mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-15 23:25:07 +00:00
NFS: Fix asynchronous read error handling
We must always call ->read_done() before we truncate the page data, or decide to flag an error. The reasons are that in NFSv2, ->read_done() is where the eof flag gets set. in NFSv3/v4 ->read_done() handles EJUKEBOX-type errors, and v4 state recovery. However, we need to mark the pages as uptodate before we deal with short read errors, since we may need to modify the nfs_read_data arguments. We therefore split the current nfs_readpage_result() into two parts: nfs_readpage_result(), which calls ->read_done() etc, and nfs_readpage_retry(), which subsequently handles short reads. Note: Removing the code that retries in case of a short read also fixes a bug in nfs_direct_read_result(), which used to return a corrupted number of bytes. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
parent
46b9f8e148
commit
0b67130149
1 changed files with 69 additions and 71 deletions
138
fs/nfs/read.c
138
fs/nfs/read.c
|
@ -460,6 +460,55 @@ nfs_pagein_list(struct list_head *head, int rpages)
|
||||||
return error;
|
return error;
|
||||||
}
|
}
|
||||||
|
|
||||||
|
/*
|
||||||
|
* This is the callback from RPC telling us whether a reply was
|
||||||
|
* received or some error occurred (timeout or socket shutdown).
|
||||||
|
*/
|
||||||
|
int nfs_readpage_result(struct rpc_task *task, struct nfs_read_data *data)
|
||||||
|
{
|
||||||
|
int status;
|
||||||
|
|
||||||
|
dprintk("%s: %4d, (status %d)\n", __FUNCTION__, task->tk_pid,
|
||||||
|
task->tk_status);
|
||||||
|
|
||||||
|
status = NFS_PROTO(data->inode)->read_done(task, data);
|
||||||
|
if (status != 0)
|
||||||
|
return status;
|
||||||
|
|
||||||
|
nfs_add_stats(data->inode, NFSIOS_SERVERREADBYTES, data->res.count);
|
||||||
|
|
||||||
|
if (task->tk_status == -ESTALE) {
|
||||||
|
set_bit(NFS_INO_STALE, &NFS_FLAGS(data->inode));
|
||||||
|
nfs_mark_for_revalidate(data->inode);
|
||||||
|
}
|
||||||
|
spin_lock(&data->inode->i_lock);
|
||||||
|
NFS_I(data->inode)->cache_validity |= NFS_INO_INVALID_ATIME;
|
||||||
|
spin_unlock(&data->inode->i_lock);
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
|
||||||
|
static int nfs_readpage_retry(struct rpc_task *task, struct nfs_read_data *data)
|
||||||
|
{
|
||||||
|
struct nfs_readargs *argp = &data->args;
|
||||||
|
struct nfs_readres *resp = &data->res;
|
||||||
|
|
||||||
|
if (resp->eof || resp->count == argp->count)
|
||||||
|
return 0;
|
||||||
|
|
||||||
|
/* This is a short read! */
|
||||||
|
nfs_inc_stats(data->inode, NFSIOS_SHORTREAD);
|
||||||
|
/* Has the server at least made some progress? */
|
||||||
|
if (resp->count == 0)
|
||||||
|
return 0;
|
||||||
|
|
||||||
|
/* Yes, so retry the read at the end of the data */
|
||||||
|
argp->offset += resp->count;
|
||||||
|
argp->pgbase += resp->count;
|
||||||
|
argp->count -= resp->count;
|
||||||
|
rpc_restart_call(task);
|
||||||
|
return -EAGAIN;
|
||||||
|
}
|
||||||
|
|
||||||
/*
|
/*
|
||||||
* Handle a read reply that fills part of a page.
|
* Handle a read reply that fills part of a page.
|
||||||
*/
|
*/
|
||||||
|
@ -469,12 +518,16 @@ static void nfs_readpage_result_partial(struct rpc_task *task, void *calldata)
|
||||||
struct nfs_page *req = data->req;
|
struct nfs_page *req = data->req;
|
||||||
struct page *page = req->wb_page;
|
struct page *page = req->wb_page;
|
||||||
|
|
||||||
if (likely(task->tk_status >= 0))
|
|
||||||
nfs_readpage_truncate_uninitialised_page(data);
|
|
||||||
else
|
|
||||||
SetPageError(page);
|
|
||||||
if (nfs_readpage_result(task, data) != 0)
|
if (nfs_readpage_result(task, data) != 0)
|
||||||
return;
|
return;
|
||||||
|
|
||||||
|
if (likely(task->tk_status >= 0)) {
|
||||||
|
nfs_readpage_truncate_uninitialised_page(data);
|
||||||
|
if (nfs_readpage_retry(task, data) != 0)
|
||||||
|
return;
|
||||||
|
}
|
||||||
|
if (unlikely(task->tk_status < 0))
|
||||||
|
SetPageError(page);
|
||||||
if (atomic_dec_and_test(&req->wb_complete)) {
|
if (atomic_dec_and_test(&req->wb_complete)) {
|
||||||
if (!PageError(page))
|
if (!PageError(page))
|
||||||
SetPageUptodate(page);
|
SetPageUptodate(page);
|
||||||
|
@ -502,25 +555,13 @@ static void nfs_readpage_set_pages_uptodate(struct nfs_read_data *data)
|
||||||
count += base;
|
count += base;
|
||||||
for (;count >= PAGE_CACHE_SIZE; count -= PAGE_CACHE_SIZE, pages++)
|
for (;count >= PAGE_CACHE_SIZE; count -= PAGE_CACHE_SIZE, pages++)
|
||||||
SetPageUptodate(*pages);
|
SetPageUptodate(*pages);
|
||||||
if (count != 0)
|
if (count == 0)
|
||||||
|
return;
|
||||||
|
/* Was this a short read? */
|
||||||
|
if (data->res.eof || data->res.count == data->args.count)
|
||||||
SetPageUptodate(*pages);
|
SetPageUptodate(*pages);
|
||||||
}
|
}
|
||||||
|
|
||||||
static void nfs_readpage_set_pages_error(struct nfs_read_data *data)
|
|
||||||
{
|
|
||||||
unsigned int count = data->args.count;
|
|
||||||
unsigned int base = data->args.pgbase;
|
|
||||||
struct page **pages;
|
|
||||||
|
|
||||||
pages = &data->args.pages[base >> PAGE_CACHE_SHIFT];
|
|
||||||
base &= ~PAGE_CACHE_MASK;
|
|
||||||
count += base;
|
|
||||||
for (;count >= PAGE_CACHE_SIZE; count -= PAGE_CACHE_SIZE, pages++)
|
|
||||||
SetPageError(*pages);
|
|
||||||
if (count != 0)
|
|
||||||
SetPageError(*pages);
|
|
||||||
}
|
|
||||||
|
|
||||||
/*
|
/*
|
||||||
* This is the callback from RPC telling us whether a reply was
|
* This is the callback from RPC telling us whether a reply was
|
||||||
* received or some error occurred (timeout or socket shutdown).
|
* received or some error occurred (timeout or socket shutdown).
|
||||||
|
@ -529,19 +570,20 @@ static void nfs_readpage_result_full(struct rpc_task *task, void *calldata)
|
||||||
{
|
{
|
||||||
struct nfs_read_data *data = calldata;
|
struct nfs_read_data *data = calldata;
|
||||||
|
|
||||||
|
if (nfs_readpage_result(task, data) != 0)
|
||||||
|
return;
|
||||||
/*
|
/*
|
||||||
* Note: nfs_readpage_result may change the values of
|
* Note: nfs_readpage_retry may change the values of
|
||||||
* data->args. In the multi-page case, we therefore need
|
* data->args. In the multi-page case, we therefore need
|
||||||
* to ensure that we call the next nfs_readpage_set_page_uptodate()
|
* to ensure that we call nfs_readpage_set_pages_uptodate()
|
||||||
* first in the multi-page case.
|
* first.
|
||||||
*/
|
*/
|
||||||
if (likely(task->tk_status >= 0)) {
|
if (likely(task->tk_status >= 0)) {
|
||||||
nfs_readpage_truncate_uninitialised_page(data);
|
nfs_readpage_truncate_uninitialised_page(data);
|
||||||
nfs_readpage_set_pages_uptodate(data);
|
nfs_readpage_set_pages_uptodate(data);
|
||||||
} else
|
if (nfs_readpage_retry(task, data) != 0)
|
||||||
nfs_readpage_set_pages_error(data);
|
|
||||||
if (nfs_readpage_result(task, data) != 0)
|
|
||||||
return;
|
return;
|
||||||
|
}
|
||||||
while (!list_empty(&data->pages)) {
|
while (!list_empty(&data->pages)) {
|
||||||
struct nfs_page *req = nfs_list_entry(data->pages.next);
|
struct nfs_page *req = nfs_list_entry(data->pages.next);
|
||||||
|
|
||||||
|
@ -555,50 +597,6 @@ static const struct rpc_call_ops nfs_read_full_ops = {
|
||||||
.rpc_release = nfs_readdata_release,
|
.rpc_release = nfs_readdata_release,
|
||||||
};
|
};
|
||||||
|
|
||||||
/*
|
|
||||||
* This is the callback from RPC telling us whether a reply was
|
|
||||||
* received or some error occurred (timeout or socket shutdown).
|
|
||||||
*/
|
|
||||||
int nfs_readpage_result(struct rpc_task *task, struct nfs_read_data *data)
|
|
||||||
{
|
|
||||||
struct nfs_readargs *argp = &data->args;
|
|
||||||
struct nfs_readres *resp = &data->res;
|
|
||||||
int status;
|
|
||||||
|
|
||||||
dprintk("NFS: %4d nfs_readpage_result, (status %d)\n",
|
|
||||||
task->tk_pid, task->tk_status);
|
|
||||||
|
|
||||||
status = NFS_PROTO(data->inode)->read_done(task, data);
|
|
||||||
if (status != 0)
|
|
||||||
return status;
|
|
||||||
|
|
||||||
nfs_add_stats(data->inode, NFSIOS_SERVERREADBYTES, resp->count);
|
|
||||||
|
|
||||||
if (task->tk_status < 0) {
|
|
||||||
if (task->tk_status == -ESTALE) {
|
|
||||||
set_bit(NFS_INO_STALE, &NFS_FLAGS(data->inode));
|
|
||||||
nfs_mark_for_revalidate(data->inode);
|
|
||||||
}
|
|
||||||
} else if (resp->count < argp->count && !resp->eof) {
|
|
||||||
/* This is a short read! */
|
|
||||||
nfs_inc_stats(data->inode, NFSIOS_SHORTREAD);
|
|
||||||
/* Has the server at least made some progress? */
|
|
||||||
if (resp->count != 0) {
|
|
||||||
/* Yes, so retry the read at the end of the data */
|
|
||||||
argp->offset += resp->count;
|
|
||||||
argp->pgbase += resp->count;
|
|
||||||
argp->count -= resp->count;
|
|
||||||
rpc_restart_call(task);
|
|
||||||
return -EAGAIN;
|
|
||||||
}
|
|
||||||
task->tk_status = -EIO;
|
|
||||||
}
|
|
||||||
spin_lock(&data->inode->i_lock);
|
|
||||||
NFS_I(data->inode)->cache_validity |= NFS_INO_INVALID_ATIME;
|
|
||||||
spin_unlock(&data->inode->i_lock);
|
|
||||||
return 0;
|
|
||||||
}
|
|
||||||
|
|
||||||
/*
|
/*
|
||||||
* Read a page over NFS.
|
* Read a page over NFS.
|
||||||
* We read the page synchronously in the following case:
|
* We read the page synchronously in the following case:
|
||||||
|
|
Loading…
Reference in a new issue