Commit 046aca3c authored by Paulo Alcantara (SUSE)'s avatar Paulo Alcantara (SUSE) Committed by Steve French
Browse files

cifs: Optimize readdir on reparse points 



When listing a directory with thounsands of files and most of them are
reparse points, we simply marked all those dentries for revalidation
and then sending additional (compounded) create/getinfo/close requests
for each of them.

Instead, upon receiving a response from an SMB2_QUERY_DIRECTORY
(FileIdFullDirectoryInformation) command, the directory entries that
have a file attribute of FILE_ATTRIBUTE_REPARSE_POINT will contain an
EaSize field with a reparse tag in it, so we parse it and mark the
dentry for revalidation only if it is a DFS or a symlink.

Signed-off-by: default avatarPaulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: default avatarPavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent 7935799e

fs/cifs/cifsglob.h

+1 −0
Original line number Diff line number Diff line
@@ -1693,6 +1693,7 @@ struct cifs_fattr { 
	struct timespec64 cf_atime;

	struct timespec64 cf_mtime;

	struct timespec64 cf_ctime;

	u32             cf_cifstag;

};



static inline void free_dfs_info_param(struct dfs_info3_param *param)

fs/cifs/readdir.c

+54 −9
Original line number Diff line number Diff line
@@ -139,6 +139,28 @@ retry: 
	dput(dentry);

}



static bool reparse_file_needs_reval(const struct cifs_fattr *fattr)

{

	if (!(fattr->cf_cifsattrs & ATTR_REPARSE))

		return false;

	/*

	 * The DFS tags should be only intepreted by server side as per

	 * MS-FSCC 2.1.2.1, but let's include them anyway.

	 *

	 * Besides, if cf_cifstag is unset (0), then we still need it to be

	 * revalidated to know exactly what reparse point it is.

	 */

	switch (fattr->cf_cifstag) {

	case IO_REPARSE_TAG_DFS:

	case IO_REPARSE_TAG_DFSR:

	case IO_REPARSE_TAG_SYMLINK:

	case IO_REPARSE_TAG_NFS:

	case 0:

		return true;

	}

	return false;

}



static void

cifs_fill_common_info(struct cifs_fattr *fattr, struct cifs_sb_info *cifs_sb)

{
@@ -158,7 +180,7 @@ cifs_fill_common_info(struct cifs_fattr *fattr, struct cifs_sb_info *cifs_sb) 
	 * is a symbolic link, DFS referral or a reparse point with a direct

	 * access like junctions, deduplicated files, NFS symlinks.

	 */

	if (fattr->cf_cifsattrs & ATTR_REPARSE)

	if (reparse_file_needs_reval(fattr))

		fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;



	/* non-unix readdir doesn't provide nlink */
@@ -194,19 +216,37 @@ cifs_fill_common_info(struct cifs_fattr *fattr, struct cifs_sb_info *cifs_sb) 
	}

}



static void __dir_info_to_fattr(struct cifs_fattr *fattr, const void *info)

{

	const FILE_DIRECTORY_INFO *fi = info;



	memset(fattr, 0, sizeof(*fattr));

	fattr->cf_cifsattrs = le32_to_cpu(fi->ExtFileAttributes);

	fattr->cf_eof = le64_to_cpu(fi->EndOfFile);

	fattr->cf_bytes = le64_to_cpu(fi->AllocationSize);

	fattr->cf_createtime = le64_to_cpu(fi->CreationTime);

	fattr->cf_atime = cifs_NTtimeToUnix(fi->LastAccessTime);

	fattr->cf_ctime = cifs_NTtimeToUnix(fi->ChangeTime);

	fattr->cf_mtime = cifs_NTtimeToUnix(fi->LastWriteTime);

}



void

cifs_dir_info_to_fattr(struct cifs_fattr *fattr, FILE_DIRECTORY_INFO *info,

		       struct cifs_sb_info *cifs_sb)

{

	memset(fattr, 0, sizeof(*fattr));

	fattr->cf_cifsattrs = le32_to_cpu(info->ExtFileAttributes);

	fattr->cf_eof = le64_to_cpu(info->EndOfFile);

	fattr->cf_bytes = le64_to_cpu(info->AllocationSize);

	fattr->cf_createtime = le64_to_cpu(info->CreationTime);

	fattr->cf_atime = cifs_NTtimeToUnix(info->LastAccessTime);

	fattr->cf_ctime = cifs_NTtimeToUnix(info->ChangeTime);

	fattr->cf_mtime = cifs_NTtimeToUnix(info->LastWriteTime);

	__dir_info_to_fattr(fattr, info);

	cifs_fill_common_info(fattr, cifs_sb);

}



static void cifs_fulldir_info_to_fattr(struct cifs_fattr *fattr,

				       SEARCH_ID_FULL_DIR_INFO *info,

				       struct cifs_sb_info *cifs_sb)

{

	__dir_info_to_fattr(fattr, info);



	/* See MS-FSCC 2.4.18 FileIdFullDirectoryInformation */

	if (fattr->cf_cifsattrs & ATTR_REPARSE)

		fattr->cf_cifstag = le32_to_cpu(info->EaSize);

	cifs_fill_common_info(fattr, cifs_sb);

}
@@ -755,6 +795,11 @@ static int cifs_filldir(char *find_entry, struct file *file, 
				       (FIND_FILE_STANDARD_INFO *)find_entry,

				       cifs_sb);

		break;

	case SMB_FIND_FILE_ID_FULL_DIR_INFO:

		cifs_fulldir_info_to_fattr(&fattr,

					   (SEARCH_ID_FULL_DIR_INFO *)find_entry,

					   cifs_sb);

		break;

	default:

		cifs_dir_info_to_fattr(&fattr,

				       (FILE_DIRECTORY_INFO *)find_entry,

CRA Git | Maintained and supported by SUSTech CRA and CCSE