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/*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#include "kerncompat.h"
#include <unistd.h>
#include <fcntl.h>
#include <uuid/uuid.h>
#include "common/sysfs-utils.h"
#include "common/path-utils.h"
#include "common/utils.h"
/*
* Open a file in fsid directory in sysfs and return the file descriptor or
* error
*/
static int sysfs_open_fsid_file_flags(int fd, const char *filename, int flags)
{
u8 fsid[BTRFS_UUID_SIZE];
char fsid_str[BTRFS_UUID_UNPARSED_SIZE];
char sysfs_file[PATH_MAX];
int ret;
ret = get_fsid_fd(fd, fsid);
if (ret < 0)
return ret;
uuid_unparse(fsid, fsid_str);
ret = path_cat3_out(sysfs_file, "/sys/fs/btrfs", fsid_str, filename);
if (ret < 0)
return ret;
ret = open(sysfs_file, flags);
return (ret < 0 ? -errno : ret);
}
int sysfs_open_fsid_file(int fd, const char *filename)
{
return sysfs_open_fsid_file_flags(fd, filename, O_RDONLY);
}
int sysfs_open_fsid_file_rw(int fd, const char *filename)
{
return sysfs_open_fsid_file_flags(fd, filename, O_RDWR);
}
/*
* Open a file in the toplevel sysfs directory and return the file descriptor
* or error.
*/
static int sysfs_open_file_flags(const char *name, int flags)
{
char path[PATH_MAX];
int ret;
ret = path_cat_out(path, "/sys/fs/btrfs", name);
if (ret < 0)
return ret;
ret = open(path, flags);
return (ret < 0 ? -errno : ret);
}
int sysfs_open_file(const char *name)
{
return sysfs_open_file_flags(name, O_RDONLY);
}
int sysfs_open_file_rw(const char *name)
{
return sysfs_open_file_flags(name, O_RDWR);
}
/*
* Open a directory by name in fsid directory in sysfs and return the file
* descriptor or error, filedescriptor suitable for fdreaddir. The @dirname
* must be a directory name.
*/
int sysfs_open_fsid_dir(int fd, const char *dirname)
{
u8 fsid[BTRFS_UUID_SIZE];
char fsid_str[BTRFS_UUID_UNPARSED_SIZE];
char sysfs_file[PATH_MAX];
int ret;
ret = get_fsid_fd(fd, fsid);
if (ret < 0)
return ret;
uuid_unparse(fsid, fsid_str);
ret = path_cat3_out(sysfs_file, "/sys/fs/btrfs", fsid_str, dirname);
if (ret < 0)
return ret;
ret = open(sysfs_file, O_DIRECTORY | O_RDONLY);
return (ret < 0 ? -errno : ret);
}
/*
* Read up to @size bytes to @buf from @fd
*/
int sysfs_read_file(int fd, char *buf, size_t size)
{
int ret;
lseek(fd, 0, SEEK_SET);
memset(buf, 0, size);
ret = read(fd, buf, size);
return (ret < 0 ? -errno : ret);
}
int sysfs_write_file(int fd, const char *buf, size_t size)
{
int ret;
lseek(fd, 0, SEEK_SET);
ret = write(fd, buf, size);
return (ret < 0 ? -errno : ret);
}
int sysfs_read_file_u64(const char *name, u64 *value)
{
int fd = -1;
int ret;
char str[32] = { 0 };
fd = sysfs_open_file(name);
if (fd < 0)
return fd;
ret = sysfs_read_file(fd, str, sizeof(str));
if (ret < 0)
goto out;
/* Raw value in any numeric format should work, followed by a newline. */
errno = 0;
*value = strtoull(str, NULL, 0);
ret = -errno;
out:
close(fd);
return ret;
}
int sysfs_write_file_u64(const char *name, u64 value)
{
int fd;
int ret;
char str[32] = { 0 };
fd = sysfs_open_file_rw(name);
if (fd < 0)
return fd;
ret = snprintf(str, sizeof(str), "%llu", value);
ret = sysfs_write_file(fd, str, ret);
close(fd);
return ret;
}
int sysfs_read_fsid_file_u64(int fd, const char *name, u64 *value)
{
int ret;
char str[32] = { 0 };
fd = sysfs_open_fsid_file(fd, name);
if (fd < 0)
return fd;
ret = sysfs_read_file(fd, str, sizeof(str));
if (ret < 0)
goto out;
/* Raw value in any numeric format should work, followed by a newline. */
errno = 0;
*value = strtoull(str, NULL, 0);
ret = -errno;
out:
close(fd);
return ret;
}
int sysfs_write_fsid_file_u64(int fd, const char *name, u64 value)
{
int ret;
char str[32] = { 0 };
fd = sysfs_open_fsid_file_rw(fd, name);
if (fd < 0)
return fd;
ret = snprintf(str, sizeof(str), "%llu", value);
ret = sysfs_write_file(fd, str, ret);
close(fd);
return ret;
}
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