From: David Howells <dhowells@redhat.com>
To: Jeff Layton <jlayton@kernel.org>, Steve French <smfrench@gmail.com>
Cc: David Howells <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
Subject: [PATCH v5 18/40] netfs: Limit subrequest by size or number of segments
Date: Thu, 21 Dec 2023 13:23:13 +0000 [thread overview]
Message-ID: <20231221132400.1601991-19-dhowells@redhat.com> (raw)
In-Reply-To: <20231221132400.1601991-1-dhowells@redhat.com>
Limit a subrequest to a maximum size and/or a maximum number of contiguous
physical regions. This permits, for instance, an subreq's iterator to be
limited to the number of DMA'able segments that a large RDMA request can
handle.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
---
fs/netfs/io.c | 18 ++++++++++++++++++
include/linux/netfs.h | 1 +
include/trace/events/netfs.h | 1 +
3 files changed, 20 insertions(+)
diff --git a/fs/netfs/io.c b/fs/netfs/io.c
index e9d408e211b8..e228bfb530ea 100644
--- a/fs/netfs/io.c
+++ b/fs/netfs/io.c
@@ -525,6 +525,7 @@ netfs_rreq_prepare_read(struct netfs_io_request *rreq,
struct iov_iter *io_iter)
{
enum netfs_io_source source;
+ size_t lsize;
_enter("%llx-%llx,%llx", subreq->start, subreq->start + subreq->len, rreq->i_size);
@@ -547,13 +548,30 @@ netfs_rreq_prepare_read(struct netfs_io_request *rreq,
source = NETFS_INVALID_READ;
goto out;
}
+
+ if (subreq->max_nr_segs) {
+ lsize = netfs_limit_iter(io_iter, 0, subreq->len,
+ subreq->max_nr_segs);
+ if (subreq->len > lsize) {
+ subreq->len = lsize;
+ trace_netfs_sreq(subreq, netfs_sreq_trace_limited);
+ }
+ }
}
+ if (subreq->len > rreq->len)
+ pr_warn("R=%08x[%u] SREQ>RREQ %zx > %zx\n",
+ rreq->debug_id, subreq->debug_index,
+ subreq->len, rreq->len);
+
if (WARN_ON(subreq->len == 0)) {
source = NETFS_INVALID_READ;
goto out;
}
+ subreq->source = source;
+ trace_netfs_sreq(subreq, netfs_sreq_trace_prepare);
+
subreq->io_iter = *io_iter;
iov_iter_truncate(&subreq->io_iter, subreq->len);
iov_iter_advance(io_iter, subreq->len);
diff --git a/include/linux/netfs.h b/include/linux/netfs.h
index 41d438e5d6db..2ece21fccb02 100644
--- a/include/linux/netfs.h
+++ b/include/linux/netfs.h
@@ -161,6 +161,7 @@ struct netfs_io_subrequest {
refcount_t ref;
short error; /* 0 or error that occurred */
unsigned short debug_index; /* Index in list (for debugging output) */
+ unsigned int max_nr_segs; /* 0 or max number of segments in an iterator */
enum netfs_io_source source; /* Where to read from/write to */
unsigned long flags;
#define NETFS_SREQ_COPY_TO_CACHE 0 /* Set if should copy the data to the cache */
diff --git a/include/trace/events/netfs.h b/include/trace/events/netfs.h
index beec534cbaab..fce6d0bc78e5 100644
--- a/include/trace/events/netfs.h
+++ b/include/trace/events/netfs.h
@@ -44,6 +44,7 @@
#define netfs_sreq_traces \
EM(netfs_sreq_trace_download_instead, "RDOWN") \
EM(netfs_sreq_trace_free, "FREE ") \
+ EM(netfs_sreq_trace_limited, "LIMIT") \
EM(netfs_sreq_trace_prepare, "PREP ") \
EM(netfs_sreq_trace_resubmit_short, "SHORT") \
EM(netfs_sreq_trace_submit, "SUBMT") \
next prev parent reply other threads:[~2023-12-21 13:25 UTC|newest]
Thread overview: 80+ 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 ` David Howells [this message]
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
2024-01-02 20:37 ` Gao Xiang
2024-01-03 9:18 ` Yiqun Leng
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 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
2024-05-30 19:16 ` Emanuele Rocca
2024-05-31 15:06 ` Emanuele Rocca
2024-06-17 17:10 ` Christian Kastner
2024-06-17 21:50 ` Dominique Martinet
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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