On Fri, 1 Nov 2013 17:57:39 +0400
Pavel Shilovsky <piastryyy@xxxxxxxxx> wrote:
> From: Pavel Shilovsky <piastry@xxxxxxxxxxx>
>
> Now we treat any reparse point as a symbolic link and map it to a Unix
> one that is not true in a common case due to many reparse point types
> supported by SMB servers.
>
> Distinguish reparse point types into two groups:
> 1) that can be accessed directly through a reparse point
> (junctions, deduplicated files, NFS symlinks);
> 2) that need to be processed manually (Windows symbolic links, DFS);
>
> and map only Windows symbolic links to Unix ones.
>
> Signed-off-by: Pavel Shilovsky <piastry@xxxxxxxxxxx>
> ---
> fs/cifs/cifsglob.h | 2 +-
> fs/cifs/inode.c | 23 +++++++++++++----------
> fs/cifs/readdir.c | 40 ++++++++--------------------------------
> fs/cifs/smb1ops.c | 21 ++++++++++++++++++++-
> fs/cifs/smb2inode.c | 16 ++++++++++++----
> fs/cifs/smb2proto.h | 2 +-
> 6 files changed, 55 insertions(+), 49 deletions(-)
>
> diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
> index a67cf12..b688f2b 100644
> --- a/fs/cifs/cifsglob.h
> +++ b/fs/cifs/cifsglob.h
> @@ -261,7 +261,7 @@ struct smb_version_operations {
> /* query path data from the server */
> int (*query_path_info)(const unsigned int, struct cifs_tcon *,
> struct cifs_sb_info *, const char *,
> - FILE_ALL_INFO *, bool *);
> + FILE_ALL_INFO *, bool *, bool *);
This looks much better for performance, but I think it really shines a
light on what an abortion the query_path_info and query_file_info
operations are. They work with a FILE_ALL_INFO struct which is SMB1
specific, so for SMB2/3 we have to convert data to something that
doesn't even match the protocol.
I think it would be best to base this fix on top of a patchset to fix
that properly. Those functions should be changed to pass data around in
a cifs_fattr. With that, you could just add a new cifs_fattr->flags
value and you wouldn't need to add this extra bool * argument.
> /* query file data from the server */
> int (*query_file_info)(const unsigned int, struct cifs_tcon *,
> struct cifs_fid *, FILE_ALL_INFO *);
> diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
> index 867b7cd..36f9ebb 100644
> --- a/fs/cifs/inode.c
> +++ b/fs/cifs/inode.c
> @@ -542,7 +542,8 @@ static int cifs_sfu_mode(struct cifs_fattr *fattr, const unsigned char *path,
> /* Fill a cifs_fattr struct with info from FILE_ALL_INFO */
> static void
> cifs_all_info_to_fattr(struct cifs_fattr *fattr, FILE_ALL_INFO *info,
> - struct cifs_sb_info *cifs_sb, bool adjust_tz)
> + struct cifs_sb_info *cifs_sb, bool adjust_tz,
> + bool symlink)
> {
> struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
>
> @@ -569,7 +570,11 @@ cifs_all_info_to_fattr(struct cifs_fattr *fattr, FILE_ALL_INFO *info,
> fattr->cf_createtime = le64_to_cpu(info->CreationTime);
>
> fattr->cf_nlink = le32_to_cpu(info->NumberOfLinks);
> - if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
> +
> + if (symlink) {
> + fattr->cf_mode = S_IFLNK;
> + fattr->cf_dtype = DT_LNK;
> + } else if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
> fattr->cf_mode = S_IFDIR | cifs_sb->mnt_dir_mode;
> fattr->cf_dtype = DT_DIR;
> /*
> @@ -578,10 +583,6 @@ cifs_all_info_to_fattr(struct cifs_fattr *fattr, FILE_ALL_INFO *info,
> */
> if (!tcon->unix_ext)
> fattr->cf_flags |= CIFS_FATTR_UNKNOWN_NLINK;
> - } else if (fattr->cf_cifsattrs & ATTR_REPARSE) {
> - fattr->cf_mode = S_IFLNK;
> - fattr->cf_dtype = DT_LNK;
> - fattr->cf_nlink = le32_to_cpu(info->NumberOfLinks);
> } else {
> fattr->cf_mode = S_IFREG | cifs_sb->mnt_file_mode;
> fattr->cf_dtype = DT_REG;
> @@ -626,7 +627,8 @@ cifs_get_file_info(struct file *filp)
> rc = server->ops->query_file_info(xid, tcon, &cfile->fid, &find_data);
> switch (rc) {
> case 0:
> - cifs_all_info_to_fattr(&fattr, &find_data, cifs_sb, false);
> + cifs_all_info_to_fattr(&fattr, &find_data, cifs_sb, false,
> + false);
> break;
> case -EREMOTE:
> cifs_create_dfs_fattr(&fattr, inode->i_sb);
> @@ -673,6 +675,7 @@ cifs_get_inode_info(struct inode **inode, const char *full_path,
> bool adjust_tz = false;
> struct cifs_fattr fattr;
> struct cifs_search_info *srchinf = NULL;
> + bool symlink = false;
>
> tlink = cifs_sb_tlink(cifs_sb);
> if (IS_ERR(tlink))
> @@ -702,12 +705,12 @@ cifs_get_inode_info(struct inode **inode, const char *full_path,
> }
> data = (FILE_ALL_INFO *)buf;
> rc = server->ops->query_path_info(xid, tcon, cifs_sb, full_path,
> - data, &adjust_tz);
> + data, &adjust_tz, &symlink);
> }
>
> if (!rc) {
> - cifs_all_info_to_fattr(&fattr, (FILE_ALL_INFO *)data, cifs_sb,
> - adjust_tz);
> + cifs_all_info_to_fattr(&fattr, data, cifs_sb, adjust_tz,
> + symlink);
> } else if (rc == -EREMOTE) {
> cifs_create_dfs_fattr(&fattr, sb);
> rc = 0;
> diff --git a/fs/cifs/readdir.c b/fs/cifs/readdir.c
> index 53a75f3..5940eca 100644
> --- a/fs/cifs/readdir.c
> +++ b/fs/cifs/readdir.c
> @@ -134,22 +134,6 @@ out:
> dput(dentry);
> }
>
> -/*
> - * Is it possible that this directory might turn out to be a DFS referral
> - * once we go to try and use it?
> - */
> -static bool
> -cifs_dfs_is_possible(struct cifs_sb_info *cifs_sb)
> -{
> -#ifdef CONFIG_CIFS_DFS_UPCALL
> - struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
> -
> - if (tcon->Flags & SMB_SHARE_IS_IN_DFS)
> - return true;
> -#endif
> - return false;
> -}
> -
> static void
> cifs_fill_common_info(struct cifs_fattr *fattr, struct cifs_sb_info *cifs_sb)
> {
> @@ -159,27 +143,19 @@ cifs_fill_common_info(struct cifs_fattr *fattr, struct cifs_sb_info *cifs_sb)
> if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
> fattr->cf_mode = S_IFDIR | cifs_sb->mnt_dir_mode;
> fattr->cf_dtype = DT_DIR;
> - /*
> - * Windows CIFS servers generally make DFS referrals look
> - * like directories in FIND_* responses with the reparse
> - * attribute flag also set (since DFS junctions are
> - * reparse points). We must revalidate at least these
> - * directory inodes before trying to use them (if
> - * they are DFS we will get PATH_NOT_COVERED back
> - * when queried directly and can then try to connect
> - * to the DFS target)
> - */
> - if (cifs_dfs_is_possible(cifs_sb) &&
> - (fattr->cf_cifsattrs & ATTR_REPARSE))
> - fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
> - } else if (fattr->cf_cifsattrs & ATTR_REPARSE) {
> - fattr->cf_mode = S_IFLNK;
> - fattr->cf_dtype = DT_LNK;
> } else {
> fattr->cf_mode = S_IFREG | cifs_sb->mnt_file_mode;
> fattr->cf_dtype = DT_REG;
> }
>
> + /*
> + * We need to revalidate it further to make a decision about whether it
> + * 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)
> + fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
> +
> /* non-unix readdir doesn't provide nlink */
> fattr->cf_flags |= CIFS_FATTR_UNKNOWN_NLINK;
>
> diff --git a/fs/cifs/smb1ops.c b/fs/cifs/smb1ops.c
> index ea99efe..47ab035 100644
> --- a/fs/cifs/smb1ops.c
> +++ b/fs/cifs/smb1ops.c
> @@ -534,10 +534,12 @@ cifs_is_path_accessible(const unsigned int xid, struct cifs_tcon *tcon,
> static int
> cifs_query_path_info(const unsigned int xid, struct cifs_tcon *tcon,
> struct cifs_sb_info *cifs_sb, const char *full_path,
> - FILE_ALL_INFO *data, bool *adjustTZ)
> + FILE_ALL_INFO *data, bool *adjustTZ, bool *symlink)
> {
> int rc;
>
> + *symlink = false;
> +
> /* could do find first instead but this returns more info */
> rc = CIFSSMBQPathInfo(xid, tcon, full_path, data, 0 /* not legacy */,
> cifs_sb->local_nls, cifs_sb->mnt_cifs_flags &
> @@ -554,6 +556,23 @@ cifs_query_path_info(const unsigned int xid, struct cifs_tcon *tcon,
> CIFS_MOUNT_MAP_SPECIAL_CHR);
> *adjustTZ = true;
> }
> +
> + if (!rc && (le32_to_cpu(data->Attributes) & ATTR_REPARSE)) {
> + int tmprc;
> + int oplock = 0;
> + __u16 netfid;
> +
> + /* Need to check if this is a symbolic link or not */
> + tmprc = CIFSSMBOpen(xid, tcon, full_path, FILE_OPEN,
> + FILE_READ_ATTRIBUTES, 0, &netfid, &oplock,
> + NULL, cifs_sb->local_nls,
> + cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
> + if (tmprc == -EOPNOTSUPP)
> + *symlink = true;
> + else
> + CIFSSMBClose(xid, tcon, netfid);
> + }
> +
> return rc;
> }
>
> diff --git a/fs/cifs/smb2inode.c b/fs/cifs/smb2inode.c
> index 78ff88c..84c012a 100644
> --- a/fs/cifs/smb2inode.c
> +++ b/fs/cifs/smb2inode.c
> @@ -123,12 +123,13 @@ move_smb2_info_to_cifs(FILE_ALL_INFO *dst, struct smb2_file_all_info *src)
> int
> smb2_query_path_info(const unsigned int xid, struct cifs_tcon *tcon,
> struct cifs_sb_info *cifs_sb, const char *full_path,
> - FILE_ALL_INFO *data, bool *adjust_tz)
> + FILE_ALL_INFO *data, bool *adjust_tz, bool *symlink)
> {
> int rc;
> struct smb2_file_all_info *smb2_data;
>
> *adjust_tz = false;
> + *symlink = false;
>
> smb2_data = kzalloc(sizeof(struct smb2_file_all_info) + MAX_NAME * 2,
> GFP_KERNEL);
> @@ -136,9 +137,16 @@ smb2_query_path_info(const unsigned int xid, struct cifs_tcon *tcon,
> return -ENOMEM;
>
> rc = smb2_open_op_close(xid, tcon, cifs_sb, full_path,
> - FILE_READ_ATTRIBUTES, FILE_OPEN,
> - OPEN_REPARSE_POINT, smb2_data,
> - SMB2_OP_QUERY_INFO);
> + FILE_READ_ATTRIBUTES, FILE_OPEN, 0,
> + smb2_data, SMB2_OP_QUERY_INFO);
> + if (rc == -EOPNOTSUPP) {
> + *symlink = true;
> + /* Failed on a symbolic link - query a reparse point info */
> + rc = smb2_open_op_close(xid, tcon, cifs_sb, full_path,
> + FILE_READ_ATTRIBUTES, FILE_OPEN,
> + OPEN_REPARSE_POINT, smb2_data,
> + SMB2_OP_QUERY_INFO);
> + }
> if (rc)
> goto out;
>
> diff --git a/fs/cifs/smb2proto.h b/fs/cifs/smb2proto.h
> index 313813e..b4eea10 100644
> --- a/fs/cifs/smb2proto.h
> +++ b/fs/cifs/smb2proto.h
> @@ -61,7 +61,7 @@ extern void move_smb2_info_to_cifs(FILE_ALL_INFO *dst,
> extern int smb2_query_path_info(const unsigned int xid, struct cifs_tcon *tcon,
> struct cifs_sb_info *cifs_sb,
> const char *full_path, FILE_ALL_INFO *data,
> - bool *adjust_tz);
> + bool *adjust_tz, bool *symlink);
> extern int smb2_set_path_size(const unsigned int xid, struct cifs_tcon *tcon,
> const char *full_path, __u64 size,
> struct cifs_sb_info *cifs_sb, bool set_alloc);
--
Jeff Layton <jlayton@xxxxxxxxxx>
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