += allocate_without_wrapping_disk(hint,
new_blocknrs +
nr_allocated,
start, finish,
1,
amount_needed -
nr_allocated,
hint->
prealloc_size))
< amount_needed);
if (!hint->formatted_node &&
amount_needed + hint->prealloc_size >
nr_allocated + REISERFS_I(hint->inode)->i_prealloc_count) {
/* Some of preallocation blocks were not allocated */
#ifdef REISERQUOTA_DEBUG
reiserfs_debug(s, REISERFS_DEBUG_CODE,
"reiserquota: freeing (failed prealloc) %d blocks id=%u",
amount_needed + hint->prealloc_size -
nr_allocated -
REISERFS_I(hint->inode)->i_prealloc_count,
hint->inode->i_uid);
#endif
depth = reiserfs_write_unlock_nested(s);
dquot_free_block_nodirty(hint->inode, amount_needed +
hint->prealloc_size - nr_allocated -
REISERFS_I(hint->inode)->
i_prealloc_count);
reiserfs_write_lock_nested(s, depth);
}
return CARRY_ON;
}
/* grab new blocknrs from preallocated list */
/* return amount still needed after using them */
static int use_preallocated_list_if_available(reiserfs_blocknr_hint_t * hint,
b_blocknr_t * new_blocknrs,
int amount_needed)
{
struct inode *inode = hint->inode;
if (REISERFS_I(inode)->i_prealloc_count > 0) {
while (amount_needed) {
*new_blocknrs++ = REISERFS_I(inode)->i_prealloc_block++;
REISERFS_I(inode)->i_prealloc_count--;
amount_needed--;
if (REISERFS_I(inode)->i_prealloc_count <= 0) {
list_del(&REISERFS_I(inode)->i_prealloc_list);
break;
}
}
}
/* return amount still needed after using preallocated blocks */
return amount_needed;
}
int reiserfs_allocate_blocknrs(reiserfs_blocknr_hint_t *hint,
b_blocknr_t *new_blocknrs,
int amount_needed,
/* Amount of blocks we have already reserved */
int reserved_by_us)
{
int initial_amount_needed = amount_needed;
int ret;
struct super_block *s = hint->th->t_super;
/* Check if there is enough space, taking into account reserved space */
if (SB_FREE_BLOCKS(s) - REISERFS_SB(s)->reserved_blocks <
amount_needed - reserved_by_us)
return NO_DISK_SPACE;
/* should this be if !hint->inode && hint->preallocate? */
/* do you mean hint->formatted_node can be removed ? - Zam */
/*
* hint->formatted_node cannot be removed because we try to access
* inode information here, and there is often no inode associated with
* metadata allocations - green
*/
if (!hint->formatted_node && hint->preallocate) {
amount_needed = use_preallocated_list_if_available
(hint, new_blocknrs, amount_needed);
/*
* We have all the block numbers we need from the
* prealloc list
*/
if (amount_needed == 0)
return CARRY_ON;
new_blocknrs += (initial_amount_needed - amount_needed);
}
/* find search start and save it in hint structure */
determine_search_start(hint, amount_needed);
if (hint->search_start >= SB_BLOCK_COUNT(s))
hint->search_start = SB_BLOCK_COUNT(s) - 1;
/* allocation itself; fill new_blocknrs and preallocation arrays */
ret = blocknrs_and_prealloc_arrays_from_search_start
(hint, new_blocknrs, amount_needed);
/*
* We used prealloc. list to fill (partially) new_blocknrs array.
* If final allocation fails we need to return blocks back to
* prealloc. list or just free them. -- Zam (I chose second
* variant)
*/
if (ret != CARRY_ON) {
while (amount_needed++ < initial_amount_needed) {
reiserfs_free_block(hint->th, hint->inode,
*(--new_blocknrs), 1);
}
}
return ret;
}
void reiserfs_cache_bitmap_metadata(struct super_block *sb,
struct buffer_head *bh,
struct reiserfs_bitmap_info *info)
{
unsigned long *cur = (unsigned long *)(bh->b_data + bh->b_size);
/* The first bit must ALWAYS be 1 */
if (!reiserfs_test_le_bit(0, (unsigned long *)bh->b_data))
reiserfs_error(sb, "reiserfs-2025", "bitmap block %lu is "
"corrupted: first bit must be 1", bh->b_blocknr);
info->free_count = 0;
while (--cur >= (unsigned long *)bh->b_data) {
/* 0 and ~0 are special, we can optimize for them */
if (*cur == 0)
info->free_count += BITS_PER_LONG;
else if (*cur != ~0L) /* A mix, investigate */
info->free_count += BITS_PER_LONG - hweight_long(*cur);
}
}
struct buffer_head *reiserfs_read_bitmap_block(struct super_block *sb,
unsigned int bitmap)
{
b_blocknr_t block = (sb->s_blocksize << 3) * bitmap;
struct reiserfs_bitmap_info *info = SB_AP_BITMAP(sb) + bitmap;
struct buffer_head *bh;
/*
* Way old format filesystems had the bitmaps packed up front.
* I doubt there are any of these left, but just in case...
*/
if (unlikely(test_bit(REISERFS_OLD_FORMAT,
&REISERFS_SB(sb)->s_properties)))
block = REISERFS_SB(sb)->s_sbh->b_blocknr + 1 + bitmap;
else if (bitmap == 0)
block = (REISERFS_DISK_OFFSET_IN_BYTES >> sb->s_blocksize_bits) + 1;
bh = sb_bread(sb, block);
if (bh == NULL)
reiserfs_warning(sb, "sh-2029: %s: bitmap block (#%u) "
"reading failed", __func__, block);
else {
if (buffer_locked(bh)) {
int depth;
PROC_INFO_INC(sb, scan_bitmap.wait);
depth = reiserfs_write_unlock_nested(sb);
__wait_on_buffer(bh);
reiserfs_write_lock_nested(sb, depth);
}
BUG_ON(!buffer_uptodate(bh));
BUG_ON(atomic_read(&bh->b_count) == 0);
if (info->free_count == UINT_MAX)
reiserfs_cache_bitmap_metadata(sb, bh, info);
}
return bh;
}
int reiserfs_init_bitmap_cache(struct super_block *sb)
{
struct reiserfs_bitmap_info *bitmap;
unsigned int bmap_nr = reiserfs_bmap_count(sb);
bitmap = vmalloc(array_size(bmap_nr, sizeof(*bitmap)));
if (bitmap == NULL)
return -ENOMEM;
memset(bitmap, 0xff, sizeof(*bitmap) * bmap_nr);
SB_AP_BITMAP(sb) = bitmap;
return 0;
}
void reiserfs_free_bitmap_cache(struct super_block *sb)
{
if (SB_AP_BITMAP(sb)) {
vfree(SB_AP_BITMAP(sb));
SB_AP_BITMAP(sb) = NULL;
}
}