| /* |
| * unix_io.c --- This is the Unix (well, really POSIX) implementation |
| * of the I/O manager. |
| * |
| * Implements a one-block write-through cache. |
| * |
| * Includes support for Windows NT support under Cygwin. |
| * |
| * Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, |
| * 2002 by Theodore Ts'o. |
| * |
| * %Begin-Header% |
| * This file may be redistributed under the terms of the GNU Library |
| * General Public License, version 2. |
| * %End-Header% |
| */ |
| |
| #if !defined(__FreeBSD__) && !defined(__NetBSD__) && !defined(__OpenBSD__) |
| #define _XOPEN_SOURCE 600 |
| #define _DARWIN_C_SOURCE |
| #define _FILE_OFFSET_BITS 64 |
| #ifndef _LARGEFILE_SOURCE |
| #define _LARGEFILE_SOURCE |
| #endif |
| #ifndef _LARGEFILE64_SOURCE |
| #define _LARGEFILE64_SOURCE |
| #endif |
| #ifndef _GNU_SOURCE |
| #define _GNU_SOURCE |
| #endif |
| #endif |
| |
| #include "config.h" |
| #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_TYPES_H |
| #include <sys/types.h> |
| #endif |
| #ifdef HAVE_SYS_IOCTL_H |
| #include <sys/ioctl.h> |
| #endif |
| #ifdef HAVE_SYS_MOUNT_H |
| #include <sys/mount.h> |
| #endif |
| #if HAVE_SYS_STAT_H |
| #include <sys/stat.h> |
| #endif |
| #if HAVE_SYS_RESOURCE_H |
| #include <sys/resource.h> |
| #endif |
| #if HAVE_LINUX_FALLOC_H |
| #include <linux/falloc.h> |
| #endif |
| |
| #if defined(__linux__) && defined(_IO) && !defined(BLKROGET) |
| #define BLKROGET _IO(0x12, 94) /* Get read-only status (0 = read_write). */ |
| #endif |
| |
| #undef ALIGN_DEBUG |
| |
| #include "ext2_fs.h" |
| #include "ext2fs.h" |
| |
| /* |
| * For checking structure magic numbers... |
| */ |
| |
| #define EXT2_CHECK_MAGIC(struct, code) \ |
| if ((struct)->magic != (code)) return (code) |
| |
| struct unix_cache { |
| char *buf; |
| unsigned long long block; |
| int access_time; |
| unsigned dirty:1; |
| unsigned in_use:1; |
| }; |
| |
| #define CACHE_SIZE 8 |
| #define WRITE_DIRECT_SIZE 4 /* Must be smaller than CACHE_SIZE */ |
| #define READ_DIRECT_SIZE 4 /* Should be smaller than CACHE_SIZE */ |
| |
| struct unix_private_data { |
| int magic; |
| int dev; |
| int flags; |
| int align; |
| int access_time; |
| ext2_loff_t offset; |
| struct unix_cache cache[CACHE_SIZE]; |
| void *bounce; |
| struct struct_io_stats io_stats; |
| }; |
| |
| #define IS_ALIGNED(n, align) ((((uintptr_t) n) & \ |
| ((uintptr_t) ((align)-1))) == 0) |
| |
| static errcode_t unix_get_stats(io_channel channel, io_stats *stats) |
| { |
| errcode_t retval = 0; |
| |
| struct unix_private_data *data; |
| |
| 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 (stats) |
| *stats = &data->io_stats; |
| |
| return retval; |
| } |
| |
| /* |
| * Here are the raw I/O functions |
| */ |
| static errcode_t raw_read_blk(io_channel channel, |
| struct unix_private_data *data, |
| unsigned long long block, |
| int count, void *bufv) |
| { |
| errcode_t retval; |
| ssize_t size; |
| ext2_loff_t location; |
| int actual = 0; |
| unsigned char *buf = bufv; |
| |
| size = (count < 0) ? -count : count * channel->block_size; |
| data->io_stats.bytes_read += size; |
| location = ((ext2_loff_t) block * channel->block_size) + data->offset; |
| |
| #ifdef HAVE_PREAD64 |
| /* Try an aligned pread */ |
| if ((channel->align == 0) || |
| (IS_ALIGNED(buf, channel->align) && |
| IS_ALIGNED(size, channel->align))) { |
| actual = pread64(data->dev, buf, size, location); |
| if (actual == size) |
| return 0; |
| } |
| #elif HAVE_PREAD |
| /* Try an aligned pread */ |
| if ((sizeof(off_t) >= sizeof(ext2_loff_t)) && |
| ((channel->align == 0) || |
| (IS_ALIGNED(buf, channel->align) && |
| IS_ALIGNED(size, channel->align)))) { |
| actual = pread(data->dev, buf, size, location); |
| if (actual == size) |
| return 0; |
| } |
| #endif /* HAVE_PREAD */ |
| |
| if (ext2fs_llseek(data->dev, location, SEEK_SET) != location) { |
| retval = errno ? errno : EXT2_ET_LLSEEK_FAILED; |
| goto error_out; |
| } |
| if ((channel->align == 0) || |
| (IS_ALIGNED(buf, channel->align) && |
| IS_ALIGNED(size, channel->align))) { |
| actual = read(data->dev, buf, size); |
| if (actual != size) { |
| short_read: |
| if (actual < 0) |
| actual = 0; |
| retval = EXT2_ET_SHORT_READ; |
| goto error_out; |
| } |
| return 0; |
| } |
| |
| #ifdef ALIGN_DEBUG |
| printf("raw_read_blk: O_DIRECT fallback: %p %lu\n", buf, |
| (unsigned long) size); |
| #endif |
| |
| /* |
| * The buffer or size which we're trying to read isn't aligned |
| * to the O_DIRECT rules, so we need to do this the hard way... |
| */ |
| while (size > 0) { |
| actual = read(data->dev, data->bounce, channel->block_size); |
| if (actual != channel->block_size) |
| goto short_read; |
| actual = size; |
| if (size > channel->block_size) |
| actual = channel->block_size; |
| memcpy(buf, data->bounce, actual); |
| size -= actual; |
| buf += actual; |
| } |
| 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; |
| } |
| |
| static errcode_t raw_write_blk(io_channel channel, |
| struct unix_private_data *data, |
| unsigned long long block, |
| int count, const void *bufv) |
| { |
| ssize_t size; |
| ext2_loff_t location; |
| int actual = 0; |
| errcode_t retval; |
| const unsigned char *buf = bufv; |
| |
| if (count == 1) |
| size = channel->block_size; |
| else { |
| if (count < 0) |
| size = -count; |
| else |
| size = count * channel->block_size; |
| } |
| data->io_stats.bytes_written += size; |
| |
| location = ((ext2_loff_t) block * channel->block_size) + data->offset; |
| |
| #ifdef HAVE_PWRITE64 |
| /* Try an aligned pwrite */ |
| if ((channel->align == 0) || |
| (IS_ALIGNED(buf, channel->align) && |
| IS_ALIGNED(size, channel->align))) { |
| actual = pwrite64(data->dev, buf, size, location); |
| if (actual == size) |
| return 0; |
| } |
| #elif HAVE_PWRITE |
| /* Try an aligned pwrite */ |
| if ((sizeof(off_t) >= sizeof(ext2_loff_t)) && |
| ((channel->align == 0) || |
| (IS_ALIGNED(buf, channel->align) && |
| IS_ALIGNED(size, channel->align)))) { |
| actual = pwrite(data->dev, buf, size, location); |
| if (actual == size) |
| return 0; |
| } |
| #endif /* HAVE_PWRITE */ |
| |
| if (ext2fs_llseek(data->dev, location, SEEK_SET) != location) { |
| retval = errno ? errno : EXT2_ET_LLSEEK_FAILED; |
| goto error_out; |
| } |
| |
| if ((channel->align == 0) || |
| (IS_ALIGNED(buf, channel->align) && |
| IS_ALIGNED(size, channel->align))) { |
| actual = write(data->dev, buf, size); |
| if (actual != size) { |
| short_write: |
| retval = EXT2_ET_SHORT_WRITE; |
| goto error_out; |
| } |
| return 0; |
| } |
| |
| #ifdef ALIGN_DEBUG |
| printf("raw_write_blk: O_DIRECT fallback: %p %lu\n", buf, |
| (unsigned long) size); |
| #endif |
| /* |
| * The buffer or size which we're trying to write isn't aligned |
| * to the O_DIRECT rules, so we need to do this the hard way... |
| */ |
| while (size > 0) { |
| if (size < channel->block_size) { |
| actual = read(data->dev, data->bounce, |
| channel->block_size); |
| if (actual != channel->block_size) { |
| retval = EXT2_ET_SHORT_READ; |
| goto error_out; |
| } |
| } |
| actual = size; |
| if (size > channel->block_size) |
| actual = channel->block_size; |
| memcpy(data->bounce, buf, actual); |
| if (ext2fs_llseek(data->dev, location, SEEK_SET) != location) { |
| retval = errno ? errno : EXT2_ET_LLSEEK_FAILED; |
| goto error_out; |
| } |
| actual = write(data->dev, data->bounce, channel->block_size); |
| if (actual != channel->block_size) |
| goto short_write; |
| size -= actual; |
| buf += actual; |
| } |
| return 0; |
| |
| error_out: |
| if (channel->write_error) |
| retval = (channel->write_error)(channel, block, count, buf, |
| size, actual, retval); |
| return retval; |
| } |
| |
| |
| /* |
| * Here we implement the cache functions |
| */ |
| |
| /* Allocate the cache buffers */ |
| 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 (cache->buf) |
| ext2fs_free_mem(&cache->buf); |
| retval = io_channel_alloc_buf(channel, 0, &cache->buf); |
| if (retval) |
| return retval; |
| } |
| if (channel->align) { |
| if (data->bounce) |
| ext2fs_free_mem(&data->bounce); |
| retval = io_channel_alloc_buf(channel, 0, &data->bounce); |
| } |
| return retval; |
| } |
| |
| /* Free the cache buffers */ |
| 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; |
| if (cache->buf) |
| ext2fs_free_mem(&cache->buf); |
| } |
| if (data->bounce) |
| ext2fs_free_mem(&data->bounce); |
| } |
| |
| #ifndef NO_IO_CACHE |
| /* |
| * Try to find a block in the cache. If the block is not found, and |
| * eldest is a non-zero pointer, then fill in eldest with the cache |
| * entry to that should be reused. |
| */ |
| static struct unix_cache *find_cached_block(struct unix_private_data *data, |
| unsigned long 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; |
| } |
| |
| /* |
| * Reuse a particular cache entry for another block. |
| */ |
| static void reuse_cache(io_channel channel, struct unix_private_data *data, |
| struct unix_cache *cache, unsigned long 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; |
| } |
| |
| /* |
| * Flush all of the blocks in the cache |
| */ |
| 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 /* NO_IO_CACHE */ |
| |
| #ifdef __linux__ |
| #ifndef BLKDISCARDZEROES |
| #define BLKDISCARDZEROES _IO(0x12,124) |
| #endif |
| #endif |
| |
| int ext2fs_open_file(const char *pathname, int flags, mode_t mode) |
| { |
| if (mode) |
| #if defined(HAVE_OPEN64) && !defined(__OSX_AVAILABLE_BUT_DEPRECATED) |
| return open64(pathname, flags, mode); |
| else |
| return open64(pathname, flags); |
| #else |
| return open(pathname, flags, mode); |
| else |
| return open(pathname, flags); |
| #endif |
| } |
| |
| int ext2fs_stat(const char *path, ext2fs_struct_stat *buf) |
| { |
| #if defined(HAVE_FSTAT64) && !defined(__OSX_AVAILABLE_BUT_DEPRECATED) |
| return stat64(path, buf); |
| #else |
| return stat(path, buf); |
| #endif |
| } |
| |
| int ext2fs_fstat(int fd, ext2fs_struct_stat *buf) |
| { |
| #if defined(HAVE_FSTAT64) && !defined(__OSX_AVAILABLE_BUT_DEPRECATED) |
| return fstat64(fd, buf); |
| #else |
| return fstat(fd, buf); |
| #endif |
| } |
| |
| |
| static errcode_t unix_open_channel(const char *name, int fd, |
| int flags, io_channel *channel, |
| io_manager io_mgr) |
| { |
| io_channel io = NULL; |
| struct unix_private_data *data = NULL; |
| errcode_t retval; |
| ext2fs_struct_stat st; |
| #ifdef __linux__ |
| struct utsname ut; |
| #endif |
| |
| retval = ext2fs_get_mem(sizeof(struct struct_io_channel), &io); |
| if (retval) |
| goto cleanup; |
| 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 = io_mgr; |
| 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; |
| data->io_stats.num_fields = 2; |
| data->flags = flags; |
| data->dev = fd; |
| |
| #if defined(O_DIRECT) |
| if (flags & IO_FLAG_DIRECT_IO) |
| io->align = ext2fs_get_dio_alignment(data->dev); |
| #elif defined(F_NOCACHE) |
| if (flags & IO_FLAG_DIRECT_IO) |
| io->align = 4096; |
| #endif |
| |
| /* |
| * If the device is really a block device, then set the |
| * appropriate flag, otherwise we can set DISCARD_ZEROES flag |
| * because we are going to use punch hole instead of discard |
| * and if it succeed, subsequent read from sparse area returns |
| * zero. |
| */ |
| if (ext2fs_fstat(data->dev, &st) == 0) { |
| if (S_ISBLK(st.st_mode)) |
| io->flags |= CHANNEL_FLAGS_BLOCK_DEVICE; |
| else |
| io->flags |= CHANNEL_FLAGS_DISCARD_ZEROES; |
| } |
| |
| #ifdef BLKDISCARDZEROES |
| { |
| int zeroes = 0; |
| if (ioctl(data->dev, BLKDISCARDZEROES, &zeroes) == 0 && |
| zeroes) |
| io->flags |= CHANNEL_FLAGS_DISCARD_ZEROES; |
| } |
| #endif |
| |
| #if defined(__CYGWIN__) || defined(__FreeBSD__) || defined(__FreeBSD_kernel__) |
| /* |
| * Some operating systems require that the buffers be aligned, |
| * regardless of O_DIRECT |
| */ |
| if (!io->align) |
| io->align = 512; |
| #endif |
| |
| |
| if ((retval = alloc_cache(io, data))) |
| goto cleanup; |
| |
| #ifdef BLKROGET |
| if (flags & IO_FLAG_RW) { |
| int error; |
| int readonly = 0; |
| |
| /* Is the block device actually writable? */ |
| error = ioctl(data->dev, BLKROGET, &readonly); |
| if (!error && readonly) { |
| retval = EPERM; |
| goto cleanup; |
| } |
| } |
| #endif |
| |
| #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 |
| /* |
| * Work around a bug in 2.4.10-2.4.18 kernels where writes to |
| * block devices are wrongly getting hit by the filesize |
| * limit. This workaround isn't perfect, since it won't work |
| * if glibc wasn't built against 2.2 header files. (Sigh.) |
| * |
| */ |
| 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')) && |
| (ext2fs_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) { |
| if (data->dev >= 0) |
| close(data->dev); |
| free_cache(data); |
| ext2fs_free_mem(&data); |
| } |
| if (io) { |
| if (io->name) { |
| ext2fs_free_mem(&io->name); |
| } |
| ext2fs_free_mem(&io); |
| } |
| return retval; |
| } |
| |
| static errcode_t unixfd_open(const char *str_fd, int flags, |
| io_channel *channel) |
| { |
| int fd; |
| int fd_flags; |
| |
| fd = atoi(str_fd); |
| fd_flags = fcntl(fd, F_GETFD); |
| if (fd_flags == -1) |
| return -EBADF; |
| |
| flags = 0; |
| if (fd_flags & O_RDWR) |
| flags |= IO_FLAG_RW; |
| if (fd_flags & O_EXCL) |
| flags |= IO_FLAG_EXCLUSIVE; |
| #if defined(O_DIRECT) |
| if (fd_flags & O_DIRECT) |
| flags |= IO_FLAG_DIRECT_IO; |
| #endif |
| |
| return unix_open_channel(str_fd, fd, flags, channel, unixfd_io_manager); |
| } |
| |
| static errcode_t unix_open(const char *name, int flags, |
| io_channel *channel) |
| { |
| int fd = -1; |
| int open_flags; |
| |
| if (name == 0) |
| return EXT2_ET_BAD_DEVICE_NAME; |
| |
| open_flags = (flags & IO_FLAG_RW) ? O_RDWR : O_RDONLY; |
| if (flags & IO_FLAG_EXCLUSIVE) |
| open_flags |= O_EXCL; |
| #if defined(O_DIRECT) |
| if (flags & IO_FLAG_DIRECT_IO) |
| open_flags |= O_DIRECT; |
| #endif |
| fd = ext2fs_open_file(name, open_flags, 0); |
| if (fd < 0) |
| return errno; |
| #if defined(F_NOCACHE) && !defined(IO_DIRECT) |
| if (flags & IO_FLAG_DIRECT_IO) { |
| if (fcntl(fd, F_NOCACHE, 1) < 0) |
| return errno; |
| } |
| #endif |
| return unix_open_channel(name, fd, flags, channel, unix_io_manager); |
| } |
| |
| 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); |
| if (channel->name) |
| 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_blk64(io_channel channel, unsigned long 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 we're doing an odd-sized read or a very large read, |
| * flush out the cache and then do a direct read. |
| */ |
| 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 it's in the cache, use it! */ |
| if ((cache = find_cached_block(data, block, &reuse[0]))) { |
| #ifdef DEBUG |
| printf("Using cached block %lu\n", block); |
| #endif |
| memcpy(cp, cache->buf, channel->block_size); |
| count--; |
| block++; |
| cp += channel->block_size; |
| continue; |
| } |
| if (count == 1) { |
| /* |
| * Special case where we read directly into the |
| * cache buffer; important in the O_DIRECT case |
| */ |
| cache = reuse[0]; |
| reuse_cache(channel, data, cache, block); |
| if ((retval = raw_read_blk(channel, data, block, 1, |
| cache->buf))) { |
| cache->in_use = 0; |
| return retval; |
| } |
| memcpy(cp, cache->buf, channel->block_size); |
| return 0; |
| } |
| |
| /* |
| * Find the number of uncached blocks so we can do a |
| * single read request |
| */ |
| for (i=1; i < count; i++) |
| if (find_cached_block(data, block+i, &reuse[i])) |
| break; |
| #ifdef DEBUG |
| printf("Reading %d blocks starting at %lu\n", i, block); |
| #endif |
| if ((retval = raw_read_blk(channel, data, block, i, cp))) |
| return retval; |
| |
| /* Save the results in the cache */ |
| 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 /* NO_IO_CACHE */ |
| } |
| |
| static errcode_t unix_read_blk(io_channel channel, unsigned long block, |
| int count, void *buf) |
| { |
| return unix_read_blk64(channel, block, count, buf); |
| } |
| |
| static errcode_t unix_write_blk64(io_channel channel, unsigned long 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 we're doing an odd-sized write or a very large write, |
| * flush out the cache completely and then do a direct write. |
| */ |
| 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); |
| } |
| |
| /* |
| * For a moderate-sized multi-block write, first force a write |
| * if we're in write-through cache mode, and then fill the |
| * cache with the blocks. |
| */ |
| 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); |
| } |
| if (cache->buf != cp) |
| memcpy(cache->buf, cp, channel->block_size); |
| cache->dirty = !writethrough; |
| count--; |
| block++; |
| cp += channel->block_size; |
| } |
| return retval; |
| #endif /* NO_IO_CACHE */ |
| } |
| |
| static errcode_t unix_cache_readahead(io_channel channel, |
| unsigned long long block, |
| unsigned long long count) |
| { |
| #ifdef POSIX_FADV_WILLNEED |
| struct unix_private_data *data; |
| |
| data = (struct unix_private_data *)channel->private_data; |
| EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL); |
| return posix_fadvise(data->dev, |
| (ext2_loff_t)block * channel->block_size + data->offset, |
| (ext2_loff_t)count * channel->block_size, |
| POSIX_FADV_WILLNEED); |
| #else |
| return EXT2_ET_OP_NOT_SUPPORTED; |
| #endif |
| } |
| |
| static errcode_t unix_write_blk(io_channel channel, unsigned long block, |
| int count, const void *buf) |
| { |
| return unix_write_blk64(channel, block, count, buf); |
| } |
| |
| 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); |
| |
| if (channel->align != 0) { |
| #ifdef ALIGN_DEBUG |
| printf("unix_write_byte: O_DIRECT fallback\n"); |
| #endif |
| return EXT2_ET_UNIMPLEMENTED; |
| } |
| |
| #ifndef NO_IO_CACHE |
| /* |
| * Flush out the cache completely |
| */ |
| 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; |
| } |
| |
| /* |
| * Flush data buffers to disk. |
| */ |
| 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 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 = strtoull(arg, &end, 0); |
| if (*end) |
| return EXT2_ET_INVALID_ARGUMENT; |
| data->offset = tmp; |
| if (data->offset < 0) |
| return EXT2_ET_INVALID_ARGUMENT; |
| return 0; |
| } |
| return EXT2_ET_INVALID_ARGUMENT; |
| } |
| |
| #if defined(__linux__) && !defined(BLKDISCARD) |
| #define BLKDISCARD _IO(0x12,119) |
| #endif |
| |
| static errcode_t unix_discard(io_channel channel, unsigned long long block, |
| unsigned long long count) |
| { |
| struct unix_private_data *data; |
| int ret; |
| |
| 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->flags & CHANNEL_FLAGS_BLOCK_DEVICE) { |
| #ifdef BLKDISCARD |
| __u64 range[2]; |
| |
| range[0] = (__u64)(block) * channel->block_size + data->offset; |
| range[1] = (__u64)(count) * channel->block_size; |
| |
| ret = ioctl(data->dev, BLKDISCARD, &range); |
| #else |
| goto unimplemented; |
| #endif |
| } else { |
| #if defined(HAVE_FALLOCATE) && defined(FALLOC_FL_PUNCH_HOLE) |
| /* |
| * If we are not on block device, try to use punch hole |
| * to reclaim free space. |
| */ |
| ret = fallocate(data->dev, |
| FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, |
| (off_t)(block) * channel->block_size + data->offset, |
| (off_t)(count) * channel->block_size); |
| #else |
| goto unimplemented; |
| #endif |
| } |
| if (ret < 0) { |
| if (errno == EOPNOTSUPP) |
| goto unimplemented; |
| return errno; |
| } |
| return 0; |
| unimplemented: |
| return EXT2_ET_UNIMPLEMENTED; |
| } |
| |
| /* parameters might not be used if OS doesn't support zeroout */ |
| #pragma GCC diagnostic push |
| #pragma GCC diagnostic ignored "-Wunused-parameter" |
| static errcode_t unix_zeroout(io_channel channel, unsigned long long block, |
| unsigned long long count) |
| { |
| struct unix_private_data *data; |
| int ret; |
| |
| 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 (getenv("UNIX_IO_NOZEROOUT")) |
| goto unimplemented; |
| |
| if (channel->flags & CHANNEL_FLAGS_BLOCK_DEVICE) { |
| /* Not implemented until the BLKZEROOUT mess is fixed */ |
| goto unimplemented; |
| } else { |
| /* Regular file, try to use truncate/punch/zero. */ |
| struct stat statbuf; |
| |
| if (count == 0) |
| return 0; |
| /* |
| * If we're trying to zero a range past the end of the file, |
| * extend the file size, then truncate everything. |
| */ |
| ret = fstat(data->dev, &statbuf); |
| if (ret) |
| goto err; |
| if ((unsigned long long) statbuf.st_size < |
| (block + count) * channel->block_size + data->offset) { |
| ret = ftruncate(data->dev, |
| (block + count) * channel->block_size + data->offset); |
| if (ret) |
| goto err; |
| } |
| #if defined(HAVE_FALLOCATE) && (defined(FALLOC_FL_ZERO_RANGE) || \ |
| (defined(FALLOC_FL_PUNCH_HOLE) && defined(FALLOC_FL_KEEP_SIZE))) |
| #if defined(FALLOC_FL_PUNCH_HOLE) && defined(FALLOC_FL_KEEP_SIZE) |
| ret = fallocate(data->dev, |
| FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, |
| (off_t)(block) * channel->block_size + data->offset, |
| (off_t)(count) * channel->block_size); |
| if (ret == 0) |
| goto err; |
| #endif |
| #ifdef FALLOC_FL_ZERO_RANGE |
| ret = fallocate(data->dev, |
| FALLOC_FL_ZERO_RANGE, |
| (off_t)(block) * channel->block_size + data->offset, |
| (off_t)(count) * channel->block_size); |
| #endif |
| #else |
| goto unimplemented; |
| #endif /* HAVE_FALLOCATE && (ZERO_RANGE || (PUNCH_HOLE && KEEP_SIZE)) */ |
| } |
| err: |
| if (ret < 0) { |
| if (errno == EOPNOTSUPP) |
| goto unimplemented; |
| return errno; |
| } |
| return 0; |
| unimplemented: |
| return EXT2_ET_UNIMPLEMENTED; |
| } |
| #pragma GCC diagnostic pop |
| |
| static struct struct_io_manager struct_unix_manager = { |
| .magic = EXT2_ET_MAGIC_IO_MANAGER, |
| .name = "Unix I/O Manager", |
| .open = unix_open, |
| .close = unix_close, |
| .set_blksize = unix_set_blksize, |
| .read_blk = unix_read_blk, |
| .write_blk = unix_write_blk, |
| .flush = unix_flush, |
| .write_byte = unix_write_byte, |
| .set_option = unix_set_option, |
| .get_stats = unix_get_stats, |
| .read_blk64 = unix_read_blk64, |
| .write_blk64 = unix_write_blk64, |
| .discard = unix_discard, |
| .cache_readahead = unix_cache_readahead, |
| .zeroout = unix_zeroout, |
| }; |
| |
| io_manager unix_io_manager = &struct_unix_manager; |
| |
| static struct struct_io_manager struct_unixfd_manager = { |
| .magic = EXT2_ET_MAGIC_IO_MANAGER, |
| .name = "Unix fd I/O Manager", |
| .open = unixfd_open, |
| .close = unix_close, |
| .set_blksize = unix_set_blksize, |
| .read_blk = unix_read_blk, |
| .write_blk = unix_write_blk, |
| .flush = unix_flush, |
| .write_byte = unix_write_byte, |
| .set_option = unix_set_option, |
| .get_stats = unix_get_stats, |
| .read_blk64 = unix_read_blk64, |
| .write_blk64 = unix_write_blk64, |
| .discard = unix_discard, |
| .cache_readahead = unix_cache_readahead, |
| .zeroout = unix_zeroout, |
| }; |
| |
| io_manager unixfd_io_manager = &struct_unixfd_manager; |