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cifs: add lease tracking to the cached root fid

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Use a read lease for the cached root fid so that we can detect
when the content of the directory changes (via a break) at which time
we close the handle. On next access to the root the handle will be reopened
and cached again.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
This commit is contained in:
Ronnie Sahlberg 2018-06-14 06:48:35 +10:00 committed by Steve French
parent 2fbb56446f
commit a93864d939
6 changed files with 58 additions and 20 deletions
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12
fs/cifs/cifsglob.h
View File

@ -883,6 +883,14 @@ cap_unix(struct cifs_ses *ses)
return ses->server->vals->cap_unix & ses->capabilities;
}
struct cached_fid {
bool is_valid:1; /* Do we have a useable root fid */
struct cifs_fid *fid;
struct mutex fid_mutex;
struct cifs_tcon *tcon;
struct work_struct lease_break;
};
/*
* there is one of these for each connection to a resource on a particular
* session
@ -987,9 +995,7 @@ struct cifs_tcon {
struct fscache_cookie *fscache; /* cookie for share */
#endif
struct list_head pending_opens; /* list of incomplete opens */
bool valid_root_fid:1; /* Do we have a useable root fid */
struct mutex prfid_mutex; /* prevents reopen race after dead ses*/
struct cifs_fid *prfid; /* handle to the directory at top of share */
struct cached_fid crfid; /* Cached root fid */
/* BB add field for back pointer to sb struct(s)? */
};

1
fs/cifs/cifsproto.h
View File

@ -552,6 +552,7 @@ enum securityEnum cifs_select_sectype(struct TCP_Server_Info *,
struct cifs_aio_ctx *cifs_aio_ctx_alloc(void);
void cifs_aio_ctx_release(struct kref *refcount);
int setup_aio_ctx_iter(struct cifs_aio_ctx *ctx, struct iov_iter *iter, int rw);
void smb2_cached_lease_break(struct work_struct *work);
int cifs_alloc_hash(const char *name, struct crypto_shash **shash,
struct sdesc **sdesc);

8
fs/cifs/cifssmb.c
View File

@ -107,10 +107,10 @@ cifs_mark_open_files_invalid(struct cifs_tcon *tcon)
}
spin_unlock(&tcon->open_file_lock);
mutex_lock(&tcon->prfid_mutex);
tcon->valid_root_fid = false;
memset(tcon->prfid, 0, sizeof(struct cifs_fid));
mutex_unlock(&tcon->prfid_mutex);
mutex_lock(&tcon->crfid.fid_mutex);
tcon->crfid.is_valid = false;
memset(tcon->crfid.fid, 0, sizeof(struct cifs_fid));
mutex_unlock(&tcon->crfid.fid_mutex);
/*
* BB Add call to invalidate_inodes(sb) for all superblocks mounted

7
fs/cifs/misc.c
View File

@ -117,8 +117,9 @@ tconInfoAlloc(void)
INIT_LIST_HEAD(&ret_buf->openFileList);
INIT_LIST_HEAD(&ret_buf->tcon_list);
spin_lock_init(&ret_buf->open_file_lock);
mutex_init(&ret_buf->prfid_mutex);
ret_buf->prfid = kzalloc(sizeof(struct cifs_fid), GFP_KERNEL);
mutex_init(&ret_buf->crfid.fid_mutex);
ret_buf->crfid.fid = kzalloc(sizeof(struct cifs_fid),
GFP_KERNEL);
#ifdef CONFIG_CIFS_STATS
spin_lock_init(&ret_buf->stat_lock);
#endif
@ -136,7 +137,7 @@ tconInfoFree(struct cifs_tcon *buf_to_free)
atomic_dec(&tconInfoAllocCount);
kfree(buf_to_free->nativeFileSystem);
kzfree(buf_to_free->password);
kfree(buf_to_free->prfid);
kfree(buf_to_free->crfid.fid);
kfree(buf_to_free);
}

16
fs/cifs/smb2misc.c
View File

@ -492,10 +492,11 @@ cifs_ses_oplock_break(struct work_struct *work)
{
struct smb2_lease_break_work *lw = container_of(work,
struct smb2_lease_break_work, lease_break);
int rc;
int rc = 0;
rc = SMB2_lease_break(0, tlink_tcon(lw->tlink), lw->lease_key,
lw->lease_state);
cifs_dbg(FYI, "Lease release rc %d\n", rc);
cifs_put_tlink(lw->tlink);
kfree(lw);
@ -561,6 +562,7 @@ smb2_tcon_has_lease(struct cifs_tcon *tcon, struct smb2_lease_break *rsp,
open->oplock = lease_state;
}
return found;
}
@ -603,6 +605,18 @@ smb2_is_valid_lease_break(char *buffer)
return true;
}
spin_unlock(&tcon->open_file_lock);
if (tcon->crfid.is_valid &&
!memcmp(rsp->LeaseKey,
tcon->crfid.fid->lease_key,
SMB2_LEASE_KEY_SIZE)) {
INIT_WORK(&tcon->crfid.lease_break,
smb2_cached_lease_break);
queue_work(cifsiod_wq,
&tcon->crfid.lease_break);
spin_unlock(&cifs_tcp_ses_lock);
return true;
}
}
}
}

34
fs/cifs/smb2ops.c
View File

@ -323,6 +323,21 @@ SMB3_request_interfaces(const unsigned int xid, struct cifs_tcon *tcon)
}
#endif /* STATS2 */
void
smb2_cached_lease_break(struct work_struct *work)
{
struct cached_fid *cfid = container_of(work,
struct cached_fid, lease_break);
mutex_lock(&cfid->fid_mutex);
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);
cfid->is_valid = false;
}
mutex_unlock(&cfid->fid_mutex);
}
/*
* Open the directory at the root of a share
*/
@ -331,13 +346,13 @@ int open_shroot(unsigned int xid, struct cifs_tcon *tcon, struct cifs_fid *pfid)
struct cifs_open_parms oparams;
int rc;
__le16 srch_path = 0; /* Null - since an open of top of share */
u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
u8 oplock = SMB2_OPLOCK_LEVEL_II;
mutex_lock(&tcon->prfid_mutex);
if (tcon->valid_root_fid) {
mutex_lock(&tcon->crfid.fid_mutex);
if (tcon->crfid.is_valid) {
cifs_dbg(FYI, "found a cached root file handle\n");
memcpy(pfid, tcon->prfid, sizeof(struct cifs_fid));
mutex_unlock(&tcon->prfid_mutex);
memcpy(pfid, tcon->crfid.fid, sizeof(struct cifs_fid));
mutex_unlock(&tcon->crfid.fid_mutex);
return 0;
}
@ -350,10 +365,11 @@ int open_shroot(unsigned int xid, struct cifs_tcon *tcon, struct cifs_fid *pfid)
rc = SMB2_open(xid, &oparams, &srch_path, &oplock, NULL, NULL, NULL);
if (rc == 0) {
memcpy(tcon->prfid, pfid, sizeof(struct cifs_fid));
tcon->valid_root_fid = true;
memcpy(tcon->crfid.fid, pfid, sizeof(struct cifs_fid));
tcon->crfid.tcon = tcon;
tcon->crfid.is_valid = true;
}
mutex_unlock(&tcon->prfid_mutex);
mutex_unlock(&tcon->crfid.fid_mutex);
return rc;
}
@ -436,7 +452,7 @@ smb2_is_path_accessible(const unsigned int xid, struct cifs_tcon *tcon,
struct cifs_open_parms oparms;
struct cifs_fid fid;
if ((*full_path == 0) && tcon->valid_root_fid)
if ((*full_path == 0) && tcon->crfid.is_valid)
return 0;
utf16_path = cifs_convert_path_to_utf16(full_path, cifs_sb);