Commit 05b98fd2 authored by Ronnie Sahlberg's avatar Ronnie Sahlberg Committed by Steve French
Browse files

cifs: Move cached-dir functions into a separate file 



Also rename crfid to cfid to have consistent naming for this variable.

This commit does not change any logic.

Signed-off-by: default avatarRonnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: default avatarPaulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent cd043455

fs/cifs/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -7,7 +7,7 @@ obj-$(CONFIG_CIFS) += cifs.o 


cifs-y := trace.o cifsfs.o cifs_debug.o connect.o dir.o file.o \

	  inode.o link.o misc.o netmisc.o smbencrypt.o transport.o \

	  cifs_unicode.o nterr.o cifsencrypt.o \

	  cached_dir.o cifs_unicode.o nterr.o cifsencrypt.o \

	  readdir.o ioctl.o sess.o export.o unc.o winucase.o \

	  smb2ops.o smb2maperror.o smb2transport.o \

	  smb2misc.o smb2pdu.o smb2inode.o smb2file.o cifsacl.o fs_context.o \

fs/cifs/cached_dir.c

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+362 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/*

 *  Functions to handle the cached directory entries

 *

 *  Copyright (c) 2022, Ronnie Sahlberg <lsahlber@redhat.com>

 */



#include "cifsglob.h"

#include "cifsproto.h"

#include "cifs_debug.h"

#include "smb2proto.h"

#include "cached_dir.h"



/*

 * Open the and cache a directory handle.

 * If error then *cfid is not initialized.

 */

int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon,

		const char *path,

		struct cifs_sb_info *cifs_sb,

		struct cached_fid **cfid)

{

	struct cifs_ses *ses;

	struct TCP_Server_Info *server;

	struct cifs_open_parms oparms;

	struct smb2_create_rsp *o_rsp = NULL;

	struct smb2_query_info_rsp *qi_rsp = NULL;

	int resp_buftype[2];

	struct smb_rqst rqst[2];

	struct kvec rsp_iov[2];

	struct kvec open_iov[SMB2_CREATE_IOV_SIZE];

	struct kvec qi_iov[1];

	int rc, flags = 0;

	__le16 utf16_path = 0; /* Null - since an open of top of share */

	u8 oplock = SMB2_OPLOCK_LEVEL_II;

	struct cifs_fid *pfid;

	struct dentry *dentry;



	if (tcon == NULL || tcon->nohandlecache ||

	    is_smb1_server(tcon->ses->server))

		return -EOPNOTSUPP;



	ses = tcon->ses;

	server = ses->server;



	if (cifs_sb->root == NULL)

		return -ENOENT;



	if (strlen(path))

		return -ENOENT;



	dentry = cifs_sb->root;



	mutex_lock(&tcon->cfid.fid_mutex);

	if (tcon->cfid.is_valid) {

		cifs_dbg(FYI, "found a cached root file handle\n");

		*cfid = &tcon->cfid;

		kref_get(&tcon->cfid.refcount);

		mutex_unlock(&tcon->cfid.fid_mutex);

		return 0;

	}



	/*

	 * We do not hold the lock for the open because in case

	 * SMB2_open needs to reconnect, it will end up calling

	 * cifs_mark_open_files_invalid() which takes the lock again

	 * thus causing a deadlock

	 */



	mutex_unlock(&tcon->cfid.fid_mutex);



	if (smb3_encryption_required(tcon))

		flags |= CIFS_TRANSFORM_REQ;



	if (!server->ops->new_lease_key)

		return -EIO;



	pfid = tcon->cfid.fid;

	server->ops->new_lease_key(pfid);



	memset(rqst, 0, sizeof(rqst));

	resp_buftype[0] = resp_buftype[1] = CIFS_NO_BUFFER;

	memset(rsp_iov, 0, sizeof(rsp_iov));



	/* Open */

	memset(&open_iov, 0, sizeof(open_iov));

	rqst[0].rq_iov = open_iov;

	rqst[0].rq_nvec = SMB2_CREATE_IOV_SIZE;



	oparms.tcon = tcon;

	oparms.create_options = cifs_create_options(cifs_sb, CREATE_NOT_FILE);

	oparms.desired_access = FILE_READ_ATTRIBUTES;

	oparms.disposition = FILE_OPEN;

	oparms.fid = pfid;

	oparms.reconnect = false;



	rc = SMB2_open_init(tcon, server,

			    &rqst[0], &oplock, &oparms, &utf16_path);

	if (rc)

		goto oshr_free;

	smb2_set_next_command(tcon, &rqst[0]);



	memset(&qi_iov, 0, sizeof(qi_iov));

	rqst[1].rq_iov = qi_iov;

	rqst[1].rq_nvec = 1;



	rc = SMB2_query_info_init(tcon, server,

				  &rqst[1], COMPOUND_FID,

				  COMPOUND_FID, FILE_ALL_INFORMATION,

				  SMB2_O_INFO_FILE, 0,

				  sizeof(struct smb2_file_all_info) +

				  PATH_MAX * 2, 0, NULL);

	if (rc)

		goto oshr_free;



	smb2_set_related(&rqst[1]);



	rc = compound_send_recv(xid, ses, server,

				flags, 2, rqst,

				resp_buftype, rsp_iov);

	mutex_lock(&tcon->cfid.fid_mutex);



	/*

	 * Now we need to check again as the cached root might have

	 * been successfully re-opened from a concurrent process

	 */



	if (tcon->cfid.is_valid) {

		/* work was already done */



		/* stash fids for close() later */

		struct cifs_fid fid = {

			.persistent_fid = pfid->persistent_fid,

			.volatile_fid = pfid->volatile_fid,

		};



		/*

		 * caller expects this func to set the fid in cfid to valid

		 * cached root, so increment the refcount.

		 */

		kref_get(&tcon->cfid.refcount);



		mutex_unlock(&tcon->cfid.fid_mutex);



		if (rc == 0) {

			/* close extra handle outside of crit sec */

			SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);

		}

		rc = 0;

		goto oshr_free;

	}



	/* Cached root is still invalid, continue normaly */



	if (rc) {

		if (rc == -EREMCHG) {

			tcon->need_reconnect = true;

			pr_warn_once("server share %s deleted\n",

				     tcon->treeName);

		}

		goto oshr_exit;

	}



	atomic_inc(&tcon->num_remote_opens);



	o_rsp = (struct smb2_create_rsp *)rsp_iov[0].iov_base;

	oparms.fid->persistent_fid = o_rsp->PersistentFileId;

	oparms.fid->volatile_fid = o_rsp->VolatileFileId;

#ifdef CONFIG_CIFS_DEBUG2

	oparms.fid->mid = le64_to_cpu(o_rsp->hdr.MessageId);

#endif /* CIFS_DEBUG2 */



	tcon->cfid.tcon = tcon;

	tcon->cfid.is_valid = true;

	tcon->cfid.dentry = dentry;

	dget(dentry);

	kref_init(&tcon->cfid.refcount);



	/* BB TBD check to see if oplock level check can be removed below */

	if (o_rsp->OplockLevel == SMB2_OPLOCK_LEVEL_LEASE) {

		/*

		 * See commit 2f94a3125b87. Increment the refcount when we

		 * get a lease for root, release it if lease break occurs

		 */

		kref_get(&tcon->cfid.refcount);

		tcon->cfid.has_lease = true;

		smb2_parse_contexts(server, o_rsp,

				&oparms.fid->epoch,

				    oparms.fid->lease_key, &oplock,

				    NULL, NULL);

	} else

		goto oshr_exit;



	qi_rsp = (struct smb2_query_info_rsp *)rsp_iov[1].iov_base;

	if (le32_to_cpu(qi_rsp->OutputBufferLength) < sizeof(struct smb2_file_all_info))

		goto oshr_exit;

	if (!smb2_validate_and_copy_iov(

				le16_to_cpu(qi_rsp->OutputBufferOffset),

				sizeof(struct smb2_file_all_info),

				&rsp_iov[1], sizeof(struct smb2_file_all_info),

				(char *)&tcon->cfid.file_all_info))

		tcon->cfid.file_all_info_is_valid = true;

	tcon->cfid.time = jiffies;





oshr_exit:

	mutex_unlock(&tcon->cfid.fid_mutex);

oshr_free:

	SMB2_open_free(&rqst[0]);

	SMB2_query_info_free(&rqst[1]);

	free_rsp_buf(resp_buftype[0], rsp_iov[0].iov_base);

	free_rsp_buf(resp_buftype[1], rsp_iov[1].iov_base);

	if (rc == 0)

		*cfid = &tcon->cfid;



	return rc;

}



int open_cached_dir_by_dentry(struct cifs_tcon *tcon,

			      struct dentry *dentry,

			      struct cached_fid **cfid)

{

	mutex_lock(&tcon->cfid.fid_mutex);

	if (tcon->cfid.dentry == dentry) {

		cifs_dbg(FYI, "found a cached root file handle by dentry\n");

		*cfid = &tcon->cfid;

		kref_get(&tcon->cfid.refcount);

		mutex_unlock(&tcon->cfid.fid_mutex);

		return 0;

	}

	mutex_unlock(&tcon->cfid.fid_mutex);

	return -ENOENT;

}



static void

smb2_close_cached_fid(struct kref *ref)

{

	struct cached_fid *cfid = container_of(ref, struct cached_fid,

					       refcount);

	struct cached_dirent *dirent, *q;



	if (cfid->is_valid) {

		cifs_dbg(FYI, "clear cached root file handle\n");

		SMB2_close(0, cfid->tcon, cfid->fid->persistent_fid,

			   cfid->fid->volatile_fid);

	}



	/*

	 * We only check validity above to send SMB2_close,

	 * but we still need to invalidate these entries

	 * when this function is called

	 */

	cfid->is_valid = false;

	cfid->file_all_info_is_valid = false;

	cfid->has_lease = false;

	if (cfid->dentry) {

		dput(cfid->dentry);

		cfid->dentry = NULL;

	}

	/*

	 * Delete all cached dirent names

	 */

	mutex_lock(&cfid->dirents.de_mutex);

	list_for_each_entry_safe(dirent, q, &cfid->dirents.entries, entry) {

		list_del(&dirent->entry);

		kfree(dirent->name);

		kfree(dirent);

	}

	cfid->dirents.is_valid = 0;

	cfid->dirents.is_failed = 0;

	cfid->dirents.ctx = NULL;

	cfid->dirents.pos = 0;

	mutex_unlock(&cfid->dirents.de_mutex);



}



void close_cached_dir(struct cached_fid *cfid)

{

	mutex_lock(&cfid->fid_mutex);

	kref_put(&cfid->refcount, smb2_close_cached_fid);

	mutex_unlock(&cfid->fid_mutex);

}



void close_cached_dir_lease_locked(struct cached_fid *cfid)

{

	if (cfid->has_lease) {

		cfid->has_lease = false;

		kref_put(&cfid->refcount, smb2_close_cached_fid);

	}

}



void close_cached_dir_lease(struct cached_fid *cfid)

{

	mutex_lock(&cfid->fid_mutex);

	close_cached_dir_lease_locked(cfid);

	mutex_unlock(&cfid->fid_mutex);

}



/*

 * Called from cifs_kill_sb when we unmount a share

 */

void close_all_cached_dirs(struct cifs_sb_info *cifs_sb)

{

	struct rb_root *root = &cifs_sb->tlink_tree;

	struct rb_node *node;

	struct cached_fid *cfid;

	struct cifs_tcon *tcon;

	struct tcon_link *tlink;



	for (node = rb_first(root); node; node = rb_next(node)) {

		tlink = rb_entry(node, struct tcon_link, tl_rbnode);

		tcon = tlink_tcon(tlink);

		if (IS_ERR(tcon))

			continue;

		cfid = &tcon->cfid;

		mutex_lock(&cfid->fid_mutex);

		if (cfid->dentry) {

			dput(cfid->dentry);

			cfid->dentry = NULL;

		}

		mutex_unlock(&cfid->fid_mutex);

	}

}



/*

 * Invalidate and close all cached dirs when a TCON has been reset

 * due to a session loss.

 */

void invalidate_all_cached_dirs(struct cifs_tcon *tcon)

{

	mutex_lock(&tcon->cfid.fid_mutex);

	tcon->cfid.is_valid = false;

	/* cached handle is not valid, so SMB2_CLOSE won't be sent below */

	close_cached_dir_lease_locked(&tcon->cfid);

	memset(tcon->cfid.fid, 0, sizeof(struct cifs_fid));

	mutex_unlock(&tcon->cfid.fid_mutex);

}



static void

smb2_cached_lease_break(struct work_struct *work)

{

	struct cached_fid *cfid = container_of(work,

				struct cached_fid, lease_break);



	close_cached_dir_lease(cfid);

}



int cached_dir_lease_break(struct cifs_tcon *tcon, __u8 lease_key[16])

{

	if (tcon->cfid.is_valid &&

	    !memcmp(lease_key,

		    tcon->cfid.fid->lease_key,

		    SMB2_LEASE_KEY_SIZE)) {

		tcon->cfid.time = 0;

		INIT_WORK(&tcon->cfid.lease_break,

			  smb2_cached_lease_break);

		queue_work(cifsiod_wq,

			   &tcon->cfid.lease_break);

		return true;

	}

	return false;

}

fs/cifs/cached_dir.h

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+26 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0 */

/*

 *  Functions to handle the cached directory entries

 *

 *  Copyright (c) 2022, Ronnie Sahlberg <lsahlber@redhat.com>

 */



#ifndef _CACHED_DIR_H

#define _CACHED_DIR_H





extern int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon,

			   const char *path,

			   struct cifs_sb_info *cifs_sb,

			   struct cached_fid **cfid);

extern int open_cached_dir_by_dentry(struct cifs_tcon *tcon,

				     struct dentry *dentry,

				     struct cached_fid **cfid);

extern void close_cached_dir(struct cached_fid *cfid);

extern void close_cached_dir_lease(struct cached_fid *cfid);

extern void close_cached_dir_lease_locked(struct cached_fid *cfid);

extern void close_all_cached_dirs(struct cifs_sb_info *cifs_sb);

extern void invalidate_all_cached_dirs(struct cifs_tcon *tcon);

extern int cached_dir_lease_break(struct cifs_tcon *tcon, __u8 lease_key[16]);



#endif			/* _CACHED_DIR_H */

fs/cifs/cifsfs.c

+2 −18
Original line number Diff line number Diff line
@@ -46,6 +46,7 @@ 
#include "netlink.h"

#endif

#include "fs_context.h"

#include "cached_dir.h"



/*

 * DOS dates from 1980/1/1 through 2107/12/31
@@ -283,30 +284,13 @@ cifs_read_super(struct super_block *sb) 
static void cifs_kill_sb(struct super_block *sb)

{

	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);

	struct cifs_tcon *tcon;

	struct cached_fid *cfid;

	struct rb_root *root = &cifs_sb->tlink_tree;

	struct rb_node *node;

	struct tcon_link *tlink;



	/*

	 * We ned to release all dentries for the cached directories

	 * before we kill the sb.

	 */

	if (cifs_sb->root) {

		for (node = rb_first(root); node; node = rb_next(node)) {

			tlink = rb_entry(node, struct tcon_link, tl_rbnode);

			tcon = tlink_tcon(tlink);

			if (IS_ERR(tcon))

				continue;

			cfid = &tcon->crfid;

			mutex_lock(&cfid->fid_mutex);

			if (cfid->dentry) {

				dput(cfid->dentry);

				cfid->dentry = NULL;

			}

			mutex_unlock(&cfid->fid_mutex);

		}

		close_all_cached_dirs(cifs_sb);



		/* finally release root dentry */

		dput(cifs_sb->root);

fs/cifs/cifsglob.h

+1 −1
Original line number Diff line number Diff line
@@ -1257,7 +1257,7 @@ struct cifs_tcon { 
	struct fscache_volume *fscache;	/* cookie for share */

#endif

	struct list_head pending_opens;	/* list of incomplete opens */

	struct cached_fid crfid; /* Cached root fid */

	struct cached_fid cfid; /* Cached root fid */

	/* BB add field for back pointer to sb struct(s)? */

#ifdef CONFIG_CIFS_DFS_UPCALL

	struct list_head ulist; /* cache update list */