fs/afs/dir_edit.c

17  * Find a number of contiguous clear bits in a directory block bitmask.
20  * variable.  The first bit doesn't count as it corresponds to the block header
23 static int afs_find_contig_bits(union afs_xdr_dir_block *block, unsigned int nr_slots)
29 	bitmap  = (u64)block->hdr.bitmap[0] << 0 * 8;
30 	bitmap |= (u64)block->hdr.bitmap[1] << 1 * 8;
31 	bitmap |= (u64)block->hdr.bitmap[2] << 2 * 8;
32 	bitmap |= (u64)block->hdr.bitmap[3] << 3 * 8;
33 	bitmap |= (u64)block->hdr.bitmap[4] << 4 * 8;
34 	bitmap |= (u64)block->hdr.bitmap[5] << 5 * 8;
35 	bitmap |= (u64)block->hdr.bitmap[6] << 6 * 8;
36 	bitmap |= (u64)block->hdr.bitmap[7] << 7 * 8;
66  * Set a number of contiguous bits in the directory block bitmap.
68 static void afs_set_contig_bits(union afs_xdr_dir_block *block,
76 	block->hdr.bitmap[0] |= (u8)(mask >> 0 * 8);
77 	block->hdr.bitmap[1] |= (u8)(mask >> 1 * 8);
78 	block->hdr.bitmap[2] |= (u8)(mask >> 2 * 8);
79 	block->hdr.bitmap[3] |= (u8)(mask >> 3 * 8);
80 	block->hdr.bitmap[4] |= (u8)(mask >> 4 * 8);
81 	block->hdr.bitmap[5] |= (u8)(mask >> 5 * 8);
82 	block->hdr.bitmap[6] |= (u8)(mask >> 6 * 8);
83 	block->hdr.bitmap[7] |= (u8)(mask >> 7 * 8);
87  * Clear a number of contiguous bits in the directory block bitmap.
89 static void afs_clear_contig_bits(union afs_xdr_dir_block *block,
97 	block->hdr.bitmap[0] &= ~(u8)(mask >> 0 * 8);
98 	block->hdr.bitmap[1] &= ~(u8)(mask >> 1 * 8);
99 	block->hdr.bitmap[2] &= ~(u8)(mask >> 2 * 8);
100 	block->hdr.bitmap[3] &= ~(u8)(mask >> 3 * 8);
101 	block->hdr.bitmap[4] &= ~(u8)(mask >> 4 * 8);
102 	block->hdr.bitmap[5] &= ~(u8)(mask >> 5 * 8);
103 	block->hdr.bitmap[6] &= ~(u8)(mask >> 6 * 8);
104 	block->hdr.bitmap[7] &= ~(u8)(mask >> 7 * 8);
128  * Scan a directory block looking for a dirent of the right name.
130 static int afs_dir_scan_block(union afs_xdr_dir_block *block, struct qstr *name,
139 	bitmap  = (u64)block->hdr.bitmap[0] << 0 * 8;
140 	bitmap |= (u64)block->hdr.bitmap[1] << 1 * 8;
141 	bitmap |= (u64)block->hdr.bitmap[2] << 2 * 8;
142 	bitmap |= (u64)block->hdr.bitmap[3] << 3 * 8;
143 	bitmap |= (u64)block->hdr.bitmap[4] << 4 * 8;
144 	bitmap |= (u64)block->hdr.bitmap[5] << 5 * 8;
145 	bitmap |= (u64)block->hdr.bitmap[6] << 6 * 8;
146 	bitmap |= (u64)block->hdr.bitmap[7] << 7 * 8;
153 		de = &block->dirents[d];
157 		/* The block was NUL-terminated by afs_dir_check_page(). */
172  * Initialise a new directory block.  Note that block 0 is special and contains
176 				union afs_xdr_dir_block *block, int block_num)
178 	memset(block, 0, sizeof(*block));
179 	block->hdr.npages = htons(1);
180 	block->hdr.magic = AFS_DIR_MAGIC;
181 	block->hdr.bitmap[0] = 1;
184 		block->hdr.bitmap[0] = 0xff;
185 		block->hdr.bitmap[1] = 0x1f;
186 		memset(block->meta.alloc_ctrs,
188 		       sizeof(block->meta.alloc_ctrs));
210 	union afs_xdr_dir_block *meta, *block;
241 	/* Find a block that has sufficient slots available.  Each folio
259 		block = kmap_local_folio(folio, b * AFS_DIR_BLOCK_SIZE - folio_file_pos(folio));
265 		_debug("block %u: %2u %3u %u",
268 		       ntohs(block->hdr.npages),
269 		       ntohs(block->hdr.magic));
271 		/* Initialise the block if necessary. */
274 			afs_edit_init_block(meta, block, b);
284 			slot = afs_find_contig_bits(block, need_slots);
291 		kunmap_local(block);
311 	block = kmap_local_folio(folio, 0);
319 	de = &block->dirents[slot];
329 	afs_set_contig_bits(block, slot, need_slots);
330 	kunmap_local(block);
354 	kunmap_local(block);
377 	union afs_xdr_dir_block *meta, *block;
407 	/* Find a block that has sufficient slots available.  Each folio
420 		block = kmap_local_folio(folio, b * AFS_DIR_BLOCK_SIZE - folio_file_pos(folio));
428 			slot = afs_dir_scan_block(block, name, b);
433 		kunmap_local(block);
447 	de = &block->dirents[slot];
456 	afs_clear_contig_bits(block, slot, need_slots);
457 	kunmap_local(block);
482 	kunmap_local(block);