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"
41 #define MAX_READ_RANGE 256
45 #include "linux/ext2_fs.h"
46 #include "ext2fs/ext2fs.h"
48 static int ext2_open( struct boot_file_t* file,
49 struct partition_t* part,
50 struct boot_fspec_t* fspec);
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 struct partition_t* part,
126 struct boot_fspec_t* fspec)
129 int error = FILE_ERR_NOTFOUND;
130 static char buffer[1024];
132 char *dev_name = fspec->dev;
133 char *file_name = fspec->file;
139 DEBUG_LEAVE(FILE_ERR_FSBUSY);
140 return FILE_ERR_FSBUSY;
142 if (file->device_kind != FILE_DEVICE_BLOCK) {
143 DEBUG_LEAVE(FILE_ERR_BADDEV);
144 return FILE_ERR_BADDEV;
149 /* We don't care too much about the device block size since we run
150 * thru the deblocker. We may have to change that is we plan to be
151 * compatible with older versions of OF
156 * On the other hand, we do care about the actual size of the
157 * partition, reads or seeks past the end may cause undefined
158 * behavior on some devices. A netapp that tries to seek and
159 * read past the end of the lun takes ~30 secs to recover per
164 doff = (unsigned long long)(part->part_start) * part->blocksize;
165 dend = doff + (unsigned long long)part->part_size * part->blocksize;
170 DEBUG_F("partition offset: %Lx, end: %Lx\n", doff, dend);
172 /* Open the OF device for the entire disk */
173 strncpy(buffer, dev_name, 1020);
174 if (_machine != _MACH_bplan)
175 strcat(buffer, ":0");
177 DEBUG_F("<%s>\n", buffer);
179 file->of_device = prom_open(buffer);
181 DEBUG_F("file->of_device = %p\n", file->of_device);
183 if (file->of_device == PROM_INVALID_HANDLE) {
185 DEBUG_F("Can't open device %p\n", file->of_device);
186 DEBUG_LEAVE(FILE_IOERR);
191 /* Open the ext2 filesystem */
192 result = ext2fs_open (buffer, EXT2_FLAG_RW, 0, 0, linux_io_manager, &fs);
195 if(result == EXT2_ET_BAD_MAGIC)
197 DEBUG_F( "ext2fs_open returned bad magic loading file %p\n",
202 DEBUG_F( "ext2fs_open error #%d while loading file %s\n",
205 error = FILE_ERR_BAD_FSYS;
209 /* Allocate the block buffer */
210 block_buffer = malloc(fs->blocksize * 2);
213 DEBUG_F("ext2fs: can't alloc block buffer (%d bytes)\n", fs->blocksize * 2);
218 /* Lookup file by pathname */
219 root = cwd = EXT2_ROOT_INO;
220 result = ext2fs_namei_follow(fs, root, cwd, file_name, &file->inode);
223 DEBUG_F("ext2fs_namei error #%d while loading file %s\n", result, file_name);
224 if (result == EXT2_ET_SYMLINK_LOOP)
225 error = FILE_ERR_SYMLINK_LOOP;
226 else if (result == EXT2_ET_FILE_NOT_FOUND)
227 error = FILE_ERR_NOTFOUND;
234 result = ext2fs_follow_link(fs, root, cwd, file->inode, &file->inode);
237 DEBUG_F("ext2fs_follow_link error #%d while loading file %s\n", result, file_name);
238 error = FILE_ERR_NOTFOUND;
244 result = ext2fs_read_inode(fs, file->inode, &cur_inode);
247 DEBUG_F("ext2fs_read_inode error #%d while loading file %s\n", result, file_name);
248 if (result == EXT2_ET_FILE_TOO_BIG)
249 error = FILE_ERR_LENGTH;
250 else if (result == EXT2_ET_LLSEEK_FAILED)
251 error = FILE_CANT_SEEK;
252 else if (result == EXT2_ET_FILE_NOT_FOUND)
253 error = FILE_ERR_NOTFOUND;
258 #endif /* FAST_VERSION */
268 prom_close(file->of_device);
274 DEBUG_LEAVE_F(error);
278 DEBUG_LEAVE(FILE_ERR_OK);
285 read_dump_range(void)
287 int count = read_range_count;
291 DEBUG_F(" dumping range: start: 0x%x count: 0x%x\n",
292 read_range_count, read_range_start);
294 /* Check if we need to handle a special case for the last block */
295 if ((count * bs) > read_max)
299 read_result = io_channel_read_blk(fs->io, read_range_start, count, read_buffer);
305 read_cur_file->pos += size;
306 read_range_count -= count;
307 read_range_start += count;
308 read_last_logical += count;
310 /* Handle remaining block */
311 if (read_max && read_range_count) {
312 read_result = io_channel_read_blk(fs->io, read_range_start, 1, block_buffer);
315 memcpy(read_buffer, block_buffer, read_max);
316 read_cur_file->pos += read_max;
317 read_total += read_max;
320 read_range_count = read_range_start = 0;
322 return (read_max == 0) ? BLOCK_ABORT : 0;
326 read_iterator(ext2_filsys fs, blk_t *blocknr, int lg_block, void *private)
329 DEBUG_F("read_it: p_bloc: 0x%x, l_bloc: 0x%x, f_pos: 0x%x, rng_pos: 0x%x ",
330 *blocknr, lg_block, read_cur_file->pos, read_last_logical);
334 DEBUG_F(" <skip lg>\n");
339 /* If we have not reached the start block yet, we skip */
340 if (lg_block < read_cur_file->pos / bs) {
342 DEBUG_F(" <skip pos>\n");
347 /* If block is contiguous to current range, just extend range,
348 * exit if we pass the remaining bytes count to read
350 if (read_range_start && read_range_count < MAX_READ_RANGE
351 && (*blocknr == read_range_start + read_range_count)
352 && (lg_block == read_last_logical + read_range_count)) {
354 DEBUG_F(" block in range\n");
357 return ((read_range_count * bs) >= read_max) ? BLOCK_ABORT : 0;
360 /* Range doesn't match. Dump existing range */
361 if (read_range_start) {
363 DEBUG_F(" calling dump range \n");
365 if (read_dump_range())
369 /* Here we handle holes in the file */
370 if (lg_block && lg_block != read_last_logical) {
373 DEBUG_F(" hole from lg_bloc 0x%x\n", read_last_logical);
375 if (read_cur_file->pos % bs) {
376 int offset = read_cur_file->pos % bs;
377 int size = bs - offset;
380 memset(read_buffer, 0, size);
384 read_cur_file->pos += size;
389 nzero = (lg_block - read_last_logical) * bs;
391 if (nzero > read_max)
393 memset(read_buffer, 0, nzero);
396 read_buffer += nzero;
397 read_cur_file->pos += nzero;
401 read_last_logical = lg_block;
404 /* If we are not aligned, handle that case */
405 if (read_cur_file->pos % bs) {
406 int offset = read_cur_file->pos % bs;
407 int size = bs - offset;
409 DEBUG_F(" handle unaligned start\n");
411 read_result = io_channel_read_blk(fs->io, *blocknr, 1, block_buffer);
416 memcpy(read_buffer, block_buffer + offset, size);
417 read_cur_file->pos += size;
421 read_last_logical = lg_block + 1;
422 return (read_max == 0) ? BLOCK_ABORT : 0;
425 /* If there is still a physical block to add, then create a new range */
428 DEBUG_F(" new range\n");
430 read_range_start = *blocknr;
431 read_range_count = 1;
432 return (bs >= read_max) ? BLOCK_ABORT : 0;
441 #endif /* FAST_VERSION */
444 ext2_read( struct boot_file_t* file,
455 DEBUG_F("ext_read() from pos 0x%Lx, size: 0x%ux\n", file->pos, size);
458 read_cur_file = file;
459 read_range_start = 0;
460 read_range_count = 0;
461 read_last_logical = file->pos / bs;
464 read_buffer = (unsigned char*)buffer;
467 retval = ext2fs_block_iterate(fs, file->inode, 0, 0, read_iterator, 0);
468 if (retval == BLOCK_ABORT)
469 retval = read_result;
470 if (!retval && read_range_start) {
472 DEBUG_F("on exit: range_start is 0x%x, calling dump...\n",
476 retval = read_result;
479 prom_printf ("ext2: i/o error %ld in read\n", (long) retval);
483 #else /* FAST_VERSION */
485 unsigned int read = 0;
491 DEBUG_F("ext_read() from pos 0x%x, size: 0x%x\n", file->pos, size);
495 blk_t fblock = file->pos / bs;
497 unsigned int blkorig, s, b;
500 status = ext2fs_bmap(fs, file->inode, &cur_inode,
501 block_buffer, 0, fblock, &pblock);
504 DEBUG_F("ext2fs_bmap(fblock:%d) return: %d\n", fblock, status);
507 blkorig = fblock * bs;
508 b = file->pos - blkorig;
509 s = ((bs - b) > size) ? size : (bs - b);
511 unsigned long long pos =
512 ((unsigned long long)pblock) * (unsigned long long)bs;
514 prom_lseek(file->of_device, pos);
515 status = prom_read(file->of_device, block_buffer, bs);
517 prom_printf("ext2: io error in read, ex: %d, got: %d\n",
522 memset(block_buffer, 0, bs);
524 memcpy(buffer, block_buffer + b, s);
531 #endif /* FAST_VERSION */
535 ext2_seek( struct boot_file_t* file,
539 return FILE_CANT_SEEK;
546 ext2_close( struct boot_file_t* file)
559 prom_close(file->of_device);
560 DEBUG_F("ext2_close called\n");
567 static errcode_t linux_open (const char *name, int flags, io_channel * channel)
573 return EXT2_ET_BAD_DEVICE_NAME;
574 io = (io_channel) malloc (sizeof (struct struct_io_channel));
576 return EXT2_ET_BAD_DEVICE_NAME;
577 memset (io, 0, sizeof (struct struct_io_channel));
578 io->magic = EXT2_ET_MAGIC_IO_CHANNEL;
579 io->manager = linux_io_manager;
580 io->name = (char *) malloc (strlen (name) + 1);
581 strcpy (io->name, name);
590 static errcode_t linux_close (io_channel channel)
596 static errcode_t linux_set_blksize (io_channel channel, int blksize)
598 DEBUG_F("bs set to 0x%x\n", blksize);
599 channel->block_size = bs = blksize;
602 block_buffer = malloc(bs * 2);
607 static errcode_t linux_read_blk (io_channel channel, unsigned long block, int count, void *data)
610 unsigned long long tempb;
615 tempb = (((unsigned long long) block) *
616 ((unsigned long long)bs)) + (unsigned long long)doff;
618 * Only test tempb exceeding dend if dend is set to allow things
619 * like boot: hd:0,\xxxx
621 if (dend && tempb > dend) {
622 DEBUG_F("\nSeek error on block %lx, tempb=%Lx\n", block, tempb >> 9);
623 return EXT2_ET_LLSEEK_FAILED;
626 size = (count < 0) ? -count : count * bs;
627 prom_lseek(cur_file->of_device, tempb);
628 if (prom_read(cur_file->of_device, data, size) != size) {
629 DEBUG_F("\nRead error on block %ld\n", block);
630 return EXT2_ET_SHORT_READ;
635 static errcode_t linux_write_blk (io_channel channel, unsigned long block, int count, const void *data)
640 static errcode_t linux_flush (io_channel channel)
647 * c-file-style: "k&r"