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