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-rw-r--r--fs/smb/client/cifs_unicode.c17
-rw-r--r--fs/smb/client/reparse.c164
-rw-r--r--fs/smb/client/smb2inode.c3
-rw-r--r--fs/smb/client/smb2proto.h1
4 files changed, 178 insertions, 7 deletions
diff --git a/fs/smb/client/cifs_unicode.c b/fs/smb/client/cifs_unicode.c
index 79d99a913944..4cc6e0896fad 100644
--- a/fs/smb/client/cifs_unicode.c
+++ b/fs/smb/client/cifs_unicode.c
@@ -484,10 +484,21 @@ cifsConvertToUTF16(__le16 *target, const char *source, int srclen,
/**
* Remap spaces and periods found at the end of every
* component of the path. The special cases of '.' and
- * '..' do not need to be dealt with explicitly because
- * they are addressed in namei.c:link_path_walk().
+ * '..' are need to be handled because of symlinks.
+ * They are treated as non-end-of-string to avoid
+ * remapping and breaking symlinks pointing to . or ..
**/
- if ((i == srclen - 1) || (source[i+1] == '\\'))
+ if ((i == 0 || source[i-1] == '\\') &&
+ source[i] == '.' &&
+ (i == srclen-1 || source[i+1] == '\\'))
+ end_of_string = false; /* "." case */
+ else if (i >= 1 &&
+ (i == 1 || source[i-2] == '\\') &&
+ source[i-1] == '.' &&
+ source[i] == '.' &&
+ (i == srclen-1 || source[i+1] == '\\'))
+ end_of_string = false; /* ".." case */
+ else if ((i == srclen - 1) || (source[i+1] == '\\'))
end_of_string = true;
else
end_of_string = false;
diff --git a/fs/smb/client/reparse.c b/fs/smb/client/reparse.c
index c848b5e88d32..74abbdf5026c 100644
--- a/fs/smb/client/reparse.c
+++ b/fs/smb/client/reparse.c
@@ -14,6 +14,12 @@
#include "fs_context.h"
#include "reparse.h"
+static int detect_directory_symlink_target(struct cifs_sb_info *cifs_sb,
+ const unsigned int xid,
+ const char *full_path,
+ const char *symname,
+ bool *directory);
+
int smb2_create_reparse_symlink(const unsigned int xid, struct inode *inode,
struct dentry *dentry, struct cifs_tcon *tcon,
const char *full_path, const char *symname)
@@ -24,6 +30,7 @@ int smb2_create_reparse_symlink(const unsigned int xid, struct inode *inode,
struct inode *new;
struct kvec iov;
__le16 *path;
+ bool directory;
char *sym, sep = CIFS_DIR_SEP(cifs_sb);
u16 len, plen;
int rc = 0;
@@ -45,6 +52,18 @@ int smb2_create_reparse_symlink(const unsigned int xid, struct inode *inode,
goto out;
}
+ /*
+ * SMB distinguish between symlink to directory and symlink to file.
+ * They cannot be exchanged (symlink of file type which points to
+ * directory cannot be resolved and vice-versa). Try to detect if
+ * the symlink target could be a directory or not. When detection
+ * fails then treat symlink as a file (non-directory) symlink.
+ */
+ directory = false;
+ rc = detect_directory_symlink_target(cifs_sb, xid, full_path, symname, &directory);
+ if (rc < 0)
+ goto out;
+
plen = 2 * UniStrnlen((wchar_t *)path, PATH_MAX);
len = sizeof(*buf) + plen * 2;
buf = kzalloc(len, GFP_KERNEL);
@@ -69,7 +88,8 @@ int smb2_create_reparse_symlink(const unsigned int xid, struct inode *inode,
iov.iov_base = buf;
iov.iov_len = len;
new = smb2_get_reparse_inode(&data, inode->i_sb, xid,
- tcon, full_path, &iov, NULL);
+ tcon, full_path, directory,
+ &iov, NULL);
if (!IS_ERR(new))
d_instantiate(dentry, new);
else
@@ -81,6 +101,144 @@ out:
return rc;
}
+static int detect_directory_symlink_target(struct cifs_sb_info *cifs_sb,
+ const unsigned int xid,
+ const char *full_path,
+ const char *symname,
+ bool *directory)
+{
+ char sep = CIFS_DIR_SEP(cifs_sb);
+ struct cifs_open_parms oparms;
+ struct tcon_link *tlink;
+ struct cifs_tcon *tcon;
+ const char *basename;
+ struct cifs_fid fid;
+ char *resolved_path;
+ int full_path_len;
+ int basename_len;
+ int symname_len;
+ char *path_sep;
+ __u32 oplock;
+ int open_rc;
+
+ /*
+ * First do some simple check. If the original Linux symlink target ends
+ * with slash, or last path component is dot or dot-dot then it is for
+ * sure symlink to the directory.
+ */
+ basename = kbasename(symname);
+ basename_len = strlen(basename);
+ if (basename_len == 0 || /* symname ends with slash */
+ (basename_len == 1 && basename[0] == '.') || /* last component is "." */
+ (basename_len == 2 && basename[0] == '.' && basename[1] == '.')) { /* or ".." */
+ *directory = true;
+ return 0;
+ }
+
+ /*
+ * For absolute symlinks it is not possible to determinate
+ * if it should point to directory or file.
+ */
+ if (symname[0] == '/') {
+ cifs_dbg(FYI,
+ "%s: cannot determinate if the symlink target path '%s' "
+ "is directory or not, creating '%s' as file symlink\n",
+ __func__, symname, full_path);
+ return 0;
+ }
+
+ /*
+ * If it was not detected as directory yet and the symlink is relative
+ * then try to resolve the path on the SMB server, check if the path
+ * exists and determinate if it is a directory or not.
+ */
+
+ full_path_len = strlen(full_path);
+ symname_len = strlen(symname);
+
+ tlink = cifs_sb_tlink(cifs_sb);
+ if (IS_ERR(tlink))
+ return PTR_ERR(tlink);
+
+ resolved_path = kzalloc(full_path_len + symname_len + 1, GFP_KERNEL);
+ if (!resolved_path) {
+ cifs_put_tlink(tlink);
+ return -ENOMEM;
+ }
+
+ /*
+ * Compose the resolved SMB symlink path from the SMB full path
+ * and Linux target symlink path.
+ */
+ memcpy(resolved_path, full_path, full_path_len+1);
+ path_sep = strrchr(resolved_path, sep);
+ if (path_sep)
+ path_sep++;
+ else
+ path_sep = resolved_path;
+ memcpy(path_sep, symname, symname_len+1);
+ if (sep == '\\')
+ convert_delimiter(path_sep, sep);
+
+ tcon = tlink_tcon(tlink);
+ oparms = CIFS_OPARMS(cifs_sb, tcon, resolved_path,
+ FILE_READ_ATTRIBUTES, FILE_OPEN, 0, ACL_NO_MODE);
+ oparms.fid = &fid;
+
+ /* Try to open as a directory (NOT_FILE) */
+ oplock = 0;
+ oparms.create_options = cifs_create_options(cifs_sb,
+ CREATE_NOT_FILE | OPEN_REPARSE_POINT);
+ open_rc = tcon->ses->server->ops->open(xid, &oparms, &oplock, NULL);
+ if (open_rc == 0) {
+ /* Successful open means that the target path is definitely a directory. */
+ *directory = true;
+ tcon->ses->server->ops->close(xid, tcon, &fid);
+ } else if (open_rc == -ENOTDIR) {
+ /* -ENOTDIR means that the target path is definitely a file. */
+ *directory = false;
+ } else if (open_rc == -ENOENT) {
+ /* -ENOENT means that the target path does not exist. */
+ cifs_dbg(FYI,
+ "%s: symlink target path '%s' does not exist, "
+ "creating '%s' as file symlink\n",
+ __func__, symname, full_path);
+ } else {
+ /* Try to open as a file (NOT_DIR) */
+ oplock = 0;
+ oparms.create_options = cifs_create_options(cifs_sb,
+ CREATE_NOT_DIR | OPEN_REPARSE_POINT);
+ open_rc = tcon->ses->server->ops->open(xid, &oparms, &oplock, NULL);
+ if (open_rc == 0) {
+ /* Successful open means that the target path is definitely a file. */
+ *directory = false;
+ tcon->ses->server->ops->close(xid, tcon, &fid);
+ } else if (open_rc == -EISDIR) {
+ /* -EISDIR means that the target path is definitely a directory. */
+ *directory = true;
+ } else {
+ /*
+ * This code branch is called when we do not have a permission to
+ * open the resolved_path or some other client/process denied
+ * opening the resolved_path.
+ *
+ * TODO: Try to use ops->query_dir_first on the parent directory
+ * of resolved_path, search for basename of resolved_path and
+ * check if the ATTR_DIRECTORY is set in fi.Attributes. In some
+ * case this could work also when opening of the path is denied.
+ */
+ cifs_dbg(FYI,
+ "%s: cannot determinate if the symlink target path '%s' "
+ "is directory or not, creating '%s' as file symlink\n",
+ __func__, symname, full_path);
+ }
+ }
+
+ kfree(resolved_path);
+ cifs_put_tlink(tlink);
+ return 0;
+}
+
static int nfs_set_reparse_buf(struct reparse_posix_data *buf,
mode_t mode, dev_t dev,
struct kvec *iov)
@@ -137,7 +295,7 @@ static int mknod_nfs(unsigned int xid, struct inode *inode,
};
new = smb2_get_reparse_inode(&data, inode->i_sb, xid,
- tcon, full_path, &iov, NULL);
+ tcon, full_path, false, &iov, NULL);
if (!IS_ERR(new))
d_instantiate(dentry, new);
else
@@ -283,7 +441,7 @@ static int mknod_wsl(unsigned int xid, struct inode *inode,
data.wsl.eas_len = len;
new = smb2_get_reparse_inode(&data, inode->i_sb,
- xid, tcon, full_path,
+ xid, tcon, full_path, false,
&reparse_iov, &xattr_iov);
if (!IS_ERR(new))
d_instantiate(dentry, new);
diff --git a/fs/smb/client/smb2inode.c b/fs/smb/client/smb2inode.c
index 4e9e225520a6..e49d0c25eb03 100644
--- a/fs/smb/client/smb2inode.c
+++ b/fs/smb/client/smb2inode.c
@@ -1198,6 +1198,7 @@ struct inode *smb2_get_reparse_inode(struct cifs_open_info_data *data,
const unsigned int xid,
struct cifs_tcon *tcon,
const char *full_path,
+ bool directory,
struct kvec *reparse_iov,
struct kvec *xattr_iov)
{
@@ -1217,7 +1218,7 @@ struct inode *smb2_get_reparse_inode(struct cifs_open_info_data *data,
FILE_READ_ATTRIBUTES |
FILE_WRITE_ATTRIBUTES,
FILE_CREATE,
- CREATE_NOT_DIR | OPEN_REPARSE_POINT,
+ (directory ? CREATE_NOT_FILE : CREATE_NOT_DIR) | OPEN_REPARSE_POINT,
ACL_NO_MODE);
if (xattr_iov)
oparms.ea_cctx = xattr_iov;
diff --git a/fs/smb/client/smb2proto.h b/fs/smb/client/smb2proto.h
index c7e1b149877a..6f9885e4f66c 100644
--- a/fs/smb/client/smb2proto.h
+++ b/fs/smb/client/smb2proto.h
@@ -61,6 +61,7 @@ struct inode *smb2_get_reparse_inode(struct cifs_open_info_data *data,
const unsigned int xid,
struct cifs_tcon *tcon,
const char *full_path,
+ bool directory,
struct kvec *reparse_iov,
struct kvec *xattr_iov);
int smb2_query_reparse_point(const unsigned int xid,
generated by cgit v1.2.3-70-g09d2 (git 2.47.1) at 2024-12-23 07:54:59 +0000