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