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- #include <stdio.h>
- #include <string.h>
- #if HAVE_UNISTD_H
- #include <unistd.h>
- #endif
- #if HAVE_ERRNO_H
- #include <errno.h>
- #endif
- #include <fcntl.h>
- #include <time.h>
- #ifdef __linux__
- #include <sys/utsname.h>
- #endif
- #if HAVE_SYS_STAT_H
- #include <sys/stat.h>
- #endif
- #if HAVE_SYS_TYPES_H
- #include <sys/types.h>
- #endif
- #include <sys/resource.h>
- #include "ext2_fs.h"
- #include "ext2fs.h"
- #define EXT2_CHECK_MAGIC(struct, code) \
- if ((struct)->magic != (code)) return (code)
- struct unix_cache {
- char *buf;
- unsigned long block;
- int access_time;
- unsigned dirty:1;
- unsigned in_use:1;
- };
- #define CACHE_SIZE 8
- #define WRITE_DIRECT_SIZE 4
- #define READ_DIRECT_SIZE 4
- struct unix_private_data {
- int magic;
- int dev;
- int flags;
- int access_time;
- ext2_loff_t offset;
- struct unix_cache cache[CACHE_SIZE];
- };
- static errcode_t unix_open(const char *name, int flags, io_channel *channel);
- static errcode_t unix_close(io_channel channel);
- static errcode_t unix_set_blksize(io_channel channel, int blksize);
- static errcode_t unix_read_blk(io_channel channel, unsigned long block,
- int count, void *data);
- static errcode_t unix_write_blk(io_channel channel, unsigned long block,
- int count, const void *data);
- static errcode_t unix_flush(io_channel channel);
- static errcode_t unix_write_byte(io_channel channel, unsigned long offset,
- int size, const void *data);
- static errcode_t unix_set_option(io_channel channel, const char *option,
- const char *arg);
- static void reuse_cache(io_channel channel, struct unix_private_data *data,
- struct unix_cache *cache, unsigned long block);
- #if defined(__CYGWIN__) || defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
- #define NEED_BOUNCE_BUFFER
- #else
- #undef NEED_BOUNCE_BUFFER
- #endif
- static struct struct_io_manager struct_unix_manager = {
- EXT2_ET_MAGIC_IO_MANAGER,
- "Unix I/O Manager",
- unix_open,
- unix_close,
- unix_set_blksize,
- unix_read_blk,
- unix_write_blk,
- unix_flush,
- #ifdef NEED_BOUNCE_BUFFER
- 0,
- #else
- unix_write_byte,
- #endif
- unix_set_option
- };
- io_manager unix_io_manager = &struct_unix_manager;
- #ifndef NEED_BOUNCE_BUFFER
- static errcode_t raw_read_blk(io_channel channel,
- struct unix_private_data *data,
- unsigned long block,
- int count, void *buf)
- {
- errcode_t retval;
- ssize_t size;
- ext2_loff_t location;
- int actual = 0;
- size = (count < 0) ? -count : count * channel->block_size;
- location = ((ext2_loff_t) block * channel->block_size) + data->offset;
- if (ext2fs_llseek(data->dev, location, SEEK_SET) != location) {
- retval = errno ? errno : EXT2_ET_LLSEEK_FAILED;
- goto error_out;
- }
- actual = read(data->dev, buf, size);
- if (actual != size) {
- if (actual < 0)
- actual = 0;
- retval = EXT2_ET_SHORT_READ;
- goto error_out;
- }
- return 0;
- error_out:
- memset((char *) buf+actual, 0, size-actual);
- if (channel->read_error)
- retval = (channel->read_error)(channel, block, count, buf,
- size, actual, retval);
- return retval;
- }
- #else
- static errcode_t raw_read_blk(io_channel channel,
- struct unix_private_data *data,
- unsigned long block,
- int count, void *buf)
- {
- errcode_t retval;
- size_t size, alignsize, fragment;
- ext2_loff_t location;
- int total = 0, actual;
- #define BLOCKALIGN 512
- char sector[BLOCKALIGN];
- size = (count < 0) ? -count : count * channel->block_size;
- location = ((ext2_loff_t) block * channel->block_size) + data->offset;
- #ifdef DEBUG
- printf("count=%d, size=%d, block=%d, blk_size=%d, location=%lx\n",
- count, size, block, channel->block_size, location);
- #endif
- if (ext2fs_llseek(data->dev, location, SEEK_SET) != location) {
- retval = errno ? errno : EXT2_ET_LLSEEK_FAILED;
- goto error_out;
- }
- fragment = size % BLOCKALIGN;
- alignsize = size - fragment;
- if (alignsize) {
- actual = read(data->dev, buf, alignsize);
- if (actual != alignsize)
- goto short_read;
- }
- if (fragment) {
- actual = read(data->dev, sector, BLOCKALIGN);
- if (actual != BLOCKALIGN)
- goto short_read;
- memcpy(buf+alignsize, sector, fragment);
- }
- return 0;
- short_read:
- if (actual>0)
- total += actual;
- retval = EXT2_ET_SHORT_READ;
- error_out:
- memset((char *) buf+total, 0, size-actual);
- if (channel->read_error)
- retval = (channel->read_error)(channel, block, count, buf,
- size, actual, retval);
- return retval;
- }
- #endif
- static errcode_t raw_write_blk(io_channel channel,
- struct unix_private_data *data,
- unsigned long block,
- int count, const void *buf)
- {
- ssize_t size;
- ext2_loff_t location;
- int actual = 0;
- errcode_t retval;
- if (count == 1)
- size = channel->block_size;
- else {
- if (count < 0)
- size = -count;
- else
- size = count * channel->block_size;
- }
- location = ((ext2_loff_t) block * channel->block_size) + data->offset;
- if (ext2fs_llseek(data->dev, location, SEEK_SET) != location) {
- retval = errno ? errno : EXT2_ET_LLSEEK_FAILED;
- goto error_out;
- }
- actual = write(data->dev, buf, size);
- if (actual != size) {
- retval = EXT2_ET_SHORT_WRITE;
- goto error_out;
- }
- return 0;
- error_out:
- if (channel->write_error)
- retval = (channel->write_error)(channel, block, count, buf,
- size, actual, retval);
- return retval;
- }
- static errcode_t alloc_cache(io_channel channel,
- struct unix_private_data *data)
- {
- errcode_t retval;
- struct unix_cache *cache;
- int i;
- data->access_time = 0;
- for (i=0, cache = data->cache; i < CACHE_SIZE; i++, cache++) {
- cache->block = 0;
- cache->access_time = 0;
- cache->dirty = 0;
- cache->in_use = 0;
- if ((retval = ext2fs_get_mem(channel->block_size,
- &cache->buf)))
- return retval;
- }
- return 0;
- }
- static void free_cache(struct unix_private_data *data)
- {
- struct unix_cache *cache;
- int i;
- data->access_time = 0;
- for (i=0, cache = data->cache; i < CACHE_SIZE; i++, cache++) {
- cache->block = 0;
- cache->access_time = 0;
- cache->dirty = 0;
- cache->in_use = 0;
- ext2fs_free_mem(&cache->buf);
- cache->buf = 0;
- }
- }
- #ifndef NO_IO_CACHE
- static struct unix_cache *find_cached_block(struct unix_private_data *data,
- unsigned long block,
- struct unix_cache **eldest)
- {
- struct unix_cache *cache, *unused_cache, *oldest_cache;
- int i;
- unused_cache = oldest_cache = 0;
- for (i=0, cache = data->cache; i < CACHE_SIZE; i++, cache++) {
- if (!cache->in_use) {
- if (!unused_cache)
- unused_cache = cache;
- continue;
- }
- if (cache->block == block) {
- cache->access_time = ++data->access_time;
- return cache;
- }
- if (!oldest_cache ||
- (cache->access_time < oldest_cache->access_time))
- oldest_cache = cache;
- }
- if (eldest)
- *eldest = (unused_cache) ? unused_cache : oldest_cache;
- return 0;
- }
- static void reuse_cache(io_channel channel, struct unix_private_data *data,
- struct unix_cache *cache, unsigned long block)
- {
- if (cache->dirty && cache->in_use)
- raw_write_blk(channel, data, cache->block, 1, cache->buf);
- cache->in_use = 1;
- cache->dirty = 0;
- cache->block = block;
- cache->access_time = ++data->access_time;
- }
- static errcode_t flush_cached_blocks(io_channel channel,
- struct unix_private_data *data,
- int invalidate)
- {
- struct unix_cache *cache;
- errcode_t retval, retval2;
- int i;
- retval2 = 0;
- for (i=0, cache = data->cache; i < CACHE_SIZE; i++, cache++) {
- if (!cache->in_use)
- continue;
- if (invalidate)
- cache->in_use = 0;
- if (!cache->dirty)
- continue;
- retval = raw_write_blk(channel, data,
- cache->block, 1, cache->buf);
- if (retval)
- retval2 = retval;
- else
- cache->dirty = 0;
- }
- return retval2;
- }
- #endif
- static errcode_t unix_open(const char *name, int flags, io_channel *channel)
- {
- io_channel io = NULL;
- struct unix_private_data *data = NULL;
- errcode_t retval;
- int open_flags;
- struct stat st;
- #ifdef __linux__
- struct utsname ut;
- #endif
- if (name == 0)
- return EXT2_ET_BAD_DEVICE_NAME;
- retval = ext2fs_get_mem(sizeof(struct struct_io_channel), &io);
- if (retval)
- return retval;
- memset(io, 0, sizeof(struct struct_io_channel));
- io->magic = EXT2_ET_MAGIC_IO_CHANNEL;
- retval = ext2fs_get_mem(sizeof(struct unix_private_data), &data);
- if (retval)
- goto cleanup;
- io->manager = unix_io_manager;
- retval = ext2fs_get_mem(strlen(name)+1, &io->name);
- if (retval)
- goto cleanup;
- strcpy(io->name, name);
- io->private_data = data;
- io->block_size = 1024;
- io->read_error = 0;
- io->write_error = 0;
- io->refcount = 1;
- memset(data, 0, sizeof(struct unix_private_data));
- data->magic = EXT2_ET_MAGIC_UNIX_IO_CHANNEL;
- if ((retval = alloc_cache(io, data)))
- goto cleanup;
- open_flags = (flags & IO_FLAG_RW) ? O_RDWR : O_RDONLY;
- #ifdef CONFIG_LFS
- data->dev = open64(io->name, open_flags);
- #else
- data->dev = open(io->name, open_flags);
- #endif
- if (data->dev < 0) {
- retval = errno;
- goto cleanup;
- }
- #ifdef __linux__
- #undef RLIM_INFINITY
- #if (defined(__alpha__) || ((defined(__sparc__) || defined(__mips__)) && (SIZEOF_LONG == 4)))
- #define RLIM_INFINITY ((unsigned long)(~0UL>>1))
- #else
- #define RLIM_INFINITY (~0UL)
- #endif
-
- if ((flags & IO_FLAG_RW) &&
- (uname(&ut) == 0) &&
- ((ut.release[0] == '2') && (ut.release[1] == '.') &&
- (ut.release[2] == '4') && (ut.release[3] == '.') &&
- (ut.release[4] == '1') && (ut.release[5] >= '0') &&
- (ut.release[5] < '8')) &&
- (fstat(data->dev, &st) == 0) &&
- (S_ISBLK(st.st_mode))) {
- struct rlimit rlim;
- rlim.rlim_cur = rlim.rlim_max = (unsigned long) RLIM_INFINITY;
- setrlimit(RLIMIT_FSIZE, &rlim);
- getrlimit(RLIMIT_FSIZE, &rlim);
- if (((unsigned long) rlim.rlim_cur) <
- ((unsigned long) rlim.rlim_max)) {
- rlim.rlim_cur = rlim.rlim_max;
- setrlimit(RLIMIT_FSIZE, &rlim);
- }
- }
- #endif
- *channel = io;
- return 0;
- cleanup:
- if (data) {
- free_cache(data);
- ext2fs_free_mem(&data);
- }
- ext2fs_free_mem(&io);
- return retval;
- }
- static errcode_t unix_close(io_channel channel)
- {
- struct unix_private_data *data;
- errcode_t retval = 0;
- EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
- data = (struct unix_private_data *) channel->private_data;
- EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
- if (--channel->refcount > 0)
- return 0;
- #ifndef NO_IO_CACHE
- retval = flush_cached_blocks(channel, data, 0);
- #endif
- if (close(data->dev) < 0)
- retval = errno;
- free_cache(data);
- ext2fs_free_mem(&channel->private_data);
- ext2fs_free_mem(&channel->name);
- ext2fs_free_mem(&channel);
- return retval;
- }
- static errcode_t unix_set_blksize(io_channel channel, int blksize)
- {
- struct unix_private_data *data;
- errcode_t retval;
- EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
- data = (struct unix_private_data *) channel->private_data;
- EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
- if (channel->block_size != blksize) {
- #ifndef NO_IO_CACHE
- if ((retval = flush_cached_blocks(channel, data, 0)))
- return retval;
- #endif
- channel->block_size = blksize;
- free_cache(data);
- if ((retval = alloc_cache(channel, data)))
- return retval;
- }
- return 0;
- }
- static errcode_t unix_read_blk(io_channel channel, unsigned long block,
- int count, void *buf)
- {
- struct unix_private_data *data;
- struct unix_cache *cache, *reuse[READ_DIRECT_SIZE];
- errcode_t retval;
- char *cp;
- int i, j;
- EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
- data = (struct unix_private_data *) channel->private_data;
- EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
- #ifdef NO_IO_CACHE
- return raw_read_blk(channel, data, block, count, buf);
- #else
-
- if (count < 0 || count > WRITE_DIRECT_SIZE) {
- if ((retval = flush_cached_blocks(channel, data, 0)))
- return retval;
- return raw_read_blk(channel, data, block, count, buf);
- }
- cp = buf;
- while (count > 0) {
-
- if ((cache = find_cached_block(data, block, &reuse[0]))) {
- #ifdef DEBUG
- printf("Using cached block %d\n", block);
- #endif
- memcpy(cp, cache->buf, channel->block_size);
- count--;
- block++;
- cp += channel->block_size;
- continue;
- }
-
- for (i=1; i < count; i++)
- if (find_cached_block(data, block+i, &reuse[i]))
- break;
- #ifdef DEBUG
- printf("Reading %d blocks starting at %d\n", i, block);
- #endif
- if ((retval = raw_read_blk(channel, data, block, i, cp)))
- return retval;
-
- for (j=0; j < i; j++) {
- count--;
- cache = reuse[j];
- reuse_cache(channel, data, cache, block++);
- memcpy(cache->buf, cp, channel->block_size);
- cp += channel->block_size;
- }
- }
- return 0;
- #endif
- }
- static errcode_t unix_write_blk(io_channel channel, unsigned long block,
- int count, const void *buf)
- {
- struct unix_private_data *data;
- struct unix_cache *cache, *reuse;
- errcode_t retval = 0;
- const char *cp;
- int writethrough;
- EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
- data = (struct unix_private_data *) channel->private_data;
- EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
- #ifdef NO_IO_CACHE
- return raw_write_blk(channel, data, block, count, buf);
- #else
-
- if (count < 0 || count > WRITE_DIRECT_SIZE) {
- if ((retval = flush_cached_blocks(channel, data, 1)))
- return retval;
- return raw_write_blk(channel, data, block, count, buf);
- }
-
- writethrough = channel->flags & CHANNEL_FLAGS_WRITETHROUGH;
- if (writethrough)
- retval = raw_write_blk(channel, data, block, count, buf);
- cp = buf;
- while (count > 0) {
- cache = find_cached_block(data, block, &reuse);
- if (!cache) {
- cache = reuse;
- reuse_cache(channel, data, cache, block);
- }
- memcpy(cache->buf, cp, channel->block_size);
- cache->dirty = !writethrough;
- count--;
- block++;
- cp += channel->block_size;
- }
- return retval;
- #endif
- }
- static errcode_t unix_write_byte(io_channel channel, unsigned long offset,
- int size, const void *buf)
- {
- struct unix_private_data *data;
- errcode_t retval = 0;
- ssize_t actual;
- EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
- data = (struct unix_private_data *) channel->private_data;
- EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
- #ifndef NO_IO_CACHE
-
- if ((retval = flush_cached_blocks(channel, data, 1)))
- return retval;
- #endif
- if (lseek(data->dev, offset + data->offset, SEEK_SET) < 0)
- return errno;
- actual = write(data->dev, buf, size);
- if (actual != size)
- return EXT2_ET_SHORT_WRITE;
- return 0;
- }
- static errcode_t unix_flush(io_channel channel)
- {
- struct unix_private_data *data;
- errcode_t retval = 0;
- EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
- data = (struct unix_private_data *) channel->private_data;
- EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
- #ifndef NO_IO_CACHE
- retval = flush_cached_blocks(channel, data, 0);
- #endif
- fsync(data->dev);
- return retval;
- }
- static errcode_t unix_set_option(io_channel channel, const char *option,
- const char *arg)
- {
- struct unix_private_data *data;
- unsigned long tmp;
- char *end;
- EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
- data = (struct unix_private_data *) channel->private_data;
- EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
- if (!strcmp(option, "offset")) {
- if (!arg)
- return EXT2_ET_INVALID_ARGUMENT;
- tmp = strtoul(arg, &end, 0);
- if (*end)
- return EXT2_ET_INVALID_ARGUMENT;
- data->offset = tmp;
- return 0;
- }
- return EXT2_ET_INVALID_ARGUMENT;
- }
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