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1252 lines
30 KiB
1252 lines
30 KiB
/*
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* unix_io.c --- This is the Unix (well, really POSIX) implementation
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* of the I/O manager.
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*
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* Implements a one-block write-through cache.
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*
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* Includes support for Windows NT support under Cygwin.
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*
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* Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001,
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* 2002 by Theodore Ts'o.
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*
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* %Begin-Header%
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* This file may be redistributed under the terms of the GNU Library
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* General Public License, version 2.
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* %End-Header%
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*/
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#if !defined(__FreeBSD__) && !defined(__NetBSD__) && !defined(__OpenBSD__)
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#define _XOPEN_SOURCE 600
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#define _DARWIN_C_SOURCE
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#define _FILE_OFFSET_BITS 64
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#ifndef _LARGEFILE_SOURCE
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#define _LARGEFILE_SOURCE
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#endif
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#ifndef _LARGEFILE64_SOURCE
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#define _LARGEFILE64_SOURCE
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#endif
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#ifndef _GNU_SOURCE
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#define _GNU_SOURCE
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#endif
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#endif
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#include "config.h"
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#include <stdio.h>
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#include <string.h>
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#if HAVE_UNISTD_H
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#include <unistd.h>
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#endif
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#if HAVE_ERRNO_H
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#include <errno.h>
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#endif
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#include <fcntl.h>
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#include <time.h>
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#ifdef __linux__
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#include <sys/utsname.h>
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#endif
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#if HAVE_SYS_TYPES_H
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#include <sys/types.h>
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#endif
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#ifdef HAVE_SYS_IOCTL_H
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#include <sys/ioctl.h>
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#endif
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#ifdef HAVE_SYS_MOUNT_H
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#include <sys/mount.h>
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#endif
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#ifdef HAVE_SYS_PRCTL_H
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#include <sys/prctl.h>
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#else
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#define PR_GET_DUMPABLE 3
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#endif
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#if HAVE_SYS_STAT_H
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#include <sys/stat.h>
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#endif
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#if HAVE_SYS_RESOURCE_H
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#include <sys/resource.h>
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#endif
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#if HAVE_LINUX_FALLOC_H
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#include <linux/falloc.h>
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#endif
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#if defined(__linux__) && defined(_IO) && !defined(BLKROGET)
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#define BLKROGET _IO(0x12, 94) /* Get read-only status (0 = read_write). */
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#endif
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|
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#undef ALIGN_DEBUG
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#include "ext2_fs.h"
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#include "ext2fs.h"
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#include "ext2fsP.h"
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/*
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* For checking structure magic numbers...
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*/
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#define EXT2_CHECK_MAGIC(struct, code) \
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if ((struct)->magic != (code)) return (code)
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struct unix_cache {
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char *buf;
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unsigned long long block;
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int access_time;
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unsigned dirty:1;
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unsigned in_use:1;
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};
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#define CACHE_SIZE 8
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#define WRITE_DIRECT_SIZE 4 /* Must be smaller than CACHE_SIZE */
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#define READ_DIRECT_SIZE 4 /* Should be smaller than CACHE_SIZE */
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struct unix_private_data {
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int magic;
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int dev;
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int flags;
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int align;
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int access_time;
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ext2_loff_t offset;
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struct unix_cache cache[CACHE_SIZE];
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void *bounce;
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struct struct_io_stats io_stats;
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};
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#define IS_ALIGNED(n, align) ((((uintptr_t) n) & \
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((uintptr_t) ((align)-1))) == 0)
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|
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static errcode_t unix_get_stats(io_channel channel, io_stats *stats)
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|
{
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|
errcode_t retval = 0;
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|
|
struct unix_private_data *data;
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EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
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data = (struct unix_private_data *) channel->private_data;
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EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_UNIX_IO_CHANNEL);
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|
|
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if (stats)
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*stats = &data->io_stats;
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return retval;
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|
}
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static char *safe_getenv(const char *arg)
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|
{
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if ((getuid() != geteuid()) || (getgid() != getegid()))
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return NULL;
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#ifdef HAVE_PRCTL
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if (prctl(PR_GET_DUMPABLE, 0, 0, 0, 0) == 0)
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return NULL;
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|
#else
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|
#if (defined(linux) && defined(SYS_prctl))
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|
if (syscall(SYS_prctl, PR_GET_DUMPABLE, 0, 0, 0, 0) == 0)
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return NULL;
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#endif
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|
#endif
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|
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|
#if defined(HAVE_SECURE_GETENV)
|
|
return secure_getenv(arg);
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|
#elif defined(HAVE___SECURE_GETENV)
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|
return __secure_getenv(arg);
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|
#else
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|
return getenv(arg);
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|
#endif
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|
}
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|
/*
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|
* Here are the raw I/O functions
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|
*/
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static errcode_t raw_read_blk(io_channel channel,
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struct unix_private_data *data,
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unsigned long long block,
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|
int count, void *bufv)
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|
{
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|
errcode_t retval;
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ssize_t size;
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|
ext2_loff_t location;
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int actual = 0;
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unsigned char *buf = bufv;
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|
ssize_t really_read = 0;
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|
size = (count < 0) ? -count : count * channel->block_size;
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data->io_stats.bytes_read += size;
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location = ((ext2_loff_t) block * channel->block_size) + data->offset;
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|
if (data->flags & IO_FLAG_FORCE_BOUNCE) {
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if (ext2fs_llseek(data->dev, location, SEEK_SET) != location) {
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retval = errno ? errno : EXT2_ET_LLSEEK_FAILED;
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goto error_out;
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}
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goto bounce_read;
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}
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|
#ifdef HAVE_PREAD64
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|
/* Try an aligned pread */
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if ((channel->align == 0) ||
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(IS_ALIGNED(buf, channel->align) &&
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IS_ALIGNED(size, channel->align))) {
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actual = pread64(data->dev, buf, size, location);
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if (actual == size)
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return 0;
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actual = 0;
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}
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#elif HAVE_PREAD
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/* Try an aligned pread */
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if ((sizeof(off_t) >= sizeof(ext2_loff_t)) &&
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((channel->align == 0) ||
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(IS_ALIGNED(buf, channel->align) &&
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IS_ALIGNED(size, channel->align)))) {
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actual = pread(data->dev, buf, size, location);
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if (actual == size)
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return 0;
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actual = 0;
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}
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#endif /* HAVE_PREAD */
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if (ext2fs_llseek(data->dev, location, SEEK_SET) != location) {
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retval = errno ? errno : EXT2_ET_LLSEEK_FAILED;
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goto error_out;
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}
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if ((channel->align == 0) ||
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(IS_ALIGNED(buf, channel->align) &&
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IS_ALIGNED(size, channel->align))) {
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actual = read(data->dev, buf, size);
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if (actual != size) {
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short_read:
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if (actual < 0) {
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retval = errno;
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actual = 0;
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|
} else
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retval = EXT2_ET_SHORT_READ;
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|
goto error_out;
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}
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return 0;
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}
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|
#ifdef ALIGN_DEBUG
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printf("raw_read_blk: O_DIRECT fallback: %p %lu\n", buf,
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(unsigned long) size);
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#endif
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|
/*
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|
* The buffer or size which we're trying to read isn't aligned
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|
* to the O_DIRECT rules, so we need to do this the hard way...
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|
*/
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|
bounce_read:
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|
while (size > 0) {
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|
actual = read(data->dev, data->bounce, channel->block_size);
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|
if (actual != channel->block_size) {
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actual = really_read;
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buf -= really_read;
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size += really_read;
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goto short_read;
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}
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actual = size;
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if (size > channel->block_size)
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actual = channel->block_size;
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memcpy(buf, data->bounce, actual);
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really_read += actual;
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size -= actual;
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buf += actual;
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}
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return 0;
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|
error_out:
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if (actual >= 0 && actual < size)
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memset((char *) buf+actual, 0, size-actual);
|
|
if (channel->read_error)
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|
retval = (channel->read_error)(channel, block, count, buf,
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size, actual, retval);
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return retval;
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}
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|
static errcode_t raw_write_blk(io_channel channel,
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|
struct unix_private_data *data,
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unsigned long long block,
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|
int count, const void *bufv)
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|
{
|
|
ssize_t size;
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|
ext2_loff_t location;
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|
int actual = 0;
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|
errcode_t retval;
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|
const unsigned char *buf = bufv;
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|
|
|
if (count == 1)
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size = channel->block_size;
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|
else {
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|
if (count < 0)
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size = -count;
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else
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size = count * channel->block_size;
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|
}
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data->io_stats.bytes_written += size;
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location = ((ext2_loff_t) block * channel->block_size) + data->offset;
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|
|
if (data->flags & IO_FLAG_FORCE_BOUNCE) {
|
|
if (ext2fs_llseek(data->dev, location, SEEK_SET) != location) {
|
|
retval = errno ? errno : EXT2_ET_LLSEEK_FAILED;
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|
goto error_out;
|
|
}
|
|
goto bounce_write;
|
|
}
|
|
|
|
#ifdef HAVE_PWRITE64
|
|
/* Try an aligned pwrite */
|
|
if ((channel->align == 0) ||
|
|
(IS_ALIGNED(buf, channel->align) &&
|
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IS_ALIGNED(size, channel->align))) {
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actual = pwrite64(data->dev, buf, size, location);
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if (actual == size)
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return 0;
|
|
}
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|
#elif HAVE_PWRITE
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|
/* Try an aligned pwrite */
|
|
if ((sizeof(off_t) >= sizeof(ext2_loff_t)) &&
|
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((channel->align == 0) ||
|
|
(IS_ALIGNED(buf, channel->align) &&
|
|
IS_ALIGNED(size, channel->align)))) {
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|
actual = pwrite(data->dev, buf, size, location);
|
|
if (actual == size)
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|
return 0;
|
|
}
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|
#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 < 0) {
|
|
retval = errno;
|
|
goto error_out;
|
|
}
|
|
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...
|
|
*/
|
|
bounce_write:
|
|
while (size > 0) {
|
|
if (size < channel->block_size) {
|
|
actual = read(data->dev, data->bounce,
|
|
channel->block_size);
|
|
if (actual != channel->block_size) {
|
|
if (actual < 0) {
|
|
retval = errno;
|
|
goto error_out;
|
|
}
|
|
memset((char *) data->bounce + actual, 0,
|
|
channel->block_size - actual);
|
|
}
|
|
}
|
|
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 < 0) {
|
|
retval = errno;
|
|
goto error_out;
|
|
}
|
|
if (actual != channel->block_size)
|
|
goto short_write;
|
|
size -= actual;
|
|
buf += actual;
|
|
location += 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 || data->flags & IO_FLAG_FORCE_BOUNCE) {
|
|
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
|
|
|
|
if (safe_getenv("UNIX_IO_FORCE_BOUNCE"))
|
|
flags |= IO_FLAG_FORCE_BOUNCE;
|
|
|
|
#ifdef __linux__
|
|
/*
|
|
* We need to make sure any previous errors in the block
|
|
* device are thrown away, sigh.
|
|
*/
|
|
(void) fsync(fd);
|
|
#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 (ext2fsP_is_disk_device(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__)
|
|
/*
|
|
* Some operating systems require that the buffers be aligned,
|
|
* regardless of O_DIRECT
|
|
*/
|
|
if (!io->align)
|
|
io->align = 512;
|
|
#endif
|
|
|
|
#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
|
|
if (io->flags & CHANNEL_FLAGS_BLOCK_DEVICE) {
|
|
int dio_align = ext2fs_get_dio_alignment(fd);
|
|
|
|
if (io->align < dio_align)
|
|
io->align = dio_align;
|
|
}
|
|
#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) &&
|
|
(ext2fsP_is_disk_device(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);
|
|
#if defined(HAVE_FCNTL)
|
|
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
|
|
#endif /* HAVE_FCNTL */
|
|
|
|
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 < 0)
|
|
return errno;
|
|
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
|
|
#ifdef HAVE_FSYNC
|
|
if (!retval && fsync(data->dev) != 0)
|
|
return errno;
|
|
#endif
|
|
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;
|
|
}
|
|
|
|
/*
|
|
* If we know about ZERO_RANGE, try that before we try PUNCH_HOLE because
|
|
* ZERO_RANGE doesn't unmap preallocated blocks. We prefer fallocate because
|
|
* it always invalidates page cache, and libext2fs requires that reads after
|
|
* ZERO_RANGE return zeroes.
|
|
*/
|
|
static int __unix_zeroout(int fd, off_t offset, off_t len)
|
|
{
|
|
int ret = -1;
|
|
|
|
#if defined(HAVE_FALLOCATE) && defined(FALLOC_FL_ZERO_RANGE)
|
|
ret = fallocate(fd, FALLOC_FL_ZERO_RANGE, offset, len);
|
|
if (ret == 0)
|
|
return 0;
|
|
#endif
|
|
#if defined(HAVE_FALLOCATE) && defined(FALLOC_FL_PUNCH_HOLE) && defined(FALLOC_FL_KEEP_SIZE)
|
|
ret = fallocate(fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
|
|
offset, len);
|
|
if (ret == 0)
|
|
return 0;
|
|
#endif
|
|
errno = EOPNOTSUPP;
|
|
return ret;
|
|
}
|
|
|
|
/* parameters might not be used if OS doesn't support zeroout */
|
|
#if __GNUC_PREREQ (4, 6)
|
|
#pragma GCC diagnostic push
|
|
#pragma GCC diagnostic ignored "-Wunused-parameter"
|
|
#endif
|
|
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 (safe_getenv("UNIX_IO_NOZEROOUT"))
|
|
goto unimplemented;
|
|
|
|
if (!(channel->flags & CHANNEL_FLAGS_BLOCK_DEVICE)) {
|
|
/* 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;
|
|
}
|
|
}
|
|
|
|
ret = __unix_zeroout(data->dev,
|
|
(off_t)(block) * channel->block_size + data->offset,
|
|
(off_t)(count) * channel->block_size);
|
|
err:
|
|
if (ret < 0) {
|
|
if (errno == EOPNOTSUPP)
|
|
goto unimplemented;
|
|
return errno;
|
|
}
|
|
return 0;
|
|
unimplemented:
|
|
return EXT2_ET_UNIMPLEMENTED;
|
|
}
|
|
#if __GNUC_PREREQ (4, 6)
|
|
#pragma GCC diagnostic pop
|
|
#endif
|
|
|
|
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;
|