David van Moolenbroek 5eefd0fec2 libvtreefs: API changes/extensions, part 1
- move primary I/O buffer into vtreefs; change read hook API;
- add hooks for write, truncate, symlink, mknod, unlink, chmod/chown;
- modernize message_hook;
- change procfs, devman, gpio accordingly;

Change-Id: I9f0669e41195efa3253032e95d93f0a78e9d68d6
2014-11-12 12:13:38 +00:00

130 lines
2.5 KiB
C

/* VTreeFS - link.c - support for symbolic links and device nodes */
#include "inc.h"
/*
* Retrieve a symbolic link target.
*/
ssize_t
fs_rdlink(ino_t ino_nr, struct fsdriver_data * data, size_t bytes)
{
char path[PATH_MAX];
struct inode *node;
size_t len;
int r;
if ((node = find_inode(ino_nr)) == NULL)
return EINVAL;
/* The hook should be provided for any FS that adds symlink inodes.. */
if (vtreefs_hooks->rdlink_hook == NULL)
return ENOSYS;
assert(!is_inode_deleted(node)); /* symlinks cannot be opened */
r = vtreefs_hooks->rdlink_hook(node, path, sizeof(path),
get_inode_cbdata(node));
if (r != OK) return r;
len = strlen(path);
assert(len > 0 && len < sizeof(path));
if (len > bytes)
len = bytes;
/* Copy out the result. */
if ((r = fsdriver_copyout(data, 0, path, len)) != OK)
return r;
return len;
}
/*
* Create a symbolic link.
*/
int
fs_slink(ino_t dir_nr, char * name, uid_t uid, gid_t gid,
struct fsdriver_data * data, size_t bytes)
{
char path[PATH_MAX];
struct inode *node;
struct inode_stat stat;
int r;
if ((node = find_inode(dir_nr)) == NULL)
return EINVAL;
if (vtreefs_hooks->slink_hook == NULL)
return ENOSYS;
if (get_inode_by_name(node, name) != NULL)
return EEXIST;
if (bytes >= sizeof(path))
return ENAMETOOLONG;
if ((r = fsdriver_copyin(data, 0, path, bytes)) != OK)
return r;
path[bytes] = 0;
memset(&stat, 0, sizeof(stat));
stat.mode = S_IFLNK | RWX_MODES;
stat.uid = uid;
stat.gid = gid;
stat.size = strlen(path);
stat.dev = 0;
return vtreefs_hooks->slink_hook(node, name, &stat, path,
get_inode_cbdata(node));
}
/*
* Create a device node.
*/
int
fs_mknod(ino_t dir_nr, char * name, mode_t mode, uid_t uid, gid_t gid,
dev_t rdev)
{
struct inode *node;
struct inode_stat stat;
if ((node = find_inode(dir_nr)) == NULL)
return EINVAL;
if (get_inode_by_name(node, name) != NULL)
return EEXIST;
if (vtreefs_hooks->mknod_hook == NULL)
return ENOSYS;
memset(&stat, 0, sizeof(stat));
stat.mode = mode;
stat.uid = uid;
stat.gid = gid;
stat.size = 0;
stat.dev = rdev;
return vtreefs_hooks->mknod_hook(node, name, &stat,
get_inode_cbdata(node));
}
/*
* Unlink a node.
*/
int
fs_unlink(ino_t dir_nr, char * name, int __unused call)
{
struct inode *dir_node, *node;
if ((dir_node = find_inode(dir_nr)) == NULL)
return EINVAL;
if ((node = get_inode_by_name(dir_node, name)) == NULL)
return ENOENT;
if (vtreefs_hooks->unlink_hook == NULL)
return ENOSYS;
return vtreefs_hooks->unlink_hook(node, get_inode_cbdata(node));
}