[PATCH 2/4] nfsd: Use the filehandle to look up the struct nfs4_file instead of inode

[Jeff Layton <jlayton@primarydata.com>]

From: Trond Myklebust <trond.myklebust@primarydata.com>

This makes more sense anyway since an inode pointer value can change
even when the filehandle doesn't.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
---
 fs/nfsd/nfs4state.c | 35 +++++++++++++++++++++++------------
 1 file changed, 23 insertions(+), 12 deletions(-)

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 393cd83a4f42..c540a46f6305 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -368,10 +368,22 @@ static unsigned int ownerstr_hashval(u32 clientid, struct xdr_netobj *ownername)
 #define FILE_HASH_BITS                   8
 #define FILE_HASH_SIZE                  (1 << FILE_HASH_BITS)
 
-static unsigned int file_hashval(struct inode *ino)
+static unsigned int nfsd_fh_hashval(struct knfsd_fh *fh)
 {
-	/* XXX: why are we hashing on inode pointer, anyway? */
-	return hash_ptr(ino, FILE_HASH_BITS);
+	return jhash2(fh->fh_base.fh_pad, XDR_QUADLEN(fh->fh_size), 0);
+}
+
+static unsigned int file_hashval(struct knfsd_fh *fh)
+{
+	return nfsd_fh_hashval(fh) & (FILE_HASH_SIZE - 1);
+}
+
+static bool nfsd_fh_match(struct knfsd_fh *fh1, struct knfsd_fh *fh2)
+{
+	return fh1->fh_size == fh2->fh_size &&
+		!memcmp(fh1->fh_base.fh_pad,
+				fh2->fh_base.fh_pad,
+				fh1->fh_size);
 }
 
 static struct hlist_head file_hashtbl[FILE_HASH_SIZE];
@@ -2836,7 +2848,7 @@ static struct nfs4_file *nfsd4_alloc_file(void)
 static void nfsd4_init_file(struct nfs4_file *fp, struct inode *ino,
 		struct knfsd_fh *fh)
 {
-	unsigned int hashval = file_hashval(ino);
+	unsigned int hashval = file_hashval(fh);
 
 	lockdep_assert_held(&state_lock);
 
@@ -3025,15 +3037,15 @@ find_openstateowner_str(unsigned int hashval, struct nfsd4_open *open,
 
 /* search file_hashtbl[] for file */
 static struct nfs4_file *
-find_file_locked(struct inode *ino)
+find_file_locked(struct knfsd_fh *fh)
 {
-	unsigned int hashval = file_hashval(ino);
+	unsigned int hashval = file_hashval(fh);
 	struct nfs4_file *fp;
 
 	lockdep_assert_held(&state_lock);
 
 	hlist_for_each_entry(fp, &file_hashtbl[hashval], fi_hash) {
-		if (fp->fi_inode == ino) {
+		if (nfsd_fh_match(&fp->fi_fhandle, fh)) {
 			get_nfs4_file(fp);
 			return fp;
 		}
@@ -3042,12 +3054,12 @@ find_file_locked(struct inode *ino)
 }
 
 static struct nfs4_file *
-find_file(struct inode *ino)
+find_file(struct knfsd_fh *fh)
 {
 	struct nfs4_file *fp;
 
 	spin_lock(&state_lock);
-	fp = find_file_locked(ino);
+	fp = find_file_locked(fh);
 	spin_unlock(&state_lock);
 	return fp;
 }
@@ -3058,7 +3070,7 @@ find_or_add_file(struct inode *ino, struct nfs4_file *new, struct knfsd_fh *fh)
 	struct nfs4_file *fp;
 
 	spin_lock(&state_lock);
-	fp = find_file_locked(ino);
+	fp = find_file_locked(fh);
 	if (fp == NULL) {
 		nfsd4_init_file(new, ino, fh);
 		fp = new;
@@ -3075,11 +3087,10 @@ find_or_add_file(struct inode *ino, struct nfs4_file *new, struct knfsd_fh *fh)
 static __be32
 nfs4_share_conflict(struct svc_fh *current_fh, unsigned int deny_type)
 {
-	struct inode *ino = current_fh->fh_dentry->d_inode;
 	struct nfs4_file *fp;
 	__be32 ret = nfs_ok;
 
-	fp = find_file(ino);
+	fp = find_file(&current_fh->fh_handle);
 	if (!fp)
 		return ret;
 	/* Check for conflicting share reservations */
-- 
1.9.3