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cifs: find and use the dentry for cached non-root directories also

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This allows us to use cached attributes for the entries in a cached
directory for as long as a lease is held on the directory itself.
Previously we have always allowed "used cached attributes for 1 second"
but this extends this to the lifetime of the lease as well as making the
caching safer.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
This commit is contained in:
Ronnie Sahlberg 2022-10-12 06:13:03 -05:00 committed by Steve French
parent ebe98f1447
commit e4029e0726
1 changed files with 49 additions and 14 deletions
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63
fs/cifs/cached_dir.c
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@ -5,6 +5,7 @@
* Copyright (c) 2022, Ronnie Sahlberg <lsahlber@redhat.com>
*/
#include <linux/namei.h>
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifs_debug.h"
@ -59,6 +60,44 @@ static struct cached_fid *find_or_create_cached_dir(struct cached_fids *cfids,
return cfid;
}
static struct dentry *
path_to_dentry(struct cifs_sb_info *cifs_sb, const char *path)
{
struct dentry *dentry;
const char *s, *p;
char sep;
sep = CIFS_DIR_SEP(cifs_sb);
dentry = dget(cifs_sb->root);
s = path;
do {
struct inode *dir = d_inode(dentry);
struct dentry *child;
if (!S_ISDIR(dir->i_mode)) {
dput(dentry);
dentry = ERR_PTR(-ENOTDIR);
break;
}
/* skip separators */
while (*s == sep)
s++;
if (!*s)
break;
p = s++;
/* next separator */
while (*s && *s != sep)
s++;
child = lookup_positive_unlocked(p, dentry, s - p);
dput(dentry);
dentry = child;
} while (!IS_ERR(dentry));
return dentry;
}
/*
* Open the and cache a directory handle.
* If error then *cfid is not initialized.
@ -86,7 +125,6 @@ int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon,
struct cached_fid *cfid;
struct cached_fids *cfids;
if (tcon == NULL || tcon->cfids == NULL || tcon->nohandlecache ||
is_smb1_server(tcon->ses->server))
return -EOPNOTSUPP;
@ -101,13 +139,6 @@ int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon,
if (cifs_sb->root == NULL)
return -ENOENT;
/*
* TODO: for better caching we need to find and use the dentry also
* for non-root directories.
*/
if (!path[0])
dentry = cifs_sb->root;
utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
if (!utf16_path)
return -ENOMEM;
@ -199,12 +230,6 @@ int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon,
oparms.fid->mid = le64_to_cpu(o_rsp->hdr.MessageId);
#endif /* CIFS_DEBUG2 */
cfid->tcon = tcon;
if (dentry) {
cfid->dentry = dentry;
dget(dentry);
}
/* BB TBD check to see if oplock level check can be removed below */
if (o_rsp->OplockLevel != SMB2_OPLOCK_LEVEL_LEASE)
goto oshr_free;
@ -223,6 +248,16 @@ int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon,
&rsp_iov[1], sizeof(struct smb2_file_all_info),
(char *)&cfid->file_all_info))
cfid->file_all_info_is_valid = true;
if (!path[0])
dentry = dget(cifs_sb->root);
else {
dentry = path_to_dentry(cifs_sb, path);
if (IS_ERR(dentry))
goto oshr_free;
}
cfid->dentry = dentry;
cfid->tcon = tcon;
cfid->time = jiffies;
cfid->is_open = true;
cfid->has_lease = true;