The patch titled
Subject: afs: split afs_pagecache_valid() out of afs_validate()
has been added to the -mm mm-unstable branch. Its filename is
afs-split-afs_pagecache_valid-out-of-afs_validate.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/afs-split-afs_pagecache_valid-out-of-afs_validate.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Subject: afs: split afs_pagecache_valid() out of afs_validate()
Date: Mon, 27 Mar 2023 18:45:14 +0100
For the map_pages() method, we need a test that does not sleep. The page
fault handler will continue to call the fault() method where we can sleep
and do the full revalidation there.
Link: https://lkml.kernel.org/r/20230327174515.1811532-3-willy@xxxxxxxxxxxxx
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Acked-by: David Howells <dhowells@xxxxxxxxxx>
Tested-by: David Howells <dhowells@xxxxxxxxxx>
Cc: Darrick J. Wong <djwong@xxxxxxxxxx>
Cc: Dave Chinner <david@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/afs/file.c | 14 ++------------
fs/afs/inode.c | 27 +++++++++++++++++++--------
fs/afs/internal.h | 1 +
3 files changed, 22 insertions(+), 20 deletions(-)
--- a/fs/afs/file.c~afs-split-afs_pagecache_valid-out-of-afs_validate
+++ a/fs/afs/file.c
@@ -569,20 +569,10 @@ static void afs_vm_close(struct vm_area_
static vm_fault_t afs_vm_map_pages(struct vm_fault *vmf, pgoff_t start_pgoff, pgoff_t end_pgoff)
{
struct afs_vnode *vnode = AFS_FS_I(file_inode(vmf->vma->vm_file));
- struct afs_file *af = vmf->vma->vm_file->private_data;
- switch (afs_validate(vnode, af->key)) {
- case 0:
+ if (afs_pagecache_valid(vnode))
return filemap_map_pages(vmf, start_pgoff, end_pgoff);
- case -ENOMEM:
- return VM_FAULT_OOM;
- case -EINTR:
- case -ERESTARTSYS:
- return VM_FAULT_RETRY;
- case -ESTALE:
- default:
- return VM_FAULT_SIGBUS;
- }
+ return 0;
}
static ssize_t afs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
--- a/fs/afs/inode.c~afs-split-afs_pagecache_valid-out-of-afs_validate
+++ a/fs/afs/inode.c
@@ -668,6 +668,24 @@ bool afs_check_validity(struct afs_vnode
}
/*
+ * Returns true if the pagecache is still valid. Does not sleep.
+ */
+bool afs_pagecache_valid(struct afs_vnode *vnode)
+{
+ if (unlikely(test_bit(AFS_VNODE_DELETED, &vnode->flags))) {
+ if (vnode->netfs.inode.i_nlink)
+ clear_nlink(&vnode->netfs.inode);
+ return true;
+ }
+
+ if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags) &&
+ afs_check_validity(vnode))
+ return true;
+
+ return false;
+}
+
+/*
* validate a vnode/inode
* - there are several things we need to check
* - parent dir data changes (rm, rmdir, rename, mkdir, create, link,
@@ -684,14 +702,7 @@ int afs_validate(struct afs_vnode *vnode
vnode->fid.vid, vnode->fid.vnode, vnode->flags,
key_serial(key));
- if (unlikely(test_bit(AFS_VNODE_DELETED, &vnode->flags))) {
- if (vnode->netfs.inode.i_nlink)
- clear_nlink(&vnode->netfs.inode);
- goto valid;
- }
-
- if (test_bit(AFS_VNODE_CB_PROMISED, &vnode->flags) &&
- afs_check_validity(vnode))
+ if (afs_pagecache_valid(vnode))
goto valid;
down_write(&vnode->validate_lock);
--- a/fs/afs/internal.h~afs-split-afs_pagecache_valid-out-of-afs_validate
+++ a/fs/afs/internal.h
@@ -1171,6 +1171,7 @@ extern struct inode *afs_iget(struct afs
extern struct inode *afs_root_iget(struct super_block *, struct key *);
extern bool afs_check_validity(struct afs_vnode *);
extern int afs_validate(struct afs_vnode *, struct key *);
+bool afs_pagecache_valid(struct afs_vnode *);
extern int afs_getattr(struct mnt_idmap *idmap, const struct path *,
struct kstat *, u32, unsigned int);
extern int afs_setattr(struct mnt_idmap *idmap, struct dentry *, struct iattr *);
_
Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are
xfs-remove-xfs_filemap_map_pages-wrapper.patch
afs-split-afs_pagecache_valid-out-of-afs_validate.patch
mm-hold-the-rcu-read-lock-over-calls-to-map_pages.patch
