RepoMirrors
/
btrfs-progs
mirror of https://github.com/kdave/btrfs-progs
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

btrfs-progs: add more helpers to read values from sysfs 

In some places we want to read a single u64 value from a sysfs path, or
from fsid directory. Add helpers that do that in one go.

Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
David Sterba 2023-08-21 21:26:31 +02:00
parent 4a96a935ad
commit 5aa2ea7db0
2 changed files with 41 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

38
common/sysfs-utils.c
View File

@ -94,3 +94,41 @@ int sysfs_read_file(int fd, char *buf, size_t size)
return read(fd, buf, size);
}
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. */
*value = strtoull(str, NULL, 0);
out:
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. */
*value = strtoull(str, NULL, 0);
out:
close(fd);
return ret;
}

4
common/sysfs-utils.h
View File

@ -19,7 +19,9 @@
int sysfs_open_file(const char *name);
int sysfs_open_fsid_file(int fd, const char *filename);
int sysfs_read_file(int fd, char *buf, size_t size);
int sysfs_open_fsid_dir(int fd, const char *dirname);
int sysfs_read_fsid_file_u64(int fd, const char *name, u64 *value);
int sysfs_read_file(int fd, char *buf, size_t size);
int sysfs_read_file_u64(const char *name, u64 *value);
#endif