/*
* unix_io.c --- This is the Unix (well, really POSIX) implementation
- * of the I/O manager.
+ * 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.
+ * 2002 by Theodore Ts'o.
*
* %Begin-Header%
* This file may be redistributed under the terms of the GNU Library
* %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>
#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
+#ifdef HAVE_SYS_PRCTL_H
+#include <sys/prctl.h>
+#else
+#define PR_GET_DUMPABLE 3
+#endif
#if HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
-#if HAVE_SYS_TYPES_H
-#include <sys/types.h>
-#endif
#if HAVE_SYS_RESOURCE_H
#include <sys/resource.h>
#endif
#include "ext2_fs.h"
#include "ext2fs.h"
+#include "ext2fsP.h"
/*
* For checking structure magic numbers...
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_read_blk(io_channel channel, unsigned long block,
- int count, void *data);
-static errcode_t unix_write_blk(io_channel channel, unsigned long block,
- int count, const void *data);
-static errcode_t unix_flush(io_channel channel);
-static errcode_t unix_write_byte(io_channel channel, unsigned long offset,
- int size, const void *data);
-static errcode_t unix_set_option(io_channel channel, const char *option,
- const char *arg);
-static 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 I/O Manager",
- unix_open,
- unix_close,
- unix_set_blksize,
- unix_read_blk,
- unix_write_blk,
- 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;
+#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;
+ errcode_t retval = 0;
struct unix_private_data *data;
return retval;
}
+static char *safe_getenv(const char *arg)
+{
+ if ((getuid() != geteuid()) || (getgid() != getegid()))
+ return NULL;
+#ifdef HAVE_PRCTL
+ if (prctl(PR_GET_DUMPABLE, 0, 0, 0, 0) == 0)
+ return NULL;
+#else
+#if (defined(linux) && defined(SYS_prctl))
+ if (syscall(SYS_prctl, PR_GET_DUMPABLE, 0, 0, 0, 0) == 0)
+ return NULL;
+#endif
+#endif
+
+#if defined(HAVE_SECURE_GETENV)
+ return secure_getenv(arg);
+#elif defined(HAVE___SECURE_GETENV)
+ return __secure_getenv(arg);
+#else
+ return getenv(arg);
+#endif
+}
+
/*
* Here are the raw I/O functions
*/
ext2_loff_t location;
int actual = 0;
unsigned char *buf = bufv;
+ ssize_t really_read = 0;
- size = (count < 0) ? -count : count * channel->block_size;
+ size = (count < 0) ? -count : (ext2_loff_t) count * channel->block_size;
data->io_stats.bytes_read += size;
location = ((ext2_loff_t) block * channel->block_size) + data->offset;
+
+ if (data->flags & IO_FLAG_FORCE_BOUNCE) {
+ if (ext2fs_llseek(data->dev, location, SEEK_SET) != location) {
+ retval = errno ? errno : EXT2_ET_LLSEEK_FAILED;
+ goto error_out;
+ }
+ goto bounce_read;
+ }
+
+#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;
+ actual = 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;
+ actual = 0;
+ }
+#endif /* HAVE_PREAD */
+
if (ext2fs_llseek(data->dev, location, SEEK_SET) != location) {
retval = errno ? errno : EXT2_ET_LLSEEK_FAILED;
goto error_out;
actual = read(data->dev, buf, size);
if (actual != size) {
short_read:
- if (actual < 0)
+ if (actual < 0) {
+ retval = errno;
actual = 0;
- retval = EXT2_ET_SHORT_READ;
+ } else
+ retval = EXT2_ET_SHORT_READ;
goto error_out;
}
return 0;
* 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...
*/
+bounce_read:
while (size > 0) {
actual = read(data->dev, data->bounce, channel->block_size);
- if (actual != channel->block_size)
+ if (actual != channel->block_size) {
+ actual = really_read;
+ buf -= really_read;
+ size += really_read;
goto short_read;
+ }
actual = size;
if (size > channel->block_size)
actual = channel->block_size;
memcpy(buf, data->bounce, actual);
+ really_read += actual;
size -= actual;
buf += actual;
}
return 0;
error_out:
- memset((char *) buf+actual, 0, size-actual);
+ if (actual >= 0 && actual < size)
+ memset((char *) buf+actual, 0, size-actual);
if (channel->read_error)
retval = (channel->read_error)(channel, block, count, buf,
size, actual, retval);
if (count < 0)
size = -count;
else
- size = count * channel->block_size;
+ size = (ext2_loff_t) count * channel->block_size;
}
data->io_stats.bytes_written += size;
location = ((ext2_loff_t) block * channel->block_size) + data->offset;
+
+ if (data->flags & IO_FLAG_FORCE_BOUNCE) {
+ if (ext2fs_llseek(data->dev, location, SEEK_SET) != location) {
+ retval = errno ? errno : EXT2_ET_LLSEEK_FAILED;
+ goto error_out;
+ }
+ goto bounce_write;
+ }
+
+#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;
(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;
* 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) {
- retval = EXT2_ET_SHORT_READ;
- goto error_out;
+ 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;
if (retval)
return retval;
}
- if (channel->align) {
+ 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);
#endif
}
-static errcode_t unix_open(const char *name, int flags, io_channel *channel)
+
+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;
- int open_flags;
- int f_nocache = 0;
ext2fs_struct_stat st;
#ifdef __linux__
- struct utsname ut;
+ 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
- if (name == 0)
- return EXT2_ET_BAD_DEVICE_NAME;
retval = ext2fs_get_mem(sizeof(struct struct_io_channel), &io);
if (retval)
goto cleanup;
if (retval)
goto cleanup;
- io->manager = unix_io_manager;
+ io->manager = io_mgr;
retval = ext2fs_get_mem(strlen(name)+1, &io->name);
if (retval)
goto cleanup;
memset(data, 0, sizeof(struct unix_private_data));
data->magic = EXT2_ET_MAGIC_UNIX_IO_CHANNEL;
data->io_stats.num_fields = 2;
- data->dev = -1;
+ data->flags = flags;
+ data->dev = fd;
- 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;
+ if (flags & IO_FLAG_DIRECT_IO)
io->align = ext2fs_get_dio_alignment(data->dev);
- }
#elif defined(F_NOCACHE)
- if (flags & IO_FLAG_DIRECT_IO) {
- f_nocache = F_NOCACHE;
+ if (flags & IO_FLAG_DIRECT_IO)
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
* and if it succeed, subsequent read from sparse area returns
* zero.
*/
- if (ext2fs_stat(io->name, &st) == 0) {
- if (S_ISBLK(st.st_mode))
+ 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;
}
#endif
-#if defined(__CYGWIN__) || defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
+#if defined(__CYGWIN__)
/*
* Some operating systems require that the buffers be aligned,
* regardless of O_DIRECT
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;
(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))) {
+ (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;
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;
return 0;
}
-
static errcode_t unix_read_blk64(io_channel channel, unsigned long long block,
int count, void *buf)
{
cache = reuse;
reuse_cache(channel, data, cache, block);
}
- memcpy(cache->buf, cp, channel->block_size);
+ if (cache->buf != cp)
+ memcpy(cache->buf, cp, channel->block_size);
cache->dirty = !writethrough;
count--;
block++;
#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 errno;
actual = write(data->dev, buf, size);
+ if (actual < 0)
+ return errno;
if (actual != size)
return EXT2_ET_SHORT_WRITE;
#ifndef NO_IO_CACHE
retval = flush_cached_blocks(channel, data, 0);
#endif
- fsync(data->dev);
+#ifdef HAVE_FSYNC
+ if (!retval && fsync(data->dev) != 0)
+ return errno;
+#endif
return retval;
}
#ifdef BLKDISCARD
__u64 range[2];
- range[0] = (__u64)(block) * channel->block_size;
+ range[0] = (__u64)(block) * channel->block_size + data->offset;
range[1] = (__u64)(count) * channel->block_size;
ret = ioctl(data->dev, BLKDISCARD, &range);
*/
ret = fallocate(data->dev,
FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
- (off_t)(block) * channel->block_size,
+ (off_t)(block) * channel->block_size + data->offset,
(off_t)(count) * channel->block_size);
#else
goto unimplemented;
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;
git://git.whamcloud.com / tools / e2fsprogs.git / blobdiff