Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) /* Generic part */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4) typedef struct {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5) 	block_t	*p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6) 	block_t	key;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7) 	struct buffer_head *bh;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8) } Indirect;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10) static DEFINE_RWLOCK(pointers_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) static inline void add_chain(Indirect *p, struct buffer_head *bh, block_t *v)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) 	p->key = *(p->p = v);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) 	p->bh = bh;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) static inline int verify_chain(Indirect *from, Indirect *to)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) 	while (from <= to && from->key == *from->p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) 		from++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) 	return (from > to);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) static inline block_t *block_end(struct buffer_head *bh)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) 	return (block_t *)((char*)bh->b_data + bh->b_size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) static inline Indirect *get_branch(struct inode *inode,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) 					int depth,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) 					int *offsets,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) 					Indirect chain[DEPTH],
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) 					int *err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) 	struct super_block *sb = inode->i_sb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) 	Indirect *p = chain;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) 	struct buffer_head *bh;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) 	*err = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) 	/* i_data is not going away, no lock needed */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) 	add_chain (chain, NULL, i_data(inode) + *offsets);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) 	if (!p->key)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) 		goto no_block;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) 	while (--depth) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) 		bh = sb_bread(sb, block_to_cpu(p->key));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) 		if (!bh)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) 			goto failure;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) 		read_lock(&pointers_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) 		if (!verify_chain(chain, p))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) 			goto changed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) 		add_chain(++p, bh, (block_t *)bh->b_data + *++offsets);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 		read_unlock(&pointers_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 		if (!p->key)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 			goto no_block;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 	return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) changed:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 	read_unlock(&pointers_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 	brelse(bh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) 	*err = -EAGAIN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) 	goto no_block;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) failure:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) 	*err = -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) no_block:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 	return p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) static int alloc_branch(struct inode *inode,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 			     int num,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 			     int *offsets,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 			     Indirect *branch)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 	int n = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 	int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 	int parent = minix_new_block(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 	int err = -ENOSPC;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 	branch[0].key = cpu_to_block(parent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 	if (parent) for (n = 1; n < num; n++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 		struct buffer_head *bh;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 		/* Allocate the next block */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 		int nr = minix_new_block(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 		if (!nr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 		branch[n].key = cpu_to_block(nr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 		bh = sb_getblk(inode->i_sb, parent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 		if (!bh) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 			minix_free_block(inode, nr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 			err = -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 		lock_buffer(bh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 		memset(bh->b_data, 0, bh->b_size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 		branch[n].bh = bh;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 		branch[n].p = (block_t*) bh->b_data + offsets[n];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 		*branch[n].p = branch[n].key;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 		set_buffer_uptodate(bh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 		unlock_buffer(bh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 		mark_buffer_dirty_inode(bh, inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 		parent = nr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 	if (n == num)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 	/* Allocation failed, free what we already allocated */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 	for (i = 1; i < n; i++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 		bforget(branch[i].bh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) 	for (i = 0; i < n; i++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 		minix_free_block(inode, block_to_cpu(branch[i].key));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 	return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) static inline int splice_branch(struct inode *inode,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) 				     Indirect chain[DEPTH],
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 				     Indirect *where,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) 				     int num)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) 	int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) 	write_lock(&pointers_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 	/* Verify that place we are splicing to is still there and vacant */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) 	if (!verify_chain(chain, where-1) || *where->p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 		goto changed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) 	*where->p = where->key;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 	write_unlock(&pointers_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 	/* We are done with atomic stuff, now do the rest of housekeeping */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 	inode->i_ctime = current_time(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 	/* had we spliced it onto indirect block? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 	if (where->bh)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 		mark_buffer_dirty_inode(where->bh, inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 	mark_inode_dirty(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) changed:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) 	write_unlock(&pointers_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 	for (i = 1; i < num; i++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 		bforget(where[i].bh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 	for (i = 0; i < num; i++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 		minix_free_block(inode, block_to_cpu(where[i].key));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 	return -EAGAIN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) static int get_block(struct inode * inode, sector_t block,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) 			struct buffer_head *bh, int create)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 	int err = -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 	int offsets[DEPTH];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 	Indirect chain[DEPTH];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 	Indirect *partial;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 	int left;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 	int depth = block_to_path(inode, block, offsets);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 	if (depth == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 		goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) reread:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 	partial = get_branch(inode, depth, offsets, chain, &err);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 	/* Simplest case - block found, no allocation needed */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 	if (!partial) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) got_it:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 		map_bh(bh, inode->i_sb, block_to_cpu(chain[depth-1].key));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 		/* Clean up and exit */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 		partial = chain+depth-1; /* the whole chain */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 		goto cleanup;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) 	/* Next simple case - plain lookup or failed read of indirect block */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 	if (!create || err == -EIO) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) cleanup:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) 		while (partial > chain) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) 			brelse(partial->bh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 			partial--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 		return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 	 * Indirect block might be removed by truncate while we were
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 	 * reading it. Handling of that case (forget what we've got and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 	 * reread) is taken out of the main path.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) 	if (err == -EAGAIN)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 		goto changed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) 	left = (chain + depth) - partial;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) 	err = alloc_branch(inode, left, offsets+(partial-chain), partial);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) 	if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) 		goto cleanup;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) 	if (splice_branch(inode, chain, partial, left) < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) 		goto changed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) 	set_buffer_new(bh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) 	goto got_it;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) changed:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) 	while (partial > chain) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) 		brelse(partial->bh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) 		partial--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) 	goto reread;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) static inline int all_zeroes(block_t *p, block_t *q)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) 	while (p < q)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) 		if (*p++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) 			return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) 	return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) static Indirect *find_shared(struct inode *inode,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) 				int depth,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) 				int offsets[DEPTH],
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) 				Indirect chain[DEPTH],
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) 				block_t *top)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) 	Indirect *partial, *p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) 	int k, err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) 	*top = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) 	for (k = depth; k > 1 && !offsets[k-1]; k--)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) 		;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) 	partial = get_branch(inode, k, offsets, chain, &err);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) 	write_lock(&pointers_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) 	if (!partial)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) 		partial = chain + k-1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) 	if (!partial->key && *partial->p) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) 		write_unlock(&pointers_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) 		goto no_top;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) 	for (p=partial;p>chain && all_zeroes((block_t*)p->bh->b_data,p->p);p--)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) 		;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) 	if (p == chain + k - 1 && p > chain) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) 		p->p--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) 	} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) 		*top = *p->p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) 		*p->p = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) 	write_unlock(&pointers_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) 	while(partial > p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) 	{
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) 		brelse(partial->bh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) 		partial--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) no_top:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) 	return partial;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) static inline void free_data(struct inode *inode, block_t *p, block_t *q)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) 	unsigned long nr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) 	for ( ; p < q ; p++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) 		nr = block_to_cpu(*p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) 		if (nr) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) 			*p = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) 			minix_free_block(inode, nr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) static void free_branches(struct inode *inode, block_t *p, block_t *q, int depth)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) 	struct buffer_head * bh;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) 	unsigned long nr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) 	if (depth--) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) 		for ( ; p < q ; p++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) 			nr = block_to_cpu(*p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) 			if (!nr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) 				continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) 			*p = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) 			bh = sb_bread(inode->i_sb, nr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) 			if (!bh)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) 				continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) 			free_branches(inode, (block_t*)bh->b_data,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) 				      block_end(bh), depth);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) 			bforget(bh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) 			minix_free_block(inode, nr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) 			mark_inode_dirty(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) 	} else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) 		free_data(inode, p, q);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) static inline void truncate (struct inode * inode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) 	struct super_block *sb = inode->i_sb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) 	block_t *idata = i_data(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) 	int offsets[DEPTH];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) 	Indirect chain[DEPTH];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) 	Indirect *partial;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) 	block_t nr = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) 	int n;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) 	int first_whole;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) 	long iblock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) 	iblock = (inode->i_size + sb->s_blocksize -1) >> sb->s_blocksize_bits;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) 	block_truncate_page(inode->i_mapping, inode->i_size, get_block);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) 	n = block_to_path(inode, iblock, offsets);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) 	if (!n)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) 	if (n == 1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) 		free_data(inode, idata+offsets[0], idata + DIRECT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) 		first_whole = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) 		goto do_indirects;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) 	first_whole = offsets[0] + 1 - DIRECT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) 	partial = find_shared(inode, n, offsets, chain, &nr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) 	if (nr) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) 		if (partial == chain)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) 			mark_inode_dirty(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) 		else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) 			mark_buffer_dirty_inode(partial->bh, inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) 		free_branches(inode, &nr, &nr+1, (chain+n-1) - partial);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) 	/* Clear the ends of indirect blocks on the shared branch */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) 	while (partial > chain) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) 		free_branches(inode, partial->p + 1, block_end(partial->bh),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) 				(chain+n-1) - partial);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) 		mark_buffer_dirty_inode(partial->bh, inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) 		brelse (partial->bh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) 		partial--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) do_indirects:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) 	/* Kill the remaining (whole) subtrees */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) 	while (first_whole < DEPTH-1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) 		nr = idata[DIRECT+first_whole];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) 		if (nr) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) 			idata[DIRECT+first_whole] = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) 			mark_inode_dirty(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) 			free_branches(inode, &nr, &nr+1, first_whole+1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) 		first_whole++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) 	inode->i_mtime = inode->i_ctime = current_time(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) 	mark_inode_dirty(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) static inline unsigned nblocks(loff_t size, struct super_block *sb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) 	int k = sb->s_blocksize_bits - 10;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) 	unsigned blocks, res, direct = DIRECT, i = DEPTH;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) 	blocks = (size + sb->s_blocksize - 1) >> (BLOCK_SIZE_BITS + k);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) 	res = blocks;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) 	while (--i && blocks > direct) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) 		blocks -= direct;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) 		blocks += sb->s_blocksize/sizeof(block_t) - 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) 		blocks /= sb->s_blocksize/sizeof(block_t);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) 		res += blocks;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) 		direct = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) 	return res;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) }