mirror of
https://github.com/containers/fuse-overlayfs.git
synced 2025-08-03 18:05:58 -04:00
containerfs: use an xattr to store redirects of a file
So we can correctly report the same issue for hard links. Closes: https://github.com/giuseppe/containerfs/issues/1 Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>
This commit is contained in:
Giuseppe Scrivano
parent
d63934d540
commit
b89b8ebf5d
@ -3,11 +3,9 @@ containerfs
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An implementation of overlay+shiftfs in FUSE for rootless containers.
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Known issues:
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Limitations:
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=======================================================
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Hard links in some cases show different inode values.
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Read-only mode is not supported, so it is always required to specify
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an upperdir and a workingdir.
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96
main.c
96
main.c
@ -58,6 +58,8 @@
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#define ATTR_TIMEOUT 1000000000.0
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#define ENTRY_TIMEOUT 1000000000.0
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#define REDIRECT_XATTR "user.containerfs.redirect"
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#define NODE_TO_INODE(x) ((fuse_ino_t) x)
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#if defined(__GNUC__) && (__GNUC__ > 4 || __GNUC__ == 4 && __GNUC_MINOR__ >= 6) && !defined __cplusplus
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@ -552,11 +554,25 @@ make_lo_node (const char *path, struct lo_layer *layer, const char *name, ino_t
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{
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struct stat st;
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struct lo_layer *it;
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char path[PATH_MAX];
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strcpy (path, ret->path);
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for (it = layer; it; it = it->next)
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{
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if (fstatat (it->fd, ret->path, &st, AT_SYMLINK_NOFOLLOW) == 0)
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ssize_t s;
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int fd = openat (it->fd, path, O_RDONLY);
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if (fd < 0)
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continue;
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if (fstat (fd, &st) == 0)
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ret->ino = st.st_ino;
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/* If a redirect is specified, use it for the next layer lookup. */
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s = fgetxattr (fd, REDIRECT_XATTR, path, sizeof (path) - 1);
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if (s > 0)
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path[s] = '\0';
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close (fd);
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}
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}
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@ -660,14 +676,7 @@ load_dir (struct lo_data *lo, struct lo_node *n, struct lo_layer *layer, char *p
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child = hash_lookup (n->children, &key);
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if (child)
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{
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/* Update the ino with the lowest one found. Ignore if the file
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was deleted by intermediate layers, we only need to keep the same
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inode after a copyup. */
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child->ino = st.st_ino;
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child->present_lowerdir = 1;
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continue;
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}
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continue;
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wh = get_whiteout_name (dent->d_name, &st);
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if (wh)
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@ -685,7 +694,7 @@ load_dir (struct lo_data *lo, struct lo_node *n, struct lo_layer *layer, char *p
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bool dirp = st.st_mode & S_IFDIR;
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sprintf (path, "%s/%s", n->path, dent->d_name);
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child = make_lo_node (path, it, dent->d_name, st.st_ino, dirp);
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child = make_lo_node (path, it, dent->d_name, 0, dirp);
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if (child == NULL)
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{
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@ -818,22 +827,17 @@ do_lookup_file (struct lo_data *lo, fuse_ino_t parent, const char *name)
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return NULL;
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}
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if (node)
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node->ino = st.st_ino;
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else
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node = make_lo_node (path, it, name, 0, st.st_mode & S_IFDIR);
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if (node == NULL)
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{
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node = make_lo_node (path, it, name, st.st_ino, st.st_mode & S_IFDIR);
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if (node == NULL)
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{
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errno = ENOMEM;
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return NULL;
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}
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if (insert_node (pnode, node, false) == NULL)
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{
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node_free (node);
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errno = ENOMEM;
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return NULL;
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}
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errno = ENOMEM;
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return NULL;
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}
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if (insert_node (pnode, node, false) == NULL)
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{
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node_free (node);
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errno = ENOMEM;
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return NULL;
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}
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}
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}
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@ -1069,7 +1073,7 @@ lo_listxattr (fuse_req_t req, fuse_ino_t ino, size_t size)
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ssize_t len;
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struct lo_node *node;
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struct lo_data *lo = lo_data (req);
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char buf[1024];
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char *buf = NULL;
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int fd;
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if (lo_debug (req))
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@ -1082,14 +1086,25 @@ lo_listxattr (fuse_req_t req, fuse_ino_t ino, size_t size)
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return;
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}
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if (size > 0)
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{
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buf = malloc (size);
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if (buf == NULL)
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{
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fuse_reply_err (req, ENOMEM);
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return;
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}
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}
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fd = openat (node_dirfd (node), node->path, O_RDONLY);
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if (fd < 0)
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{
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free (buf);
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fuse_reply_err (req, errno);
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return;
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}
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len = flistxattr (fd, buf, sizeof (buf));
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len = flistxattr (fd, buf, size);
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if (len < 0)
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fuse_reply_err (req, errno);
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else if (size == 0)
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@ -1097,6 +1112,7 @@ lo_listxattr (fuse_req_t req, fuse_ino_t ino, size_t size)
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else if (len <= size)
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fuse_reply_buf (req, buf, len);
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free (buf);
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close (fd);
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}
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@ -1106,7 +1122,7 @@ lo_getxattr (fuse_req_t req, fuse_ino_t ino, const char *name, size_t size)
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ssize_t len;
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struct lo_node *node;
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struct lo_data *lo = lo_data (req);
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char buf[1024];
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char *buf = NULL;
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int fd;
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if (lo_debug (req))
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@ -1119,14 +1135,25 @@ lo_getxattr (fuse_req_t req, fuse_ino_t ino, const char *name, size_t size)
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return;
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}
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if (size > 0)
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{
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buf = malloc (size);
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if (buf == NULL)
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{
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fuse_reply_err (req, ENOMEM);
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return;
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}
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}
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fd = openat (node_dirfd (node), node->path, O_RDONLY);
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if (fd < 0)
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{
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free (buf);
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fuse_reply_err (req, errno);
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return;
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}
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len = fgetxattr (fd, name, buf, sizeof (buf));
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len = fgetxattr (fd, name, buf, size);
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if (len < 0)
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fuse_reply_err (req, errno);
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else if (size == 0)
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@ -1134,6 +1161,7 @@ lo_getxattr (fuse_req_t req, fuse_ino_t ino, const char *name, size_t size)
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else if (len <= size)
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fuse_reply_buf (req, buf, len);
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free (buf);
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close (fd);
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}
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@ -2003,6 +2031,16 @@ lo_link (fuse_req_t req, fuse_ino_t ino, fuse_ino_t newparent, const char *newna
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fuse_reply_err (req, errno);
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return;
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}
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else
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{
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int dfd = openat (node_dirfd (newparentnode), path, O_WRONLY);
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if (dfd >= 0)
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{
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fsetxattr (dfd, REDIRECT_XATTR, node->path, strlen (node->path), 0);
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close (dfd);
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}
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}
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node = make_lo_node (path, get_upper_layer (lo), newname, node->ino, false);
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if (node == NULL)
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