diff options
Diffstat (limited to 'fs/reiserfs/bitmap.c')
| -rw-r--r-- | fs/reiserfs/bitmap.c | 1169 |
1 files changed, 1169 insertions, 0 deletions
diff --git a/fs/reiserfs/bitmap.c b/fs/reiserfs/bitmap.c new file mode 100644 index 000000000000..a4e2ed544bbe --- /dev/null +++ b/fs/reiserfs/bitmap.c @@ -0,0 +1,1169 @@ +/* + * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README + */ +/* Reiserfs block (de)allocator, bitmap-based. */ + +#include <linux/config.h> +#include <linux/time.h> +#include <linux/reiserfs_fs.h> +#include <linux/errno.h> +#include <linux/buffer_head.h> +#include <linux/kernel.h> +#include <linux/pagemap.h> +#include <linux/reiserfs_fs_sb.h> +#include <linux/reiserfs_fs_i.h> +#include <linux/quotaops.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_warning(s, "reiserfs: 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, int * bmap_nr, 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 << 3); + /* Within that bitmap block it is located at bit offset *offset. */ + *offset = block & ((s->s_blocksize << 3) - 1 ); + return; +} + +#ifdef CONFIG_REISERFS_CHECK +int is_reusable (struct super_block * s, b_blocknr_t block, int bit_value) +{ + int i, j; + + if (block == 0 || block >= SB_BLOCK_COUNT (s)) { + reiserfs_warning (s, "vs-4010: is_reusable: block number is out of range %lu (%u)", + block, SB_BLOCK_COUNT (s)); + return 0; + } + + /* it can't be one of the bitmap blocks */ + for (i = 0; i < SB_BMAP_NR (s); i ++) + if (block == SB_AP_BITMAP (s)[i].bh->b_blocknr) { + reiserfs_warning (s, "vs: 4020: is_reusable: " + "bitmap block %lu(%u) can't be freed or reused", + block, SB_BMAP_NR (s)); + return 0; + } + + get_bit_address (s, block, &i, &j); + + if (i >= SB_BMAP_NR (s)) { + reiserfs_warning (s, "vs-4030: is_reusable: there is no so many bitmap blocks: " + "block=%lu, bitmap_nr=%d", block, i); + return 0; + } + + if ((bit_value == 0 && + reiserfs_test_le_bit(j, SB_AP_BITMAP(s)[i].bh->b_data)) || + (bit_value == 1 && + reiserfs_test_le_bit(j, SB_AP_BITMAP (s)[i].bh->b_data) == 0)) { + reiserfs_warning (s, "vs-4040: is_reusable: corresponding bit of block %lu does not " + "match required value (i==%d, j==%d) test_bit==%d", + block, i, j, reiserfs_test_le_bit (j, SB_AP_BITMAP (s)[i].bh->b_data)); + + return 0; + } + + if (bit_value == 0 && block == SB_ROOT_BLOCK (s)) { + reiserfs_warning (s, "vs-4050: is_reusable: this is root block (%u), " + "it must be busy", SB_ROOT_BLOCK (s)); + return 0; + } + + return 1; +} +#endif /* CONFIG_REISERFS_CHECK */ + +/* 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, 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; +} + +/* it 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, + 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]; + int end, next; + int org = *beg; + + BUG_ON (!th->t_trans_id); + + RFALSE(bmap_n >= SB_BMAP_NR (s), "Bitmap %d is out of range (0..%d)",bmap_n, SB_BMAP_NR (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_warning (s, "NULL bitmap info pointer for bitmap %d", bmap_n); + return 0; + } + if (buffer_locked (bi->bh)) { + PROC_INFO_INC( s, scan_bitmap.wait ); + __wait_on_buffer (bi->bh); + } + + while (1) { + cont: + if (bi->free_count < min) + return 0; // No free blocks in this bitmap + + /* search for a first zero bit -- beggining of a window */ + *beg = reiserfs_find_next_zero_le_bit + ((unsigned long*)(bi->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 */ + 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, bi->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 */ + if (end - *beg >= min) { /* it seems we have found window of proper size */ + int i; + reiserfs_prepare_for_journal (s, bi->bh, 1); + /* 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. */ + if (reiserfs_test_and_set_le_bit (i, bi->bh->b_data)) { + /* 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' */ + end = i; + break; + } + /* otherwise we clear all bit were set ... */ + while (--i >= *beg) + reiserfs_test_and_clear_le_bit (i, bi->bh->b_data); + reiserfs_restore_prepared_buffer (s, bi->bh); + *beg = org; + /* ... and search again in current block from beginning */ + goto cont; + } + } + bi->free_count -= (end - *beg); + journal_mark_dirty (th, s, bi->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, s, 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 % SB_BMAP_NR(s); + if (!bm) + bm = 1; + } + /* this can only be true when SB_BMAP_NR = 1 */ + if (bm >= SB_BMAP_NR(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; + bm = bmap_hash_id(s, id); + if (SB_AP_BITMAP(s)[bm].free_count > ((s->s_blocksize << 3) * 60 / 100) ) { + return 0; + } + return 1; +} + +/* + * the packing is returned in disk byte order + */ +u32 reiserfs_choose_packing(struct inode *dir) { + u32 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, unsigned long 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. */ + + int bm, off; + int end_bm, end_off; + int off_max = s->s_blocksize << 3; + + BUG_ON (!th->t_trans_id); + + PROC_INFO_INC( s, scan_bitmap.call ); + if ( SB_FREE_BLOCKS(s) <= 0) + return 0; // No point in looking for more free blocks + + get_bit_address (s, *start, &bm, &off); + get_bit_address (s, finish, &end_bm, &end_off); + if (bm > SB_BMAP_NR(s)) + return 0; + if (end_bm > SB_BMAP_NR(s)) + end_bm = SB_BMAP_NR(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; + struct reiserfs_bitmap_info *apbi; + 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 >= sb_bmap_nr (rs)) { + reiserfs_warning (s, "vs-4075: reiserfs_free_block: " + "block %lu is out of range on %s", + block, reiserfs_bdevname (s)); + return; + } + + reiserfs_prepare_for_journal(s, apbi[nr].bh, 1 ) ; + + /* clear bit for the given block in bit map */ + if (!reiserfs_test_and_clear_le_bit (offset, apbi[nr].bh->b_data)) { + reiserfs_warning (s, "vs-4080: reiserfs_free_block: " + "free_block (%s:%lu)[dev:blocknr]: bit already cleared", + reiserfs_bdevname (s), block); + } + apbi[nr].free_count ++; + journal_mark_dirty (th, s, apbi[nr].bh); + + reiserfs_prepare_for_journal(s, sbh, 1) ; + /* update super block */ + set_sb_free_blocks( rs, sb_free_blocks(rs) + 1 ); + + journal_mark_dirty (th, s, sbh); + if (for_unformatted) + DQUOT_FREE_BLOCK_NODIRTY(inode, 1); +} + +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"); + RFALSE(is_reusable (s, block, 1) == 0, "vs-4071: can not free such block"); + /* 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) { + RFALSE(!th->t_super, "vs-4060: trying to free block on nonexistent device"); + RFALSE(is_reusable (th->t_super, block, 1) == 0, "vs-4070: can not free such block"); + BUG_ON (!th->t_trans_id); + _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_warning (th->t_super, "zam-4001:%s: inode has negative prealloc blocks count.", __FUNCTION__ ); +#endif + while (ei->i_prealloc_count > 0) { + reiserfs_free_prealloc_block(th, inode, ei->i_prealloc_block); + ei->i_prealloc_block++; + ei->i_prealloc_count --; + 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_warning (th->t_super, "zam-4001:%s: inode is in prealloc list but has no preallocated blocks.", __FUNCTION__); + } +#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; + + REISERFS_SB(s)->s_alloc_options.bits = 0; /* clear default settings */ + + 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: %s : unknown option - %s", + __FUNCTION__ , this_char); + return 1; + } + + reiserfs_warning (s, "allocator options = [%08x]\n", SB_ALLOC_OPTS(s)); + return 0; +} + +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 seperate 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 seperate 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 path * path; + struct buffer_head * bh; + struct item_head * ih; + int pos_in_item; + __u32 * 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 */ + return 0; + + path = hint->path; + bh = get_last_bh(path); + RFALSE( !bh, "green-4002: Illegal path specified to get_left_neighbor"); + ih = get_ih(path); + pos_in_item = path->pos_in_item; + item = get_item (path); + + hint->search_start = bh->b_blocknr; + + 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) { + 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 reiserfs_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 reiserfs_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) + && 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; +} + +/* 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, 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 bigalloc = 0; + + 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 + quota_ret = DQUOT_ALLOC_BLOCK_NODIRTY(hint->inode, amount_needed); + if (quota_ret) /* Quota exceeded? */ + 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 */ + bigalloc = amount_needed; + } + + do { + /* in bigalloc mode, nr_allocated should stay zero until + * the entire allocation is filled + */ + if (unlikely(bigalloc && nr_allocated)) { + reiserfs_warning(s, "bigalloc is %d, nr_allocated %d\n", + bigalloc, nr_allocated); + /* reset things to a sane value */ + bigalloc = amount_needed - nr_allocated; + } + /* + * try pass 0 and pass 1 looking for a nice big + * contiguous allocation. Then reset and look + * for anything you can find. + */ + if (passno == 2 && bigalloc) { + passno = 0; + bigalloc = 0; + } + 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 + DQUOT_FREE_BLOCK_NODIRTY(hint->inode, amount_needed + hint->prealloc_size - nr_allocated); /* Free not allocated blocks */ + } + 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, + bigalloc ? bigalloc : 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 + DQUOT_FREE_BLOCK_NODIRTY(hint->inode, amount_needed + + hint->prealloc_size - nr_allocated - + REISERFS_I(hint->inode)->i_prealloc_count); + } + + 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, + int reserved_by_us /* Amount of blocks we have + already reserved */) +{ + 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 assotiated 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 */ + 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; +} + +/* These 2 functions are here to provide blocks reservation to the rest of kernel */ +/* Reserve @blocks amount of blocks in fs pointed by @sb. Caller must make sure + there are actually this much blocks on the FS available */ +void reiserfs_claim_blocks_to_be_allocated( + struct super_block *sb, /* super block of + filesystem where + blocks should be + reserved */ + int blocks /* How much to reserve */ + ) +{ + + /* Fast case, if reservation is zero - exit immediately. */ + if ( !blocks ) + return; + + spin_lock(&REISERFS_SB(sb)->bitmap_lock); + REISERFS_SB(sb)->reserved_blocks += blocks; + spin_unlock(&REISERFS_SB(sb)->bitmap_lock); +} + +/* Unreserve @blocks amount of blocks in fs pointed by @sb */ +void reiserfs_release_claimed_blocks( + struct super_block *sb, /* super block of + filesystem where + blocks should be + reserved */ + int blocks /* How much to unreserve */ + ) +{ + + /* Fast case, if unreservation is zero - exit immediately. */ + if ( !blocks ) + return; + + spin_lock(&REISERFS_SB(sb)->bitmap_lock); + REISERFS_SB(sb)->reserved_blocks -= blocks; + spin_unlock(&REISERFS_SB(sb)->bitmap_lock); + RFALSE( REISERFS_SB(sb)->reserved_blocks < 0, "amount of blocks reserved became zero?"); +} + +/* This function estimates how much pages we will be able to write to FS + used for reiserfs_file_write() purposes for now. */ +int reiserfs_can_fit_pages ( struct super_block *sb /* superblock of filesystem + to estimate space */ ) +{ + int space; + + spin_lock(&REISERFS_SB(sb)->bitmap_lock); + space = (SB_FREE_BLOCKS(sb) - REISERFS_SB(sb)->reserved_blocks) >> ( PAGE_CACHE_SHIFT - sb->s_blocksize_bits); + spin_unlock(&REISERFS_SB(sb)->bitmap_lock); + + return space>0?space:0; +} |