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authorLinus Torvalds <torvalds@linux-foundation.org>2021-04-27 13:08:12 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-04-27 13:08:12 -0700
commit820c4bae40cb56466cfed6409e00d0f5165a990c (patch)
tree0b0b49ae9b61e4dbb04f08ad91987e91d062a401 /include/trace
parent34a456eb1fe26303d0661693d01a50e83a551da3 (diff)
parent53b776c77aca99b663a5512a04abc27670d61058 (diff)
Merge tag 'netfs-lib-20210426' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs
Pull network filesystem helper library updates from David Howells: "Here's a set of patches for 5.13 to begin the process of overhauling the local caching API for network filesystems. This set consists of two parts: (1) Add a helper library to handle the new VM readahead interface. This is intended to be used unconditionally by the filesystem (whether or not caching is enabled) and provides a common framework for doing caching, transparent huge pages and, in the future, possibly fscrypt and read bandwidth maximisation. It also allows the netfs and the cache to align, expand and slice up a read request from the VM in various ways; the netfs need only provide a function to read a stretch of data to the pagecache and the helper takes care of the rest. (2) Add an alternative fscache/cachfiles I/O API that uses the kiocb facility to do async DIO to transfer data to/from the netfs's pages, rather than using readpage with wait queue snooping on one side and vfs_write() on the other. It also uses less memory, since it doesn't do buffered I/O on the backing file. Note that this uses SEEK_HOLE/SEEK_DATA to locate the data available to be read from the cache. Whilst this is an improvement from the bmap interface, it still has a problem with regard to a modern extent-based filesystem inserting or removing bridging blocks of zeros. Fixing that requires a much greater overhaul. This is a step towards overhauling the fscache API. The change is opt-in on the part of the network filesystem. A netfs should not try to mix the old and the new API because of conflicting ways of handling pages and the PG_fscache page flag and because it would be mixing DIO with buffered I/O. Further, the helper library can't be used with the old API. This does not change any of the fscache cookie handling APIs or the way invalidation is done at this time. In the near term, I intend to deprecate and remove the old I/O API (fscache_allocate_page{,s}(), fscache_read_or_alloc_page{,s}(), fscache_write_page() and fscache_uncache_page()) and eventually replace most of fscache/cachefiles with something simpler and easier to follow. This patchset contains the following parts: - Some helper patches, including provision of an ITER_XARRAY iov iterator and a function to do readahead expansion. - Patches to add the netfs helper library. - A patch to add the fscache/cachefiles kiocb API. - A pair of patches to fix some review issues in the ITER_XARRAY and read helpers as spotted by Al and Willy. Jeff Layton has patches to add support in Ceph for this that he intends for this merge window. I have a set of patches to support AFS that I will post a separate pull request for. With this, AFS without a cache passes all expected xfstests; with a cache, there's an extra failure, but that's also there before these patches. Fixing that probably requires a greater overhaul. Ceph also passes the expected tests. I also have patches in a separate branch to tidy up the handling of PG_fscache/PG_private_2 and their contribution to page refcounting in the core kernel here, but I haven't included them in this set and will route them separately" Link: https://lore.kernel.org/lkml/3779937.1619478404@warthog.procyon.org.uk/ * tag 'netfs-lib-20210426' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: netfs: Miscellaneous fixes iov_iter: Four fixes for ITER_XARRAY fscache, cachefiles: Add alternate API to use kiocb for read/write to cache netfs: Add a tracepoint to log failures that would be otherwise unseen netfs: Define an interface to talk to a cache netfs: Add write_begin helper netfs: Gather stats netfs: Add tracepoints netfs: Provide readahead and readpage netfs helpers netfs, mm: Add set/end/wait_on_page_fscache() aliases netfs, mm: Move PG_fscache helper funcs to linux/netfs.h netfs: Documentation for helper library netfs: Make a netfs helper module mm: Implement readahead_control pageset expansion mm/readahead: Handle ractl nr_pages being modified fs: Document file_ra_state mm/filemap: Pass the file_ra_state in the ractl mm: Add set/end/wait functions for PG_private_2 iov_iter: Add ITER_XARRAY
Diffstat (limited to 'include/trace')
-rw-r--r--include/trace/events/netfs.h261
1 files changed, 261 insertions, 0 deletions
diff --git a/include/trace/events/netfs.h b/include/trace/events/netfs.h
new file mode 100644
index 000000000000..de1c64635e42
--- /dev/null
+++ b/include/trace/events/netfs.h
@@ -0,0 +1,261 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* Network filesystem support module tracepoints
+ *
+ * Copyright (C) 2021 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM netfs
+
+#if !defined(_TRACE_NETFS_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_NETFS_H
+
+#include <linux/tracepoint.h>
+
+/*
+ * Define enums for tracing information.
+ */
+#ifndef __NETFS_DECLARE_TRACE_ENUMS_ONCE_ONLY
+#define __NETFS_DECLARE_TRACE_ENUMS_ONCE_ONLY
+
+enum netfs_read_trace {
+ netfs_read_trace_expanded,
+ netfs_read_trace_readahead,
+ netfs_read_trace_readpage,
+ netfs_read_trace_write_begin,
+};
+
+enum netfs_rreq_trace {
+ netfs_rreq_trace_assess,
+ netfs_rreq_trace_done,
+ netfs_rreq_trace_free,
+ netfs_rreq_trace_resubmit,
+ netfs_rreq_trace_unlock,
+ netfs_rreq_trace_unmark,
+ netfs_rreq_trace_write,
+};
+
+enum netfs_sreq_trace {
+ netfs_sreq_trace_download_instead,
+ netfs_sreq_trace_free,
+ netfs_sreq_trace_prepare,
+ netfs_sreq_trace_resubmit_short,
+ netfs_sreq_trace_submit,
+ netfs_sreq_trace_terminated,
+ netfs_sreq_trace_write,
+ netfs_sreq_trace_write_skip,
+ netfs_sreq_trace_write_term,
+};
+
+enum netfs_failure {
+ netfs_fail_check_write_begin,
+ netfs_fail_copy_to_cache,
+ netfs_fail_read,
+ netfs_fail_short_readpage,
+ netfs_fail_short_write_begin,
+ netfs_fail_prepare_write,
+};
+
+#endif
+
+#define netfs_read_traces \
+ EM(netfs_read_trace_expanded, "EXPANDED ") \
+ EM(netfs_read_trace_readahead, "READAHEAD") \
+ EM(netfs_read_trace_readpage, "READPAGE ") \
+ E_(netfs_read_trace_write_begin, "WRITEBEGN")
+
+#define netfs_rreq_traces \
+ EM(netfs_rreq_trace_assess, "ASSESS") \
+ EM(netfs_rreq_trace_done, "DONE ") \
+ EM(netfs_rreq_trace_free, "FREE ") \
+ EM(netfs_rreq_trace_resubmit, "RESUBM") \
+ EM(netfs_rreq_trace_unlock, "UNLOCK") \
+ EM(netfs_rreq_trace_unmark, "UNMARK") \
+ E_(netfs_rreq_trace_write, "WRITE ")
+
+#define netfs_sreq_sources \
+ EM(NETFS_FILL_WITH_ZEROES, "ZERO") \
+ EM(NETFS_DOWNLOAD_FROM_SERVER, "DOWN") \
+ EM(NETFS_READ_FROM_CACHE, "READ") \
+ E_(NETFS_INVALID_READ, "INVL") \
+
+#define netfs_sreq_traces \
+ EM(netfs_sreq_trace_download_instead, "RDOWN") \
+ EM(netfs_sreq_trace_free, "FREE ") \
+ EM(netfs_sreq_trace_prepare, "PREP ") \
+ EM(netfs_sreq_trace_resubmit_short, "SHORT") \
+ EM(netfs_sreq_trace_submit, "SUBMT") \
+ EM(netfs_sreq_trace_terminated, "TERM ") \
+ EM(netfs_sreq_trace_write, "WRITE") \
+ EM(netfs_sreq_trace_write_skip, "SKIP ") \
+ E_(netfs_sreq_trace_write_term, "WTERM")
+
+#define netfs_failures \
+ EM(netfs_fail_check_write_begin, "check-write-begin") \
+ EM(netfs_fail_copy_to_cache, "copy-to-cache") \
+ EM(netfs_fail_read, "read") \
+ EM(netfs_fail_short_readpage, "short-readpage") \
+ EM(netfs_fail_short_write_begin, "short-write-begin") \
+ E_(netfs_fail_prepare_write, "prep-write")
+
+
+/*
+ * Export enum symbols via userspace.
+ */
+#undef EM
+#undef E_
+#define EM(a, b) TRACE_DEFINE_ENUM(a);
+#define E_(a, b) TRACE_DEFINE_ENUM(a);
+
+netfs_read_traces;
+netfs_rreq_traces;
+netfs_sreq_sources;
+netfs_sreq_traces;
+netfs_failures;
+
+/*
+ * Now redefine the EM() and E_() macros to map the enums to the strings that
+ * will be printed in the output.
+ */
+#undef EM
+#undef E_
+#define EM(a, b) { a, b },
+#define E_(a, b) { a, b }
+
+TRACE_EVENT(netfs_read,
+ TP_PROTO(struct netfs_read_request *rreq,
+ loff_t start, size_t len,
+ enum netfs_read_trace what),
+
+ TP_ARGS(rreq, start, len, what),
+
+ TP_STRUCT__entry(
+ __field(unsigned int, rreq )
+ __field(unsigned int, cookie )
+ __field(loff_t, start )
+ __field(size_t, len )
+ __field(enum netfs_read_trace, what )
+ ),
+
+ TP_fast_assign(
+ __entry->rreq = rreq->debug_id;
+ __entry->cookie = rreq->cookie_debug_id;
+ __entry->start = start;
+ __entry->len = len;
+ __entry->what = what;
+ ),
+
+ TP_printk("R=%08x %s c=%08x s=%llx %zx",
+ __entry->rreq,
+ __print_symbolic(__entry->what, netfs_read_traces),
+ __entry->cookie,
+ __entry->start, __entry->len)
+ );
+
+TRACE_EVENT(netfs_rreq,
+ TP_PROTO(struct netfs_read_request *rreq,
+ enum netfs_rreq_trace what),
+
+ TP_ARGS(rreq, what),
+
+ TP_STRUCT__entry(
+ __field(unsigned int, rreq )
+ __field(unsigned short, flags )
+ __field(enum netfs_rreq_trace, what )
+ ),
+
+ TP_fast_assign(
+ __entry->rreq = rreq->debug_id;
+ __entry->flags = rreq->flags;
+ __entry->what = what;
+ ),
+
+ TP_printk("R=%08x %s f=%02x",
+ __entry->rreq,
+ __print_symbolic(__entry->what, netfs_rreq_traces),
+ __entry->flags)
+ );
+
+TRACE_EVENT(netfs_sreq,
+ TP_PROTO(struct netfs_read_subrequest *sreq,
+ enum netfs_sreq_trace what),
+
+ TP_ARGS(sreq, what),
+
+ TP_STRUCT__entry(
+ __field(unsigned int, rreq )
+ __field(unsigned short, index )
+ __field(short, error )
+ __field(unsigned short, flags )
+ __field(enum netfs_read_source, source )
+ __field(enum netfs_sreq_trace, what )
+ __field(size_t, len )
+ __field(size_t, transferred )
+ __field(loff_t, start )
+ ),
+
+ TP_fast_assign(
+ __entry->rreq = sreq->rreq->debug_id;
+ __entry->index = sreq->debug_index;
+ __entry->error = sreq->error;
+ __entry->flags = sreq->flags;
+ __entry->source = sreq->source;
+ __entry->what = what;
+ __entry->len = sreq->len;
+ __entry->transferred = sreq->transferred;
+ __entry->start = sreq->start;
+ ),
+
+ TP_printk("R=%08x[%u] %s %s f=%02x s=%llx %zx/%zx e=%d",
+ __entry->rreq, __entry->index,
+ __print_symbolic(__entry->what, netfs_sreq_traces),
+ __print_symbolic(__entry->source, netfs_sreq_sources),
+ __entry->flags,
+ __entry->start, __entry->transferred, __entry->len,
+ __entry->error)
+ );
+
+TRACE_EVENT(netfs_failure,
+ TP_PROTO(struct netfs_read_request *rreq,
+ struct netfs_read_subrequest *sreq,
+ int error, enum netfs_failure what),
+
+ TP_ARGS(rreq, sreq, error, what),
+
+ TP_STRUCT__entry(
+ __field(unsigned int, rreq )
+ __field(unsigned short, index )
+ __field(short, error )
+ __field(unsigned short, flags )
+ __field(enum netfs_read_source, source )
+ __field(enum netfs_failure, what )
+ __field(size_t, len )
+ __field(size_t, transferred )
+ __field(loff_t, start )
+ ),
+
+ TP_fast_assign(
+ __entry->rreq = rreq->debug_id;
+ __entry->index = sreq ? sreq->debug_index : 0;
+ __entry->error = error;
+ __entry->flags = sreq ? sreq->flags : 0;
+ __entry->source = sreq ? sreq->source : NETFS_INVALID_READ;
+ __entry->what = what;
+ __entry->len = sreq ? sreq->len : 0;
+ __entry->transferred = sreq ? sreq->transferred : 0;
+ __entry->start = sreq ? sreq->start : 0;
+ ),
+
+ TP_printk("R=%08x[%u] %s f=%02x s=%llx %zx/%zx %s e=%d",
+ __entry->rreq, __entry->index,
+ __print_symbolic(__entry->source, netfs_sreq_sources),
+ __entry->flags,
+ __entry->start, __entry->transferred, __entry->len,
+ __print_symbolic(__entry->what, netfs_failures),
+ __entry->error)
+ );
+
+#endif /* _TRACE_NETFS_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>