[PATCH AUTOSEL 6.6 01/16] NFSv4: Fix memory leak in nfs4_set_security_label

[PATCH AUTOSEL 6.6 01/16] NFSv4: Fix memory leak in nfs4_set_security_label

[Sasha Levin]

From: Dmitry Mastykin <mastichi@gmail.com>

[ Upstream commit aad11473f8f4be3df86461081ce35ec5b145ba68 ]

We leak nfs_fattr and nfs4_label every time we set a security xattr.

Signed-off-by: Dmitry Mastykin <mastichi@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/nfs/nfs4proc.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index f0953200acd08..05490d4784f1a 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -6268,6 +6268,7 @@ nfs4_set_security_label(struct inode *inode, const void *buf, size_t buflen)
 	if (status == 0)
 		nfs_setsecurity(inode, fattr);
 
+	nfs_free_fattr(fattr);
 	return status;
 }
 #endif	/* CONFIG_NFS_V4_SECURITY_LABEL */
-- 
2.43.0

[PATCH AUTOSEL 6.6 02/16] nfs: propagate readlink errors in nfs_symlink_filler

[Sasha Levin]

From: Sagi Grimberg <sagi@grimberg.me>

[ Upstream commit 134d0b3f2440cdddd12fc3444c9c0f62331ce6fc ]

There is an inherent race where a symlink file may have been overriden
(by a different client) between lookup and readlink, resulting in a
spurious EIO error returned to userspace. Fix this by propagating back
ESTALE errors such that the vfs will retry the lookup/get_link (similar
to nfs4_file_open) at least once.

Cc: Dan Aloni <dan.aloni@vastdata.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/nfs/symlink.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/nfs/symlink.c b/fs/nfs/symlink.c
index 0e27a2e4e68b8..13818129d268f 100644
--- a/fs/nfs/symlink.c
+++ b/fs/nfs/symlink.c
@@ -41,7 +41,7 @@ static int nfs_symlink_filler(struct file *file, struct folio *folio)
 error:
 	folio_set_error(folio);
 	folio_unlock(folio);
-	return -EIO;
+	return error;
 }
 
 static const char *nfs_get_link(struct dentry *dentry,
-- 
2.43.0

[PATCH AUTOSEL 6.6 03/16] nfs: Avoid flushing many pages with NFS_FILE_SYNC

[Sasha Levin]

From: Jan Kara <jack@suse.cz>

[ Upstream commit a527c3ba41c4c61e2069bfce4091e5515f06a8dd ]

When we are doing WB_SYNC_ALL writeback, nfs submits write requests with
NFS_FILE_SYNC flag to the server (which then generally treats it as an
O_SYNC write). This helps to reduce latency for single requests but when
submitting more requests, additional fsyncs on the server side hurt
latency. NFS generally avoids this additional overhead by not setting
NFS_FILE_SYNC if desc->pg_moreio is set.

However this logic doesn't always work. When we do random 4k writes to a huge
file and then call fsync(2), each page writeback is going to be sent with
NFS_FILE_SYNC because after preparing one page for writeback, we start writing
back next, nfs_do_writepage() will call nfs_pageio_cond_complete() which finds
the page is not contiguous with previously prepared IO and submits is *without*
setting desc->pg_moreio.  Hence NFS_FILE_SYNC is used resulting in poor
performance.

Fix the problem by setting desc->pg_moreio in nfs_pageio_cond_complete() before
submitting outstanding IO. This improves throughput of
fsync-after-random-writes on my test SSD from ~70MB/s to ~250MB/s.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/nfs/pagelist.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 6efb5068c116e..040b6b79c75e5 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -1545,6 +1545,11 @@ void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *desc, pgoff_t index)
 					continue;
 			} else if (index == prev->wb_index + 1)
 				continue;
+			/*
+			 * We will submit more requests after these. Indicate
+			 * this to the underlying layers.
+			 */
+			desc->pg_moreio = 1;
 			nfs_pageio_complete(desc);
 			break;
 		}
-- 
2.43.0

[PATCH AUTOSEL 6.6 04/16] nfs: don't invalidate dentries on transient errors

[Sasha Levin]

From: Scott Mayhew <smayhew@redhat.com>

[ Upstream commit 0c8c7c559740d2d8b66048162af6c4dba8f0c88c ]

This is a slight variation on a patch previously proposed by Neil Brown
that never got merged.

Prior to commit 5ceb9d7fdaaf ("NFS: Refactor nfs_lookup_revalidate()"),
any error from nfs_lookup_verify_inode() other than -ESTALE would result
in nfs_lookup_revalidate() returning that error (-ESTALE is mapped to
zero).

Since that commit, all errors result in nfs_lookup_revalidate()
returning zero, resulting in dentries being invalidated where they
previously were not (particularly in the case of -ERESTARTSYS).

Fix it by passing the actual error code to nfs_lookup_revalidate_done(),
and leaving the decision on whether to  map the error code to zero or
one to nfs_lookup_revalidate_done().

A simple reproducer is to run the following python code in a
subdirectory of an NFS mount (not in the root of the NFS mount):

---8<---
import os
import multiprocessing
import time

if __name__=="__main__":
    multiprocessing.set_start_method("spawn")

    count = 0
    while True:
        try:
            os.getcwd()
            pool = multiprocessing.Pool(10)
            pool.close()
            pool.terminate()
            count += 1
        except Exception as e:
            print(f"Failed after {count} iterations")
            print(e)
            break
---8<---

Prior to commit 5ceb9d7fdaaf, the above code would run indefinitely.
After commit 5ceb9d7fdaaf, it fails almost immediately with -ENOENT.

Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/nfs/dir.c | 27 +++++++++++++--------------
 1 file changed, 13 insertions(+), 14 deletions(-)

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 2a0f069d5a096..39f7549afcf5b 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1625,7 +1625,16 @@ nfs_lookup_revalidate_done(struct inode *dir, struct dentry *dentry,
 	switch (error) {
 	case 1:
 		break;
-	case 0:
+	case -ETIMEDOUT:
+		if (inode && (IS_ROOT(dentry) ||
+			      NFS_SERVER(inode)->flags & NFS_MOUNT_SOFTREVAL))
+			error = 1;
+		break;
+	case -ESTALE:
+	case -ENOENT:
+		error = 0;
+		fallthrough;
+	default:
 		/*
 		 * We can't d_drop the root of a disconnected tree:
 		 * its d_hash is on the s_anon list and d_drop() would hide
@@ -1680,18 +1689,8 @@ static int nfs_lookup_revalidate_dentry(struct inode *dir,
 
 	dir_verifier = nfs_save_change_attribute(dir);
 	ret = NFS_PROTO(dir)->lookup(dir, dentry, fhandle, fattr);
-	if (ret < 0) {
-		switch (ret) {
-		case -ESTALE:
-		case -ENOENT:
-			ret = 0;
-			break;
-		case -ETIMEDOUT:
-			if (NFS_SERVER(inode)->flags & NFS_MOUNT_SOFTREVAL)
-				ret = 1;
-		}
+	if (ret < 0)
 		goto out;
-	}
 
 	/* Request help from readdirplus */
 	nfs_lookup_advise_force_readdirplus(dir, flags);
@@ -1735,7 +1734,7 @@ nfs_do_lookup_revalidate(struct inode *dir, struct dentry *dentry,
 			 unsigned int flags)
 {
 	struct inode *inode;
-	int error;
+	int error = 0;
 
 	nfs_inc_stats(dir, NFSIOS_DENTRYREVALIDATE);
 	inode = d_inode(dentry);
@@ -1780,7 +1779,7 @@ nfs_do_lookup_revalidate(struct inode *dir, struct dentry *dentry,
 out_bad:
 	if (flags & LOOKUP_RCU)
 		return -ECHILD;
-	return nfs_lookup_revalidate_done(dir, dentry, inode, 0);
+	return nfs_lookup_revalidate_done(dir, dentry, inode, error);
 }
 
 static int
-- 
2.43.0