2 * fs_ext2.c - an implementation for the Ext2/Ext3 filesystem
4 * Copyright (C) 2001, 2002 Ethan Benson
6 * Copyright (C) 1999 Benjamin Herrenschmidt
8 * Adapted from quik/silo
10 * Copyright (C) 1996 Maurizio Plaza
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation; either version 2 of the License, or
16 * (at your option) any later version.
18 * This program is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 * GNU General Public License for more details.
23 * You should have received a copy of the GNU General Public License
24 * along with this program; if not, write to the Free Software
25 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
34 #include "partition.h"
40 #define MAX_READ_RANGE 256
44 #include "linux/ext2_fs.h"
45 #include "ext2fs/ext2fs.h"
47 static int ext2_open( struct boot_file_t* file,
49 struct partition_t* part,
50 const char* file_name);
51 static int ext2_read( struct boot_file_t* file,
54 static int ext2_seek( struct boot_file_t* file,
56 static int ext2_close( struct boot_file_t* file);
58 struct fs_t ext2_filesystem =
67 /* IO manager structure for the ext2 library */
69 static errcode_t linux_open (const char *name, int flags, io_channel * channel);
70 static errcode_t linux_close (io_channel channel);
71 static errcode_t linux_set_blksize (io_channel channel, int blksize);
72 static errcode_t linux_read_blk (io_channel channel, unsigned long block, int count, void *data);
73 static errcode_t linux_write_blk (io_channel channel, unsigned long block, int count, const void *data);
74 static errcode_t linux_flush (io_channel channel);
76 static struct struct_io_manager struct_linux_manager =
78 EXT2_ET_MAGIC_IO_MANAGER,
88 static io_manager linux_io_manager = &struct_linux_manager;
90 /* Currently, we have a mess between what is in the file structure
91 * and what is stored globally here. I'll clean this up later
93 static int opened = 0; /* We can't open twice ! */
94 static unsigned int bs; /* Blocksize */
95 static unsigned long long doff; /* Byte offset where partition starts */
96 static unsigned long long dend; /* Byte offset where partition ends */
97 static ino_t root,cwd;
98 static ext2_filsys fs = 0;
99 static struct boot_file_t* cur_file;
100 static char *block_buffer = NULL;
103 static unsigned long read_range_start;
104 static unsigned long read_range_count;
105 static unsigned long read_last_logical;
106 static unsigned long read_total;
107 static unsigned long read_max;
108 static struct boot_file_t* read_cur_file;
109 static errcode_t read_result;
110 static char* read_buffer;
112 static int read_dump_range(void);
113 static int read_iterator(ext2_filsys fs, blk_t *blocknr, int lg_block, void *private);
114 #else /* FAST_VERSION */
115 static struct ext2_inode cur_inode;
116 #endif /* FAST_VERSION */
118 void com_err (const char *a, long i, const char *fmt,...)
120 prom_printf ((char *) fmt);
124 ext2_open( struct boot_file_t* file,
125 const char* dev_name,
126 struct partition_t* part,
127 const char* file_name)
130 int error = FILE_ERR_NOTFOUND;
131 static char buffer[1024];
138 DEBUG_LEAVE(FILE_ERR_FSBUSY);
139 return FILE_ERR_FSBUSY;
141 if (file->device_kind != FILE_DEVICE_BLOCK) {
142 DEBUG_LEAVE(FILE_ERR_BADDEV);
143 return FILE_ERR_BADDEV;
148 /* We don't care too much about the device block size since we run
149 * thru the deblocker. We may have to change that is we plan to be
150 * compatible with older versions of OF
155 * On the other hand, we do care about the actual size of the
156 * partition, reads or seeks past the end may cause undefined
157 * behavior on some devices. A netapp that tries to seek and
158 * read past the end of the lun takes ~30 secs to recover per
163 doff = (unsigned long long)(part->part_start) * part->blocksize;
164 dend = doff + (unsigned long long)part->part_size * part->blocksize;
169 DEBUG_F("partition offset: %Lx, end: %Lx\n", doff, dend);
171 /* Open the OF device for the entire disk */
172 strncpy(buffer, dev_name, 1020);
173 strcat(buffer, ":0");
175 DEBUG_F("<%s>\n", buffer);
177 file->of_device = prom_open(buffer);
179 DEBUG_F("file->of_device = %p\n", file->of_device);
181 if (file->of_device == PROM_INVALID_HANDLE) {
183 DEBUG_F("Can't open device %p\n", file->of_device);
184 DEBUG_LEAVE(FILE_IOERR);
189 /* Open the ext2 filesystem */
190 result = ext2fs_open (buffer, EXT2_FLAG_RW, 0, 0, linux_io_manager, &fs);
193 if(result == EXT2_ET_BAD_MAGIC)
195 DEBUG_F( "ext2fs_open returned bad magic loading file %p\n",
200 DEBUG_F( "ext2fs_open error #%d while loading file %s\n",
203 error = FILE_ERR_BAD_FSYS;
207 /* Allocate the block buffer */
208 block_buffer = malloc(fs->blocksize * 2);
211 DEBUG_F("ext2fs: can't alloc block buffer (%d bytes)\n", fs->blocksize * 2);
216 /* Lookup file by pathname */
217 root = cwd = EXT2_ROOT_INO;
218 result = ext2fs_namei_follow(fs, root, cwd, file_name, &file->inode);
221 DEBUG_F("ext2fs_namei error #%d while loading file %s\n", result, file_name);
222 if (result == EXT2_ET_SYMLINK_LOOP)
223 error = FILE_ERR_SYMLINK_LOOP;
224 else if (result == EXT2_ET_FILE_NOT_FOUND)
225 error = FILE_ERR_NOTFOUND;
232 result = ext2fs_follow_link(fs, root, cwd, file->inode, &file->inode);
235 DEBUG_F("ext2fs_follow_link error #%d while loading file %s\n", result, file_name);
236 error = FILE_ERR_NOTFOUND;
242 result = ext2fs_read_inode(fs, file->inode, &cur_inode);
245 DEBUG_F("ext2fs_read_inode error #%d while loading file %s\n", result, file_name);
246 if (result == EXT2_ET_FILE_TOO_BIG)
247 error = FILE_ERR_LENGTH;
248 else if (result == EXT2_ET_LLSEEK_FAILED)
249 error = FILE_CANT_SEEK;
250 else if (result == EXT2_ET_FILE_NOT_FOUND)
251 error = FILE_ERR_NOTFOUND;
256 #endif /* FAST_VERSION */
266 prom_close(file->of_device);
272 DEBUG_LEAVE_F(error);
276 DEBUG_LEAVE(FILE_ERR_OK);
283 read_dump_range(void)
285 int count = read_range_count;
289 DEBUG_F(" dumping range: start: 0x%x count: 0x%x\n",
290 read_range_count, read_range_start);
292 /* Check if we need to handle a special case for the last block */
293 if ((count * bs) > read_max)
297 read_result = io_channel_read_blk(fs->io, read_range_start, count, read_buffer);
303 read_cur_file->pos += size;
304 read_range_count -= count;
305 read_range_start += count;
306 read_last_logical += count;
308 /* Handle remaining block */
309 if (read_max && read_range_count) {
310 read_result = io_channel_read_blk(fs->io, read_range_start, 1, block_buffer);
313 memcpy(read_buffer, block_buffer, read_max);
314 read_cur_file->pos += read_max;
315 read_total += read_max;
318 read_range_count = read_range_start = 0;
320 return (read_max == 0) ? BLOCK_ABORT : 0;
324 read_iterator(ext2_filsys fs, blk_t *blocknr, int lg_block, void *private)
327 DEBUG_F("read_it: p_bloc: 0x%x, l_bloc: 0x%x, f_pos: 0x%x, rng_pos: 0x%x ",
328 *blocknr, lg_block, read_cur_file->pos, read_last_logical);
332 DEBUG_F(" <skip lg>\n");
337 /* If we have not reached the start block yet, we skip */
338 if (lg_block < read_cur_file->pos / bs) {
340 DEBUG_F(" <skip pos>\n");
345 /* If block is contiguous to current range, just extend range,
346 * exit if we pass the remaining bytes count to read
348 if (read_range_start && read_range_count < MAX_READ_RANGE
349 && (*blocknr == read_range_start + read_range_count)
350 && (lg_block == read_last_logical + read_range_count)) {
352 DEBUG_F(" block in range\n");
355 return ((read_range_count * bs) >= read_max) ? BLOCK_ABORT : 0;
358 /* Range doesn't match. Dump existing range */
359 if (read_range_start) {
361 DEBUG_F(" calling dump range \n");
363 if (read_dump_range())
367 /* Here we handle holes in the file */
368 if (lg_block && lg_block != read_last_logical) {
371 DEBUG_F(" hole from lg_bloc 0x%x\n", read_last_logical);
373 if (read_cur_file->pos % bs) {
374 int offset = read_cur_file->pos % bs;
375 int size = bs - offset;
378 memset(read_buffer, 0, size);
382 read_cur_file->pos += size;
387 nzero = (lg_block - read_last_logical) * bs;
389 if (nzero > read_max)
391 memset(read_buffer, 0, nzero);
394 read_buffer += nzero;
395 read_cur_file->pos += nzero;
399 read_last_logical = lg_block;
402 /* If we are not aligned, handle that case */
403 if (read_cur_file->pos % bs) {
404 int offset = read_cur_file->pos % bs;
405 int size = bs - offset;
407 DEBUG_F(" handle unaligned start\n");
409 read_result = io_channel_read_blk(fs->io, *blocknr, 1, block_buffer);
414 memcpy(read_buffer, block_buffer + offset, size);
415 read_cur_file->pos += size;
419 read_last_logical = lg_block + 1;
420 return (read_max == 0) ? BLOCK_ABORT : 0;
423 /* If there is still a physical block to add, then create a new range */
426 DEBUG_F(" new range\n");
428 read_range_start = *blocknr;
429 read_range_count = 1;
430 return (bs >= read_max) ? BLOCK_ABORT : 0;
439 #endif /* FAST_VERSION */
442 ext2_read( struct boot_file_t* file,
453 DEBUG_F("ext_read() from pos 0x%Lx, size: 0x%ux\n", file->pos, size);
456 read_cur_file = file;
457 read_range_start = 0;
458 read_range_count = 0;
459 read_last_logical = file->pos / bs;
462 read_buffer = (unsigned char*)buffer;
465 retval = ext2fs_block_iterate(fs, file->inode, 0, 0, read_iterator, 0);
466 if (retval == BLOCK_ABORT)
467 retval = read_result;
468 if (!retval && read_range_start) {
470 DEBUG_F("on exit: range_start is 0x%x, calling dump...\n",
474 retval = read_result;
477 prom_printf ("ext2: i/o error %ld in read\n", (long) retval);
481 #else /* FAST_VERSION */
483 unsigned int read = 0;
489 DEBUG_F("ext_read() from pos 0x%x, size: 0x%x\n", file->pos, size);
493 blk_t fblock = file->pos / bs;
495 unsigned int blkorig, s, b;
498 status = ext2fs_bmap(fs, file->inode, &cur_inode,
499 block_buffer, 0, fblock, &pblock);
502 DEBUG_F("ext2fs_bmap(fblock:%d) return: %d\n", fblock, status);
505 blkorig = fblock * bs;
506 b = file->pos - blkorig;
507 s = ((bs - b) > size) ? size : (bs - b);
509 unsigned long long pos =
510 ((unsigned long long)pblock) * (unsigned long long)bs;
512 prom_lseek(file->of_device, pos);
513 status = prom_read(file->of_device, block_buffer, bs);
515 prom_printf("ext2: io error in read, ex: %d, got: %d\n",
520 memset(block_buffer, 0, bs);
522 memcpy(buffer, block_buffer + b, s);
529 #endif /* FAST_VERSION */
533 ext2_seek( struct boot_file_t* file,
537 return FILE_CANT_SEEK;
544 ext2_close( struct boot_file_t* file)
557 prom_close(file->of_device);
558 DEBUG_F("ext2_close called\n");
565 static errcode_t linux_open (const char *name, int flags, io_channel * channel)
571 return EXT2_ET_BAD_DEVICE_NAME;
572 io = (io_channel) malloc (sizeof (struct struct_io_channel));
574 return EXT2_ET_BAD_DEVICE_NAME;
575 memset (io, 0, sizeof (struct struct_io_channel));
576 io->magic = EXT2_ET_MAGIC_IO_CHANNEL;
577 io->manager = linux_io_manager;
578 io->name = (char *) malloc (strlen (name) + 1);
579 strcpy (io->name, name);
588 static errcode_t linux_close (io_channel channel)
594 static errcode_t linux_set_blksize (io_channel channel, int blksize)
596 DEBUG_F("bs set to 0x%x\n", blksize);
597 channel->block_size = bs = blksize;
600 block_buffer = malloc(bs * 2);
605 static errcode_t linux_read_blk (io_channel channel, unsigned long block, int count, void *data)
608 unsigned long long tempb;
613 tempb = (((unsigned long long) block) *
614 ((unsigned long long)bs)) + (unsigned long long)doff;
616 * Only test tempb exceeding dend if dend is set to allow things
617 * like boot: hd:0,\xxxx
619 if (dend && tempb > dend) {
620 DEBUG_F("\nSeek error on block %lx, tempb=%Lx\n", block, tempb >> 9);
621 return EXT2_ET_LLSEEK_FAILED;
624 size = (count < 0) ? -count : count * bs;
625 prom_lseek(cur_file->of_device, tempb);
626 if (prom_read(cur_file->of_device, data, size) != size) {
627 DEBUG_F("\nRead error on block %ld\n", block);
628 return EXT2_ET_SHORT_READ;
633 static errcode_t linux_write_blk (io_channel channel, unsigned long block, int count, const void *data)
638 static errcode_t linux_flush (io_channel channel)
645 * c-file-style: "k&r"