Commit 76894f3e authored by Paulo Alcantara's avatar Paulo Alcantara Committed by Steve French
Browse files

cifs: improve symlink handling for smb2+ 



When creating inode for symlink, the client used to send below
requests to fill it in:

    * create+query_info+close (STATUS_STOPPED_ON_SYMLINK)
    * create(+reparse_flag)+query_info+close (set file attrs)
    * create+ioctl(get_reparse)+close (query reparse tag)

and then for every access to the symlink dentry, the ->link() method
would send another:

    * create+ioctl(get_reparse)+close (parse symlink)

So, in order to improve:

    (i) Get rid of unnecessary roundtrips and then resolve symlinks as
	follows:

        * create+query_info+close (STATUS_STOPPED_ON_SYMLINK +
	                           parse symlink + get reparse tag)
        * create(+reparse_flag)+query_info+close (set file attrs)

    (ii) Set the resolved symlink target directly in inode->i_link and
         use simple_get_link() for ->link() to simply return it.

Signed-off-by: default avatarPaulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: default avatarRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent 977bb653

fs/cifs/cifsfs.c

+7 −2
Original line number Diff line number Diff line
@@ -396,6 +396,7 @@ cifs_alloc_inode(struct super_block *sb) 
	cifs_inode->epoch = 0;

	spin_lock_init(&cifs_inode->open_file_lock);

	generate_random_uuid(cifs_inode->lease_key);

	cifs_inode->symlink_target = NULL;



	/*

	 * Can not set i_flags here - they get immediately overwritten to zero
@@ -412,7 +413,11 @@ cifs_alloc_inode(struct super_block *sb) 
static void

cifs_free_inode(struct inode *inode)

{

	kmem_cache_free(cifs_inode_cachep, CIFS_I(inode));

	struct cifsInodeInfo *cinode = CIFS_I(inode);



	if (S_ISLNK(inode->i_mode))

		kfree(cinode->symlink_target);

	kmem_cache_free(cifs_inode_cachep, cinode);

}



static void
@@ -1139,7 +1144,7 @@ const struct inode_operations cifs_file_inode_ops = { 
};



const struct inode_operations cifs_symlink_inode_ops = {

	.get_link = cifs_get_link,

	.get_link = simple_get_link,

	.permission = cifs_permission,

	.listxattr = cifs_listxattr,

};

fs/cifs/cifsglob.h

+36 −10
Original line number Diff line number Diff line
@@ -185,6 +185,19 @@ struct cifs_cred { 
	struct cifs_ace *aces;

};



struct cifs_open_info_data {

	char *symlink_target;

	union {

		struct smb2_file_all_info fi;

		struct smb311_posix_qinfo posix_fi;

	};

};



static inline void cifs_free_open_info(struct cifs_open_info_data *data)

{

	kfree(data->symlink_target);

}



/*

 *****************************************************************

 * Except the CIFS PDUs themselves all the
@@ -307,20 +320,20 @@ struct smb_version_operations { 
	int (*is_path_accessible)(const unsigned int, struct cifs_tcon *,

				  struct cifs_sb_info *, const char *);

	/* 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 *, bool *);

	int (*query_path_info)(const unsigned int xid, struct cifs_tcon *tcon,

			       struct cifs_sb_info *cifs_sb, const char *full_path,

			       struct cifs_open_info_data *data, bool *adjust_tz, bool *reparse);

	/* query file data from the server */

	int (*query_file_info)(const unsigned int, struct cifs_tcon *,

			       struct cifs_fid *, FILE_ALL_INFO *);

	int (*query_file_info)(const unsigned int xid, struct cifs_tcon *tcon,

			       struct cifsFileInfo *cfile, struct cifs_open_info_data *data);

	/* query reparse tag from srv to determine which type of special file */

	int (*query_reparse_tag)(const unsigned int xid, struct cifs_tcon *tcon,

				struct cifs_sb_info *cifs_sb, const char *path,

				__u32 *reparse_tag);

	/* get server index number */

	int (*get_srv_inum)(const unsigned int, struct cifs_tcon *,

			    struct cifs_sb_info *, const char *,

			    u64 *uniqueid, FILE_ALL_INFO *);

	int (*get_srv_inum)(const unsigned int xid, struct cifs_tcon *tcon,

			    struct cifs_sb_info *cifs_sb, const char *full_path, u64 *uniqueid,

			    struct cifs_open_info_data *data);

	/* set size by path */

	int (*set_path_size)(const unsigned int, struct cifs_tcon *,

			     const char *, __u64, struct cifs_sb_info *, bool);
@@ -369,8 +382,8 @@ struct smb_version_operations { 
			     struct cifs_sb_info *, const char *,

			     char **, bool);

	/* open a file for non-posix mounts */

	int (*open)(const unsigned int, struct cifs_open_parms *,

		    __u32 *, FILE_ALL_INFO *);

	int (*open)(const unsigned int xid, struct cifs_open_parms *oparms, __u32 *oplock,

		    void *buf);

	/* set fid protocol-specific info */

	void (*set_fid)(struct cifsFileInfo *, struct cifs_fid *, __u32);

	/* close a file */
@@ -1123,6 +1136,7 @@ struct cifs_fattr { 
	struct timespec64 cf_mtime;

	struct timespec64 cf_ctime;

	u32             cf_cifstag;

	char            *cf_symlink_target;

};



/*
@@ -1385,6 +1399,7 @@ struct cifsFileInfo { 
	struct work_struct put; /* work for the final part of _put */

	struct delayed_work deferred;

	bool deferred_close_scheduled; /* Flag to indicate close is scheduled */

	char *symlink_target;

};



struct cifs_io_parms {
@@ -1543,6 +1558,7 @@ struct cifsInodeInfo { 
	struct list_head deferred_closes; /* list of deferred closes */

	spinlock_t deferred_lock; /* protection on deferred list */

	bool lease_granted; /* Flag to indicate whether lease or oplock is granted. */

	char *symlink_target;

};



static inline struct cifsInodeInfo *
@@ -2111,4 +2127,14 @@ static inline size_t ntlmssp_workstation_name_size(const struct cifs_ses *ses) 
	return sizeof(ses->workstation_name);

}



static inline void move_cifs_info_to_smb2(struct smb2_file_all_info *dst, const FILE_ALL_INFO *src)

{

	memcpy(dst, src, (size_t)((u8 *)&src->AccessFlags - (u8 *)src));

	dst->AccessFlags = src->AccessFlags;

	dst->CurrentByteOffset = src->CurrentByteOffset;

	dst->Mode = src->Mode;

	dst->AlignmentRequirement = src->AlignmentRequirement;

	dst->FileNameLength = src->FileNameLength;

}



#endif	/* _CIFS_GLOB_H */

fs/cifs/cifsproto.h

+6 −7
Original line number Diff line number Diff line
@@ -182,10 +182,9 @@ extern int cifs_unlock_range(struct cifsFileInfo *cfile, 
extern int cifs_push_mandatory_locks(struct cifsFileInfo *cfile);



extern void cifs_down_write(struct rw_semaphore *sem);

extern struct cifsFileInfo *cifs_new_fileinfo(struct cifs_fid *fid,

					      struct file *file,

					      struct tcon_link *tlink,

					      __u32 oplock);

struct cifsFileInfo *cifs_new_fileinfo(struct cifs_fid *fid, struct file *file,

				       struct tcon_link *tlink, __u32 oplock,

				       const char *symlink_target);

extern int cifs_posix_open(const char *full_path, struct inode **inode,

			   struct super_block *sb, int mode,

			   unsigned int f_flags, __u32 *oplock, __u16 *netfid,
@@ -200,9 +199,9 @@ extern int cifs_fattr_to_inode(struct inode *inode, struct cifs_fattr *fattr); 
extern struct inode *cifs_iget(struct super_block *sb,

			       struct cifs_fattr *fattr);



extern int cifs_get_inode_info(struct inode **inode, const char *full_path,

			       FILE_ALL_INFO *data, struct super_block *sb,

			       int xid, const struct cifs_fid *fid);

int cifs_get_inode_info(struct inode **inode, const char *full_path,

			struct cifs_open_info_data *data, struct super_block *sb, int xid,

			const struct cifs_fid *fid);

extern int smb311_posix_get_inode_info(struct inode **pinode, const char *search_path,

			struct super_block *sb, unsigned int xid);

extern int cifs_get_inode_info_unix(struct inode **pinode,

fs/cifs/dir.c

+11 −19
Original line number Diff line number Diff line
@@ -165,10 +165,9 @@ check_name(struct dentry *direntry, struct cifs_tcon *tcon) 


/* Inode operations in similar order to how they appear in Linux file fs.h */



static int

cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned int xid,

	       struct tcon_link *tlink, unsigned oflags, umode_t mode,

	       __u32 *oplock, struct cifs_fid *fid)

static int cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned int xid,

			  struct tcon_link *tlink, unsigned int oflags, umode_t mode, __u32 *oplock,

			  struct cifs_fid *fid, struct cifs_open_info_data *buf)

{

	int rc = -ENOENT;

	int create_options = CREATE_NOT_DIR;
@@ -177,7 +176,6 @@ cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned int xid, 
	struct cifs_tcon *tcon = tlink_tcon(tlink);

	const char *full_path;

	void *page = alloc_dentry_path();

	FILE_ALL_INFO *buf = NULL;

	struct inode *newinode = NULL;

	int disposition;

	struct TCP_Server_Info *server = tcon->ses->server;
@@ -290,12 +288,6 @@ cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned int xid, 
		goto out;

	}



	buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);

	if (buf == NULL) {

		rc = -ENOMEM;

		goto out;

	}



	/*

	 * if we're not using unix extensions, see if we need to set

	 * ATTR_READONLY on the create call
@@ -364,8 +356,7 @@ cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned int xid, 
	{

#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */

		/* TODO: Add support for calling POSIX query info here, but passing in fid */

		rc = cifs_get_inode_info(&newinode, full_path, buf, inode->i_sb,

					 xid, fid);

		rc = cifs_get_inode_info(&newinode, full_path, buf, inode->i_sb, xid, fid);

		if (newinode) {

			if (server->ops->set_lease_key)

				server->ops->set_lease_key(newinode, fid);
@@ -402,7 +393,6 @@ cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned int xid, 
	d_add(direntry, newinode);



out:

	kfree(buf);

	free_dentry_path(page);

	return rc;
@@ -427,6 +417,7 @@ cifs_atomic_open(struct inode *inode, struct dentry *direntry, 
	struct cifs_pending_open open;

	__u32 oplock;

	struct cifsFileInfo *file_info;

	struct cifs_open_info_data buf = {};



	if (unlikely(cifs_forced_shutdown(CIFS_SB(inode->i_sb))))

		return -EIO;
@@ -484,8 +475,7 @@ cifs_atomic_open(struct inode *inode, struct dentry *direntry, 
	cifs_add_pending_open(&fid, tlink, &open);



	rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode,

			    &oplock, &fid);



			    &oplock, &fid, &buf);

	if (rc) {

		cifs_del_pending_open(&open);

		goto out;
@@ -510,7 +500,7 @@ cifs_atomic_open(struct inode *inode, struct dentry *direntry, 
			file->f_op = &cifs_file_direct_ops;

		}



	file_info = cifs_new_fileinfo(&fid, file, tlink, oplock);

	file_info = cifs_new_fileinfo(&fid, file, tlink, oplock, buf.symlink_target);

	if (file_info == NULL) {

		if (server->ops->close)

			server->ops->close(xid, tcon, &fid);
@@ -526,6 +516,7 @@ cifs_atomic_open(struct inode *inode, struct dentry *direntry, 
	cifs_put_tlink(tlink);

out_free_xid:

	free_xid(xid);

	cifs_free_open_info(&buf);

	return rc;

}
@@ -547,6 +538,7 @@ int cifs_create(struct user_namespace *mnt_userns, struct inode *inode, 
	struct TCP_Server_Info *server;

	struct cifs_fid fid;

	__u32 oplock;

	struct cifs_open_info_data buf = {};



	cifs_dbg(FYI, "cifs_create parent inode = 0x%p name is: %pd and dentry = 0x%p\n",

		 inode, direntry, direntry);
@@ -565,11 +557,11 @@ int cifs_create(struct user_namespace *mnt_userns, struct inode *inode, 
	if (server->ops->new_lease_key)

		server->ops->new_lease_key(&fid);



	rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode,

			    &oplock, &fid);

	rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode, &oplock, &fid, &buf);

	if (!rc && server->ops->close)

		server->ops->close(xid, tcon, &fid);



	cifs_free_open_info(&buf);

	cifs_put_tlink(tlink);

out_free_xid:

	free_xid(xid);

fs/cifs/file.c

+22 −19
Original line number Diff line number Diff line
@@ -209,16 +209,14 @@ int cifs_posix_open(const char *full_path, struct inode **pinode, 
}

#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */



static int

cifs_nt_open(const char *full_path, struct inode *inode, struct cifs_sb_info *cifs_sb,

static int cifs_nt_open(const char *full_path, struct inode *inode, struct cifs_sb_info *cifs_sb,

			struct cifs_tcon *tcon, unsigned int f_flags, __u32 *oplock,

	     struct cifs_fid *fid, unsigned int xid)

			struct cifs_fid *fid, unsigned int xid, struct cifs_open_info_data *buf)

{

	int rc;

	int desired_access;

	int disposition;

	int create_options = CREATE_NOT_DIR;

	FILE_ALL_INFO *buf;

	struct TCP_Server_Info *server = tcon->ses->server;

	struct cifs_open_parms oparms;
@@ -255,10 +253,6 @@ cifs_nt_open(const char *full_path, struct inode *inode, struct cifs_sb_info *ci 


	/* BB pass O_SYNC flag through on file attributes .. BB */



	buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);

	if (!buf)

		return -ENOMEM;



	/* O_SYNC also has bit for O_DSYNC so following check picks up either */

	if (f_flags & O_SYNC)

		create_options |= CREATE_WRITE_THROUGH;
@@ -276,9 +270,8 @@ cifs_nt_open(const char *full_path, struct inode *inode, struct cifs_sb_info *ci 
	oparms.reconnect = false;



	rc = server->ops->open(xid, &oparms, oplock, buf);



	if (rc)

		goto out;

		return rc;



	/* TODO: Add support for calling posix query info but with passing in fid */

	if (tcon->unix_ext)
@@ -294,8 +287,6 @@ cifs_nt_open(const char *full_path, struct inode *inode, struct cifs_sb_info *ci 
			rc = -EOPENSTALE;

	}



out:

	kfree(buf);

	return rc;

}
@@ -325,9 +316,9 @@ cifs_down_write(struct rw_semaphore *sem) 


static void cifsFileInfo_put_work(struct work_struct *work);



struct cifsFileInfo *

cifs_new_fileinfo(struct cifs_fid *fid, struct file *file,

		  struct tcon_link *tlink, __u32 oplock)

struct cifsFileInfo *cifs_new_fileinfo(struct cifs_fid *fid, struct file *file,

				       struct tcon_link *tlink, __u32 oplock,

				       const char *symlink_target)

{

	struct dentry *dentry = file_dentry(file);

	struct inode *inode = d_inode(dentry);
@@ -347,6 +338,15 @@ cifs_new_fileinfo(struct cifs_fid *fid, struct file *file, 
		return NULL;

	}



	if (symlink_target) {

		cfile->symlink_target = kstrdup(symlink_target, GFP_KERNEL);

		if (!cfile->symlink_target) {

			kfree(fdlocks);

			kfree(cfile);

			return NULL;

		}

	}



	INIT_LIST_HEAD(&fdlocks->locks);

	fdlocks->cfile = cfile;

	cfile->llist = fdlocks;
@@ -440,6 +440,7 @@ static void cifsFileInfo_put_final(struct cifsFileInfo *cifs_file) 
	cifs_put_tlink(cifs_file->tlink);

	dput(cifs_file->dentry);

	cifs_sb_deactive(sb);

	kfree(cifs_file->symlink_target);

	kfree(cifs_file);

}
@@ -572,6 +573,7 @@ int cifs_open(struct inode *inode, struct file *file) 
	bool posix_open_ok = false;

	struct cifs_fid fid;

	struct cifs_pending_open open;

	struct cifs_open_info_data data = {};



	xid = get_xid();
@@ -662,15 +664,15 @@ int cifs_open(struct inode *inode, struct file *file) 
		if (server->ops->get_lease_key)

			server->ops->get_lease_key(inode, &fid);



		rc = cifs_nt_open(full_path, inode, cifs_sb, tcon,

				  file->f_flags, &oplock, &fid, xid);

		rc = cifs_nt_open(full_path, inode, cifs_sb, tcon, file->f_flags, &oplock, &fid,

				  xid, &data);

		if (rc) {

			cifs_del_pending_open(&open);

			goto out;

		}

	}



	cfile = cifs_new_fileinfo(&fid, file, tlink, oplock);

	cfile = cifs_new_fileinfo(&fid, file, tlink, oplock, data.symlink_target);

	if (cfile == NULL) {

		if (server->ops->close)

			server->ops->close(xid, tcon, &fid);
@@ -712,6 +714,7 @@ int cifs_open(struct inode *inode, struct file *file) 
	free_dentry_path(page);

	free_xid(xid);

	cifs_put_tlink(tlink);

	cifs_free_open_info(&data);

	return rc;

}