From: Frank van der Linden <fllinden@amazon.com>
To: <bfields@fieldses.org>, <chuck.lever@oracle.com>,
<linux-nfs@vger.kernel.org>
Cc: Frank van der Linden <fllinden@amazon.com>
Subject: [PATCH 02/14] xattr: modify vfs_{set,remove}xattr for NFS server use
Date: Wed, 11 Mar 2020 19:59:42 +0000 [thread overview]
Message-ID: <20200311195954.27117-3-fllinden@amazon.com> (raw)
In-Reply-To: <20200311195954.27117-1-fllinden@amazon.com>
To be called from the upcoming NFS server xattr code, the vfs_removexattr
and vfs_setxattr need some modifications.
First, they need to grow a _locked variant, since the NFS server code
will call this with i_rwsem held. It needs to do that in fh_lock to be
able to atomically provide the before and after change attributes.
Second, RFC 8276 (NFSv4 extended attribute support) specifies that
delegations should be recalled (8.4.2.4, 8.4.4.4) when a SETXATTR
or REMOVEXATTR operation is performed. So, like with other fs
operations, try to break the delegation. The _locked version of
these operations will not wait for the delegation to be successfully
broken, instead returning an error if it wasn't, so that the NFS
server code can return NFS4ERR_DELAY to the client (similar to
what e.g. vfs_link does).
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
---
fs/xattr.c | 63 +++++++++++++++++++++++++++++++++++++++++++++------
include/linux/xattr.h | 2 ++
2 files changed, 58 insertions(+), 7 deletions(-)
diff --git a/fs/xattr.c b/fs/xattr.c
index 90dd78f0eb27..58013bcbc333 100644
--- a/fs/xattr.c
+++ b/fs/xattr.c
@@ -204,10 +204,10 @@ int __vfs_setxattr_noperm(struct dentry *dentry, const char *name,
return error;
}
-
int
-vfs_setxattr(struct dentry *dentry, const char *name, const void *value,
- size_t size, int flags)
+__vfs_setxattr_locked(struct dentry *dentry, const char *name,
+ const void *value, size_t size, int flags,
+ struct inode **delegated_inode)
{
struct inode *inode = dentry->d_inode;
int error;
@@ -216,15 +216,40 @@ vfs_setxattr(struct dentry *dentry, const char *name, const void *value,
if (error)
return error;
- inode_lock(inode);
error = security_inode_setxattr(dentry, name, value, size, flags);
if (error)
goto out;
+ error = try_break_deleg(inode, delegated_inode);
+ if (error)
+ goto out;
+
error = __vfs_setxattr_noperm(dentry, name, value, size, flags);
out:
+ return error;
+}
+EXPORT_SYMBOL_GPL(__vfs_setxattr_locked);
+
+int
+vfs_setxattr(struct dentry *dentry, const char *name, const void *value,
+ size_t size, int flags)
+{
+ struct inode *inode = dentry->d_inode;
+ struct inode *delegated_inode = NULL;
+ int error;
+
+retry_deleg:
+ inode_lock(inode);
+ error = __vfs_setxattr_locked(dentry, name, value, size, flags,
+ &delegated_inode);
inode_unlock(inode);
+
+ if (delegated_inode) {
+ error = break_deleg_wait(&delegated_inode);
+ if (!error)
+ goto retry_deleg;
+ }
return error;
}
EXPORT_SYMBOL_GPL(vfs_setxattr);
@@ -379,7 +404,8 @@ __vfs_removexattr(struct dentry *dentry, const char *name)
EXPORT_SYMBOL(__vfs_removexattr);
int
-vfs_removexattr(struct dentry *dentry, const char *name)
+__vfs_removexattr_locked(struct dentry *dentry, const char *name,
+ struct inode **delegated_inode)
{
struct inode *inode = dentry->d_inode;
int error;
@@ -388,11 +414,14 @@ vfs_removexattr(struct dentry *dentry, const char *name)
if (error)
return error;
- inode_lock(inode);
error = security_inode_removexattr(dentry, name);
if (error)
goto out;
+ error = try_break_deleg(inode, delegated_inode);
+ if (error)
+ goto out;
+
error = __vfs_removexattr(dentry, name);
if (!error) {
@@ -401,12 +430,32 @@ vfs_removexattr(struct dentry *dentry, const char *name)
}
out:
+ return error;
+}
+EXPORT_SYMBOL_GPL(__vfs_removexattr_locked);
+
+int
+vfs_removexattr(struct dentry *dentry, const char *name)
+{
+ struct inode *inode = dentry->d_inode;
+ struct inode *delegated_inode = NULL;
+ int error;
+
+retry_deleg:
+ inode_lock(inode);
+ error = __vfs_removexattr_locked(dentry, name, &delegated_inode);
inode_unlock(inode);
+
+ if (delegated_inode) {
+ error = break_deleg_wait(&delegated_inode);
+ if (!error)
+ goto retry_deleg;
+ }
+
return error;
}
EXPORT_SYMBOL_GPL(vfs_removexattr);
-
/*
* Extended attribute SET operations
*/
diff --git a/include/linux/xattr.h b/include/linux/xattr.h
index 6dad031be3c2..3a71ad716da5 100644
--- a/include/linux/xattr.h
+++ b/include/linux/xattr.h
@@ -51,8 +51,10 @@ ssize_t vfs_getxattr(struct dentry *, const char *, void *, size_t);
ssize_t vfs_listxattr(struct dentry *d, char *list, size_t size);
int __vfs_setxattr(struct dentry *, struct inode *, const char *, const void *, size_t, int);
int __vfs_setxattr_noperm(struct dentry *, const char *, const void *, size_t, int);
+int __vfs_setxattr_locked(struct dentry *, const char *, const void *, size_t, int, struct inode **);
int vfs_setxattr(struct dentry *, const char *, const void *, size_t, int);
int __vfs_removexattr(struct dentry *, const char *);
+int __vfs_removexattr_locked(struct dentry *, const char *, struct inode **);
int vfs_removexattr(struct dentry *, const char *);
ssize_t generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size);
--
2.16.6
next prev parent reply other threads:[~2020-03-11 19:59 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-11 19:59 [PATCH 00/14] server side user xattr support (RFC 8276) Frank van der Linden
2020-03-11 19:59 ` [PATCH 01/14] nfs,nfsd: NFSv4.2 extended attribute protocol definitions Frank van der Linden
2020-03-11 19:59 ` Frank van der Linden [this message]
2020-03-12 16:23 ` [PATCH 02/14] xattr: modify vfs_{set,remove}xattr for NFS server use Chuck Lever
2020-03-13 15:35 ` J. Bruce Fields
2020-03-13 16:07 ` [PATCH 02/14] xattr: modify vfs_{set, remove}xattr " Frank van der Linden
2020-03-13 21:06 ` J. Bruce Fields
2020-03-11 19:59 ` [PATCH 03/14] nfsd: split off the write decode code in to a separate function Frank van der Linden
2020-03-11 19:59 ` [PATCH 04/14] nfsd: make sure the nfsd4_ops array has the right size Frank van der Linden
2020-03-11 19:59 ` [PATCH 05/14] nfsd: add defines for NFSv4.2 extended attribute support Frank van der Linden
2020-03-12 16:23 ` Chuck Lever
2020-03-11 19:59 ` [PATCH 06/14] nfsd: define xattr functions to call in to their vfs counterparts Frank van der Linden
2020-03-12 7:37 ` kbuild test robot
2020-03-12 16:23 ` Chuck Lever
2020-03-12 17:16 ` Frank van der Linden
2020-03-12 17:57 ` Chuck Lever
2020-03-11 19:59 ` [PATCH 07/14] nfsd: take xattr bits in to account for permission checks Frank van der Linden
2020-03-11 19:59 ` [PATCH 08/14] nfsd: add structure definitions for xattr requests / responses Frank van der Linden
2020-03-11 19:59 ` [PATCH 09/14] nfsd: use kvmalloc in svcxdr_tmpalloc Frank van der Linden
2020-03-11 19:59 ` [PATCH 10/14] nfsd: implement the xattr procedure functions Frank van der Linden
2020-03-12 10:28 ` kbuild test robot
2020-03-12 16:24 ` Chuck Lever
2020-03-11 19:59 ` [PATCH 11/14] nfsd: add user xattr RPC XDR encoding/decoding logic Frank van der Linden
2020-03-12 13:28 ` kbuild test robot
2020-03-12 16:24 ` Chuck Lever
2020-03-19 22:13 ` Frank van der Linden
2020-03-19 22:15 ` Chuck Lever
2020-03-25 23:44 ` Frank van der Linden
2020-03-26 14:12 ` Chuck Lever
2020-03-12 19:16 ` Chuck Lever
2020-03-20 16:47 ` Frank van der Linden
2020-03-20 17:34 ` Chuck Lever
2020-03-20 17:54 ` J. Bruce Fields
2020-03-20 19:44 ` Frank van der Linden
2020-03-11 19:59 ` [PATCH 12/14] nfsd: add xattr operations to ops array Frank van der Linden
2020-03-11 19:59 ` [PATCH 13/14] xattr: add a function to check if a namespace is supported Frank van der Linden
2020-03-12 16:24 ` Chuck Lever
2020-03-11 19:59 ` [PATCH 14/14] nfsd: add fattr support for user extended attributes Frank van der Linden
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