From: David Howells <dhowells@redhat.com>
To: viro@ZenIV.linux.org.uk
Cc: dhowells@redhat.com, linux-fsdevel@vger.kernel.org,
linux-afs@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: [PATCH 08/27] afs: Handle a short write to an AFS page
Date: Thu, 09 Mar 2017 18:56:42 +0000 [thread overview]
Message-ID: <148908580217.16794.6074718581766435975.stgit@warthog.procyon.org.uk> (raw)
In-Reply-To: <148908574888.16794.14109877851518811944.stgit@warthog.procyon.org.uk>
Handle the situation where afs_write_begin() is told to expect that a
full-page write will be made, but this doesn't happen (EFAULT, CTRL-C,
etc.), and so afs_write_end() sees a partial write took place. Currently,
no attempt is to deal with the discrepency.
Fix this by loading the gap from the server.
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
---
fs/afs/fsclient.c | 4 +++-
fs/afs/internal.h | 2 +-
fs/afs/write.c | 28 +++++++++++++++++++---------
3 files changed, 23 insertions(+), 11 deletions(-)
diff --git a/fs/afs/fsclient.c b/fs/afs/fsclient.c
index bf8904a1a58f..6f917dd1238c 100644
--- a/fs/afs/fsclient.c
+++ b/fs/afs/fsclient.c
@@ -393,8 +393,10 @@ static int afs_deliver_fs_fetch_data(struct afs_call *call)
if (req->remain > 0) {
call->offset = 0;
req->index++;
- if (req->index >= req->nr_pages)
+ if (req->index >= req->nr_pages) {
+ call->unmarshall = 4;
goto begin_discard;
+ }
goto begin_page;
}
}
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index 7784a8bc375c..dc2cb486e127 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -130,7 +130,7 @@ struct afs_call_type {
*/
struct afs_read {
loff_t pos; /* Where to start reading */
- loff_t len; /* How much to read */
+ loff_t len; /* How much we're asking for */
loff_t actual_len; /* How much we're actually getting */
atomic_t usage;
unsigned int remain; /* Amount remaining */
diff --git a/fs/afs/write.c b/fs/afs/write.c
index 3ac52f6a96ff..ea66890fc188 100644
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -84,10 +84,9 @@ void afs_put_writeback(struct afs_writeback *wb)
* partly or wholly fill a page that's under preparation for writing
*/
static int afs_fill_page(struct afs_vnode *vnode, struct key *key,
- loff_t pos, struct page *page)
+ loff_t pos, unsigned int len, struct page *page)
{
struct afs_read *req;
- loff_t i_size;
int ret;
_enter(",,%llu", (unsigned long long)pos);
@@ -99,16 +98,11 @@ static int afs_fill_page(struct afs_vnode *vnode, struct key *key,
atomic_set(&req->usage, 1);
req->pos = pos;
+ req->len = len;
req->nr_pages = 1;
req->pages[0] = page;
get_page(page);
- i_size = i_size_read(&vnode->vfs_inode);
- if (pos + PAGE_SIZE > i_size)
- req->len = i_size - pos;
- else
- req->len = PAGE_SIZE;
-
ret = afs_vnode_fetch_data(vnode, key, req);
afs_put_read(req);
if (ret < 0) {
@@ -164,7 +158,7 @@ int afs_write_begin(struct file *file, struct address_space *mapping,
/* page won't leak in error case: it eventually gets cleaned off LRU */
if (!PageUptodate(page) && len != PAGE_SIZE) {
- ret = afs_fill_page(vnode, key, index << PAGE_SHIFT, page);
+ ret = afs_fill_page(vnode, key, pos & PAGE_MASK, PAGE_SIZE, page);
if (ret < 0) {
kfree(candidate);
_leave(" = %d [prep]", ret);
@@ -258,7 +252,9 @@ int afs_write_end(struct file *file, struct address_space *mapping,
struct page *page, void *fsdata)
{
struct afs_vnode *vnode = AFS_FS_I(file_inode(file));
+ struct key *key = file->private_data;
loff_t i_size, maybe_i_size;
+ int ret;
_enter("{%x:%u},{%lx}",
vnode->fid.vid, vnode->fid.vnode, page->index);
@@ -274,6 +270,20 @@ int afs_write_end(struct file *file, struct address_space *mapping,
spin_unlock(&vnode->writeback_lock);
}
+ if (!PageUptodate(page)) {
+ if (copied < len) {
+ /* Try and load any missing data from the server. The
+ * unmarshalling routine will take care of clearing any
+ * bits that are beyond the EOF.
+ */
+ ret = afs_fill_page(vnode, key, pos + copied,
+ len - copied, page);
+ if (ret < 0)
+ return ret;
+ }
+ SetPageUptodate(page);
+ }
+
set_page_dirty(page);
if (PageDirty(page))
_debug("dirtied");
next prev parent reply other threads:[~2017-03-09 18:56 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-09 18:55 [PATCH 01/27] afs: Fix missing put_page() David Howells
2017-03-09 18:55 ` [PATCH 02/27] afs: Fix page overput in afs_fill_page() David Howells
2017-03-09 18:56 ` [PATCH 03/27] afs: Populate group ID from vnode status David Howells
2017-03-09 18:56 ` [PATCH 04/27] afs: Adjust mode bits processing David Howells
2017-03-09 18:56 ` [PATCH 05/27] afs: Deal with an empty callback array David Howells
2017-03-09 18:56 ` [PATCH 06/27] afs: Handle better the server returning excess or short data David Howells
2017-03-09 18:56 ` [PATCH 07/27] afs: Kill struct afs_read::pg_offset David Howells
2017-03-09 18:56 ` David Howells [this message]
2017-03-09 18:56 ` [PATCH 09/27] afs: Flush outstanding writes when an fd is closed David Howells
2017-03-09 18:56 ` [PATCH 10/27] afs: Distinguish mountpoints from symlinks by file mode alone David Howells
2017-03-09 18:57 ` [PATCH 11/27] afs: inode: Replace rcu_assign_pointer() with RCU_INIT_POINTER() David Howells
2017-03-09 18:57 ` [PATCH 12/27] afs: security: " David Howells
2017-03-09 18:57 ` [PATCH 13/27] afs: Migrate vlocation fields to 64-bit David Howells
2017-03-09 18:57 ` [PATCH 14/27] afs: Prevent callback expiry timer overflow David Howells
2017-03-09 18:57 ` [PATCH 15/27] afs: Fix AFS read bug David Howells
2017-03-09 18:57 ` [PATCH 16/27] afs: Make struct afs_read::remain 64-bit David Howells
2017-03-09 18:57 ` [PATCH 17/27] afs: Use a bvec rather than a kvec in afs_send_pages() David Howells
2017-03-09 18:57 ` [PATCH 18/27] afs: Fix the maths in afs_fs_store_data() David Howells
2017-03-09 18:58 ` [PATCH 19/27] afs: Invalid op ID should abort with RXGEN_OPCODE David Howells
2017-03-09 18:58 ` [PATCH 20/27] afs: Better abort and net error handling David Howells
2017-03-09 18:58 ` [PATCH 21/27] afs: Populate and use client modification time David Howells
2017-03-09 18:58 ` [PATCH 22/27] afs: Don't set PG_error on local EINTR or ENOMEM when filling a page David Howells
2017-03-09 18:58 ` [PATCH 23/27] afs: Fix page leak in afs_write_begin() David Howells
2017-03-09 18:58 ` [PATCH 24/27] afs: afs_fsync() does two flushes, one of which is redundant David Howells
2017-03-09 18:58 ` [PATCH 25/27] afs: Fix afs_kill_pages() David Howells
2017-03-09 18:58 ` [PATCH 26/27] afs: Fix an off-by-one error in afs_send_pages() David Howells
2017-03-09 18:58 ` [PATCH 27/27] afs: Fix abort on signal while waiting for call completion David Howells
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=148908580217.16794.6074718581766435975.stgit@warthog.procyon.org.uk \
--to=dhowells@redhat.com \
--cc=linux-afs@lists.infradead.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=viro@ZenIV.linux.org.uk \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).