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NFS: decode_dirent should use an xdr_stream 

Convert nfs*xdr.c to use an xdr stream in decode_dirent.  This will prevent a
kernel oops that has been occuring when reading a vmapped page.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Bryan Schumaker 2010-10-20 15:44:29 -04:00 committed by Trond Myklebust
parent ba8e452a4f
commit babddc72a9
7 changed files with 203 additions and 41 deletions
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29
fs/nfs/dir.c
View File

@ -171,7 +171,7 @@ struct nfs_cache_array {
#define MAX_READDIR_ARRAY ((PAGE_SIZE - sizeof(struct nfs_cache_array)) / sizeof(struct nfs_cache_array_entry))
typedef __be32 * (*decode_dirent_t)(__be32 *, struct nfs_entry *, int);
typedef __be32 * (*decode_dirent_t)(struct xdr_stream *, struct nfs_entry *, int);
typedef struct {
struct file *file;
struct page *page;
@ -357,13 +357,11 @@ error:
/* Fill in an entry based on the xdr code stored in desc->page */
static
int xdr_decode(nfs_readdir_descriptor_t *desc, struct nfs_entry *entry, __be32 **ptr)
int xdr_decode(nfs_readdir_descriptor_t *desc, struct nfs_entry *entry, struct xdr_stream *stream)
{
__be32 *p = *ptr;
p = desc->decode(p, entry, desc->plus);
__be32 *p = desc->decode(stream, entry, desc->plus);
if (IS_ERR(p))
return PTR_ERR(p);
*ptr = p;
entry->fattr->time_start = desc->timestamp;
entry->fattr->gencount = desc->gencount;
@ -438,10 +436,23 @@ out:
/* Perform conversion from xdr to cache array */
static
void nfs_readdir_page_filler(nfs_readdir_descriptor_t *desc, struct nfs_entry *entry,
struct page *xdr_page, struct page *page)
struct page *xdr_page, struct page *page, unsigned int buflen)
{
struct xdr_stream stream;
struct xdr_buf buf;
__be32 *ptr = kmap(xdr_page);
while (xdr_decode(desc, entry, &ptr) == 0) {
buf.head->iov_base = xdr_page;
buf.head->iov_len = buflen;
buf.tail->iov_len = 0;
buf.page_base = 0;
buf.page_len = 0;
buf.buflen = buf.head->iov_len;
buf.len = buf.head->iov_len;
xdr_init_decode(&stream, &buf, ptr);
while (xdr_decode(desc, entry, &stream) == 0) {
if (nfs_readdir_add_to_array(entry, page) == -1)
break;
if (desc->plus == 1)
@ -458,6 +469,7 @@ int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page,
struct file *file = desc->file;
struct nfs_cache_array *array;
int status = 0;
unsigned int array_size = 1;
entry.prev_cookie = 0;
entry.cookie = *desc->dir_cookie;
@ -476,9 +488,10 @@ int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page,
goto out_release_array;
do {
status = nfs_readdir_xdr_filler(xdr_page, desc, &entry, file, inode);
if (status < 0)
break;
nfs_readdir_page_filler(desc, &entry, xdr_page, page);
nfs_readdir_page_filler(desc, &entry, xdr_page, page, array_size * PAGE_SIZE);
} while (array->eof_index < 0 && array->size < MAX_READDIR_ARRAY);
put_page(xdr_page);

6
fs/nfs/internal.h
View File

@ -181,15 +181,15 @@ extern void nfs_destroy_directcache(void);
/* nfs2xdr.c */
extern int nfs_stat_to_errno(int);
extern struct rpc_procinfo nfs_procedures[];
extern __be32 * nfs_decode_dirent(__be32 *, struct nfs_entry *, int);
extern __be32 *nfs_decode_dirent(struct xdr_stream *, struct nfs_entry *, int);
/* nfs3xdr.c */
extern struct rpc_procinfo nfs3_procedures[];
extern __be32 *nfs3_decode_dirent(__be32 *, struct nfs_entry *, int);
extern __be32 *nfs3_decode_dirent(struct xdr_stream *, struct nfs_entry *, int);
/* nfs4xdr.c */
#ifdef CONFIG_NFS_V4
extern __be32 *nfs4_decode_dirent(__be32 *p, struct nfs_entry *entry, int plus);
extern __be32 *nfs4_decode_dirent(struct xdr_stream *, struct nfs_entry *entry, int plus);
#endif
#ifdef CONFIG_NFS_V4_1
extern const u32 nfs41_maxread_overhead;

41
fs/nfs/nfs2xdr.c
View File

@ -500,25 +500,56 @@ err_unmap:
goto out;
}
__be32 *
nfs_decode_dirent(__be32 *p, struct nfs_entry *entry, int plus)
static void print_overflow_msg(const char *func, const struct xdr_stream *xdr)
{
if (!*p++) {
if (!*p)
dprintk("nfs: %s: prematurely hit end of receive buffer. "
"Remaining buffer length is %tu words.\n",
func, xdr->end - xdr->p);
}
__be32 *
nfs_decode_dirent(struct xdr_stream *xdr, struct nfs_entry *entry, int plus)
{
__be32 *p;
p = xdr_inline_decode(xdr, 4);
if (unlikely(!p))
goto out_overflow;
if (!ntohl(*p++)) {
p = xdr_inline_decode(xdr, 4);
if (unlikely(!p))
goto out_overflow;
if (!ntohl(*p++))
return ERR_PTR(-EAGAIN);
entry->eof = 1;
return ERR_PTR(-EBADCOOKIE);
}
p = xdr_inline_decode(xdr, 8);
if (unlikely(!p))
goto out_overflow;
entry->ino = ntohl(*p++);
entry->len = ntohl(*p++);
p = xdr_inline_decode(xdr, entry->len + 4);
if (unlikely(!p))
goto out_overflow;
entry->name = (const char *) p;
p += XDR_QUADLEN(entry->len);
entry->prev_cookie = entry->cookie;
entry->cookie = ntohl(*p++);
entry->eof = !p[0] && p[1];
p = xdr_inline_peek(xdr, 8);
if (p != NULL)
entry->eof = !p[0] && p[1];
else
entry->eof = 0;
return p;
out_overflow:
print_overflow_msg(__func__, xdr);
return ERR_PTR(-EIO);
}
/*

93
fs/nfs/nfs3xdr.c
View File

@ -100,6 +100,13 @@ static const umode_t nfs_type2fmt[] = {
[NF3FIFO] = S_IFIFO,
};
static void print_overflow_msg(const char *func, const struct xdr_stream *xdr)
{
dprintk("nfs: %s: prematurely hit end of receive buffer. "
"Remaining buffer length is %tu words.\n",
func, xdr->end - xdr->p);
}
/*
* Common NFS XDR functions as inlines
*/
@ -119,6 +126,29 @@ xdr_decode_fhandle(__be32 *p, struct nfs_fh *fh)
return NULL;
}
static inline __be32 *
xdr_decode_fhandle_stream(struct xdr_stream *xdr, struct nfs_fh *fh)
{
__be32 *p;
p = xdr_inline_decode(xdr, 4);
if (unlikely(!p))
goto out_overflow;
fh->size = ntohl(*p++);
if (fh->size <= NFS3_FHSIZE) {
p = xdr_inline_decode(xdr, fh->size);
if (unlikely(!p))
goto out_overflow;
memcpy(fh->data, p, fh->size);
return p + XDR_QUADLEN(fh->size);
}
return NULL;
out_overflow:
print_overflow_msg(__func__, xdr);
return ERR_PTR(-EIO);
}
/*
* Encode/decode time.
*/
@ -240,6 +270,26 @@ xdr_decode_post_op_attr(__be32 *p, struct nfs_fattr *fattr)
return p;
}
static inline __be32 *
xdr_decode_post_op_attr_stream(struct xdr_stream *xdr, struct nfs_fattr *fattr)
{
__be32 *p;
p = xdr_inline_decode(xdr, 4);
if (unlikely(!p))
goto out_overflow;
if (ntohl(*p++)) {
p = xdr_inline_decode(xdr, 84);
if (unlikely(!p))
goto out_overflow;
p = xdr_decode_fattr(p, fattr);
}
return p;
out_overflow:
print_overflow_msg(__func__, xdr);
return ERR_PTR(-EIO);
}
static inline __be32 *
xdr_decode_pre_op_attr(__be32 *p, struct nfs_fattr *fattr)
{
@ -616,19 +666,33 @@ err_unmap:
}
__be32 *
nfs3_decode_dirent(__be32 *p, struct nfs_entry *entry, int plus)
nfs3_decode_dirent(struct xdr_stream *xdr, struct nfs_entry *entry, int plus)
{
__be32 *p;
struct nfs_entry old = *entry;
if (!*p++) {
if (!*p)
p = xdr_inline_decode(xdr, 4);
if (unlikely(!p))
goto out_overflow;
if (!ntohl(*p++)) {
p = xdr_inline_decode(xdr, 4);
if (unlikely(!p))
goto out_overflow;
if (!ntohl(*p++))
return ERR_PTR(-EAGAIN);
entry->eof = 1;
return ERR_PTR(-EBADCOOKIE);
}
p = xdr_inline_decode(xdr, 12);
if (unlikely(!p))
goto out_overflow;
p = xdr_decode_hyper(p, &entry->ino);
entry->len = ntohl(*p++);
p = xdr_inline_decode(xdr, entry->len + 8);
if (unlikely(!p))
goto out_overflow;
entry->name = (const char *) p;
p += XDR_QUADLEN(entry->len);
entry->prev_cookie = entry->cookie;
@ -636,10 +700,17 @@ nfs3_decode_dirent(__be32 *p, struct nfs_entry *entry, int plus)
if (plus) {
entry->fattr->valid = 0;
p = xdr_decode_post_op_attr(p, entry->fattr);
p = xdr_decode_post_op_attr_stream(xdr, entry->fattr);
if (IS_ERR(p))
goto out_overflow_exit;
/* In fact, a post_op_fh3: */
p = xdr_inline_decode(xdr, 4);
if (unlikely(!p))
goto out_overflow;
if (*p++) {
p = xdr_decode_fhandle(p, entry->fh);
p = xdr_decode_fhandle_stream(xdr, entry->fh);
if (IS_ERR(p))
goto out_overflow_exit;
/* Ugh -- server reply was truncated */
if (p == NULL) {
dprintk("NFS: FH truncated\n");
@ -650,8 +721,18 @@ nfs3_decode_dirent(__be32 *p, struct nfs_entry *entry, int plus)
memset((u8*)(entry->fh), 0, sizeof(*entry->fh));
}
entry->eof = !p[0] && p[1];
p = xdr_inline_peek(xdr, 8);
if (p != NULL)
entry->eof = !p[0] && p[1];
else
entry->eof = 0;
return p;
out_overflow:
print_overflow_msg(__func__, xdr);
out_overflow_exit:
return ERR_PTR(-EIO);
}
/*

2
fs/nfs/nfs4_fs.h
View File

@ -331,7 +331,7 @@ extern void nfs_free_seqid(struct nfs_seqid *seqid);
extern const nfs4_stateid zero_stateid;
/* nfs4xdr.c */
extern __be32 *nfs4_decode_dirent(__be32 *p, struct nfs_entry *entry, int plus);
extern __be32 *nfs4_decode_dirent(struct xdr_stream *, struct nfs_entry *entry, int plus);
extern struct rpc_procinfo nfs4_procedures[];
struct nfs4_mount_data;

71
fs/nfs/nfs4xdr.c
View File

@ -3950,13 +3950,13 @@ static int decode_lock_denied (struct xdr_stream *xdr, struct file_lock *fl)
__be32 *p;
uint32_t namelen, type;
p = xdr_inline_decode(xdr, 32);
p = xdr_inline_decode(xdr, 32); /* read 32 bytes */
if (unlikely(!p))
goto out_overflow;
p = xdr_decode_hyper(p, &offset);
p = xdr_decode_hyper(p, &offset); /* read 2 8-byte long words */
p = xdr_decode_hyper(p, &length);
type = be32_to_cpup(p++);
if (fl != NULL) {
type = be32_to_cpup(p++); /* 4 byte read */
if (fl != NULL) { /* manipulate file lock */
fl->fl_start = (loff_t)offset;
fl->fl_end = fl->fl_start + (loff_t)length - 1;
if (length == ~(uint64_t)0)
@ -3966,9 +3966,9 @@ static int decode_lock_denied (struct xdr_stream *xdr, struct file_lock *fl)
fl->fl_type = F_RDLCK;
fl->fl_pid = 0;
}
p = xdr_decode_hyper(p, &clientid);
namelen = be32_to_cpup(p);
p = xdr_inline_decode(xdr, namelen);
p = xdr_decode_hyper(p, &clientid); /* read 8 bytes */
namelen = be32_to_cpup(p); /* read 4 bytes */ /* have read all 32 bytes now */
p = xdr_inline_decode(xdr, namelen); /* variable size field */
if (likely(p))
return -NFS4ERR_DENIED;
out_overflow:
@ -5755,21 +5755,33 @@ static int nfs4_xdr_dec_reclaim_complete(struct rpc_rqst *rqstp, uint32_t *p,
}
#endif /* CONFIG_NFS_V4_1 */
__be32 *nfs4_decode_dirent(__be32 *p, struct nfs_entry *entry, int plus)
__be32 *nfs4_decode_dirent(struct xdr_stream *xdr, struct nfs_entry *entry, int plus)
{
uint32_t bitmap[2] = {0};
uint32_t len;
if (!*p++) {
if (!*p)
__be32 *p = xdr_inline_decode(xdr, 4);
if (unlikely(!p))
goto out_overflow;
if (!ntohl(*p++)) {
p = xdr_inline_decode(xdr, 4);
if (unlikely(!p))
goto out_overflow;
if (!ntohl(*p++))
return ERR_PTR(-EAGAIN);
entry->eof = 1;
return ERR_PTR(-EBADCOOKIE);
}
p = xdr_inline_decode(xdr, 12);
if (unlikely(!p))
goto out_overflow;
entry->prev_cookie = entry->cookie;
p = xdr_decode_hyper(p, &entry->cookie);
entry->len = ntohl(*p++);
p = xdr_inline_decode(xdr, entry->len + 4);
if (unlikely(!p))
goto out_overflow;
entry->name = (const char *) p;
p += XDR_QUADLEN(entry->len);
@ -5782,29 +5794,54 @@ __be32 *nfs4_decode_dirent(__be32 *p, struct nfs_entry *entry, int plus)
len = ntohl(*p++); /* bitmap length */
if (len-- > 0) {
p = xdr_inline_decode(xdr, 4);
if (unlikely(!p))
goto out_overflow;
bitmap[0] = ntohl(*p++);
if (len-- > 0) {
p = xdr_inline_decode(xdr, 4);
if (unlikely(!p))
goto out_overflow;
bitmap[1] = ntohl(*p++);
p += len;
}
}
p = xdr_inline_decode(xdr, 4);
if (unlikely(!p))
goto out_overflow;
len = XDR_QUADLEN(ntohl(*p++)); /* attribute buffer length */
if (len > 0) {
if (bitmap[0] & FATTR4_WORD0_RDATTR_ERROR) {
bitmap[0] &= ~FATTR4_WORD0_RDATTR_ERROR;
/* Ignore the return value of rdattr_error for now */
p++;
len--;
p = xdr_inline_decode(xdr, 4);
if (unlikely(!p))
goto out_overflow;
}
if (bitmap[0] == 0 && bitmap[1] == FATTR4_WORD1_MOUNTED_ON_FILEID)
if (bitmap[0] == 0 && bitmap[1] == FATTR4_WORD1_MOUNTED_ON_FILEID) {
p = xdr_inline_decode(xdr, 8);
if (unlikely(!p))
goto out_overflow;
xdr_decode_hyper(p, &entry->ino);
else if (bitmap[0] == FATTR4_WORD0_FILEID)
} else if (bitmap[0] == FATTR4_WORD0_FILEID) {
p = xdr_inline_decode(xdr, 8);
if (unlikely(!p))
goto out_overflow;
xdr_decode_hyper(p, &entry->ino);
p += len;
}
}
entry->eof = !p[0] && p[1];
p = xdr_inline_peek(xdr, 8);
if (p != NULL)
entry->eof = !p[0] && p[1];
else
entry->eof = 0;
return p;
out_overflow:
print_overflow_msg(__func__, xdr);
return ERR_PTR(-EIO);
}
/*

2
include/linux/nfs_xdr.h
View File

@ -1036,7 +1036,7 @@ struct nfs_rpc_ops {
int (*pathconf) (struct nfs_server *, struct nfs_fh *,
struct nfs_pathconf *);
int (*set_capabilities)(struct nfs_server *, struct nfs_fh *);
__be32 *(*decode_dirent)(__be32 *, struct nfs_entry *, int plus);
__be32 *(*decode_dirent)(struct xdr_stream *, struct nfs_entry *, int plus);
void (*read_setup) (struct nfs_read_data *, struct rpc_message *);
int (*read_done) (struct rpc_task *, struct nfs_read_data *);
void (*write_setup) (struct nfs_write_data *, struct rpc_message *);