cifs: implement CIFSCouldBeMFSymlink() and CIFSCheckMFSymlink() (8bfb50a8) · Commits · e / devices / android_kernel_sony_msm8994

fs/cifs/cifsproto.h

+4 −0

Original line number	Diff line number	Diff line
		@@ -409,4 +409,8 @@ extern int CIFSSMBSetPosixACL(const int xid, struct cifsTconInfo *tcon,
		extern int CIFSGetExtAttr(const int xid, struct cifsTconInfo *tcon,
		const int netfid, __u64 pExtAttrBits, __u64 pMask);
		extern void cifs_autodisable_serverino(struct cifs_sb_info *cifs_sb);
		extern bool CIFSCouldBeMFSymlink(const struct cifs_fattr *fattr);
		extern int CIFSCheckMFSymlink(struct cifs_fattr *fattr,
		const unsigned char *path,
		struct cifs_sb_info *cifs_sb, int xid);
		#endif /* _CIFSPROTO_H */

fs/cifs/link.c

+79 −0

Original line number	Diff line number	Diff line
		@@ -91,6 +91,85 @@ CIFSParseMFSymlink(const u8 *buf,
		return 0;
		}

		bool
		CIFSCouldBeMFSymlink(const struct cifs_fattr *fattr)
		{
		if (!(fattr->cf_mode & S_IFREG))
		/* it's not a symlink */
		return false;

		if (fattr->cf_eof != CIFS_MF_SYMLINK_FILE_SIZE)
		/* it's not a symlink */
		return false;

		return true;
		}

		int
		CIFSCheckMFSymlink(struct cifs_fattr *fattr,
		const unsigned char *path,
		struct cifs_sb_info *cifs_sb, int xid)
		{
		int rc;
		int oplock = 0;
		__u16 netfid = 0;
		struct cifsTconInfo *pTcon = cifs_sb->tcon;
		u8 *buf;
		char *pbuf;
		unsigned int bytes_read = 0;
		int buf_type = CIFS_NO_BUFFER;
		unsigned int link_len = 0;
		FILE_ALL_INFO file_info;

		if (!CIFSCouldBeMFSymlink(fattr))
		/* it's not a symlink */
		return 0;

		rc = CIFSSMBOpen(xid, pTcon, path, FILE_OPEN, GENERIC_READ,
		CREATE_NOT_DIR, &netfid, &oplock, &file_info,
		cifs_sb->local_nls,
		cifs_sb->mnt_cifs_flags &
		CIFS_MOUNT_MAP_SPECIAL_CHR);
		if (rc != 0)
		return rc;

		if (file_info.EndOfFile != CIFS_MF_SYMLINK_FILE_SIZE) {
		CIFSSMBClose(xid, pTcon, netfid);
		/* it's not a symlink */
		return 0;
		}

		buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
		if (!buf)
		return -ENOMEM;
		pbuf = buf;

		rc = CIFSSMBRead(xid, pTcon, netfid,
		CIFS_MF_SYMLINK_FILE_SIZE /* length */,
		0 /* offset */,
		&bytes_read, &pbuf, &buf_type);
		CIFSSMBClose(xid, pTcon, netfid);
		if (rc != 0) {
		kfree(buf);
		return rc;
		}

		rc = CIFSParseMFSymlink(buf, bytes_read, &link_len, NULL);
		kfree(buf);
		if (rc == -EINVAL)
		/* it's not a symlink */
		return 0;
		if (rc != 0)
		return rc;

		/* it is a symlink */
		fattr->cf_eof = link_len;
		fattr->cf_mode &= ~S_IFMT;
		fattr->cf_mode \|= S_IFLNK \| S_IRWXU \| S_IRWXG \| S_IRWXO;
		fattr->cf_dtype = DT_LNK;
		return 0;
		}

		int
		cifs_hardlink(struct dentry old_file, struct inode inode,
		struct dentry *direntry)