Commit 14121bdc authored by Jeff Layton's avatar Jeff Layton Committed by Steve French
Browse files

cifs: make cifs_rename handle -EACCES errors 



cifs: make cifs_rename handle -EACCES errors

Some servers seem to return -EACCES when attempting to rename one
open file on top of another. Refactor the cifs_rename logic to
attempt to rename the target file out of the way in this situation.

This also fixes the "unlink_target" logic to be undoable if the
subsequent rename fails.

Signed-off-by: default avatarJeff Layton <jlayton@redhat.com>
Signed-off-by: default avatarSteve French <sfrench@us.ibm.com>
parent 41346098

fs/cifs/inode.c

+122 −52
Original line number Diff line number Diff line
@@ -1285,22 +1285,24 @@ cifs_do_rename(int xid, struct dentry *from_dentry, const char *fromPath, 
	return rc;

}



int cifs_rename(struct inode *source_inode, struct dentry *source_direntry,

	struct inode *target_inode, struct dentry *target_direntry)

int cifs_rename(struct inode *source_dir, struct dentry *source_dentry,

	struct inode *target_dir, struct dentry *target_dentry)

{

	char *fromName = NULL;

	char *toName = NULL;

	struct cifs_sb_info *cifs_sb_source;

	struct cifs_sb_info *cifs_sb_target;

	struct cifsTconInfo *pTcon;

	struct cifsTconInfo *tcon;

	struct cifsInodeInfo *target_cinode;

	FILE_UNIX_BASIC_INFO *info_buf_source = NULL;

	FILE_UNIX_BASIC_INFO *info_buf_target;

	int xid;

	int rc;

	__u16 dstfid;

	int xid, rc, tmprc, oplock = 0;

	bool delete_already_pending;



	cifs_sb_target = CIFS_SB(target_inode->i_sb);

	cifs_sb_source = CIFS_SB(source_inode->i_sb);

	pTcon = cifs_sb_source->tcon;

	cifs_sb_target = CIFS_SB(target_dir->i_sb);

	cifs_sb_source = CIFS_SB(source_dir->i_sb);

	tcon = cifs_sb_source->tcon;



	xid = GetXid();
@@ -1308,7 +1310,7 @@ int cifs_rename(struct inode *source_inode, struct dentry *source_direntry, 
	 * BB: this might be allowed if same server, but different share.

	 * Consider adding support for this

	 */

	if (pTcon != cifs_sb_target->tcon) {

	if (tcon != cifs_sb_target->tcon) {

		rc = -EXDEV;

		goto cifs_rename_exit;

	}
@@ -1317,23 +1319,22 @@ int cifs_rename(struct inode *source_inode, struct dentry *source_direntry, 
	 * we already have the rename sem so we do not need to

	 * grab it again here to protect the path integrity

	 */

	fromName = build_path_from_dentry(source_direntry);

	fromName = build_path_from_dentry(source_dentry);

	if (fromName == NULL) {

		rc = -ENOMEM;

		goto cifs_rename_exit;

	}



	toName = build_path_from_dentry(target_direntry);

	toName = build_path_from_dentry(target_dentry);

	if (toName == NULL) {

		rc = -ENOMEM;

		goto cifs_rename_exit;

	}



	rc = cifs_do_rename(xid, source_direntry, fromName,

			    target_direntry, toName);

	rc = cifs_do_rename(xid, source_dentry, fromName,

			    target_dentry, toName);



	if (rc == -EEXIST) {

		if (pTcon->unix_ext) {

	if (rc == -EEXIST && tcon->unix_ext) {

		/*

		 * Are src and dst hardlinks of same inode? We can

		 * only tell with unix extensions enabled
@@ -1341,11 +1342,13 @@ int cifs_rename(struct inode *source_inode, struct dentry *source_direntry, 
		info_buf_source =

			kmalloc(2 * sizeof(FILE_UNIX_BASIC_INFO),

					GFP_KERNEL);

			if (info_buf_source == NULL)

				goto unlink_target;

		if (info_buf_source == NULL) {

			rc = -ENOMEM;

			goto cifs_rename_exit;

		}



		info_buf_target = info_buf_source + 1;

			rc = CIFSSMBUnixQPathInfo(xid, pTcon, fromName,

		rc = CIFSSMBUnixQPathInfo(xid, tcon, fromName,

					info_buf_source,

					cifs_sb_source->local_nls,

					cifs_sb_source->mnt_cifs_flags &
@@ -1353,7 +1356,7 @@ int cifs_rename(struct inode *source_inode, struct dentry *source_direntry, 
		if (rc != 0)

			goto unlink_target;



			rc = CIFSSMBUnixQPathInfo(xid, pTcon,

		rc = CIFSSMBUnixQPathInfo(xid, tcon,

					toName, info_buf_target,

					cifs_sb_target->local_nls,

					/* remap based on source sb */
@@ -1364,18 +1367,85 @@ int cifs_rename(struct inode *source_inode, struct dentry *source_direntry, 
				info_buf_target->UniqueId))

			/* same file, POSIX says that this is a noop */

			goto cifs_rename_exit;



		rc = -EEXIST;

	} /* else ... BB we could add the same check for Windows by

		     checking the UniqueId via FILE_INTERNAL_INFO */



	if ((rc == -EACCES) || (rc == -EEXIST)) {

unlink_target:

		/* don't bother if this is a negative dentry */

		if (!target_dentry->d_inode)

			goto cifs_rename_exit;



		target_cinode = CIFS_I(target_dentry->d_inode);



		/* try to move the target out of the way */

		tmprc = CIFSSMBOpen(xid, tcon, toName, FILE_OPEN, DELETE,

				    CREATE_NOT_DIR, &dstfid, &oplock, NULL,

				    cifs_sb_target->local_nls,

				    cifs_sb_target->mnt_cifs_flags &

					CIFS_MOUNT_MAP_SPECIAL_CHR);

		if (tmprc)

			goto cifs_rename_exit;



		/* rename the file to random name */

		tmprc = CIFSSMBRenameOpenFile(xid, tcon, dstfid, NULL,

					      cifs_sb_target->local_nls,

					      cifs_sb_target->mnt_cifs_flags &

						CIFS_MOUNT_MAP_SPECIAL_CHR);



		if (tmprc)

			goto close_target;



		delete_already_pending = target_cinode->delete_pending;



		if (!delete_already_pending) {

			/* set delete on close */

			tmprc = CIFSSMBSetFileDisposition(xid, tcon,

							  true, dstfid,

							  current->tgid);

			/*

		 * we either can not tell the files are hardlinked (as with

		 * Windows servers) or files are not hardlinked. Delete the

		 * target manually before renaming to follow POSIX rather than

		 * Windows semantics

			 * This hack is for broken samba servers, remove this

			 * once more fixed ones are in the field.

			 */

		cifs_unlink(target_inode, target_direntry);

		rc = cifs_do_rename(xid, source_direntry, fromName,

				    target_direntry, toName);

			if (tmprc == -ENOENT)

				delete_already_pending = false;

			else if (tmprc)

				goto undo_target_rename;



			target_cinode->delete_pending = true;

		}





		rc = cifs_do_rename(xid, source_dentry, fromName,

				    target_dentry, toName);



		if (rc == 0)

			goto close_target;



		/*

		 * after this point, we can't bother with error handling on

		 * the undo's. This is best effort since we can't do anything

		 * about failures here.

		 */

		if (!delete_already_pending) {

			tmprc = CIFSSMBSetFileDisposition(xid, tcon,

							  false, dstfid,

							  current->tgid);

			if (tmprc == 0)

				target_cinode->delete_pending = false;

		}



undo_target_rename:

		/* rename failed: undo target rename */

		CIFSSMBRenameOpenFile(xid, tcon, dstfid,

				      target_dentry->d_name.name,

				      cifs_sb_target->local_nls,

				      cifs_sb_target->mnt_cifs_flags &

					CIFS_MOUNT_MAP_SPECIAL_CHR);

close_target:

		CIFSSMBClose(xid, tcon, dstfid);

	}



cifs_rename_exit:

CRA Git | Maintained and supported by SUSTech CRA and CCSE