linux/fs/nfs/nfs42.h
Anna Schumaker 303a780520 NFSv4.2: Rework scratch handling for READ_PLUS (again)
I found that the read code might send multiple requests using the same
nfs_pgio_header, but nfs4_proc_read_setup() is only called once. This is
how we ended up occasionally double-freeing the scratch buffer, but also
means we set a NULL pointer but non-zero length to the xdr scratch
buffer. This results in an oops the first time decoding needs to copy
something to scratch, which frequently happens when decoding READ_PLUS
hole segments.

I fix this by moving scratch handling into the pageio read code. I
provide a function to allocate scratch space for decoding read replies,
and free the scratch buffer when the nfs_pgio_header is freed.

Fixes: fbd2a05f29 (NFSv4.2: Rework scratch handling for READ_PLUS)
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2023-08-23 15:58:47 -04:00

66 lines
2.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (c) 2014 Anna Schumaker <Anna.Schumaker@Netapp.com>
*/
#ifndef __LINUX_FS_NFS_NFS4_2_H
#define __LINUX_FS_NFS_NFS4_2_H
#include <linux/xattr.h>
/*
* FIXME: four LAYOUTSTATS calls per compound at most! Do we need to support
* more? Need to consider not to pre-alloc too much for a compound.
*/
#define PNFS_LAYOUTSTATS_MAXDEV (4)
#define READ_PLUS_SCRATCH_SIZE (16)
/* nfs4.2proc.c */
#ifdef CONFIG_NFS_V4_2
int nfs42_proc_allocate(struct file *, loff_t, loff_t);
ssize_t nfs42_proc_copy(struct file *, loff_t, struct file *, loff_t, size_t,
struct nl4_server *, nfs4_stateid *, bool);
int nfs42_proc_deallocate(struct file *, loff_t, loff_t);
loff_t nfs42_proc_llseek(struct file *, loff_t, int);
int nfs42_proc_layoutstats_generic(struct nfs_server *,
struct nfs42_layoutstat_data *);
int nfs42_proc_clone(struct file *, struct file *, loff_t, loff_t, loff_t);
int nfs42_proc_layouterror(struct pnfs_layout_segment *lseg,
const struct nfs42_layout_error *errors,
size_t n);
int nfs42_proc_copy_notify(struct file *, struct file *,
struct nfs42_copy_notify_res *);
static inline bool nfs42_files_from_same_server(struct file *in,
struct file *out)
{
struct nfs_client *c_in = (NFS_SERVER(file_inode(in)))->nfs_client;
struct nfs_client *c_out = (NFS_SERVER(file_inode(out)))->nfs_client;
return nfs4_check_serverowner_major_id(c_in->cl_serverowner,
c_out->cl_serverowner);
}
ssize_t nfs42_proc_getxattr(struct inode *inode, const char *name,
void *buf, size_t buflen);
int nfs42_proc_setxattr(struct inode *inode, const char *name,
const void *buf, size_t buflen, int flags);
ssize_t nfs42_proc_listxattrs(struct inode *inode, void *buf,
size_t buflen, u64 *cookiep, bool *eofp);
int nfs42_proc_removexattr(struct inode *inode, const char *name);
/*
* Maximum XDR buffer size needed for a listxattr buffer of buflen size.
*
* The upper boundary is a buffer with all 1-byte sized attribute names.
* They would be 7 bytes long in the eventual buffer ("user.x\0"), and
* 8 bytes long XDR-encoded.
*
* Include the trailing eof word as well.
*/
static inline u32 nfs42_listxattr_xdrsize(u32 buflen)
{
return ((buflen / (XATTR_USER_PREFIX_LEN + 2)) * 8) + 4;
}
#endif /* CONFIG_NFS_V4_2 */
#endif /* __LINUX_FS_NFS_NFS4_2_H */