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![Ronnie Sahlberg](/assets/img/avatar_default.png)
cfids will soon keep a list of cached fids so we should not access this directly from outside of cached_dir.c Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
388 lines
9.3 KiB
C
388 lines
9.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Functions to handle the cached directory entries
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*
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* Copyright (c) 2022, Ronnie Sahlberg <lsahlber@redhat.com>
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*/
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#include "cifsglob.h"
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#include "cifsproto.h"
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#include "cifs_debug.h"
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#include "smb2proto.h"
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#include "cached_dir.h"
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/*
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* Open the and cache a directory handle.
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* If error then *cfid is not initialized.
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*/
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int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon,
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const char *path,
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struct cifs_sb_info *cifs_sb,
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bool lookup_only, struct cached_fid **ret_cfid)
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{
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struct cifs_ses *ses;
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struct TCP_Server_Info *server;
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struct cifs_open_parms oparms;
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struct smb2_create_rsp *o_rsp = NULL;
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struct smb2_query_info_rsp *qi_rsp = NULL;
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int resp_buftype[2];
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struct smb_rqst rqst[2];
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struct kvec rsp_iov[2];
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struct kvec open_iov[SMB2_CREATE_IOV_SIZE];
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struct kvec qi_iov[1];
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int rc, flags = 0;
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__le16 utf16_path = 0; /* Null - since an open of top of share */
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u8 oplock = SMB2_OPLOCK_LEVEL_II;
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struct cifs_fid *pfid;
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struct dentry *dentry;
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struct cached_fid *cfid;
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if (tcon == NULL || tcon->nohandlecache ||
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is_smb1_server(tcon->ses->server))
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return -EOPNOTSUPP;
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ses = tcon->ses;
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server = ses->server;
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if (cifs_sb->root == NULL)
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return -ENOENT;
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if (strlen(path))
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return -ENOENT;
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dentry = cifs_sb->root;
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cfid = tcon->cfid;
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mutex_lock(&cfid->fid_mutex);
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if (cfid->is_valid) {
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cifs_dbg(FYI, "found a cached root file handle\n");
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*ret_cfid = cfid;
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kref_get(&cfid->refcount);
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mutex_unlock(&cfid->fid_mutex);
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return 0;
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}
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/*
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* We do not hold the lock for the open because in case
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* SMB2_open needs to reconnect, it will end up calling
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* cifs_mark_open_files_invalid() which takes the lock again
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* thus causing a deadlock
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*/
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mutex_unlock(&cfid->fid_mutex);
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if (lookup_only)
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return -ENOENT;
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if (smb3_encryption_required(tcon))
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flags |= CIFS_TRANSFORM_REQ;
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if (!server->ops->new_lease_key)
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return -EIO;
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pfid = &cfid->fid;
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server->ops->new_lease_key(pfid);
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memset(rqst, 0, sizeof(rqst));
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resp_buftype[0] = resp_buftype[1] = CIFS_NO_BUFFER;
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memset(rsp_iov, 0, sizeof(rsp_iov));
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/* Open */
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memset(&open_iov, 0, sizeof(open_iov));
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rqst[0].rq_iov = open_iov;
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rqst[0].rq_nvec = SMB2_CREATE_IOV_SIZE;
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oparms.tcon = tcon;
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oparms.create_options = cifs_create_options(cifs_sb, CREATE_NOT_FILE);
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oparms.desired_access = FILE_READ_ATTRIBUTES;
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oparms.disposition = FILE_OPEN;
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oparms.fid = pfid;
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oparms.reconnect = false;
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rc = SMB2_open_init(tcon, server,
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&rqst[0], &oplock, &oparms, &utf16_path);
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if (rc)
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goto oshr_free;
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smb2_set_next_command(tcon, &rqst[0]);
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memset(&qi_iov, 0, sizeof(qi_iov));
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rqst[1].rq_iov = qi_iov;
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rqst[1].rq_nvec = 1;
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rc = SMB2_query_info_init(tcon, server,
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&rqst[1], COMPOUND_FID,
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COMPOUND_FID, FILE_ALL_INFORMATION,
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SMB2_O_INFO_FILE, 0,
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sizeof(struct smb2_file_all_info) +
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PATH_MAX * 2, 0, NULL);
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if (rc)
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goto oshr_free;
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smb2_set_related(&rqst[1]);
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rc = compound_send_recv(xid, ses, server,
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flags, 2, rqst,
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resp_buftype, rsp_iov);
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mutex_lock(&cfid->fid_mutex);
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/*
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* Now we need to check again as the cached root might have
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* been successfully re-opened from a concurrent process
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*/
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if (cfid->is_valid) {
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/* work was already done */
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/* stash fids for close() later */
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struct cifs_fid fid = {
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.persistent_fid = pfid->persistent_fid,
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.volatile_fid = pfid->volatile_fid,
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};
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/*
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* caller expects this func to set the fid in cfid to valid
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* cached root, so increment the refcount.
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*/
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kref_get(&cfid->refcount);
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mutex_unlock(&cfid->fid_mutex);
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if (rc == 0) {
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/* close extra handle outside of crit sec */
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SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
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}
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rc = 0;
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goto oshr_free;
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}
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/* Cached root is still invalid, continue normaly */
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if (rc) {
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if (rc == -EREMCHG) {
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tcon->need_reconnect = true;
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pr_warn_once("server share %s deleted\n",
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tcon->treeName);
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}
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goto oshr_exit;
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}
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atomic_inc(&tcon->num_remote_opens);
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o_rsp = (struct smb2_create_rsp *)rsp_iov[0].iov_base;
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oparms.fid->persistent_fid = o_rsp->PersistentFileId;
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oparms.fid->volatile_fid = o_rsp->VolatileFileId;
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#ifdef CONFIG_CIFS_DEBUG2
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oparms.fid->mid = le64_to_cpu(o_rsp->hdr.MessageId);
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#endif /* CIFS_DEBUG2 */
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cfid->tcon = tcon;
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cfid->is_valid = true;
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cfid->dentry = dentry;
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dget(dentry);
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kref_init(&cfid->refcount);
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/* BB TBD check to see if oplock level check can be removed below */
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if (o_rsp->OplockLevel == SMB2_OPLOCK_LEVEL_LEASE) {
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/*
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* See commit 2f94a3125b87. Increment the refcount when we
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* get a lease for root, release it if lease break occurs
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*/
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kref_get(&cfid->refcount);
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cfid->has_lease = true;
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smb2_parse_contexts(server, o_rsp,
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&oparms.fid->epoch,
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oparms.fid->lease_key, &oplock,
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NULL, NULL);
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} else
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goto oshr_exit;
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qi_rsp = (struct smb2_query_info_rsp *)rsp_iov[1].iov_base;
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if (le32_to_cpu(qi_rsp->OutputBufferLength) < sizeof(struct smb2_file_all_info))
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goto oshr_exit;
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if (!smb2_validate_and_copy_iov(
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le16_to_cpu(qi_rsp->OutputBufferOffset),
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sizeof(struct smb2_file_all_info),
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&rsp_iov[1], sizeof(struct smb2_file_all_info),
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(char *)&cfid->file_all_info))
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cfid->file_all_info_is_valid = true;
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cfid->time = jiffies;
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oshr_exit:
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mutex_unlock(&cfid->fid_mutex);
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oshr_free:
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SMB2_open_free(&rqst[0]);
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SMB2_query_info_free(&rqst[1]);
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free_rsp_buf(resp_buftype[0], rsp_iov[0].iov_base);
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free_rsp_buf(resp_buftype[1], rsp_iov[1].iov_base);
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if (rc == 0)
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*ret_cfid = cfid;
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return rc;
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}
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int open_cached_dir_by_dentry(struct cifs_tcon *tcon,
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struct dentry *dentry,
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struct cached_fid **ret_cfid)
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{
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struct cached_fid *cfid;
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cfid = tcon->cfid;
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mutex_lock(&cfid->fid_mutex);
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if (cfid->dentry == dentry) {
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cifs_dbg(FYI, "found a cached root file handle by dentry\n");
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*ret_cfid = cfid;
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kref_get(&cfid->refcount);
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mutex_unlock(&cfid->fid_mutex);
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return 0;
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}
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mutex_unlock(&cfid->fid_mutex);
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return -ENOENT;
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}
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static void
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smb2_close_cached_fid(struct kref *ref)
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{
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struct cached_fid *cfid = container_of(ref, struct cached_fid,
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refcount);
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struct cached_dirent *dirent, *q;
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if (cfid->is_valid) {
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cifs_dbg(FYI, "clear cached root file handle\n");
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SMB2_close(0, cfid->tcon, cfid->fid.persistent_fid,
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cfid->fid.volatile_fid);
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}
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/*
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* We only check validity above to send SMB2_close,
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* but we still need to invalidate these entries
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* when this function is called
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*/
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cfid->is_valid = false;
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cfid->file_all_info_is_valid = false;
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cfid->has_lease = false;
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if (cfid->dentry) {
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dput(cfid->dentry);
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cfid->dentry = NULL;
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}
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/*
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* Delete all cached dirent names
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*/
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mutex_lock(&cfid->dirents.de_mutex);
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list_for_each_entry_safe(dirent, q, &cfid->dirents.entries, entry) {
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list_del(&dirent->entry);
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kfree(dirent->name);
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kfree(dirent);
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}
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cfid->dirents.is_valid = 0;
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cfid->dirents.is_failed = 0;
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cfid->dirents.ctx = NULL;
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cfid->dirents.pos = 0;
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mutex_unlock(&cfid->dirents.de_mutex);
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}
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void close_cached_dir(struct cached_fid *cfid)
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{
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mutex_lock(&cfid->fid_mutex);
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kref_put(&cfid->refcount, smb2_close_cached_fid);
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mutex_unlock(&cfid->fid_mutex);
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}
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void close_cached_dir_lease_locked(struct cached_fid *cfid)
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{
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if (cfid->has_lease) {
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cfid->has_lease = false;
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kref_put(&cfid->refcount, smb2_close_cached_fid);
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}
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}
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void close_cached_dir_lease(struct cached_fid *cfid)
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{
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mutex_lock(&cfid->fid_mutex);
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close_cached_dir_lease_locked(cfid);
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mutex_unlock(&cfid->fid_mutex);
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}
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/*
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* Called from cifs_kill_sb when we unmount a share
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*/
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void close_all_cached_dirs(struct cifs_sb_info *cifs_sb)
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{
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struct rb_root *root = &cifs_sb->tlink_tree;
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struct rb_node *node;
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struct cached_fid *cfid;
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struct cifs_tcon *tcon;
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struct tcon_link *tlink;
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for (node = rb_first(root); node; node = rb_next(node)) {
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tlink = rb_entry(node, struct tcon_link, tl_rbnode);
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tcon = tlink_tcon(tlink);
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if (IS_ERR(tcon))
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continue;
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cfid = tcon->cfid;
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mutex_lock(&cfid->fid_mutex);
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if (cfid->dentry) {
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dput(cfid->dentry);
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cfid->dentry = NULL;
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}
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mutex_unlock(&cfid->fid_mutex);
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}
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}
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/*
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* Invalidate and close all cached dirs when a TCON has been reset
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* due to a session loss.
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*/
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void invalidate_all_cached_dirs(struct cifs_tcon *tcon)
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{
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mutex_lock(&tcon->cfid->fid_mutex);
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tcon->cfid->is_valid = false;
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/* cached handle is not valid, so SMB2_CLOSE won't be sent below */
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close_cached_dir_lease_locked(tcon->cfid);
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memset(&tcon->cfid->fid, 0, sizeof(struct cifs_fid));
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mutex_unlock(&tcon->cfid->fid_mutex);
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}
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static void
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smb2_cached_lease_break(struct work_struct *work)
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{
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struct cached_fid *cfid = container_of(work,
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struct cached_fid, lease_break);
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close_cached_dir_lease(cfid);
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}
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int cached_dir_lease_break(struct cifs_tcon *tcon, __u8 lease_key[16])
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{
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if (tcon->cfid->is_valid &&
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!memcmp(lease_key,
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tcon->cfid->fid.lease_key,
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SMB2_LEASE_KEY_SIZE)) {
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tcon->cfid->time = 0;
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INIT_WORK(&tcon->cfid->lease_break,
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smb2_cached_lease_break);
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queue_work(cifsiod_wq,
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&tcon->cfid->lease_break);
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return true;
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}
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return false;
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}
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struct cached_fid *init_cached_dir(void)
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{
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struct cached_fid *cfid;
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cfid = kzalloc(sizeof(*cfid), GFP_KERNEL);
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if (!cfid)
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return NULL;
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INIT_LIST_HEAD(&cfid->dirents.entries);
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mutex_init(&cfid->dirents.de_mutex);
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mutex_init(&cfid->fid_mutex);
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return cfid;
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}
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void free_cached_dir(struct cifs_tcon *tcon)
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{
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kfree(tcon->cfid);
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}
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