From: David Howells <dhowells@redhat.com>
To: Gao Xiang <hsiangkao@linux.alibaba.com>
Cc: dhowells@redhat.com, Matthew Wilcox <willy@infradead.org>,
Marc Dionne <marc.dionne@auristor.com>,
Paulo Alcantara <pc@manguebit.com>,
Shyam Prasad N <sprasad@microsoft.com>,
Tom Talpey <tom@talpey.com>,
Dominique Martinet <asmadeus@codewreck.org>,
Eric Van Hensbergen <ericvh@kernel.org>,
Ilya Dryomov <idryomov@gmail.com>,
Christian Brauner <christian@brauner.io>,
linux-cachefs@redhat.com, linux-afs@lists.infradead.org,
linux-cifs@vger.kernel.org, linux-nfs@vger.kernel.org,
ceph-devel@vger.kernel.org, v9fs@lists.linux.dev,
linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
Jeff Layton <jlayton@kernel.org>,
Steve French <smfrench@gmail.com>
Subject: Re: [PATCH v5 33/40] netfs, cachefiles: Pass upper bound length to allow expansion
Date: Tue, 02 Jan 2024 17:11:17 +0000 [thread overview]
Message-ID: <198744.1704215477@warthog.procyon.org.uk> (raw)
In-Reply-To: <750e8251-ba30-4f53-a17b-73c79e3739ce@linux.alibaba.com>
Gao Xiang <hsiangkao@linux.alibaba.com> wrote:
> > down = start - round_down(start, PAGE_SIZE);
> > *_start = start - down;
> > *_len = round_up(down + len, PAGE_SIZE);
> > + if (down < start || *_len > upper_len)
> > + return -ENOBUFS;
>
> Sorry for bothering. We just found some strange when testing
> today-next EROFS over fscache.
>
> I'm not sure the meaning of
> if (down < start
>
> For example, if start is page-aligned, down == 0.
>
> so as long as start > 0 and page-aligned, it will return
> -ENOBUFS. Does it an intended behavior?
Yeah, I think that's wrong.
Does the attached help?
David
---
diff --git a/fs/cachefiles/io.c b/fs/cachefiles/io.c
index bffffedce4a9..7529b40bc95a 100644
--- a/fs/cachefiles/io.c
+++ b/fs/cachefiles/io.c
@@ -522,16 +522,22 @@ int __cachefiles_prepare_write(struct cachefiles_object *object,
bool no_space_allocated_yet)
{
struct cachefiles_cache *cache = object->volume->cache;
- loff_t start = *_start, pos;
- size_t len = *_len, down;
+ unsigned long long start = *_start, pos;
+ size_t len = *_len;
int ret;
/* Round to DIO size */
- down = start - round_down(start, PAGE_SIZE);
- *_start = start - down;
- *_len = round_up(down + len, PAGE_SIZE);
- if (down < start || *_len > upper_len)
+ start = round_down(*_start, PAGE_SIZE);
+ if (start != *_start) {
+ kleave(" = -ENOBUFS [down]");
+ return -ENOBUFS;
+ }
+ if (*_len > upper_len) {
+ kleave(" = -ENOBUFS [up]");
return -ENOBUFS;
+ }
+
+ *_len = round_up(len, PAGE_SIZE);
/* We need to work out whether there's sufficient disk space to perform
* the write - but we can skip that check if we have space already
@@ -542,7 +548,7 @@ int __cachefiles_prepare_write(struct cachefiles_object *object,
pos = cachefiles_inject_read_error();
if (pos == 0)
- pos = vfs_llseek(file, *_start, SEEK_DATA);
+ pos = vfs_llseek(file, start, SEEK_DATA);
if (pos < 0 && pos >= (loff_t)-MAX_ERRNO) {
if (pos == -ENXIO)
goto check_space; /* Unallocated tail */
@@ -550,7 +556,7 @@ int __cachefiles_prepare_write(struct cachefiles_object *object,
cachefiles_trace_seek_error);
return pos;
}
- if ((u64)pos >= (u64)*_start + *_len)
+ if (pos >= start + *_len)
goto check_space; /* Unallocated region */
/* We have a block that's at least partially filled - if we're low on
@@ -563,13 +569,13 @@ int __cachefiles_prepare_write(struct cachefiles_object *object,
pos = cachefiles_inject_read_error();
if (pos == 0)
- pos = vfs_llseek(file, *_start, SEEK_HOLE);
+ pos = vfs_llseek(file, start, SEEK_HOLE);
if (pos < 0 && pos >= (loff_t)-MAX_ERRNO) {
trace_cachefiles_io_error(object, file_inode(file), pos,
cachefiles_trace_seek_error);
return pos;
}
- if ((u64)pos >= (u64)*_start + *_len)
+ if (pos >= start + *_len)
return 0; /* Fully allocated */
/* Partially allocated, but insufficient space: cull. */
@@ -577,7 +583,7 @@ int __cachefiles_prepare_write(struct cachefiles_object *object,
ret = cachefiles_inject_remove_error();
if (ret == 0)
ret = vfs_fallocate(file, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
- *_start, *_len);
+ start, *_len);
if (ret < 0) {
trace_cachefiles_io_error(object, file_inode(file), ret,
cachefiles_trace_fallocate_error);
next prev parent reply other threads:[~2024-01-02 17:11 UTC|newest]
Thread overview: 76+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-21 13:22 [PATCH v5 00/40] netfs, afs, 9p: Delegate high-level I/O to netfslib David Howells
2023-12-21 13:22 ` [PATCH v5 01/40] afs: Remove whitespace before most ')' from the trace header David Howells
2023-12-21 13:22 ` [PATCH v5 02/40] afs: Automatically generate trace tag enums David Howells
2023-12-21 13:22 ` [PATCH v5 03/40] netfs, fscache: Move fs/fscache/* into fs/netfs/ David Howells
2023-12-21 13:22 ` [PATCH v5 04/40] netfs, fscache: Combine fscache with netfs David Howells
2023-12-21 13:23 ` [PATCH v5 05/40] netfs, fscache: Remove ->begin_cache_operation David Howells
2023-12-21 13:23 ` [PATCH v5 06/40] netfs, fscache: Move /proc/fs/fscache to /proc/fs/netfs and put in a symlink David Howells
2024-01-03 16:49 ` Marc Dionne
2023-12-21 13:23 ` [PATCH v5 07/40] netfs: Move pinning-for-writeback from fscache to netfs David Howells
2023-12-21 13:23 ` [PATCH v5 08/40] netfs: Add a procfile to list in-progress requests David Howells
2023-12-21 13:23 ` [PATCH v5 09/40] netfs: Allow the netfs to make the io (sub)request alloc larger David Howells
2023-12-21 13:23 ` [PATCH v5 10/40] netfs: Add a ->free_subrequest() op David Howells
2023-12-21 13:23 ` [PATCH v5 11/40] afs: Don't use folio->private to record partial modification David Howells
2023-12-21 13:23 ` [PATCH v5 12/40] netfs: Provide invalidate_folio and release_folio calls David Howells
2023-12-21 13:23 ` [PATCH v5 13/40] netfs: Implement unbuffered/DIO vs buffered I/O locking David Howells
2023-12-21 13:23 ` [PATCH v5 14/40] netfs: Add iov_iters to (sub)requests to describe various buffers David Howells
2023-12-21 13:23 ` [PATCH v5 15/40] netfs: Add support for DIO buffering David Howells
2023-12-26 16:54 ` Nathan Chancellor
2023-12-28 10:47 ` Christian Brauner
2023-12-28 16:58 ` Nathan Chancellor
2023-12-21 13:23 ` [PATCH v5 16/40] netfs: Provide tools to create a buffer in an xarray David Howells
2023-12-21 13:23 ` [PATCH v5 17/40] netfs: Add func to calculate pagecount/size-limited span of an iterator David Howells
2023-12-21 13:23 ` [PATCH v5 18/40] netfs: Limit subrequest by size or number of segments David Howells
2023-12-21 13:23 ` [PATCH v5 19/40] netfs: Extend the netfs_io_*request structs to handle writes David Howells
2023-12-21 13:23 ` [PATCH v5 20/40] netfs: Add a hook to allow tell the netfs to update its i_size David Howells
2023-12-21 13:23 ` [PATCH v5 21/40] netfs: Make netfs_put_request() handle a NULL pointer David Howells
2023-12-21 13:23 ` [PATCH v5 22/40] netfs: Make the refcounting of netfs_begin_read() easier to use David Howells
2023-12-21 13:23 ` [PATCH v5 23/40] netfs: Prep to use folio->private for write grouping and streaming write David Howells
2023-12-21 13:23 ` [PATCH v5 24/40] netfs: Dispatch write requests to process a writeback slice David Howells
2023-12-21 13:23 ` [PATCH v5 25/40] netfs: Provide func to copy data to pagecache for buffered write David Howells
2023-12-21 13:23 ` [PATCH v5 26/40] netfs: Make netfs_read_folio() handle streaming-write pages David Howells
2023-12-21 13:23 ` [PATCH v5 27/40] netfs: Allocate multipage folios in the writepath David Howells
2023-12-21 13:23 ` [PATCH v5 28/40] netfs: Implement unbuffered/DIO read support David Howells
2023-12-21 13:23 ` [PATCH v5 29/40] netfs: Implement unbuffered/DIO write support David Howells
2023-12-21 13:23 ` [PATCH v5 30/40] netfs: Implement buffered write API David Howells
2023-12-21 13:23 ` [PATCH v5 31/40] netfs: Allow buffered shared-writeable mmap through netfs_page_mkwrite() David Howells
2023-12-21 13:23 ` [PATCH v5 32/40] netfs: Provide netfs_file_read_iter() David Howells
2023-12-21 13:23 ` [PATCH v5 33/40] netfs, cachefiles: Pass upper bound length to allow expansion David Howells
2024-01-02 14:04 ` Gao Xiang
2024-01-02 17:11 ` David Howells [this message]
2024-01-02 20:37 ` Gao Xiang
2024-01-03 10:15 ` Jia Zhu
2023-12-21 13:23 ` [PATCH v5 34/40] netfs: Provide a writepages implementation David Howells
2023-12-21 13:23 ` [PATCH v5 35/40] netfs: Provide a launder_folio implementation David Howells
2023-12-21 13:23 ` [PATCH v5 36/40] netfs: Implement a write-through caching option David Howells
2023-12-21 13:23 ` [PATCH v5 37/40] netfs: Optimise away reads above the point at which there can be no data David Howells
2023-12-21 23:01 ` Nathan Chancellor
2023-12-22 11:49 ` David Howells
2023-12-22 12:00 ` [PATCH] Fix oops in NFS David Howells
2024-01-05 4:52 ` Matthew Wilcox
2024-01-05 10:12 ` David Howells
2024-01-05 13:17 ` Matthew Wilcox
2024-01-05 17:20 ` Dominique Martinet
2024-01-05 11:48 ` David Howells
2024-01-05 14:33 ` David Howells
2023-12-21 13:23 ` [PATCH v5 38/40] netfs: Export the netfs_sreq tracepoint David Howells
2023-12-21 13:23 ` [PATCH v5 39/40] afs: Use the netfs write helpers David Howells
2023-12-21 13:23 ` [PATCH v5 40/40] 9p: Use netfslib read/write_iter David Howells
2024-01-03 7:22 ` Dominique Martinet
2024-01-03 19:52 ` Eric Van Hensbergen
2024-01-03 12:08 ` David Howells
2024-01-03 12:39 ` David Howells
2024-01-03 13:00 ` Dominique Martinet
2024-05-09 17:15 ` Andrea Righi
2024-05-09 21:33 ` David Howells
2024-05-10 5:53 ` Andrea Righi
2024-05-10 7:57 ` David Howells
2024-05-23 7:44 ` David Howells
2023-12-22 13:02 ` [PATCH] Fix EROFS Kconfig David Howells
2023-12-23 3:55 ` Jingbo Xu
2023-12-23 13:32 ` Gao Xiang
2024-01-02 15:39 ` [PATCH v5 40/40] 9p: Use netfslib read/write_iter David Howells
2024-01-02 21:49 ` [PATCH] 9p: Fix initialisation of netfs_inode for 9p David Howells
2024-01-03 13:10 ` Dominique Martinet
2024-01-03 13:59 ` David Howells
2024-01-03 14:04 ` David Howells
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