/*
- * unix_io.c --- This is the Unix I/O interface to the I/O manager.
+ * unix_io.c --- This is the Unix (well, really POSIX) implementation
+ * of the I/O manager.
*
* Implements a one-block write-through cache.
*
- * Copyright (C) 1993, 1994, 1995 Theodore Ts'o.
+ * 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 Public
- * License.
+ * This file may be redistributed under the terms of the GNU Library
+ * General Public License, version 2.
* %End-Header%
*/
+#define _LARGEFILE_SOURCE
+#define _LARGEFILE64_SOURCE
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+
+#include "config.h"
#include <stdio.h>
#include <string.h>
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
-#include <stdlib.h>
+#if HAVE_ERRNO_H
+#include <errno.h>
+#endif
#include <fcntl.h>
#include <time.h>
+#ifdef __linux__
+#include <sys/utsname.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_TYPES_H
#include <sys/types.h>
-#if HAVE_ERRNO_H
-#include <errno.h>
+#endif
+#if HAVE_SYS_RESOURCE_H
+#include <sys/resource.h>
+#endif
+#if HAVE_LINUX_FALLOC_H
+#include <linux/falloc.h>
#endif
-#include "et/com_err.h"
-#include "ext2fs/ext2_err.h"
-#include "io.h"
+#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 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;
- char *buf;
- int buf_block_nr;
+ 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) ((((unsigned long) n) & \
+ ((unsigned long) ((align)-1))) == 0)
+
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_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 errcode_t unix_get_stats(io_channel channel, io_stats *stats)
+;
+static void reuse_cache(io_channel channel, struct unix_private_data *data,
+ struct unix_cache *cache, unsigned long long block);
+static errcode_t unix_read_blk64(io_channel channel, unsigned long long block,
+ int count, void *data);
+static errcode_t unix_write_blk64(io_channel channel, unsigned long long block,
+ int count, const void *data);
+static errcode_t unix_discard(io_channel channel, unsigned long long block,
+ unsigned long long count);
static struct struct_io_manager struct_unix_manager = {
EXT2_ET_MAGIC_IO_MANAGER,
unix_set_blksize,
unix_read_blk,
unix_write_blk,
- unix_flush
+ unix_flush,
+ unix_write_byte,
+ unix_set_option,
+ unix_get_stats,
+ unix_read_blk64,
+ unix_write_blk64,
+ unix_discard,
};
io_manager unix_io_manager = &struct_unix_manager;
+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;
+ 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;
+ 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);
+ 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
+
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, zeroes = 0;
+ int f_nocache = 0;
+ ext2fs_struct_stat st;
+#ifdef __linux__
+ struct utsname ut;
+#endif
if (name == 0)
return EXT2_ET_BAD_DEVICE_NAME;
- io = (io_channel) malloc(sizeof(struct struct_io_channel));
- if (!io)
- return ENOMEM;
+ 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;
- data = (struct unix_private_data *)
- malloc(sizeof(struct unix_private_data));
- if (!data) {
- retval = ENOMEM;
+ retval = ext2fs_get_mem(sizeof(struct unix_private_data), &data);
+ if (retval)
goto cleanup;
- }
+
io->manager = unix_io_manager;
- io->name = malloc(strlen(name)+1);
- if (!io->name) {
- retval = ENOMEM;
+ 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;
memset(data, 0, sizeof(struct unix_private_data));
data->magic = EXT2_ET_MAGIC_UNIX_IO_CHANNEL;
- data->buf = malloc(io->block_size);
- data->buf_block_nr = -1;
- if (!data->buf) {
- retval = ENOMEM;
- goto cleanup;
+ data->io_stats.num_fields = 2;
+
+ 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;
+ io->align = ext2fs_get_dio_alignment(data->dev);
}
- data->dev = open(name, (flags & IO_FLAG_RW) ? O_RDWR : O_RDONLY);
+#elif defined(F_NOCACHE)
+ if (flags & IO_FLAG_DIRECT_IO) {
+ f_nocache = F_NOCACHE;
+ io->align = 4096;
+ }
+#endif
+ data->flags = flags;
+
+ data->dev = ext2fs_open_file(io->name, open_flags, 0);
if (data->dev < 0) {
retval = errno;
goto cleanup;
}
+ if (f_nocache) {
+ if (fcntl(data->dev, f_nocache, 1) < 0) {
+ retval = errno;
+ goto cleanup;
+ }
+ }
+
+ /*
+ * 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_stat(io->name, &st) == 0) {
+ if (S_ISBLK(st.st_mode))
+ io->flags |= CHANNEL_FLAGS_BLOCK_DEVICE;
+ else
+ io->flags |= CHANNEL_FLAGS_DISCARD_ZEROES;
+ }
+
+#ifdef BLKDISCARDZEROES
+ ioctl(data->dev, BLKDISCARDZEROES, &zeroes);
+ if (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) {
+ close(data->dev);
+ 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_stat(io->name, &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 (io)
- free(io);
if (data) {
- if (data->buf)
- free(data->buf);
- free(data);
+ free_cache(data);
+ ext2fs_free_mem(&data);
}
+ if (io)
+ ext2fs_free_mem(&io);
return retval;
}
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;
- if (data->buf)
- free(data->buf);
- if (channel->private_data)
- free(channel->private_data);
+ free_cache(data);
+
+ ext2fs_free_mem(&channel->private_data);
if (channel->name)
- free(channel->name);
- free(channel);
+ 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(data->buf);
- data->buf = malloc(blksize);
- if (!data->buf)
- return ENOMEM;
- data->buf_block_nr = -1;
+ 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,
+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;
- size_t size;
- ext2_loff_t location;
- int actual = 0;
+ 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 it's in the cache, use it!
+ * 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 == 1) && (block == data->buf_block_nr)) {
- memcpy(buf, data->buf, channel->block_size);
- return 0;
+ 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);
}
-#if 0
- printf("read_block %lu (%d)\n", block, count);
+
+ 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
- size = (count < 0) ? -count : count * channel->block_size;
- location = (ext2_loff_t) block * channel->block_size;
- if (ext2fs_llseek(data->dev, location, SEEK_SET) != location) {
- retval = errno ? errno : EXT2_IO_LLSEEK_FAILED;
- goto error_out;
+ 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;
+ }
}
- actual = read(data->dev, buf, size);
- if (actual != size) {
- if (actual < 0)
- actual = 0;
- retval = EXT2_ET_SHORT_READ;
- goto error_out;
+ 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);
}
- if (count == 1) {
- data->buf_block_nr = block;
- memcpy(data->buf, buf, size); /* Update the cache */
+
+ /*
+ * 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);
+ }
+ memcpy(cache->buf, cp, channel->block_size);
+ cache->dirty = !writethrough;
+ count--;
+ block++;
+ cp += channel->block_size;
}
- 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;
+#endif /* NO_IO_CACHE */
}
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;
- size_t size;
- ext2_loff_t location;
- int actual = 0;
- errcode_t retval;
+ 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 (count == 1)
- size = channel->block_size;
- else {
- data->buf_block_nr = -1; /* Invalidate the cache */
- if (count < 0)
- size = -count;
- else
- size = count * channel->block_size;
- }
-
- location = (ext2_loff_t) block * channel->block_size;
- if (ext2fs_llseek(data->dev, location, SEEK_SET) != location) {
- retval = errno ? errno : EXT2_IO_LLSEEK_FAILED;
- goto error_out;
+ 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) {
- retval = EXT2_ET_SHORT_WRITE;
- goto error_out;
- }
+ if (actual != size)
+ return EXT2_ET_SHORT_WRITE;
- if ((count == 1) && (block == data->buf_block_nr))
- memcpy(data->buf, buf, size); /* Update the cache */
-
return 0;
-
-error_out:
- if (channel->write_error)
- retval = (channel->write_error)(channel, block, count, buf,
- size, actual, retval);
- return retval;
}
/*
- * Flush data buffers to disk.
+ * 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 0;
+ 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;
+ __uint64_t range[2];
+ 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
+ range[0] = (__uint64_t)(block) * channel->block_size;
+ range[1] = (__uint64_t)(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,
+ (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;
+}
git://git.whamcloud.com / tools / e2fsprogs.git / blobdiff