diff options
Diffstat (limited to 'fs/afs')
| -rw-r--r-- | fs/afs/file.c | 7 | ||||
| -rw-r--r-- | fs/afs/fsclient.c | 49 |
2 files changed, 40 insertions, 16 deletions
diff --git a/fs/afs/file.c b/fs/afs/file.c index ba7b71fba34b..a38e1c30d110 100644 --- a/fs/afs/file.c +++ b/fs/afs/file.c @@ -184,10 +184,13 @@ int afs_page_filler(void *data, struct page *page) if (!req) goto enomem; + /* We request a full page. If the page is a partial one at the + * end of the file, the server will return a short read and the + * unmarshalling code will clear the unfilled space. + */ atomic_set(&req->usage, 1); req->pos = (loff_t)page->index << PAGE_SHIFT; - req->len = min_t(size_t, i_size_read(inode) - req->pos, - PAGE_SIZE); + req->len = PAGE_SIZE; req->nr_pages = 1; req->pages[0] = page; get_page(page); diff --git a/fs/afs/fsclient.c b/fs/afs/fsclient.c index ac8e766978dc..bf8904a1a58f 100644 --- a/fs/afs/fsclient.c +++ b/fs/afs/fsclient.c @@ -17,6 +17,12 @@ #include "afs_fs.h" /* + * We need somewhere to discard into in case the server helpfully returns more + * than we asked for in FS.FetchData{,64}. + */ +static u8 afs_discard_buffer[64]; + +/* * decode an AFSFid block */ static void xdr_decode_AFSFid(const __be32 **_bp, struct afs_fid *fid) @@ -353,12 +359,6 @@ static int afs_deliver_fs_fetch_data(struct afs_call *call) req->actual_len |= ntohl(call->tmp); _debug("DATA length: %llu", req->actual_len); - /* Check that the server didn't want to send us extra. We - * might want to just discard instead, but that requires - * cooperation from AF_RXRPC. - */ - if (req->actual_len > req->len) - return -EBADMSG; req->remain = req->actual_len; call->offset = req->pos & (PAGE_SIZE - 1); @@ -368,6 +368,7 @@ static int afs_deliver_fs_fetch_data(struct afs_call *call) call->unmarshall++; begin_page: + ASSERTCMP(req->index, <, req->nr_pages); if (req->remain > PAGE_SIZE - call->offset) size = PAGE_SIZE - call->offset; else @@ -390,18 +391,37 @@ static int afs_deliver_fs_fetch_data(struct afs_call *call) if (req->page_done) req->page_done(call, req); if (req->remain > 0) { - req->index++; call->offset = 0; + req->index++; + if (req->index >= req->nr_pages) + goto begin_discard; goto begin_page; } } + goto no_more_data; + + /* Discard any excess data the server gave us */ + begin_discard: + case 4: + size = min_t(size_t, sizeof(afs_discard_buffer), req->remain); + call->count = size; + _debug("extract discard %u/%llu %zu/%u", + req->remain, req->actual_len, call->offset, call->count); + + call->offset = 0; + ret = afs_extract_data(call, afs_discard_buffer, call->count, true); + req->remain -= call->offset; + if (ret < 0) + return ret; + if (req->remain > 0) + goto begin_discard; no_more_data: call->offset = 0; - call->unmarshall++; + call->unmarshall = 5; /* extract the metadata */ - case 4: + case 5: ret = afs_extract_data(call, call->buffer, (21 + 3 + 6) * 4, false); if (ret < 0) @@ -416,16 +436,17 @@ static int afs_deliver_fs_fetch_data(struct afs_call *call) call->offset = 0; call->unmarshall++; - case 5: + case 6: break; } - if (call->count < PAGE_SIZE) { - buffer = kmap(req->pages[req->index]); - memset(buffer + call->count, 0, PAGE_SIZE - call->count); - kunmap(req->pages[req->index]); + for (; req->index < req->nr_pages; req->index++) { + if (call->count < PAGE_SIZE) + zero_user_segment(req->pages[req->index], + call->count, PAGE_SIZE); if (req->page_done) req->page_done(call, req); + call->count = 0; } _leave(" = 0 [done]"); |