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Commit 2eacc0ac authored by Steve French's avatar Steve French Committed by Greg Kroah-Hartman
Browse files

smb3: do not error on fsync when readonly 



[ Upstream commit 71e6864eacbef0b2645ca043cdfbac272cb6cea3 ]

Linux allows doing a flush/fsync on a file open for read-only,
but the protocol does not allow that.  If the file passed in
on the flush is read-only try to find a writeable handle for
the same inode, if that is not possible skip sending the
fsync call to the server to avoid breaking the apps.

Reported-by: default avatarJulian Sikorski <belegdol@gmail.com>
Tested-by: default avatarJulian Sikorski <belegdol@gmail.com>
Suggested-by: default avatarJeremy Allison <jra@samba.org>
Reviewed-by: default avatarPaulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 51be334d

fs/cifs/file.c

+29 −6
Original line number Original line Diff line number Diff line
@@ -2577,12 +2577,23 @@ int cifs_strict_fsync(struct file *file, loff_t start, loff_t end, 
	tcon = tlink_tcon(smbfile->tlink);

	tcon = tlink_tcon(smbfile->tlink);

	if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) {

	if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) {

		server = tcon->ses->server;

		server = tcon->ses->server;

		if (server->ops->flush)

		if (server->ops->flush == NULL) {

			rc = server->ops->flush(xid, tcon, &smbfile->fid);

		else

			rc = -ENOSYS;

			rc = -ENOSYS;

			goto strict_fsync_exit;

		}

		}





		if ((OPEN_FMODE(smbfile->f_flags) & FMODE_WRITE) == 0) {

			smbfile = find_writable_file(CIFS_I(inode), FIND_WR_ANY);

			if (smbfile) {

				rc = server->ops->flush(xid, tcon, &smbfile->fid);

				cifsFileInfo_put(smbfile);

			} else

				cifs_dbg(FYI, "ignore fsync for file not open for write\n");

		} else

			rc = server->ops->flush(xid, tcon, &smbfile->fid);

	}



strict_fsync_exit:

	free_xid(xid);

	free_xid(xid);

	return rc;

	return rc;

}

}
@@ -2594,6 +2605,7 @@ int cifs_fsync(struct file *file, loff_t start, loff_t end, int datasync) 
	struct cifs_tcon *tcon;

	struct cifs_tcon *tcon;

	struct TCP_Server_Info *server;

	struct TCP_Server_Info *server;

	struct cifsFileInfo *smbfile = file->private_data;

	struct cifsFileInfo *smbfile = file->private_data;

	struct inode *inode = file_inode(file);

	struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);

	struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);





	rc = file_write_and_wait_range(file, start, end);

	rc = file_write_and_wait_range(file, start, end);
@@ -2608,12 +2620,23 @@ int cifs_fsync(struct file *file, loff_t start, loff_t end, int datasync) 
	tcon = tlink_tcon(smbfile->tlink);

	tcon = tlink_tcon(smbfile->tlink);

	if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) {

	if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) {

		server = tcon->ses->server;

		server = tcon->ses->server;

		if (server->ops->flush)

		if (server->ops->flush == NULL) {

			rc = server->ops->flush(xid, tcon, &smbfile->fid);

		else

			rc = -ENOSYS;

			rc = -ENOSYS;

			goto fsync_exit;

		}



		if ((OPEN_FMODE(smbfile->f_flags) & FMODE_WRITE) == 0) {

			smbfile = find_writable_file(CIFS_I(inode), FIND_WR_ANY);

			if (smbfile) {

				rc = server->ops->flush(xid, tcon, &smbfile->fid);

				cifsFileInfo_put(smbfile);

			} else

				cifs_dbg(FYI, "ignore fsync for file not open for write\n");

		} else

			rc = server->ops->flush(xid, tcon, &smbfile->fid);

	}

	}





fsync_exit:

	free_xid(xid);

	free_xid(xid);

	return rc;

	return rc;

}

}