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Diffstat (limited to 'fs/reiserfs/stree.c')
| -rw-r--r-- | fs/reiserfs/stree.c | 2073 | 
1 files changed, 2073 insertions, 0 deletions
diff --git a/fs/reiserfs/stree.c b/fs/reiserfs/stree.c new file mode 100644 index 000000000000..73ec5212178b --- /dev/null +++ b/fs/reiserfs/stree.c @@ -0,0 +1,2073 @@ +/* + *  Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README + */ + +/* + *  Written by Anatoly P. Pinchuk pap@namesys.botik.ru + *  Programm System Institute + *  Pereslavl-Zalessky Russia + */ + +/* + *  This file contains functions dealing with S+tree + * + * B_IS_IN_TREE + * copy_item_head + * comp_short_keys + * comp_keys + * comp_short_le_keys + * le_key2cpu_key + * comp_le_keys + * bin_search + * get_lkey + * get_rkey + * key_in_buffer + * decrement_bcount + * decrement_counters_in_path + * reiserfs_check_path + * pathrelse_and_restore + * pathrelse + * search_by_key_reada + * search_by_key + * search_for_position_by_key + * comp_items + * prepare_for_direct_item + * prepare_for_direntry_item + * prepare_for_delete_or_cut + * calc_deleted_bytes_number + * init_tb_struct + * padd_item + * reiserfs_delete_item + * reiserfs_delete_solid_item + * reiserfs_delete_object + * maybe_indirect_to_direct + * indirect_to_direct_roll_back + * reiserfs_cut_from_item + * truncate_directory + * reiserfs_do_truncate + * reiserfs_paste_into_item + * reiserfs_insert_item + */ + +#include <linux/config.h> +#include <linux/time.h> +#include <linux/string.h> +#include <linux/pagemap.h> +#include <linux/reiserfs_fs.h> +#include <linux/smp_lock.h> +#include <linux/buffer_head.h> +#include <linux/quotaops.h> + +/* Does the buffer contain a disk block which is in the tree. */ +inline int B_IS_IN_TREE (const struct buffer_head * p_s_bh) +{ + +  RFALSE( B_LEVEL (p_s_bh) > MAX_HEIGHT, +	  "PAP-1010: block (%b) has too big level (%z)", p_s_bh, p_s_bh); + +  return ( B_LEVEL (p_s_bh) != FREE_LEVEL ); +} + +// +// to gets item head in le form +// +inline void copy_item_head(struct item_head * p_v_to,  +			   const struct item_head * p_v_from) +{ +  memcpy (p_v_to, p_v_from, IH_SIZE); +} + + +/* k1 is pointer to on-disk structure which is stored in little-endian +   form. k2 is pointer to cpu variable. For key of items of the same +   object this returns 0. +   Returns: -1 if key1 < key2  +   0 if key1 == key2 +   1 if key1 > key2 */ +inline int  comp_short_keys (const struct reiserfs_key * le_key, +			     const struct cpu_key * cpu_key) +{ +  __u32 * p_s_le_u32, * p_s_cpu_u32; +  int n_key_length = REISERFS_SHORT_KEY_LEN; + +  p_s_le_u32 = (__u32 *)le_key; +  p_s_cpu_u32 = (__u32 *)&cpu_key->on_disk_key; +  for( ; n_key_length--; ++p_s_le_u32, ++p_s_cpu_u32 ) { +    if ( le32_to_cpu (*p_s_le_u32) < *p_s_cpu_u32 ) +      return -1; +    if ( le32_to_cpu (*p_s_le_u32) > *p_s_cpu_u32 ) +      return 1; +  } + +  return 0; +} + + +/* k1 is pointer to on-disk structure which is stored in little-endian +   form. k2 is pointer to cpu variable. +   Compare keys using all 4 key fields. +   Returns: -1 if key1 < key2 0 +   if key1 = key2 1 if key1 > key2 */ +static inline int  comp_keys (const struct reiserfs_key * le_key, const struct cpu_key * cpu_key) +{ +  int retval; + +  retval = comp_short_keys (le_key, cpu_key); +  if (retval) +      return retval; +  if (le_key_k_offset (le_key_version(le_key), le_key) < cpu_key_k_offset (cpu_key)) +      return -1; +  if (le_key_k_offset (le_key_version(le_key), le_key) > cpu_key_k_offset (cpu_key)) +      return 1; + +  if (cpu_key->key_length == 3) +      return 0; + +  /* this part is needed only when tail conversion is in progress */ +  if (le_key_k_type (le_key_version(le_key), le_key) < cpu_key_k_type (cpu_key)) +    return -1; + +  if (le_key_k_type (le_key_version(le_key), le_key) > cpu_key_k_type (cpu_key)) +    return 1; + +  return 0; +} + + +inline int comp_short_le_keys (const struct reiserfs_key * key1, const struct reiserfs_key * key2) +{ +  __u32 * p_s_1_u32, * p_s_2_u32; +  int n_key_length = REISERFS_SHORT_KEY_LEN; + +  p_s_1_u32 = (__u32 *)key1; +  p_s_2_u32 = (__u32 *)key2; +  for( ; n_key_length--; ++p_s_1_u32, ++p_s_2_u32 ) { +    if ( le32_to_cpu (*p_s_1_u32) < le32_to_cpu (*p_s_2_u32) ) +      return -1; +    if ( le32_to_cpu (*p_s_1_u32) > le32_to_cpu (*p_s_2_u32) ) +      return 1; +  } +  return 0; +} + +inline void le_key2cpu_key (struct cpu_key * to, const struct reiserfs_key * from) +{ +    to->on_disk_key.k_dir_id = le32_to_cpu (from->k_dir_id); +    to->on_disk_key.k_objectid = le32_to_cpu (from->k_objectid); +     +    // find out version of the key +    to->version = le_key_version (from); +    if (to->version == KEY_FORMAT_3_5) { +	to->on_disk_key.u.k_offset_v1.k_offset = le32_to_cpu (from->u.k_offset_v1.k_offset); +	to->on_disk_key.u.k_offset_v1.k_uniqueness = le32_to_cpu (from->u.k_offset_v1.k_uniqueness); +    } else { +	to->on_disk_key.u.k_offset_v2.k_offset = offset_v2_k_offset(&from->u.k_offset_v2); +	to->on_disk_key.u.k_offset_v2.k_type = offset_v2_k_type(&from->u.k_offset_v2); +    }  +} + + + +// this does not say which one is bigger, it only returns 1 if keys +// are not equal, 0 otherwise +inline int comp_le_keys (const struct reiserfs_key * k1, const struct reiserfs_key * k2) +{ +    return memcmp (k1, k2, sizeof (struct reiserfs_key)); +} + +/************************************************************************** + *  Binary search toolkit function                                        * + *  Search for an item in the array by the item key                       * + *  Returns:    1 if found,  0 if not found;                              * + *        *p_n_pos = number of the searched element if found, else the    * + *        number of the first element that is larger than p_v_key.        * + **************************************************************************/ +/* For those not familiar with binary search: n_lbound is the leftmost item that it + could be, n_rbound the rightmost item that it could be.  We examine the item + halfway between n_lbound and n_rbound, and that tells us either that we can increase + n_lbound, or decrease n_rbound, or that we have found it, or if n_lbound <= n_rbound that + there are no possible items, and we have not found it. With each examination we + cut the number of possible items it could be by one more than half rounded down, + or we find it. */ +static inline	int bin_search ( +              const void * p_v_key, /* Key to search for.                   */ +	      const void * p_v_base,/* First item in the array.             */ +	      int       p_n_num,    /* Number of items in the array.        */ +	      int       p_n_width,  /* Item size in the array. +				       searched. Lest the reader be +				       confused, note that this is crafted +				       as a general function, and when it +				       is applied specifically to the array +				       of item headers in a node, p_n_width +				       is actually the item header size not +				       the item size.                      */ +	      int     * p_n_pos     /* Number of the searched for element. */ +            ) { +    int   n_rbound, n_lbound, n_j; + +   for ( n_j = ((n_rbound = p_n_num - 1) + (n_lbound = 0))/2; n_lbound <= n_rbound; n_j = (n_rbound + n_lbound)/2 ) +     switch( comp_keys((struct reiserfs_key *)((char * )p_v_base + n_j * p_n_width), (struct cpu_key *)p_v_key) )  { +     case -1: n_lbound = n_j + 1; continue; +     case  1: n_rbound = n_j - 1; continue; +     case  0: *p_n_pos = n_j;     return ITEM_FOUND; /* Key found in the array.  */ +        } + +    /* bin_search did not find given key, it returns position of key, +        that is minimal and greater than the given one. */ +    *p_n_pos = n_lbound; +    return ITEM_NOT_FOUND; +} + +#ifdef CONFIG_REISERFS_CHECK +extern struct tree_balance * cur_tb; +#endif + + + +/* Minimal possible key. It is never in the tree. */ +const struct reiserfs_key  MIN_KEY = {0, 0, {{0, 0},}}; + +/* Maximal possible key. It is never in the tree. */ +const struct reiserfs_key  MAX_KEY = {0xffffffff, 0xffffffff, {{0xffffffff, 0xffffffff},}}; + + +/* Get delimiting key of the buffer by looking for it in the buffers in the path, starting from the bottom +   of the path, and going upwards.  We must check the path's validity at each step.  If the key is not in +   the path, there is no delimiting key in the tree (buffer is first or last buffer in tree), and in this +   case we return a special key, either MIN_KEY or MAX_KEY. */ +static inline	const struct  reiserfs_key * get_lkey  ( +	                const struct path         * p_s_chk_path, +                        const struct super_block  * p_s_sb +                      ) { +  int                   n_position, n_path_offset = p_s_chk_path->path_length; +  struct buffer_head  * p_s_parent; +   +  RFALSE( n_path_offset < FIRST_PATH_ELEMENT_OFFSET,  +	  "PAP-5010: invalid offset in the path"); + +  /* While not higher in path than first element. */ +  while ( n_path_offset-- > FIRST_PATH_ELEMENT_OFFSET ) { + +    RFALSE( ! buffer_uptodate(PATH_OFFSET_PBUFFER(p_s_chk_path, n_path_offset)), +	    "PAP-5020: parent is not uptodate"); + +    /* Parent at the path is not in the tree now. */ +    if ( ! B_IS_IN_TREE(p_s_parent = PATH_OFFSET_PBUFFER(p_s_chk_path, n_path_offset)) ) +      return &MAX_KEY; +    /* Check whether position in the parent is correct. */ +    if ( (n_position = PATH_OFFSET_POSITION(p_s_chk_path, n_path_offset)) > B_NR_ITEMS(p_s_parent) ) +       return &MAX_KEY; +    /* Check whether parent at the path really points to the child. */ +    if ( B_N_CHILD_NUM(p_s_parent, n_position) != +	 PATH_OFFSET_PBUFFER(p_s_chk_path, n_path_offset + 1)->b_blocknr ) +      return &MAX_KEY; +    /* Return delimiting key if position in the parent is not equal to zero. */ +    if ( n_position ) +      return B_N_PDELIM_KEY(p_s_parent, n_position - 1); +  } +  /* Return MIN_KEY if we are in the root of the buffer tree. */ +  if ( PATH_OFFSET_PBUFFER(p_s_chk_path, FIRST_PATH_ELEMENT_OFFSET)->b_blocknr == +       SB_ROOT_BLOCK (p_s_sb) ) +    return &MIN_KEY; +  return  &MAX_KEY; +} + + +/* Get delimiting key of the buffer at the path and its right neighbor. */ +inline	const struct  reiserfs_key * get_rkey  ( +	                const struct path         * p_s_chk_path, +                        const struct super_block  * p_s_sb +                      ) { +  int                   n_position, +    			n_path_offset = p_s_chk_path->path_length; +  struct buffer_head  * p_s_parent; + +  RFALSE( n_path_offset < FIRST_PATH_ELEMENT_OFFSET, +	  "PAP-5030: invalid offset in the path"); + +  while ( n_path_offset-- > FIRST_PATH_ELEMENT_OFFSET ) { + +    RFALSE( ! buffer_uptodate(PATH_OFFSET_PBUFFER(p_s_chk_path, n_path_offset)), +	    "PAP-5040: parent is not uptodate"); + +    /* Parent at the path is not in the tree now. */ +    if ( ! B_IS_IN_TREE(p_s_parent = PATH_OFFSET_PBUFFER(p_s_chk_path, n_path_offset)) ) +      return &MIN_KEY; +    /* Check whether position in the parent is correct. */ +    if ( (n_position = PATH_OFFSET_POSITION(p_s_chk_path, n_path_offset)) > B_NR_ITEMS(p_s_parent) ) +      return &MIN_KEY; +    /* Check whether parent at the path really points to the child. */ +    if ( B_N_CHILD_NUM(p_s_parent, n_position) != +                                        PATH_OFFSET_PBUFFER(p_s_chk_path, n_path_offset + 1)->b_blocknr ) +      return &MIN_KEY; +    /* Return delimiting key if position in the parent is not the last one. */ +    if ( n_position != B_NR_ITEMS(p_s_parent) ) +      return B_N_PDELIM_KEY(p_s_parent, n_position); +  } +  /* Return MAX_KEY if we are in the root of the buffer tree. */ +  if ( PATH_OFFSET_PBUFFER(p_s_chk_path, FIRST_PATH_ELEMENT_OFFSET)->b_blocknr == +       SB_ROOT_BLOCK (p_s_sb) ) +    return &MAX_KEY; +  return  &MIN_KEY; +} + + +/* Check whether a key is contained in the tree rooted from a buffer at a path. */ +/* This works by looking at the left and right delimiting keys for the buffer in the last path_element in +   the path.  These delimiting keys are stored at least one level above that buffer in the tree. If the +   buffer is the first or last node in the tree order then one of the delimiting keys may be absent, and in +   this case get_lkey and get_rkey return a special key which is MIN_KEY or MAX_KEY. */ +static  inline  int key_in_buffer ( +                      struct path         * p_s_chk_path, /* Path which should be checked.  */ +                      const struct cpu_key      * p_s_key,      /* Key which should be checked.   */ +                      struct super_block  * p_s_sb        /* Super block pointer.           */ +		      ) { + +  RFALSE( ! p_s_key || p_s_chk_path->path_length < FIRST_PATH_ELEMENT_OFFSET || +	  p_s_chk_path->path_length > MAX_HEIGHT, +	  "PAP-5050: pointer to the key(%p) is NULL or invalid path length(%d)", +	  p_s_key, p_s_chk_path->path_length); +  RFALSE( !PATH_PLAST_BUFFER(p_s_chk_path)->b_bdev, +	  "PAP-5060: device must not be NODEV"); + +  if ( comp_keys(get_lkey(p_s_chk_path, p_s_sb), p_s_key) == 1 ) +    /* left delimiting key is bigger, that the key we look for */ +    return 0; +  //  if ( comp_keys(p_s_key, get_rkey(p_s_chk_path, p_s_sb)) != -1 ) +  if ( comp_keys(get_rkey(p_s_chk_path, p_s_sb), p_s_key) != 1 ) +    /* p_s_key must be less than right delimitiing key */ +    return 0; +  return 1; +} + + +inline void decrement_bcount( +              struct buffer_head  * p_s_bh +            ) {  +  if ( p_s_bh ) { +    if ( atomic_read (&(p_s_bh->b_count)) ) { +      put_bh(p_s_bh) ; +      return; +    } +    reiserfs_panic(NULL, "PAP-5070: decrement_bcount: trying to free free buffer %b", p_s_bh); +  } +} + + +/* Decrement b_count field of the all buffers in the path. */ +void decrement_counters_in_path ( +              struct path * p_s_search_path +            ) { +  int n_path_offset = p_s_search_path->path_length; + +  RFALSE( n_path_offset < ILLEGAL_PATH_ELEMENT_OFFSET || +	  n_path_offset > EXTENDED_MAX_HEIGHT - 1, +	  "PAP-5080: invalid path offset of %d", n_path_offset); + +  while ( n_path_offset > ILLEGAL_PATH_ELEMENT_OFFSET ) { +    struct buffer_head * bh; + +    bh = PATH_OFFSET_PBUFFER(p_s_search_path, n_path_offset--); +    decrement_bcount (bh); +  } +  p_s_search_path->path_length = ILLEGAL_PATH_ELEMENT_OFFSET; +} + + +int reiserfs_check_path(struct path *p) { +  RFALSE( p->path_length != ILLEGAL_PATH_ELEMENT_OFFSET, +	  "path not properly relsed") ; +  return 0 ; +} + + +/* Release all buffers in the path. Restore dirty bits clean +** when preparing the buffer for the log +** +** only called from fix_nodes() +*/ +void  pathrelse_and_restore ( +	struct super_block *s,  +        struct path * p_s_search_path +      ) { +  int n_path_offset = p_s_search_path->path_length; + +  RFALSE( n_path_offset < ILLEGAL_PATH_ELEMENT_OFFSET,  +	  "clm-4000: invalid path offset"); +   +  while ( n_path_offset > ILLEGAL_PATH_ELEMENT_OFFSET )  { +    reiserfs_restore_prepared_buffer(s, PATH_OFFSET_PBUFFER(p_s_search_path,  +                                     n_path_offset)); +    brelse(PATH_OFFSET_PBUFFER(p_s_search_path, n_path_offset--)); +  } +  p_s_search_path->path_length = ILLEGAL_PATH_ELEMENT_OFFSET; +} + +/* Release all buffers in the path. */ +void  pathrelse ( +        struct path * p_s_search_path +      ) { +  int n_path_offset = p_s_search_path->path_length; + +  RFALSE( n_path_offset < ILLEGAL_PATH_ELEMENT_OFFSET, +	  "PAP-5090: invalid path offset"); +   +  while ( n_path_offset > ILLEGAL_PATH_ELEMENT_OFFSET )   +    brelse(PATH_OFFSET_PBUFFER(p_s_search_path, n_path_offset--)); + +  p_s_search_path->path_length = ILLEGAL_PATH_ELEMENT_OFFSET; +} + + + +static int is_leaf (char * buf, int blocksize, struct buffer_head * bh) +{ +    struct block_head * blkh; +    struct item_head * ih; +    int used_space; +    int prev_location; +    int i; +    int nr; + +    blkh = (struct block_head *)buf; +    if ( blkh_level(blkh) != DISK_LEAF_NODE_LEVEL) { +	reiserfs_warning (NULL, "is_leaf: this should be caught earlier"); +	return 0; +    } + +    nr = blkh_nr_item(blkh); +    if (nr < 1 || nr > ((blocksize - BLKH_SIZE) / (IH_SIZE + MIN_ITEM_LEN))) { +	/* item number is too big or too small */ +	reiserfs_warning (NULL, "is_leaf: nr_item seems wrong: %z", bh); +	return 0; +    } +    ih = (struct item_head *)(buf + BLKH_SIZE) + nr - 1; +    used_space = BLKH_SIZE + IH_SIZE * nr + (blocksize - ih_location (ih)); +    if (used_space != blocksize - blkh_free_space(blkh)) { +	/* free space does not match to calculated amount of use space */ +	reiserfs_warning (NULL, "is_leaf: free space seems wrong: %z", bh); +	return 0; +    } + +    // FIXME: it is_leaf will hit performance too much - we may have +    // return 1 here + +    /* check tables of item heads */ +    ih = (struct item_head *)(buf + BLKH_SIZE); +    prev_location = blocksize; +    for (i = 0; i < nr; i ++, ih ++) { +	if ( le_ih_k_type(ih) == TYPE_ANY) { +	    reiserfs_warning (NULL, "is_leaf: wrong item type for item %h",ih); +	    return 0; +	} +	if (ih_location (ih) >= blocksize || ih_location (ih) < IH_SIZE * nr) { +	    reiserfs_warning (NULL, "is_leaf: item location seems wrong: %h", ih); +	    return 0; +	} +	if (ih_item_len (ih) < 1 || ih_item_len (ih) > MAX_ITEM_LEN (blocksize)) { +	    reiserfs_warning (NULL, "is_leaf: item length seems wrong: %h", ih); +	    return 0; +	} +	if (prev_location - ih_location (ih) != ih_item_len (ih)) { +	    reiserfs_warning (NULL, "is_leaf: item location seems wrong (second one): %h", ih); +	    return 0; +	} +	prev_location = ih_location (ih); +    } + +    // one may imagine much more checks +    return 1; +} + + +/* returns 1 if buf looks like an internal node, 0 otherwise */ +static int is_internal (char * buf, int blocksize, struct buffer_head * bh) +{ +    struct block_head * blkh; +    int nr; +    int used_space; + +    blkh = (struct block_head *)buf; +    nr = blkh_level(blkh); +    if (nr <= DISK_LEAF_NODE_LEVEL || nr > MAX_HEIGHT) { +	/* this level is not possible for internal nodes */ +	reiserfs_warning (NULL, "is_internal: this should be caught earlier"); +	return 0; +    } +     +    nr = blkh_nr_item(blkh); +    if (nr > (blocksize - BLKH_SIZE - DC_SIZE) / (KEY_SIZE + DC_SIZE)) { +	/* for internal which is not root we might check min number of keys */ +	reiserfs_warning (NULL, "is_internal: number of key seems wrong: %z", bh); +	return 0; +    } + +    used_space = BLKH_SIZE + KEY_SIZE * nr + DC_SIZE * (nr + 1); +    if (used_space != blocksize - blkh_free_space(blkh)) { +	reiserfs_warning (NULL, "is_internal: free space seems wrong: %z", bh); +	return 0; +    } + +    // one may imagine much more checks +    return 1; +} + + +// make sure that bh contains formatted node of reiserfs tree of +// 'level'-th level +static int is_tree_node (struct buffer_head * bh, int level) +{ +    if (B_LEVEL (bh) != level) { +	reiserfs_warning (NULL, "is_tree_node: node level %d does not match to the expected one %d", +		B_LEVEL (bh), level); +	return 0; +    } +    if (level == DISK_LEAF_NODE_LEVEL) +	return is_leaf (bh->b_data, bh->b_size, bh); + +    return is_internal (bh->b_data, bh->b_size, bh); +} + + + +#define SEARCH_BY_KEY_READA 16 + +/* The function is NOT SCHEDULE-SAFE! */ +static void search_by_key_reada (struct super_block * s, +                                 struct buffer_head **bh, +				 unsigned long *b, int num) +{ +    int i,j; +   +    for (i = 0 ; i < num ; i++) { +	bh[i] = sb_getblk (s, b[i]); +    } +    for (j = 0 ; j < i ; j++) { +	/* +	 * note, this needs attention if we are getting rid of the BKL +	 * you have to make sure the prepared bit isn't set on this buffer +	 */ +	if (!buffer_uptodate(bh[j])) +	    ll_rw_block(READA, 1, bh + j); +    	brelse(bh[j]); +    } +} + +/************************************************************************** + * Algorithm   SearchByKey                                                * + *             look for item in the Disk S+Tree by its key                * + * Input:  p_s_sb   -  super block                                        * + *         p_s_key  - pointer to the key to search                        * + * Output: ITEM_FOUND, ITEM_NOT_FOUND or IO_ERROR                         * + *         p_s_search_path - path from the root to the needed leaf        * + **************************************************************************/ + +/* This function fills up the path from the root to the leaf as it +   descends the tree looking for the key.  It uses reiserfs_bread to +   try to find buffers in the cache given their block number.  If it +   does not find them in the cache it reads them from disk.  For each +   node search_by_key finds using reiserfs_bread it then uses +   bin_search to look through that node.  bin_search will find the +   position of the block_number of the next node if it is looking +   through an internal node.  If it is looking through a leaf node +   bin_search will find the position of the item which has key either +   equal to given key, or which is the maximal key less than the given +   key.  search_by_key returns a path that must be checked for the +   correctness of the top of the path but need not be checked for the +   correctness of the bottom of the path */ +/* The function is NOT SCHEDULE-SAFE! */ +int search_by_key (struct super_block * p_s_sb, +		   const struct cpu_key * p_s_key, /* Key to search. */ +		   struct path * p_s_search_path, /* This structure was +						     allocated and initialized +						     by the calling +						     function. It is filled up +						     by this function.  */ +		   int n_stop_level /* How far down the tree to search. To +                                       stop at leaf level - set to +                                       DISK_LEAF_NODE_LEVEL */ +    ) { +    int  n_block_number; +    int  expected_level; +    struct buffer_head  *       p_s_bh; +    struct path_element *       p_s_last_element; +    int				n_node_level, n_retval; +    int 			right_neighbor_of_leaf_node; +    int				fs_gen; +    struct buffer_head *reada_bh[SEARCH_BY_KEY_READA]; +    unsigned long      reada_blocks[SEARCH_BY_KEY_READA]; +    int reada_count = 0; + +#ifdef CONFIG_REISERFS_CHECK +    int n_repeat_counter = 0; +#endif +     +    PROC_INFO_INC( p_s_sb, search_by_key ); +     +    /* As we add each node to a path we increase its count.  This means that +       we must be careful to release all nodes in a path before we either +       discard the path struct or re-use the path struct, as we do here. */ + +    decrement_counters_in_path(p_s_search_path); + +    right_neighbor_of_leaf_node = 0; + +    /* With each iteration of this loop we search through the items in the +       current node, and calculate the next current node(next path element) +       for the next iteration of this loop.. */ +    n_block_number = SB_ROOT_BLOCK (p_s_sb); +    expected_level = -1; +    while ( 1 ) { + +#ifdef CONFIG_REISERFS_CHECK +	if ( !(++n_repeat_counter % 50000) ) +	    reiserfs_warning (p_s_sb, "PAP-5100: search_by_key: %s:" +			      "there were %d iterations of while loop " +			      "looking for key %K", +			      current->comm, n_repeat_counter, p_s_key); +#endif + +	/* prep path to have another element added to it. */ +	p_s_last_element = PATH_OFFSET_PELEMENT(p_s_search_path, ++p_s_search_path->path_length); +	fs_gen = get_generation (p_s_sb); + +	/* Read the next tree node, and set the last element in the path to +           have a pointer to it. */ +	if ((p_s_bh = p_s_last_element->pe_buffer = +	     sb_getblk(p_s_sb, n_block_number)) ) { +	    if (!buffer_uptodate(p_s_bh) && reada_count > 1) { +		search_by_key_reada (p_s_sb, reada_bh, +		                     reada_blocks, reada_count); +	    } +	    ll_rw_block(READ, 1, &p_s_bh); +	    wait_on_buffer(p_s_bh); +	    if (!buffer_uptodate(p_s_bh)) +	        goto io_error; +	} else { +io_error: +	    p_s_search_path->path_length --; +	    pathrelse(p_s_search_path); +	    return IO_ERROR; +	} +	reada_count = 0; +	if (expected_level == -1) +		expected_level = SB_TREE_HEIGHT (p_s_sb); +	expected_level --; + +	/* It is possible that schedule occurred. We must check whether the key +	   to search is still in the tree rooted from the current buffer. If +	   not then repeat search from the root. */ +	if ( fs_changed (fs_gen, p_s_sb) &&  +	    (!B_IS_IN_TREE (p_s_bh) || +	     B_LEVEL(p_s_bh) != expected_level || +	     !key_in_buffer(p_s_search_path, p_s_key, p_s_sb))) { +	    PROC_INFO_INC( p_s_sb, search_by_key_fs_changed ); +	    PROC_INFO_INC( p_s_sb, search_by_key_restarted ); +	    PROC_INFO_INC( p_s_sb, sbk_restarted[ expected_level - 1 ] ); +	    decrement_counters_in_path(p_s_search_path); +	     +	    /* Get the root block number so that we can repeat the search +	       starting from the root. */ +	    n_block_number = SB_ROOT_BLOCK (p_s_sb); +	    expected_level = -1; +	    right_neighbor_of_leaf_node = 0; +	     +	    /* repeat search from the root */ +	    continue; +	} + +        /* only check that the key is in the buffer if p_s_key is not +           equal to the MAX_KEY. Latter case is only possible in +           "finish_unfinished()" processing during mount. */ +        RFALSE( comp_keys( &MAX_KEY, p_s_key ) && +                ! key_in_buffer(p_s_search_path, p_s_key, p_s_sb), +		"PAP-5130: key is not in the buffer"); +#ifdef CONFIG_REISERFS_CHECK +	if ( cur_tb ) { +	    print_cur_tb ("5140"); +	    reiserfs_panic(p_s_sb, "PAP-5140: search_by_key: schedule occurred in do_balance!"); +	} +#endif + +	// make sure, that the node contents look like a node of +	// certain level +	if (!is_tree_node (p_s_bh, expected_level)) { +	    reiserfs_warning (p_s_sb, "vs-5150: search_by_key: " +			      "invalid format found in block %ld. Fsck?", +			      p_s_bh->b_blocknr); +	    pathrelse (p_s_search_path); +	    return IO_ERROR; +	} +	 +	/* ok, we have acquired next formatted node in the tree */ +	n_node_level = B_LEVEL (p_s_bh); + +	PROC_INFO_BH_STAT( p_s_sb, p_s_bh, n_node_level - 1 ); + +	RFALSE( n_node_level < n_stop_level, +		"vs-5152: tree level (%d) is less than stop level (%d)", +		n_node_level, n_stop_level); + +	n_retval = bin_search( p_s_key, B_N_PITEM_HEAD(p_s_bh, 0), +                B_NR_ITEMS(p_s_bh), +                ( n_node_level == DISK_LEAF_NODE_LEVEL ) ? IH_SIZE : KEY_SIZE, +                &(p_s_last_element->pe_position)); +	if (n_node_level == n_stop_level) { +	    return n_retval; +	} + +	/* we are not in the stop level */ +	if (n_retval == ITEM_FOUND) +	    /* item has been found, so we choose the pointer which is to the right of the found one */ +	    p_s_last_element->pe_position++; + +	/* if item was not found we choose the position which is to +	   the left of the found item. This requires no code, +	   bin_search did it already.*/ + +	/* So we have chosen a position in the current node which is +	   an internal node.  Now we calculate child block number by +	   position in the node. */ +	n_block_number = B_N_CHILD_NUM(p_s_bh, p_s_last_element->pe_position); + +	/* if we are going to read leaf nodes, try for read ahead as well */ +	if ((p_s_search_path->reada & PATH_READA) && +	    n_node_level == DISK_LEAF_NODE_LEVEL + 1) +	{ +	    int pos = p_s_last_element->pe_position; +	    int limit = B_NR_ITEMS(p_s_bh); +	    struct reiserfs_key *le_key; + +	    if (p_s_search_path->reada & PATH_READA_BACK) +		limit = 0; +	    while(reada_count < SEARCH_BY_KEY_READA) { +		if (pos == limit) +		    break; +	        reada_blocks[reada_count++] = B_N_CHILD_NUM(p_s_bh, pos); +		if (p_s_search_path->reada & PATH_READA_BACK) +		    pos--; +		else +		    pos++; + +		/* +		 * check to make sure we're in the same object +		 */ +		le_key = B_N_PDELIM_KEY(p_s_bh, pos); +		if (le32_to_cpu(le_key->k_objectid) != +		    p_s_key->on_disk_key.k_objectid) +		{ +		    break; +		} +	    } +        } +    } +} + + +/* Form the path to an item and position in this item which contains +   file byte defined by p_s_key. If there is no such item +   corresponding to the key, we point the path to the item with +   maximal key less than p_s_key, and *p_n_pos_in_item is set to one +   past the last entry/byte in the item.  If searching for entry in a +   directory item, and it is not found, *p_n_pos_in_item is set to one +   entry more than the entry with maximal key which is less than the +   sought key. + +   Note that if there is no entry in this same node which is one more, +   then we point to an imaginary entry.  for direct items, the +   position is in units of bytes, for indirect items the position is +   in units of blocknr entries, for directory items the position is in +   units of directory entries.  */ + +/* The function is NOT SCHEDULE-SAFE! */ +int search_for_position_by_key (struct super_block  * p_s_sb,         /* Pointer to the super block.          */ +				const struct cpu_key  * p_cpu_key,      /* Key to search (cpu variable)         */ +				struct path         * p_s_search_path /* Filled up by this function.          */ +    ) { +    struct item_head    * p_le_ih; /* pointer to on-disk structure */ +    int                   n_blk_size; +    loff_t item_offset, offset; +    struct reiserfs_dir_entry de; +    int retval; + +    /* If searching for directory entry. */ +    if ( is_direntry_cpu_key (p_cpu_key) ) +	return  search_by_entry_key (p_s_sb, p_cpu_key, p_s_search_path, &de); + +    /* If not searching for directory entry. */ +     +    /* If item is found. */ +    retval = search_item (p_s_sb, p_cpu_key, p_s_search_path); +    if (retval == IO_ERROR) +	return retval; +    if ( retval == ITEM_FOUND )  { + +	RFALSE( ! ih_item_len( +                B_N_PITEM_HEAD(PATH_PLAST_BUFFER(p_s_search_path), +			       PATH_LAST_POSITION(p_s_search_path))), +	        "PAP-5165: item length equals zero"); + +	pos_in_item(p_s_search_path) = 0; +	return POSITION_FOUND; +    } + +    RFALSE( ! PATH_LAST_POSITION(p_s_search_path), +	    "PAP-5170: position equals zero"); + +    /* Item is not found. Set path to the previous item. */ +    p_le_ih = B_N_PITEM_HEAD(PATH_PLAST_BUFFER(p_s_search_path), --PATH_LAST_POSITION(p_s_search_path)); +    n_blk_size = p_s_sb->s_blocksize; + +    if (comp_short_keys (&(p_le_ih->ih_key), p_cpu_key)) { +	return FILE_NOT_FOUND; +    } + +    // FIXME: quite ugly this far + +    item_offset = le_ih_k_offset (p_le_ih); +    offset = cpu_key_k_offset (p_cpu_key); + +    /* Needed byte is contained in the item pointed to by the path.*/ +    if (item_offset <= offset && +	item_offset + op_bytes_number (p_le_ih, n_blk_size) > offset) { +	pos_in_item (p_s_search_path) = offset - item_offset; +	if ( is_indirect_le_ih(p_le_ih) ) { +	    pos_in_item (p_s_search_path) /= n_blk_size; +	} +	return POSITION_FOUND; +    } + +    /* Needed byte is not contained in the item pointed to by the +     path. Set pos_in_item out of the item. */ +    if ( is_indirect_le_ih (p_le_ih) ) +	pos_in_item (p_s_search_path) = ih_item_len(p_le_ih) / UNFM_P_SIZE; +    else +        pos_in_item (p_s_search_path) = ih_item_len( p_le_ih ); +   +    return POSITION_NOT_FOUND; +} + + +/* Compare given item and item pointed to by the path. */ +int comp_items (const struct item_head * stored_ih, const struct path * p_s_path) +{ +    struct buffer_head  * p_s_bh; +    struct item_head    * ih; + +    /* Last buffer at the path is not in the tree. */ +    if ( ! B_IS_IN_TREE(p_s_bh = PATH_PLAST_BUFFER(p_s_path)) ) +	return 1; + +    /* Last path position is invalid. */ +    if ( PATH_LAST_POSITION(p_s_path) >= B_NR_ITEMS(p_s_bh) ) +	return 1; + +    /* we need only to know, whether it is the same item */ +    ih = get_ih (p_s_path); +    return memcmp (stored_ih, ih, IH_SIZE); +} + + +/* unformatted nodes are not logged anymore, ever.  This is safe +** now +*/ +#define held_by_others(bh) (atomic_read(&(bh)->b_count) > 1) + +// block can not be forgotten as it is in I/O or held by someone +#define block_in_use(bh) (buffer_locked(bh) || (held_by_others(bh))) + + + +// prepare for delete or cut of direct item +static inline int prepare_for_direct_item (struct path * path, +					   struct item_head * le_ih, +					   struct inode * inode, +					   loff_t new_file_length, +					   int * cut_size) +{ +    loff_t round_len; + + +    if ( new_file_length == max_reiserfs_offset (inode) ) { +	/* item has to be deleted */ +	*cut_size = -(IH_SIZE + ih_item_len(le_ih)); +	return M_DELETE; +    } +	 +    // new file gets truncated +    if (get_inode_item_key_version (inode) == KEY_FORMAT_3_6) { +	//  +	round_len = ROUND_UP (new_file_length);  +	/* this was n_new_file_length < le_ih ... */ +	if ( round_len < le_ih_k_offset (le_ih) )  { +	    *cut_size = -(IH_SIZE + ih_item_len(le_ih)); +	    return M_DELETE; /* Delete this item. */ +	} +	/* Calculate first position and size for cutting from item. */ +	pos_in_item (path) = round_len - (le_ih_k_offset (le_ih) - 1); +	*cut_size = -(ih_item_len(le_ih) - pos_in_item(path)); +	 +	return M_CUT; /* Cut from this item. */ +    } + + +    // old file: items may have any length + +    if ( new_file_length < le_ih_k_offset (le_ih) )  { +	*cut_size = -(IH_SIZE + ih_item_len(le_ih)); +	return M_DELETE; /* Delete this item. */ +    } +    /* Calculate first position and size for cutting from item. */ +    *cut_size = -(ih_item_len(le_ih) - +		      (pos_in_item (path) = new_file_length + 1 - le_ih_k_offset (le_ih))); +    return M_CUT; /* Cut from this item. */ +} + + +static inline int prepare_for_direntry_item (struct path * path, +					     struct item_head * le_ih, +					     struct inode * inode, +					     loff_t new_file_length, +					     int * cut_size) +{ +    if (le_ih_k_offset (le_ih) == DOT_OFFSET &&  +	new_file_length == max_reiserfs_offset (inode)) { +	RFALSE( ih_entry_count (le_ih) != 2, +	        "PAP-5220: incorrect empty directory item (%h)", le_ih); +	*cut_size = -(IH_SIZE + ih_item_len(le_ih)); +	return M_DELETE; /* Delete the directory item containing "." and ".." entry. */ +    } +     +    if ( ih_entry_count (le_ih) == 1 )  { +	/* Delete the directory item such as there is one record only +	   in this item*/ +	*cut_size = -(IH_SIZE + ih_item_len(le_ih)); +	return M_DELETE; +    } +     +    /* Cut one record from the directory item. */ +    *cut_size = -(DEH_SIZE + entry_length (get_last_bh (path), le_ih, pos_in_item (path))); +    return M_CUT;  +} + + +/*  If the path points to a directory or direct item, calculate mode and the size cut, for balance. +    If the path points to an indirect item, remove some number of its unformatted nodes. +    In case of file truncate calculate whether this item must be deleted/truncated or last +    unformatted node of this item will be converted to a direct item. +    This function returns a determination of what balance mode the calling function should employ. */ +static char  prepare_for_delete_or_cut( +				       struct reiserfs_transaction_handle *th,  +				       struct inode * inode, +				       struct path         * p_s_path, +				       const struct cpu_key      * p_s_item_key, +				       int                 * p_n_removed,      /* Number of unformatted nodes which were removed +										  from end of the file. */ +				       int                 * p_n_cut_size, +				       unsigned long long    n_new_file_length /* MAX_KEY_OFFSET in case of delete. */ +    ) { +    struct super_block  * p_s_sb = inode->i_sb; +    struct item_head    * p_le_ih = PATH_PITEM_HEAD(p_s_path); +    struct buffer_head  * p_s_bh = PATH_PLAST_BUFFER(p_s_path); + +    BUG_ON (!th->t_trans_id); + +    /* Stat_data item. */ +    if ( is_statdata_le_ih (p_le_ih) ) { + +	RFALSE( n_new_file_length != max_reiserfs_offset (inode), +		"PAP-5210: mode must be M_DELETE"); + +	*p_n_cut_size = -(IH_SIZE + ih_item_len(p_le_ih)); +	return M_DELETE; +    } + + +    /* Directory item. */ +    if ( is_direntry_le_ih (p_le_ih) ) +	return prepare_for_direntry_item (p_s_path, p_le_ih, inode, n_new_file_length, p_n_cut_size); + +    /* Direct item. */ +    if ( is_direct_le_ih (p_le_ih) ) +	return prepare_for_direct_item (p_s_path, p_le_ih, inode, n_new_file_length, p_n_cut_size); + + +    /* Case of an indirect item. */ +    { +	int                   n_unfm_number,    /* Number of the item unformatted nodes. */ +	    n_counter, +	    n_blk_size; +	__u32               * p_n_unfm_pointer; /* Pointer to the unformatted node number. */ +	__u32 tmp; +	struct item_head      s_ih;           /* Item header. */ +	char                  c_mode;           /* Returned mode of the balance. */ +	int need_research; + + +	n_blk_size = p_s_sb->s_blocksize; + +	/* Search for the needed object indirect item until there are no unformatted nodes to be removed. */ +	do  { +	    need_research = 0; +            p_s_bh = PATH_PLAST_BUFFER(p_s_path); +	    /* Copy indirect item header to a temp variable. */ +	    copy_item_head(&s_ih, PATH_PITEM_HEAD(p_s_path)); +	    /* Calculate number of unformatted nodes in this item. */ +	    n_unfm_number = I_UNFM_NUM(&s_ih); + +	    RFALSE( ! is_indirect_le_ih(&s_ih) || ! n_unfm_number || +		    pos_in_item (p_s_path) + 1 !=  n_unfm_number, +		    "PAP-5240: invalid item %h " +		    "n_unfm_number = %d *p_n_pos_in_item = %d",  +		    &s_ih, n_unfm_number, pos_in_item (p_s_path)); + +	    /* Calculate balance mode and position in the item to remove unformatted nodes. */ +	    if ( n_new_file_length == max_reiserfs_offset (inode) ) {/* Case of delete. */ +		pos_in_item (p_s_path) = 0; +		*p_n_cut_size = -(IH_SIZE + ih_item_len(&s_ih)); +		c_mode = M_DELETE; +	    } +	    else  { /* Case of truncate. */ +		if ( n_new_file_length < le_ih_k_offset (&s_ih) )  { +		    pos_in_item (p_s_path) = 0; +		    *p_n_cut_size = -(IH_SIZE + ih_item_len(&s_ih)); +		    c_mode = M_DELETE; /* Delete this item. */ +		} +		else  { +		    /* indirect item must be truncated starting from *p_n_pos_in_item-th position */ +		    pos_in_item (p_s_path) = (n_new_file_length + n_blk_size - le_ih_k_offset (&s_ih) ) >> p_s_sb->s_blocksize_bits; + +		    RFALSE( pos_in_item (p_s_path) > n_unfm_number, +			    "PAP-5250: invalid position in the item"); + +		    /* Either convert last unformatted node of indirect item to direct item or increase +		       its free space.  */ +		    if ( pos_in_item (p_s_path) == n_unfm_number )  { +			*p_n_cut_size = 0; /* Nothing to cut. */ +			return M_CONVERT; /* Maybe convert last unformatted node to the direct item. */ +		    } +		    /* Calculate size to cut. */ +		    *p_n_cut_size = -(ih_item_len(&s_ih) - pos_in_item(p_s_path) * UNFM_P_SIZE); + +		    c_mode = M_CUT;     /* Cut from this indirect item. */ +		} +	    } + +	    RFALSE( n_unfm_number <= pos_in_item (p_s_path), +		    "PAP-5260: invalid position in the indirect item"); + +	    /* pointers to be cut */ +	    n_unfm_number -= pos_in_item (p_s_path); +	    /* Set pointer to the last unformatted node pointer that is to be cut. */ +	    p_n_unfm_pointer = (__u32 *)B_I_PITEM(p_s_bh, &s_ih) + I_UNFM_NUM(&s_ih) - 1 - *p_n_removed; + + +	    /* We go through the unformatted nodes pointers of the indirect +	       item and look for the unformatted nodes in the cache. If we +	       found some of them we free it, zero corresponding indirect item +	       entry and log buffer containing that indirect item. For this we +	       need to prepare last path element for logging. If some +	       unformatted node has b_count > 1 we must not free this +	       unformatted node since it is in use. */ +	    reiserfs_prepare_for_journal(p_s_sb, p_s_bh, 1); +	    // note: path could be changed, first line in for loop takes care +	    // of it + +	    for (n_counter = *p_n_removed; +		 n_counter < n_unfm_number; n_counter++, p_n_unfm_pointer-- ) { + +		cond_resched(); +		if (item_moved (&s_ih, p_s_path)) { +		    need_research = 1 ; +		    break; +		} +		RFALSE( p_n_unfm_pointer < (__u32 *)B_I_PITEM(p_s_bh, &s_ih) || +			p_n_unfm_pointer > (__u32 *)B_I_PITEM(p_s_bh, &s_ih) + I_UNFM_NUM(&s_ih) - 1, +			"vs-5265: pointer out of range"); + +		/* Hole, nothing to remove. */ +		if ( ! get_block_num(p_n_unfm_pointer,0) )  { +			(*p_n_removed)++; +			continue; +		} + +		(*p_n_removed)++; + +		tmp = get_block_num(p_n_unfm_pointer,0); +		put_block_num(p_n_unfm_pointer, 0, 0); +		journal_mark_dirty (th, p_s_sb, p_s_bh); +		reiserfs_free_block(th, inode, tmp, 1); +		if ( item_moved (&s_ih, p_s_path) )  { +			need_research = 1; +			break ; +		} +	    } + +	    /* a trick.  If the buffer has been logged, this +	    ** will do nothing.  If we've broken the loop without +	    ** logging it, it will restore the buffer +	    ** +	    */ +	    reiserfs_restore_prepared_buffer(p_s_sb, p_s_bh); + +	    /* This loop can be optimized. */ +	} while ( (*p_n_removed < n_unfm_number || need_research) && +		  search_for_position_by_key(p_s_sb, p_s_item_key, p_s_path) == POSITION_FOUND ); + +	RFALSE( *p_n_removed < n_unfm_number,  +		"PAP-5310: indirect item is not found"); +	RFALSE( item_moved (&s_ih, p_s_path),  +		"after while, comp failed, retry") ; + +	if (c_mode == M_CUT) +	    pos_in_item (p_s_path) *= UNFM_P_SIZE; +	return c_mode; +    } +} + +/* Calculate number of bytes which will be deleted or cut during balance */ +static int calc_deleted_bytes_number( +    struct  tree_balance  * p_s_tb, +    char                    c_mode +    ) { +    int                     n_del_size; +    struct  item_head     * p_le_ih = PATH_PITEM_HEAD(p_s_tb->tb_path); + +    if ( is_statdata_le_ih (p_le_ih) ) +	return 0; + +    n_del_size = ( c_mode == M_DELETE ) ? ih_item_len(p_le_ih) : -p_s_tb->insert_size[0]; +    if ( is_direntry_le_ih (p_le_ih) ) { +	// return EMPTY_DIR_SIZE; /* We delete emty directoris only. */ +	// we can't use EMPTY_DIR_SIZE, as old format dirs have a different +	// empty size.  ick. FIXME, is this right? +	// +	return n_del_size ; +    } + +    if ( is_indirect_le_ih (p_le_ih) ) +	n_del_size = (n_del_size/UNFM_P_SIZE)* +	  (PATH_PLAST_BUFFER(p_s_tb->tb_path)->b_size);// - get_ih_free_space (p_le_ih); +    return n_del_size; +} + +static void init_tb_struct( +    struct reiserfs_transaction_handle *th, +    struct tree_balance * p_s_tb, +    struct super_block  * p_s_sb, +    struct path         * p_s_path, +    int                   n_size +    ) { + +    BUG_ON (!th->t_trans_id); + +    memset (p_s_tb,'\0',sizeof(struct tree_balance)); +    p_s_tb->transaction_handle = th ; +    p_s_tb->tb_sb = p_s_sb; +    p_s_tb->tb_path = p_s_path; +    PATH_OFFSET_PBUFFER(p_s_path, ILLEGAL_PATH_ELEMENT_OFFSET) = NULL; +    PATH_OFFSET_POSITION(p_s_path, ILLEGAL_PATH_ELEMENT_OFFSET) = 0; +    p_s_tb->insert_size[0] = n_size; +} + + + +void padd_item (char * item, int total_length, int length) +{ +    int i; + +    for (i = total_length; i > length; ) +	item [--i] = 0; +} + +#ifdef REISERQUOTA_DEBUG +char key2type(struct reiserfs_key *ih) +{ +  if (is_direntry_le_key(2, ih)) +    return 'd'; +  if (is_direct_le_key(2, ih)) +    return 'D'; +  if (is_indirect_le_key(2, ih)) +    return 'i'; +  if (is_statdata_le_key(2, ih)) +    return 's'; +  return 'u'; +} + +char head2type(struct item_head *ih) +{ +  if (is_direntry_le_ih(ih)) +    return 'd'; +  if (is_direct_le_ih(ih)) +    return 'D'; +  if (is_indirect_le_ih(ih)) +    return 'i'; +  if (is_statdata_le_ih(ih)) +    return 's'; +  return 'u'; +} +#endif + +/* Delete object item. */ +int reiserfs_delete_item (struct reiserfs_transaction_handle *th,  +			  struct path * p_s_path, /* Path to the deleted item. */ +			  const struct cpu_key * p_s_item_key, /* Key to search for the deleted item.  */ +			  struct inode * p_s_inode,/* inode is here just to update i_blocks and quotas */ +			  struct buffer_head  * p_s_un_bh)    /* NULL or unformatted node pointer.    */ +{ +    struct super_block * p_s_sb = p_s_inode->i_sb; +    struct tree_balance   s_del_balance; +    struct item_head      s_ih; +    struct item_head      *q_ih; +    int			  quota_cut_bytes; +    int                   n_ret_value, +	n_del_size, +	n_removed; + +#ifdef CONFIG_REISERFS_CHECK +    char                  c_mode; +    int			n_iter = 0; +#endif + +    BUG_ON (!th->t_trans_id); + +    init_tb_struct(th, &s_del_balance, p_s_sb, p_s_path, 0/*size is unknown*/); + +    while ( 1 ) { +	n_removed = 0; + +#ifdef CONFIG_REISERFS_CHECK +	n_iter++; +	c_mode = +#endif +	    prepare_for_delete_or_cut(th, p_s_inode, p_s_path, p_s_item_key, &n_removed, &n_del_size, max_reiserfs_offset (p_s_inode)); + +	RFALSE( c_mode != M_DELETE, "PAP-5320: mode must be M_DELETE"); + +	copy_item_head(&s_ih, PATH_PITEM_HEAD(p_s_path)); +	s_del_balance.insert_size[0] = n_del_size; + +	n_ret_value = fix_nodes(M_DELETE, &s_del_balance, NULL, NULL); +	if ( n_ret_value != REPEAT_SEARCH ) +	    break; + +	PROC_INFO_INC( p_s_sb, delete_item_restarted ); + +	// file system changed, repeat search +	n_ret_value = search_for_position_by_key(p_s_sb, p_s_item_key, p_s_path); +	if (n_ret_value == IO_ERROR) +	    break; +	if (n_ret_value == FILE_NOT_FOUND) { +	    reiserfs_warning (p_s_sb, "vs-5340: reiserfs_delete_item: " +			      "no items of the file %K found", p_s_item_key); +	    break; +	} +    } /* while (1) */ + +    if ( n_ret_value != CARRY_ON ) { +	unfix_nodes(&s_del_balance); +	return 0; +    } + +    // reiserfs_delete_item returns item length when success +    n_ret_value = calc_deleted_bytes_number(&s_del_balance, M_DELETE); +    q_ih = get_ih(p_s_path) ; +    quota_cut_bytes = ih_item_len(q_ih) ; + +    /* hack so the quota code doesn't have to guess if the file +    ** has a tail.  On tail insert, we allocate quota for 1 unformatted node. +    ** We test the offset because the tail might have been +    ** split into multiple items, and we only want to decrement for +    ** the unfm node once +    */ +    if (!S_ISLNK (p_s_inode->i_mode) && is_direct_le_ih(q_ih)) { +        if ((le_ih_k_offset(q_ih) & (p_s_sb->s_blocksize - 1)) == 1) { +            quota_cut_bytes = p_s_sb->s_blocksize + UNFM_P_SIZE; +        } else { +	    quota_cut_bytes = 0 ; +	} +    } + +    if ( p_s_un_bh )  { +	int off; +        char *data ; + +	/* We are in direct2indirect conversion, so move tail contents +           to the unformatted node */ +	/* note, we do the copy before preparing the buffer because we +	** don't care about the contents of the unformatted node yet. +	** the only thing we really care about is the direct item's data +	** is in the unformatted node. +	** +	** Otherwise, we would have to call reiserfs_prepare_for_journal on +	** the unformatted node, which might schedule, meaning we'd have to +	** loop all the way back up to the start of the while loop. +	** +	** The unformatted node must be dirtied later on.  We can't be +	** sure here if the entire tail has been deleted yet. +        ** +        ** p_s_un_bh is from the page cache (all unformatted nodes are +        ** from the page cache) and might be a highmem page.  So, we +        ** can't use p_s_un_bh->b_data. +	** -clm +	*/ + +        data = kmap_atomic(p_s_un_bh->b_page, KM_USER0); +	off = ((le_ih_k_offset (&s_ih) - 1) & (PAGE_CACHE_SIZE - 1)); +	memcpy(data + off, +	       B_I_PITEM(PATH_PLAST_BUFFER(p_s_path), &s_ih), n_ret_value); +	kunmap_atomic(data, KM_USER0); +    } +    /* Perform balancing after all resources have been collected at once. */  +    do_balance(&s_del_balance, NULL, NULL, M_DELETE); + +#ifdef REISERQUOTA_DEBUG +    reiserfs_debug (p_s_sb, REISERFS_DEBUG_CODE, "reiserquota delete_item(): freeing %u, id=%u type=%c", quota_cut_bytes, p_s_inode->i_uid, head2type(&s_ih)); +#endif +    DQUOT_FREE_SPACE_NODIRTY(p_s_inode, quota_cut_bytes); + +    /* Return deleted body length */ +    return n_ret_value; +} + + +/* Summary Of Mechanisms For Handling Collisions Between Processes: + + deletion of the body of the object is performed by iput(), with the + result that if multiple processes are operating on a file, the + deletion of the body of the file is deferred until the last process + that has an open inode performs its iput(). + + writes and truncates are protected from collisions by use of + semaphores. + + creates, linking, and mknod are protected from collisions with other + processes by making the reiserfs_add_entry() the last step in the + creation, and then rolling back all changes if there was a collision. + - Hans +*/ + + +/* this deletes item which never gets split */ +void reiserfs_delete_solid_item (struct reiserfs_transaction_handle *th, +				 struct inode *inode, +				 struct reiserfs_key * key) +{ +    struct tree_balance tb; +    INITIALIZE_PATH (path); +    int item_len = 0; +    int tb_init = 0 ; +    struct cpu_key cpu_key; +    int retval; +    int quota_cut_bytes = 0; + +    BUG_ON (!th->t_trans_id); +     +    le_key2cpu_key (&cpu_key, key); +     +    while (1) { +	retval = search_item (th->t_super, &cpu_key, &path); +	if (retval == IO_ERROR) { +	    reiserfs_warning (th->t_super, +			      "vs-5350: reiserfs_delete_solid_item: " +			      "i/o failure occurred trying to delete %K", +			      &cpu_key); +	    break; +	} +	if (retval != ITEM_FOUND) { +	    pathrelse (&path); +	    // No need for a warning, if there is just no free space to insert '..' item into the newly-created subdir +	    if ( !( (unsigned long long) GET_HASH_VALUE (le_key_k_offset (le_key_version (key), key)) == 0 && \ +		 (unsigned long long) GET_GENERATION_NUMBER (le_key_k_offset (le_key_version (key), key)) == 1 ) ) +		reiserfs_warning (th->t_super, "vs-5355: reiserfs_delete_solid_item: %k not found", key); +	    break; +	} +	if (!tb_init) { +	    tb_init = 1 ; +	    item_len = ih_item_len( PATH_PITEM_HEAD(&path) ); +	    init_tb_struct (th, &tb, th->t_super, &path, - (IH_SIZE + item_len)); +	} +	quota_cut_bytes = ih_item_len(PATH_PITEM_HEAD(&path)) ; + +	retval = fix_nodes (M_DELETE, &tb, NULL, NULL); +	if (retval == REPEAT_SEARCH) { +	    PROC_INFO_INC( th -> t_super, delete_solid_item_restarted ); +	    continue; +	} + +	if (retval == CARRY_ON) { +	    do_balance (&tb, NULL, NULL, M_DELETE); +	    if (inode) {	/* Should we count quota for item? (we don't count quotas for save-links) */ +#ifdef REISERQUOTA_DEBUG +		reiserfs_debug (th->t_super, REISERFS_DEBUG_CODE, "reiserquota delete_solid_item(): freeing %u id=%u type=%c", quota_cut_bytes, inode->i_uid, key2type(key)); +#endif +		DQUOT_FREE_SPACE_NODIRTY(inode, quota_cut_bytes); +	    } +	    break; +	} + +	// IO_ERROR, NO_DISK_SPACE, etc +	reiserfs_warning (th->t_super, "vs-5360: reiserfs_delete_solid_item: " +			  "could not delete %K due to fix_nodes failure", &cpu_key); +	unfix_nodes (&tb); +	break; +    } + +    reiserfs_check_path(&path) ; +} + + +int reiserfs_delete_object (struct reiserfs_transaction_handle *th, struct inode * inode) +{ +    int err; +    inode->i_size = 0; +    BUG_ON (!th->t_trans_id); + +    /* for directory this deletes item containing "." and ".." */ +    err = reiserfs_do_truncate (th, inode, NULL, 0/*no timestamp updates*/); +    if (err) +        return err; +     +#if defined( USE_INODE_GENERATION_COUNTER ) +    if( !old_format_only ( th -> t_super ) ) +      { +       __u32 *inode_generation; +        +       inode_generation =  +         &REISERFS_SB(th -> t_super) -> s_rs -> s_inode_generation; +       *inode_generation = cpu_to_le32( le32_to_cpu( *inode_generation ) + 1 ); +      } +/* USE_INODE_GENERATION_COUNTER */ +#endif +    reiserfs_delete_solid_item (th, inode, INODE_PKEY (inode)); + +    return err; +} + +static void +unmap_buffers(struct page *page, loff_t pos) { +    struct buffer_head *bh ; +    struct buffer_head *head ; +    struct buffer_head *next ; +    unsigned long tail_index ; +    unsigned long cur_index ; + +    if (page) { +	if (page_has_buffers(page)) { +	    tail_index = pos & (PAGE_CACHE_SIZE - 1) ; +	    cur_index = 0 ; +	    head = page_buffers(page) ; +	    bh = head ; +	    do { +		next = bh->b_this_page ; + +		/* we want to unmap the buffers that contain the tail, and +		** all the buffers after it (since the tail must be at the +		** end of the file).  We don't want to unmap file data +		** before the tail, since it might be dirty and waiting to +		** reach disk +		*/ +		cur_index += bh->b_size ; +		if (cur_index > tail_index) { +		    reiserfs_unmap_buffer(bh) ; +		} +		bh = next ; +	    } while (bh != head) ; +	    if ( PAGE_SIZE == bh->b_size ) { +		clear_page_dirty(page); +	    } +	} +    } +} + +static int maybe_indirect_to_direct (struct reiserfs_transaction_handle *th,  +			      struct inode * p_s_inode, +			      struct page *page,  +			      struct path         * p_s_path, +			      const struct cpu_key      * p_s_item_key, +			      loff_t         n_new_file_size, +			      char                * p_c_mode +			      ) { +    struct super_block * p_s_sb = p_s_inode->i_sb; +    int n_block_size = p_s_sb->s_blocksize; +    int cut_bytes; +    BUG_ON (!th->t_trans_id); + +    if (n_new_file_size != p_s_inode->i_size) +	BUG (); + +    /* the page being sent in could be NULL if there was an i/o error +    ** reading in the last block.  The user will hit problems trying to +    ** read the file, but for now we just skip the indirect2direct +    */ +    if (atomic_read(&p_s_inode->i_count) > 1 ||  +        !tail_has_to_be_packed (p_s_inode) ||  +	!page || (REISERFS_I(p_s_inode)->i_flags & i_nopack_mask)) { +	// leave tail in an unformatted node	 +	*p_c_mode = M_SKIP_BALANCING; +	cut_bytes = n_block_size - (n_new_file_size & (n_block_size - 1)); +	pathrelse(p_s_path); +	return cut_bytes; +    } +    /* Permorm the conversion to a direct_item. */ +    /*return indirect_to_direct (p_s_inode, p_s_path, p_s_item_key, n_new_file_size, p_c_mode);*/ +    return indirect2direct (th, p_s_inode, page, p_s_path, p_s_item_key, n_new_file_size, p_c_mode); +} + + +/* we did indirect_to_direct conversion. And we have inserted direct +   item successesfully, but there were no disk space to cut unfm +   pointer being converted. Therefore we have to delete inserted +   direct item(s) */ +static void indirect_to_direct_roll_back (struct reiserfs_transaction_handle *th, struct inode * inode, struct path * path) +{ +    struct cpu_key tail_key; +    int tail_len; +    int removed; +    BUG_ON (!th->t_trans_id); + +    make_cpu_key (&tail_key, inode, inode->i_size + 1, TYPE_DIRECT, 4);// !!!! +    tail_key.key_length = 4; + +    tail_len = (cpu_key_k_offset (&tail_key) & (inode->i_sb->s_blocksize - 1)) - 1; +    while (tail_len) { +	/* look for the last byte of the tail */ +	if (search_for_position_by_key (inode->i_sb, &tail_key, path) == POSITION_NOT_FOUND) +	    reiserfs_panic (inode->i_sb, "vs-5615: indirect_to_direct_roll_back: found invalid item"); +	RFALSE( path->pos_in_item != ih_item_len(PATH_PITEM_HEAD (path)) - 1, +	        "vs-5616: appended bytes found"); +	PATH_LAST_POSITION (path) --; +	 +	removed = reiserfs_delete_item (th, path, &tail_key, inode, NULL/*unbh not needed*/); +	RFALSE( removed <= 0 || removed > tail_len, +	        "vs-5617: there was tail %d bytes, removed item length %d bytes", +                tail_len, removed); +	tail_len -= removed; +	set_cpu_key_k_offset (&tail_key, cpu_key_k_offset (&tail_key) - removed); +    } +    reiserfs_warning (inode->i_sb, "indirect_to_direct_roll_back: indirect_to_direct conversion has been rolled back due to lack of disk space"); +    //mark_file_without_tail (inode); +    mark_inode_dirty (inode); +} + + +/* (Truncate or cut entry) or delete object item. Returns < 0 on failure */ +int reiserfs_cut_from_item (struct reiserfs_transaction_handle *th,  +			    struct path * p_s_path, +			    struct cpu_key * p_s_item_key, +			    struct inode * p_s_inode, +			    struct page *page,  +			    loff_t n_new_file_size) +{ +    struct super_block * p_s_sb = p_s_inode->i_sb; +    /* Every function which is going to call do_balance must first +       create a tree_balance structure.  Then it must fill up this +       structure by using the init_tb_struct and fix_nodes functions. +       After that we can make tree balancing. */ +    struct tree_balance s_cut_balance; +    struct item_head *p_le_ih; +    int n_cut_size = 0,        /* Amount to be cut. */ +	n_ret_value = CARRY_ON, +	n_removed = 0,     /* Number of the removed unformatted nodes. */ +	n_is_inode_locked = 0; +    char                c_mode;            /* Mode of the balance. */ +    int retval2 = -1; +    int quota_cut_bytes; +    loff_t tail_pos = 0; + +    BUG_ON (!th->t_trans_id); +     +    init_tb_struct(th, &s_cut_balance, p_s_inode->i_sb, p_s_path, n_cut_size); + + +    /* Repeat this loop until we either cut the item without needing +       to balance, or we fix_nodes without schedule occurring */ +    while ( 1 ) { +	/* Determine the balance mode, position of the first byte to +	   be cut, and size to be cut.  In case of the indirect item +	   free unformatted nodes which are pointed to by the cut +	   pointers. */ +       +	c_mode = prepare_for_delete_or_cut(th, p_s_inode, p_s_path, p_s_item_key, &n_removed,  +					   &n_cut_size, n_new_file_size); +	if ( c_mode == M_CONVERT )  { +	    /* convert last unformatted node to direct item or leave +               tail in the unformatted node */ +	    RFALSE( n_ret_value != CARRY_ON, "PAP-5570: can not convert twice"); + +	    n_ret_value = maybe_indirect_to_direct (th, p_s_inode, page, p_s_path, p_s_item_key, +						    n_new_file_size, &c_mode); +	    if ( c_mode == M_SKIP_BALANCING ) +		/* tail has been left in the unformatted node */ +		return n_ret_value; + +	    n_is_inode_locked = 1; +	   +	    /* removing of last unformatted node will change value we +               have to return to truncate. Save it */ +	    retval2 = n_ret_value; +	    /*retval2 = p_s_sb->s_blocksize - (n_new_file_size & (p_s_sb->s_blocksize - 1));*/ +	   +	    /* So, we have performed the first part of the conversion: +	       inserting the new direct item.  Now we are removing the +	       last unformatted node pointer. Set key to search for +	       it. */ +      	    set_cpu_key_k_type (p_s_item_key, TYPE_INDIRECT); +	    p_s_item_key->key_length = 4; +	    n_new_file_size -= (n_new_file_size & (p_s_sb->s_blocksize - 1)); +	    tail_pos = n_new_file_size; +	    set_cpu_key_k_offset (p_s_item_key, n_new_file_size + 1); +	    if ( search_for_position_by_key(p_s_sb, p_s_item_key, p_s_path) == POSITION_NOT_FOUND ){ +		print_block (PATH_PLAST_BUFFER (p_s_path), 3, PATH_LAST_POSITION (p_s_path) - 1, PATH_LAST_POSITION (p_s_path) + 1); +		reiserfs_panic(p_s_sb, "PAP-5580: reiserfs_cut_from_item: item to convert does not exist (%K)", p_s_item_key); +	    } +	    continue; +	} +	if (n_cut_size == 0) { +	    pathrelse (p_s_path); +	    return 0; +	} + +	s_cut_balance.insert_size[0] = n_cut_size; +	 +	n_ret_value = fix_nodes(c_mode, &s_cut_balance, NULL, NULL); +      	if ( n_ret_value != REPEAT_SEARCH ) +	    break; +	 +	PROC_INFO_INC( p_s_sb, cut_from_item_restarted ); + +	n_ret_value = search_for_position_by_key(p_s_sb, p_s_item_key, p_s_path); +	if (n_ret_value == POSITION_FOUND) +	    continue; + +	reiserfs_warning (p_s_sb, "PAP-5610: reiserfs_cut_from_item: item %K not found", p_s_item_key); +	unfix_nodes (&s_cut_balance); +	return (n_ret_value == IO_ERROR) ? -EIO : -ENOENT; +    } /* while */ +   +    // check fix_nodes results (IO_ERROR or NO_DISK_SPACE) +    if ( n_ret_value != CARRY_ON ) { +	if ( n_is_inode_locked ) { +	    // FIXME: this seems to be not needed: we are always able +	    // to cut item +	    indirect_to_direct_roll_back (th, p_s_inode, p_s_path); +	} +	if (n_ret_value == NO_DISK_SPACE) +	    reiserfs_warning (p_s_sb, "NO_DISK_SPACE"); +	unfix_nodes (&s_cut_balance); +	return -EIO; +    } + +    /* go ahead and perform balancing */ +     +    RFALSE( c_mode == M_PASTE || c_mode == M_INSERT, "invalid mode"); + +    /* Calculate number of bytes that need to be cut from the item. */ +    quota_cut_bytes = ( c_mode == M_DELETE ) ? ih_item_len(get_ih(p_s_path)) : -s_cut_balance.insert_size[0]; +    if (retval2 == -1) +	n_ret_value = calc_deleted_bytes_number(&s_cut_balance, c_mode); +    else +	n_ret_value = retval2; + + +    /* For direct items, we only change the quota when deleting the last +    ** item. +    */ +    p_le_ih = PATH_PITEM_HEAD (s_cut_balance.tb_path); +    if (!S_ISLNK (p_s_inode->i_mode) && is_direct_le_ih(p_le_ih)) { +        if (c_mode == M_DELETE && +	   (le_ih_k_offset (p_le_ih) & (p_s_sb->s_blocksize - 1)) == 1 ) { +	    // FIXME: this is to keep 3.5 happy +	    REISERFS_I(p_s_inode)->i_first_direct_byte = U32_MAX; +	    quota_cut_bytes = p_s_sb->s_blocksize + UNFM_P_SIZE ; +        } else { +	    quota_cut_bytes = 0 ; +	} +    } +#ifdef CONFIG_REISERFS_CHECK +    if (n_is_inode_locked) { +	struct item_head * le_ih = PATH_PITEM_HEAD (s_cut_balance.tb_path); +	/* we are going to complete indirect2direct conversion. Make +           sure, that we exactly remove last unformatted node pointer +           of the item */ +	if (!is_indirect_le_ih (le_ih)) +	    reiserfs_panic (p_s_sb, "vs-5652: reiserfs_cut_from_item: " +			    "item must be indirect %h", le_ih); + +	if (c_mode == M_DELETE && ih_item_len(le_ih) != UNFM_P_SIZE) +	    reiserfs_panic (p_s_sb, "vs-5653: reiserfs_cut_from_item: " +			    "completing indirect2direct conversion indirect item %h " +			    "being deleted must be of 4 byte long", le_ih); + +	if (c_mode == M_CUT && s_cut_balance.insert_size[0] != -UNFM_P_SIZE) { +	    reiserfs_panic (p_s_sb, "vs-5654: reiserfs_cut_from_item: " +			    "can not complete indirect2direct conversion of %h (CUT, insert_size==%d)", +			    le_ih, s_cut_balance.insert_size[0]); +	} +	/* it would be useful to make sure, that right neighboring +           item is direct item of this file */ +    } +#endif +     +    do_balance(&s_cut_balance, NULL, NULL, c_mode); +    if ( n_is_inode_locked ) { +	/* we've done an indirect->direct conversion.  when the data block +	** was freed, it was removed from the list of blocks that must +	** be flushed before the transaction commits, make sure to +	** unmap and invalidate it +	*/ +	unmap_buffers(page, tail_pos); +	REISERFS_I(p_s_inode)->i_flags &= ~i_pack_on_close_mask ; +    } +#ifdef REISERQUOTA_DEBUG +    reiserfs_debug (p_s_inode->i_sb, REISERFS_DEBUG_CODE, "reiserquota cut_from_item(): freeing %u id=%u type=%c", quota_cut_bytes, p_s_inode->i_uid, '?'); +#endif +    DQUOT_FREE_SPACE_NODIRTY(p_s_inode, quota_cut_bytes); +    return n_ret_value; +} + +static void truncate_directory (struct reiserfs_transaction_handle *th, struct inode * inode) +{ +    BUG_ON (!th->t_trans_id); +    if (inode->i_nlink) +	reiserfs_warning (inode->i_sb, +			  "vs-5655: truncate_directory: link count != 0"); + +    set_le_key_k_offset (KEY_FORMAT_3_5, INODE_PKEY (inode), DOT_OFFSET); +    set_le_key_k_type (KEY_FORMAT_3_5, INODE_PKEY (inode), TYPE_DIRENTRY); +    reiserfs_delete_solid_item (th, inode, INODE_PKEY (inode)); +    reiserfs_update_sd(th, inode) ; +    set_le_key_k_offset (KEY_FORMAT_3_5, INODE_PKEY (inode), SD_OFFSET); +    set_le_key_k_type (KEY_FORMAT_3_5, INODE_PKEY (inode), TYPE_STAT_DATA);     +} + + + + +/* Truncate file to the new size. Note, this must be called with a transaction +   already started */ +int reiserfs_do_truncate (struct reiserfs_transaction_handle *th, +			   struct  inode * p_s_inode, /* ->i_size contains new +                                                         size */ +			   struct page *page, /* up to date for last block */ +			   int update_timestamps  /* when it is called by +						     file_release to convert +						     the tail - no timestamps +						     should be updated */ +    ) { +    INITIALIZE_PATH (s_search_path);       /* Path to the current object item. */ +    struct item_head    * p_le_ih;         /* Pointer to an item header. */ +    struct cpu_key      s_item_key;     /* Key to search for a previous file item. */ +    loff_t         n_file_size,    /* Old file size. */ +	n_new_file_size;/* New file size. */ +    int                   n_deleted;      /* Number of deleted or truncated bytes. */ +    int retval; +    int err = 0; + +    BUG_ON (!th->t_trans_id); +    if ( ! (S_ISREG(p_s_inode->i_mode) || S_ISDIR(p_s_inode->i_mode) || S_ISLNK(p_s_inode->i_mode)) ) +	return 0; + +    if (S_ISDIR(p_s_inode->i_mode)) { +	// deletion of directory - no need to update timestamps +	truncate_directory (th, p_s_inode); +	return 0; +    } + +    /* Get new file size. */ +    n_new_file_size = p_s_inode->i_size; + +    // FIXME: note, that key type is unimportant here +    make_cpu_key (&s_item_key, p_s_inode, max_reiserfs_offset (p_s_inode), TYPE_DIRECT, 3); + +    retval = search_for_position_by_key(p_s_inode->i_sb, &s_item_key, &s_search_path); +    if (retval == IO_ERROR) { +	reiserfs_warning (p_s_inode->i_sb, "vs-5657: reiserfs_do_truncate: " +			  "i/o failure occurred trying to truncate %K", &s_item_key); +        err = -EIO; +        goto out; +    } +    if (retval == POSITION_FOUND || retval == FILE_NOT_FOUND) { +	reiserfs_warning (p_s_inode->i_sb, "PAP-5660: reiserfs_do_truncate: " +			  "wrong result %d of search for %K", retval, &s_item_key); + +        err = -EIO; +        goto out; +    } + +    s_search_path.pos_in_item --; + +    /* Get real file size (total length of all file items) */ +    p_le_ih = PATH_PITEM_HEAD(&s_search_path); +    if ( is_statdata_le_ih (p_le_ih) ) +	n_file_size = 0; +    else { +	loff_t offset = le_ih_k_offset (p_le_ih); +	int bytes = op_bytes_number (p_le_ih,p_s_inode->i_sb->s_blocksize); + +	/* this may mismatch with real file size: if last direct item +           had no padding zeros and last unformatted node had no free +           space, this file would have this file size */ +	n_file_size = offset + bytes - 1; +    } +    /* +     * are we doing a full truncate or delete, if so +     * kick in the reada code +     */ +    if (n_new_file_size == 0) +        s_search_path.reada = PATH_READA | PATH_READA_BACK; + +    if ( n_file_size == 0 || n_file_size < n_new_file_size ) { +	goto update_and_out ; +    } + +    /* Update key to search for the last file item. */ +    set_cpu_key_k_offset (&s_item_key, n_file_size); + +    do  { +	/* Cut or delete file item. */ +	n_deleted = reiserfs_cut_from_item(th, &s_search_path, &s_item_key, p_s_inode,  page, n_new_file_size); +	if (n_deleted < 0) { +	    reiserfs_warning (p_s_inode->i_sb, "vs-5665: reiserfs_do_truncate: reiserfs_cut_from_item failed"); +	    reiserfs_check_path(&s_search_path) ; +	    return 0; +	} + +	RFALSE( n_deleted > n_file_size, +		"PAP-5670: reiserfs_cut_from_item: too many bytes deleted: deleted %d, file_size %lu, item_key %K", +		n_deleted, n_file_size, &s_item_key); + +	/* Change key to search the last file item. */ +	n_file_size -= n_deleted; + +	set_cpu_key_k_offset (&s_item_key, n_file_size); + +	/* While there are bytes to truncate and previous file item is presented in the tree. */ + +	/* +	** This loop could take a really long time, and could log  +	** many more blocks than a transaction can hold.  So, we do a polite +	** journal end here, and if the transaction needs ending, we make +	** sure the file is consistent before ending the current trans +	** and starting a new one +	*/ +        if (journal_transaction_should_end(th, th->t_blocks_allocated)) { +	  int orig_len_alloc = th->t_blocks_allocated ; +	  decrement_counters_in_path(&s_search_path) ; + +	  if (update_timestamps) { +	      p_s_inode->i_mtime = p_s_inode->i_ctime = CURRENT_TIME_SEC; +	  }  +	  reiserfs_update_sd(th, p_s_inode) ; + +	  err = journal_end(th, p_s_inode->i_sb, orig_len_alloc) ; +	  if (err) +	    goto out; +	  err = journal_begin (th, p_s_inode->i_sb, +                               JOURNAL_PER_BALANCE_CNT * 6); +	  if (err) +	    goto out; +	  reiserfs_update_inode_transaction(p_s_inode) ; +	} +    } while ( n_file_size > ROUND_UP (n_new_file_size) && +	      search_for_position_by_key(p_s_inode->i_sb, &s_item_key, &s_search_path) == POSITION_FOUND )  ; + +    RFALSE( n_file_size > ROUND_UP (n_new_file_size), +	    "PAP-5680: truncate did not finish: new_file_size %Ld, current %Ld, oid %d", +	    n_new_file_size, n_file_size, s_item_key.on_disk_key.k_objectid); + +update_and_out: +    if (update_timestamps) { +	// this is truncate, not file closing +	    p_s_inode->i_mtime = p_s_inode->i_ctime = CURRENT_TIME_SEC; +    } +    reiserfs_update_sd (th, p_s_inode); + +out: +    pathrelse(&s_search_path) ; +    return err; +} + + +#ifdef CONFIG_REISERFS_CHECK +// this makes sure, that we __append__, not overwrite or add holes +static void check_research_for_paste (struct path * path,  +				      const struct cpu_key * p_s_key) +{ +    struct item_head * found_ih = get_ih (path); +     +    if (is_direct_le_ih (found_ih)) { +	if (le_ih_k_offset (found_ih) + op_bytes_number (found_ih, get_last_bh (path)->b_size) != +	    cpu_key_k_offset (p_s_key) || +	    op_bytes_number (found_ih, get_last_bh (path)->b_size) != pos_in_item (path)) +	    reiserfs_panic (NULL, "PAP-5720: check_research_for_paste: " +			    "found direct item %h or position (%d) does not match to key %K", +			    found_ih, pos_in_item (path), p_s_key); +    } +    if (is_indirect_le_ih (found_ih)) { +	if (le_ih_k_offset (found_ih) + op_bytes_number (found_ih, get_last_bh (path)->b_size) != cpu_key_k_offset (p_s_key) ||  +	    I_UNFM_NUM (found_ih) != pos_in_item (path) || +	    get_ih_free_space (found_ih) != 0) +	    reiserfs_panic (NULL, "PAP-5730: check_research_for_paste: " +			    "found indirect item (%h) or position (%d) does not match to key (%K)", +			    found_ih, pos_in_item (path), p_s_key); +    } +} +#endif /* config reiserfs check */ + + +/* Paste bytes to the existing item. Returns bytes number pasted into the item. */ +int reiserfs_paste_into_item (struct reiserfs_transaction_handle *th,  +			      struct path         * p_s_search_path,	/* Path to the pasted item.          */ +			      const struct cpu_key      * p_s_key,        	/* Key to search for the needed item.*/ +			      struct inode	  * inode,		/* Inode item belongs to */ +			      const char          * p_c_body,       	/* Pointer to the bytes to paste.    */ +			      int                   n_pasted_size)  	/* Size of pasted bytes.             */ +{ +    struct tree_balance s_paste_balance; +    int                 retval; +    int			fs_gen; + +    BUG_ON (!th->t_trans_id); + +    fs_gen = get_generation(inode->i_sb) ; + +#ifdef REISERQUOTA_DEBUG +    reiserfs_debug (inode->i_sb, REISERFS_DEBUG_CODE, "reiserquota paste_into_item(): allocating %u id=%u type=%c", n_pasted_size, inode->i_uid, key2type(&(p_s_key->on_disk_key))); +#endif + +    if (DQUOT_ALLOC_SPACE_NODIRTY(inode, n_pasted_size)) { +	pathrelse(p_s_search_path); +	return -EDQUOT; +    } +    init_tb_struct(th, &s_paste_balance, th->t_super, p_s_search_path, n_pasted_size); +#ifdef DISPLACE_NEW_PACKING_LOCALITIES +    s_paste_balance.key = p_s_key->on_disk_key; +#endif + +    /* DQUOT_* can schedule, must check before the fix_nodes */ +    if (fs_changed(fs_gen, inode->i_sb)) { +	goto search_again; +    } + +    while ((retval = fix_nodes(M_PASTE, &s_paste_balance, NULL, p_c_body)) == +REPEAT_SEARCH ) { +search_again: +	/* file system changed while we were in the fix_nodes */ +	PROC_INFO_INC( th -> t_super, paste_into_item_restarted ); +	retval = search_for_position_by_key (th->t_super, p_s_key, p_s_search_path); +	if (retval == IO_ERROR) { +	    retval = -EIO ; +	    goto error_out ; +	} +	if (retval == POSITION_FOUND) { +	    reiserfs_warning (inode->i_sb, "PAP-5710: reiserfs_paste_into_item: entry or pasted byte (%K) exists", p_s_key); +	    retval = -EEXIST ; +	    goto error_out ; +	} +	 +#ifdef CONFIG_REISERFS_CHECK +	check_research_for_paste (p_s_search_path, p_s_key); +#endif +    } + +    /* Perform balancing after all resources are collected by fix_nodes, and +       accessing them will not risk triggering schedule. */ +    if ( retval == CARRY_ON ) { +	do_balance(&s_paste_balance, NULL/*ih*/, p_c_body, M_PASTE); +	return 0; +    } +    retval = (retval == NO_DISK_SPACE) ? -ENOSPC : -EIO; +error_out: +    /* this also releases the path */ +    unfix_nodes(&s_paste_balance); +#ifdef REISERQUOTA_DEBUG +    reiserfs_debug (inode->i_sb, REISERFS_DEBUG_CODE, "reiserquota paste_into_item(): freeing %u id=%u type=%c", n_pasted_size, inode->i_uid, key2type(&(p_s_key->on_disk_key))); +#endif +    DQUOT_FREE_SPACE_NODIRTY(inode, n_pasted_size); +    return retval ; +} + + +/* Insert new item into the buffer at the path. */ +int reiserfs_insert_item(struct reiserfs_transaction_handle *th,  +			 struct path         * 	p_s_path,         /* Path to the inserteded item.         */ +			 const struct cpu_key      * key, +			 struct item_head    * 	p_s_ih,           /* Pointer to the item header to insert.*/ +			 struct inode        * inode, +			 const char          * 	p_c_body)         /* Pointer to the bytes to insert.      */ +{ +    struct tree_balance s_ins_balance; +    int                 retval; +    int fs_gen = 0 ; +    int quota_bytes = 0 ; + +    BUG_ON (!th->t_trans_id); + +    if (inode) {      /* Do we count quotas for item? */ +	fs_gen = get_generation(inode->i_sb); +	quota_bytes = ih_item_len(p_s_ih); + +	/* hack so the quota code doesn't have to guess if the file has +	 ** a tail, links are always tails, so there's no guessing needed +	 */ +	if (!S_ISLNK (inode->i_mode) && is_direct_le_ih(p_s_ih)) { +	    quota_bytes = inode->i_sb->s_blocksize + UNFM_P_SIZE ; +	} +#ifdef REISERQUOTA_DEBUG +	reiserfs_debug (inode->i_sb, REISERFS_DEBUG_CODE, "reiserquota insert_item(): allocating %u id=%u type=%c", quota_bytes, inode->i_uid, head2type(p_s_ih)); +#endif +	/* We can't dirty inode here. It would be immediately written but +	 * appropriate stat item isn't inserted yet... */ +	if (DQUOT_ALLOC_SPACE_NODIRTY(inode, quota_bytes)) { +	    pathrelse(p_s_path); +	    return -EDQUOT; +	} +    } +    init_tb_struct(th, &s_ins_balance, th->t_super, p_s_path, IH_SIZE + ih_item_len(p_s_ih)); +#ifdef DISPLACE_NEW_PACKING_LOCALITIES +    s_ins_balance.key = key->on_disk_key; +#endif +    /* DQUOT_* can schedule, must check to be sure calling fix_nodes is safe */ +    if (inode && fs_changed(fs_gen, inode->i_sb)) { +	goto search_again; +    } + +    while ( (retval = fix_nodes(M_INSERT, &s_ins_balance, p_s_ih, p_c_body)) == REPEAT_SEARCH) { +search_again: +	/* file system changed while we were in the fix_nodes */ +	PROC_INFO_INC( th -> t_super, insert_item_restarted ); +	retval = search_item (th->t_super, key, p_s_path); +	if (retval == IO_ERROR) { +	    retval = -EIO; +	    goto error_out ; +	} +	if (retval == ITEM_FOUND) { +	    reiserfs_warning (th->t_super, "PAP-5760: reiserfs_insert_item: " +			      "key %K already exists in the tree", key); +	    retval = -EEXIST ; +	    goto error_out;  +	} +    } + +    /* make balancing after all resources will be collected at a time */  +    if ( retval == CARRY_ON ) { +	do_balance (&s_ins_balance, p_s_ih, p_c_body, M_INSERT); +	return 0; +    } + +    retval = (retval == NO_DISK_SPACE) ? -ENOSPC : -EIO; +error_out: +    /* also releases the path */ +    unfix_nodes(&s_ins_balance); +#ifdef REISERQUOTA_DEBUG +    reiserfs_debug (th->t_super, REISERFS_DEBUG_CODE, "reiserquota insert_item(): freeing %u id=%u type=%c", quota_bytes, inode->i_uid, head2type(p_s_ih)); +#endif +    if (inode) +	DQUOT_FREE_SPACE_NODIRTY(inode, quota_bytes) ; +    return retval;  +} + + + +  |