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Diffstat (limited to 'fs/reiserfs/bitmap.c')
-rw-r--r--fs/reiserfs/bitmap.c237
1 files changed, 156 insertions, 81 deletions
diff --git a/fs/reiserfs/bitmap.c b/fs/reiserfs/bitmap.c
index c3de6501a5cb..70daba6fa6a5 100644
--- a/fs/reiserfs/bitmap.c
+++ b/fs/reiserfs/bitmap.c
@@ -50,8 +50,10 @@ static inline void get_bit_address(struct super_block *s,
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. */
+ /*
+ * 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);
@@ -71,8 +73,10 @@ int is_reusable(struct super_block *s, b_blocknr_t block, int bit_value)
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. */
+ /*
+ * 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;
@@ -108,8 +112,11 @@ int is_reusable(struct super_block *s, b_blocknr_t block, int bit_value)
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. */
+/*
+ * 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)
{
@@ -120,7 +127,7 @@ static inline int is_block_in_journal(struct super_block *s, unsigned int bmap,
*next = tmp;
PROC_INFO_INC(s, scan_bitmap.in_journal_hint);
} else {
- (*next) = off + 1; /* inc offset to avoid looping. */
+ (*next) = off + 1; /* inc offset to avoid looping. */
PROC_INFO_INC(s, scan_bitmap.in_journal_nohint);
}
PROC_INFO_INC(s, scan_bitmap.retry);
@@ -129,8 +136,10 @@ static inline int is_block_in_journal(struct super_block *s, unsigned int bmap,
return 0;
}
-/* it searches for a window of zero bits with given minimum and maximum lengths in one bitmap
- * block; */
+/*
+ * 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)
@@ -146,10 +155,6 @@ static int scan_bitmap_block(struct reiserfs_transaction_handle *th,
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);
-/* this is unclear and lacks comments, explain how journal bitmaps
- work here for the reader. Convey a sense of the design here. What
- is a window? */
-/* - I mean `a window of zero bits' as in description of this function - Zam. */
if (!bi) {
reiserfs_error(s, "jdm-4055", "NULL bitmap info pointer "
@@ -165,15 +170,18 @@ static int scan_bitmap_block(struct reiserfs_transaction_handle *th,
cont:
if (bi->free_count < min) {
brelse(bh);
- return 0; // No free blocks in this bitmap
+ 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);
- if (*beg + min > boundary) { /* search for a zero bit fails or the rest of bitmap block
- * cannot contain a zero window of minimum size */
+ /*
+ * 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;
}
@@ -187,37 +195,63 @@ static int scan_bitmap_block(struct reiserfs_transaction_handle *th,
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) */
+
+ /*
+ * 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 */
- if (end - *beg >= min) { /* it seems we have found window of proper size */
+ /*
+ * 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 */
+ /*
+ * try to set all blocks used checking are
+ * they still free
+ */
for (i = *beg; i < end; i++) {
- /* It seems that we should not check in journal again. */
+ /* 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() */
+ /*
+ * bit was set by another process while
+ * we slept in prepare_for_journal()
+ */
PROC_INFO_INC(s, scan_bitmap.stolen);
- if (i >= *beg + min) { /* we can continue with smaller set of allocated blocks,
- * if length of this set is more or equal to `min' */
+
+ /*
+ * 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 ... */
+
+ /*
+ * 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;
- /* ... and search again in current block from beginning */
+
+ /*
+ * Search again in current block
+ * from beginning
+ */
goto cont;
}
}
@@ -268,11 +302,13 @@ 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
+ /*
+ * 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. */
+ * 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);
@@ -305,17 +341,16 @@ __le32 reiserfs_choose_packing(struct inode * dir)
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. */
+/*
+ * 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;
- /* find every bm and bmap and bmap_nr in this file, and change them all to bitmap_blocknr
- * - Hans, it is not a block number - Zam. */
-
unsigned int bm, off;
unsigned int end_bm, end_off;
unsigned int off_max = s->s_blocksize << 3;
@@ -323,8 +358,10 @@ static int scan_bitmap(struct reiserfs_transaction_handle *th,
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; // No point in looking for more free blocks
+ return 0;
get_bit_address(s, *start, &bm, &off);
get_bit_address(s, finish, &end_bm, &end_off);
@@ -333,7 +370,8 @@ static int scan_bitmap(struct reiserfs_transaction_handle *th,
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 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.
@@ -532,7 +570,8 @@ int reiserfs_parse_alloc_options(struct super_block *s, char *options)
{
char *this_char, *value;
- REISERFS_SB(s)->s_alloc_options.bits = 0; /* clear default settings */
+ /* clear default settings */
+ REISERFS_SB(s)->s_alloc_options.bits = 0;
while ((this_char = strsep(&options, ":")) != NULL) {
if ((value = strchr(this_char, '=')) != NULL)
@@ -733,7 +772,7 @@ static inline void new_hashed_relocation(reiserfs_blocknr_hint_t * hint)
hash_in = (char *)&hint->key.k_dir_id;
} else {
if (!hint->inode) {
- //hint->search_start = hint->beg;
+ /*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))
@@ -786,7 +825,8 @@ static void oid_groups(reiserfs_blocknr_hint_t * hint)
dirid = le32_to_cpu(INODE_PKEY(hint->inode)->k_dir_id);
- /* keep the root dir and it's first set of subdirs close to
+ /*
+ * keep the root dir and it's first set of subdirs close to
* the start of the disk
*/
if (dirid <= 2)
@@ -800,7 +840,8 @@ static void oid_groups(reiserfs_blocknr_hint_t * hint)
}
}
-/* returns 1 if it finds an indirect item and gets valid hint info
+/*
+ * 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)
@@ -812,8 +853,11 @@ static int get_left_neighbor(reiserfs_blocknr_hint_t * hint)
__le32 *item;
int ret = 0;
- if (!hint->path) /* reiserfs code can call this function w/o pointer to path
- * structure supplied; then we rely on supplied search_start */
+ /*
+ * 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;
@@ -825,12 +869,13 @@ static int get_left_neighbor(reiserfs_blocknr_hint_t * hint)
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)) {
- /* for indirect item: go to left and look for the first non-hole entry
- in the indirect item */
if (pos_in_item == I_UNFM_NUM(ih))
pos_in_item--;
-// pos_in_item = I_UNFM_NUM (ih) - 1;
while (pos_in_item >= 0) {
int t = get_block_num(item, pos_in_item);
if (t) {
@@ -846,10 +891,12 @@ static int get_left_neighbor(reiserfs_blocknr_hint_t * hint)
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. */
+/*
+ * 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)
{
@@ -975,21 +1022,27 @@ static void determine_search_start(reiserfs_blocknr_hint_t * hint,
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 */
+ /*
+ * 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 */
+ /*
+ * 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 */
+ /*
+ * 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)) {
@@ -997,8 +1050,10 @@ static void determine_search_start(reiserfs_blocknr_hint_t * 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 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;
@@ -1006,10 +1061,13 @@ static void determine_search_start(reiserfs_blocknr_hint_t * hint,
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 */
+ /*
+ * 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))
@@ -1038,11 +1096,13 @@ static void determine_search_start(reiserfs_blocknr_hint_t * hint,
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);
@@ -1080,8 +1140,6 @@ static int determine_prealloc_size(reiserfs_blocknr_hint_t * hint)
return CARRY_ON;
}
-/* XXX I know it could be merged with upper-level function;
- but may be result function would be too complex. */
static inline int allocate_without_wrapping_disk(reiserfs_blocknr_hint_t * hint,
b_blocknr_t * new_blocknrs,
b_blocknr_t start,
@@ -1109,7 +1167,10 @@ static inline int allocate_without_wrapping_disk(reiserfs_blocknr_hint_t * hint,
/* 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 */
+ /*
+ * 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);
@@ -1177,7 +1238,8 @@ static inline int blocknrs_and_prealloc_arrays_from_search_start
start = 0;
finish = hint->beg;
break;
- default: /* We've tried searching everywhere, not enough space */
+ default:
+ /* We've tried searching everywhere, not enough space */
/* Free the blocks */
if (!hint->formatted_node) {
#ifdef REISERQUOTA_DEBUG
@@ -1262,8 +1324,11 @@ static int use_preallocated_list_if_available(reiserfs_blocknr_hint_t * hint,
return amount_needed;
}
-int reiserfs_allocate_blocknrs(reiserfs_blocknr_hint_t * hint, b_blocknr_t * new_blocknrs, int amount_needed, int reserved_by_us /* Amount of blocks we have
- already reserved */ )
+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;
@@ -1275,15 +1340,21 @@ int reiserfs_allocate_blocknrs(reiserfs_blocknr_hint_t * hint, b_blocknr_t * new
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 assotiated with
- metadata allocations - green */
+ /*
+ * 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);
- if (amount_needed == 0) /* all blocknrs we need we got from
- prealloc. list */
+
+ /*
+ * 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);
}
@@ -1297,10 +1368,12 @@ int reiserfs_allocate_blocknrs(reiserfs_blocknr_hint_t * hint, b_blocknr_t * new
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) */
-
+ /*
+ * 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,
@@ -1339,8 +1412,10 @@ struct buffer_head *reiserfs_read_bitmap_block(struct super_block *sb,
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... */
+ /*
+ * 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;