2022-03-13 19:01:39

by Trond Myklebust

Subject: [PATCH v10 17/26] NFS: Readdirplus can't help lookup for case insensitive filesystems

From: Trond Myklebust <[email protected]>

If the filesystem is case insensitive, then readdirplus can't help with
cache misses, since it won't return case folded variants of the filename.

Signed-off-by: Trond Myklebust <[email protected]>
---
fs/nfs/dir.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 098fc1bdaac8..dcfc44411787 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -696,6 +696,8 @@ void nfs_readdir_record_entry_cache_miss(struct inode *dir)

static void nfs_lookup_advise_force_readdirplus(struct inode *dir)
{
+ if (nfs_server_capable(dir, NFS_CAP_CASE_INSENSITIVE))
+ return;
nfs_readdir_record_entry_cache_miss(dir);
}

--
2.35.1

2022-03-14 07:58:47

by Trond Myklebust

Subject: [PATCH v10 18/26] NFS: Don't request readdirplus when revalidation was forced

From: Trond Myklebust <[email protected]>

If the revalidation was forced, due to the presence of a LOOKUP_EXCL or
a LOOKUP_REVAL flag, then readdirplus won't help. It also can't help
when we're doing a path component lookup.

Signed-off-by: Trond Myklebust <[email protected]>
---
fs/nfs/dir.c | 26 ++++++++++++++++----------
1 file changed, 16 insertions(+), 10 deletions(-)

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index dcfc44411787..cf7974642a19 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -694,10 +694,13 @@ void nfs_readdir_record_entry_cache_miss(struct inode *dir)
}
}

-static void nfs_lookup_advise_force_readdirplus(struct inode *dir)
+static void nfs_lookup_advise_force_readdirplus(struct inode *dir,
+ unsigned int flags)
{
if (nfs_server_capable(dir, NFS_CAP_CASE_INSENSITIVE))
return;
+ if (flags & (LOOKUP_EXCL | LOOKUP_PARENT | LOOKUP_REVAL))
+ return;
nfs_readdir_record_entry_cache_miss(dir);
}

@@ -1596,15 +1599,17 @@ nfs_lookup_revalidate_delegated(struct inode *dir, struct dentry *dentry,
return nfs_lookup_revalidate_done(dir, dentry, inode, 1);
}

-static int
-nfs_lookup_revalidate_dentry(struct inode *dir, struct dentry *dentry,
- struct inode *inode)
+static int nfs_lookup_revalidate_dentry(struct inode *dir,
+ struct dentry *dentry,
+ struct inode *inode, unsigned int flags)
{
struct nfs_fh *fhandle;
struct nfs_fattr *fattr;
unsigned long dir_verifier;
int ret;

+ trace_nfs_lookup_revalidate_enter(dir, dentry, flags);
+
ret = -ENOMEM;
fhandle = nfs_alloc_fhandle();
fattr = nfs_alloc_fattr_with_label(NFS_SERVER(inode));
@@ -1625,6 +1630,10 @@ nfs_lookup_revalidate_dentry(struct inode *dir, struct dentry *dentry,
}
goto out;
}
+
+ /* Request help from readdirplus */
+ nfs_lookup_advise_force_readdirplus(dir, flags);
+
ret = 0;
if (nfs_compare_fh(NFS_FH(inode), fhandle))
goto out;
@@ -1634,8 +1643,6 @@ nfs_lookup_revalidate_dentry(struct inode *dir, struct dentry *dentry,
nfs_setsecurity(inode, fattr);
nfs_set_verifier(dentry, dir_verifier);

- /* set a readdirplus hint that we had a cache miss */
- nfs_lookup_advise_force_readdirplus(dir);
ret = 1;
out:
nfs_free_fattr(fattr);
@@ -1701,8 +1708,7 @@ nfs_do_lookup_revalidate(struct inode *dir, struct dentry *dentry,
if (NFS_STALE(inode))
goto out_bad;

- trace_nfs_lookup_revalidate_enter(dir, dentry, flags);
- return nfs_lookup_revalidate_dentry(dir, dentry, inode);
+ return nfs_lookup_revalidate_dentry(dir, dentry, inode, flags);
out_valid:
return nfs_lookup_revalidate_done(dir, dentry, inode, 1);
out_bad:
@@ -1896,7 +1902,7 @@ struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, unsigned in
goto out;

/* Notify readdir to use READDIRPLUS */
- nfs_lookup_advise_force_readdirplus(dir);
+ nfs_lookup_advise_force_readdirplus(dir, flags);

no_entry:
res = d_splice_alias(inode, dentry);
@@ -2159,7 +2165,7 @@ nfs4_do_lookup_revalidate(struct inode *dir, struct dentry *dentry,
reval_dentry:
if (flags & LOOKUP_RCU)
return -ECHILD;
- return nfs_lookup_revalidate_dentry(dir, dentry, inode);
+ return nfs_lookup_revalidate_dentry(dir, dentry, inode, flags);

full_reval:
return nfs_do_lookup_revalidate(dir, dentry, flags);
--
2.35.1