David Howells
874c8ca1e6
netfs: Fix gcc-12 warning by embedding vfs inode in netfs_i_context
...
While randstruct was satisfied with using an open-coded "void *" offset
cast for the netfs_i_context <-> inode casting, __builtin_object_size() as
used by FORTIFY_SOURCE was not as easily fooled. This was causing the
following complaint[1] from gcc v12:
In file included from include/linux/string.h:253,
from include/linux/ceph/ceph_debug.h:7,
from fs/ceph/inode.c:2:
In function 'fortify_memset_chk',
inlined from 'netfs_i_context_init' at include/linux/netfs.h:326:2,
inlined from 'ceph_alloc_inode' at fs/ceph/inode.c:463:2:
include/linux/fortify-string.h:242:25: warning: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Wattribute-warning]
242 | __write_overflow_field(p_size_field, size);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Fix this by embedding a struct inode into struct netfs_i_context (which
should perhaps be renamed to struct netfs_inode). The struct inode
vfs_inode fields are then removed from the 9p, afs, ceph and cifs inode
structs and vfs_inode is then simply changed to "netfs.inode" in those
filesystems.
Further, rename netfs_i_context to netfs_inode, get rid of the
netfs_inode() function that converted a netfs_i_context pointer to an
inode pointer (that can now be done with &ctx->inode) and rename the
netfs_i_context() function to netfs_inode() (which is now a wrapper
around container_of()).
Most of the changes were done with:
perl -p -i -e 's/vfs_inode/netfs.inode/'g \
`git grep -l 'vfs_inode' -- fs/{9p,afs,ceph,cifs}/*.[ch]`
Kees suggested doing it with a pair structure[2] and a special
declarator to insert that into the network filesystem's inode
wrapper[3], but I think it's cleaner to embed it - and then it doesn't
matter if struct randomisation reorders things.
Dave Chinner suggested using a filesystem-specific VFS_I() function in
each filesystem to convert that filesystem's own inode wrapper struct
into the VFS inode struct[4].
Version #2 :
- Fix a couple of missed name changes due to a disabled cifs option.
- Rename nfs_i_context to nfs_inode
- Use "netfs" instead of "nic" as the member name in per-fs inode wrapper
structs.
[ This also undoes commit 507160f46cbc899ee1c8linux-doc@vger.kernel.org
cc: v9fs-developer@lists.sourceforge.net
cc: linux-afs@lists.infradead.org
cc: ceph-devel@vger.kernel.org
cc: linux-cifs@vger.kernel.org
cc: samba-technical@lists.samba.org
cc: linux-fsdevel@vger.kernel.org
cc: linux-hardening@vger.kernel.org
Link: https://lore.kernel.org/r/d2ad3a3d7bdd794c6efb562d2f2b655fb67756b9.camel@kernel.org/ [1]
Link: https://lore.kernel.org/r/20220517210230.864239-1-keescook@chromium.org/ [2]
Link: https://lore.kernel.org/r/20220518202212.2322058-1-keescook@chromium.org/ [3]
Link: https://lore.kernel.org/r/20220524101205.GI2306852@dread.disaster.area/ [4]
Link: https://lore.kernel.org/r/165296786831.3591209.12111293034669289733.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/165305805651.4094995.7763502506786714216.stgit@warthog.procyon.org.uk # v2
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-06-09 13:55:00 -07:00
David Howells
b900f4b89b
netfs: Split some core bits out into their own file
...
Split some core bits out into their own file. More bits will be added to
this file later.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
Link: https://lore.kernel.org/r/164623006934.3564931.17932680017894039748.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/164678218407.1200972.1731208226140990280.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/164692920944.2099075.11990502173226013856.stgit@warthog.procyon.org.uk/ # v3
2022-03-18 09:29:05 +00:00
David Howells
3be01750d7
netfs: Rename read_helper.c to io.c
...
Rename the read_helper.c file to io.c before splitting out the buffered
read functions and some other bits.
Changes
=======
ver #2 )
- Rename read_helper.c before splitting.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
Link: https://lore.kernel.org/r/164678216109.1200972.16567696909952495832.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/164692918076.2099075.8120961172717347610.stgit@warthog.procyon.org.uk/ # v3
2022-03-18 09:29:05 +00:00
David Howells
93345c3ba5
netfs: Prepare to split read_helper.c
...
Rename netfs_rreq_unlock() to netfs_rreq_unlock_folios() to make it sound
less like it's dropping a lock on an netfs_io_request struct.
Remove the 'static' marker on netfs_rreq_unlock_folios() and declaring it
in internal.h preparatory to splitting the file.
Changes
=======
ver #2 )
- Slide this patch to after the one adding netfs_begin_read().
- As a consequence, don't need to unstatic so many functions.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
Link: https://lore.kernel.org/r/164623002861.3564931.17340149482236413375.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/164678215208.1200972.9761906209395002182.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/164692912709.2099075.4349905992838317797.stgit@warthog.procyon.org.uk/ # v3
2022-03-18 09:29:05 +00:00
David Howells
4090b31422
netfs: Add a function to consolidate beginning a read
...
Add a function to do the steps needed to begin a read request, allowing
this code to be removed from several other functions and consolidated.
Changes
=======
ver #2 )
- Move before the unstaticking patch so that some functions can be left
static.
- Set uninitialised return code in netfs_begin_read()[1][2].
- Fixed a refleak caused by non-removal of a get from netfs_write_begin()
when the request submission code got moved to netfs_begin_read().
- Use INIT_WORK() to (re-)init the request work_struct[3].
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
Link: https://lore.kernel.org/r/20220303163826.1120936-1-nathan@kernel.org/ [1]
Link: https://lore.kernel.org/r/20220303235647.1297171-1-colin.i.king@gmail.com/ [2]
Link: https://lore.kernel.org/r/9d69be49081bccff44260e4c6e0049c63d6d04a1.camel@redhat.com/ [3]
Link: https://lore.kernel.org/r/164623004355.3564931.7275693529042495641.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/164678214287.1200972.16734134007649832160.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/164692911113.2099075.1060868473229451371.stgit@warthog.procyon.org.uk/ # v3
2022-03-18 09:29:05 +00:00
David Howells
bc899ee1c8
netfs: Add a netfs inode context
...
Add a netfs_i_context struct that should be included in the network
filesystem's own inode struct wrapper, directly after the VFS's inode
struct, e.g.:
struct my_inode {
struct {
/* These must be contiguous */
struct inode vfs_inode;
struct netfs_i_context netfs_ctx;
};
};
The netfs_i_context struct so far contains a single field for the network
filesystem to use - the cache cookie:
struct netfs_i_context {
...
struct fscache_cookie *cache;
};
Three functions are provided to help with this:
(1) void netfs_i_context_init(struct inode *inode,
const struct netfs_request_ops *ops);
Initialise the netfs context and set the operations.
(2) struct netfs_i_context *netfs_i_context(struct inode *inode);
Find the netfs context from the VFS inode.
(3) struct inode *netfs_inode(struct netfs_i_context *ctx);
Find the VFS inode from the netfs context.
Changes
=======
ver #4 )
- Fix netfs_is_cache_enabled() to check cookie->cache_priv to see if a
cache is present[3].
- Fix netfs_skip_folio_read() to zero out all of the page, not just some
of it[3].
ver #3 )
- Split out the bit to move ceph cap-getting on readahead into
ceph_init_request()[1].
- Stick in a comment to the netfs inode structs indicating the contiguity
requirements[2].
ver #2 )
- Adjust documentation to match.
- Use "#if IS_ENABLED()" in netfs_i_cookie(), not "#ifdef".
- Move the cap check from ceph_readahead() to ceph_init_request() to be
called from netfslib.
- Remove ceph_readahead() and use netfs_readahead() directly instead.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
Link: https://lore.kernel.org/r/8af0d47f17d89c06bbf602496dd845f2b0bf25b3.camel@kernel.org/ [1]
Link: https://lore.kernel.org/r/beaf4f6a6c2575ed489adb14b257253c868f9a5c.camel@kernel.org/ [2]
Link: https://lore.kernel.org/r/3536452.1647421585@warthog.procyon.org.uk/ [3]
Link: https://lore.kernel.org/r/164622984545.3564931.15691742939278418580.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/164678213320.1200972.16807551936267647470.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/164692909854.2099075.9535537286264248057.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/306388.1647595110@warthog.procyon.org.uk/ # v4
2022-03-18 09:29:05 +00:00
David Howells
663dfb65c3
netfs: Refactor arguments for netfs_alloc_read_request
...
Pass start and len to the rreq allocator. This should ensure that the
fields are set so that ->init_request() can use them.
Also add a parameter to indicates the origin of the request. Ceph can use
this to tell whether to get caps.
Changes
=======
ver #3 )
- Change the author to me as Jeff feels that most of the patch is my
changes now.
ver #2 )
- Show the request origin in the netfs_rreq tracepoint.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Co-developed-by: David Howells <dhowells@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-cachefs@redhat.com
Link: https://lore.kernel.org/r/164622989020.3564931.17517006047854958747.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/164678208569.1200972.12153682697842916557.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/164692904155.2099075.14717645623034355995.stgit@warthog.procyon.org.uk/ # v3
2022-03-18 09:24:00 +00:00
David Howells
6cd3d6fd1f
netfs: Trace refcounting on the netfs_io_subrequest struct
...
Add refcount tracing for the netfs_io_subrequest structure.
Changes
=======
ver #3 )
- Switch 'W=' to 'R=' in the traceline to match other request debug IDs.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
Link: https://lore.kernel.org/r/164622998584.3564931.5052255990645723639.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/164678202603.1200972.14726007419792315578.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/164692901860.2099075.4845820886851239935.stgit@warthog.procyon.org.uk/ # v3
2022-03-18 09:24:00 +00:00
David Howells
de74023bef
netfs: Trace refcounting on the netfs_io_request struct
...
Add refcount tracing for the netfs_io_request structure.
Changes
=======
ver #3 )
- Switch 'W=' to 'R=' in the traceline to match other request debug IDs.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
Link: https://lore.kernel.org/r/164622997668.3564931.14456171619219324968.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/164678200943.1200972.7241495532327787765.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/164692900920.2099075.11847712419940675791.stgit@warthog.procyon.org.uk/ # v3
2022-03-18 09:24:00 +00:00
David Howells
3a4a38e66d
netfs: Split netfs_io_* object handling out
...
Split netfs_io_* object handling out into a file that's going to contain
object allocation, get and put routines.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
cc: linux-cachefs@redhat.com
Link: https://lore.kernel.org/r/164622995118.3564931.6089530629052064470.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/164678197044.1200972.11511937252083343775.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/164692894693.2099075.7831091294248735173.stgit@warthog.procyon.org.uk/ # v3
2022-03-18 09:24:00 +00:00
David Howells
e1b1240c1f
netfs: Add write_begin helper
...
Add a helper to do the pre-reading work for the netfs write_begin address
space op.
Changes
v6:
- Fixed a missing rreq put in netfs_write_begin()[3].
- Use DEFINE_READAHEAD()[4].
v5:
- Made the wait for PG_fscache in netfs_write_begin() killable[2].
v4:
- Added flag to netfs_subreq_terminated() to indicate that the caller may
have been running async and stuff that might sleep needs punting to a
workqueue (can't use in_softirq()[1]).
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-and-tested-by: Jeff Layton <jlayton@kernel.org>
Tested-by: Dave Wysochanski <dwysocha@redhat.com>
Tested-By: Marc Dionne <marc.dionne@auristor.com>
cc: Matthew Wilcox <willy@infradead.org>
cc: linux-mm@kvack.org
cc: linux-cachefs@redhat.com
cc: linux-afs@lists.infradead.org
cc: linux-nfs@vger.kernel.org
cc: linux-cifs@vger.kernel.org
cc: ceph-devel@vger.kernel.org
cc: v9fs-developer@lists.sourceforge.net
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/20210216084230.GA23669@lst.de/ [1]
Link: https://lore.kernel.org/r/2499407.1616505440@warthog.procyon.org.uk/ [2]
Link: https://lore.kernel.org/r/161781042127.463527.9154479794406046987.stgit@warthog.procyon.org.uk/ [3]
Link: https://lore.kernel.org/r/1234933.1617886271@warthog.procyon.org.uk/ [4]
Link: https://lore.kernel.org/r/160588543960.3465195.2792938973035886168.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/161118140165.1232039.16418853874312234477.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/161161035539.2537118.15674887534950908530.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/161340398368.1303470.11242918276563276090.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/161539541541.286939.1889738674057013729.stgit@warthog.procyon.org.uk/ # v4
Link: https://lore.kernel.org/r/161653798616.2770958.17213315845968485563.stgit@warthog.procyon.org.uk/ # v5
Link: https://lore.kernel.org/r/161789080530.6155.1011847312392330491.stgit@warthog.procyon.org.uk/ # v6
2021-04-23 10:14:32 +01:00
David Howells
289af54cc6
netfs: Gather stats
...
Gather statistics from the netfs interface that can be exported through a
seqfile. This is intended to be called by a later patch when viewing
/proc/fs/fscache/stats.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-and-tested-by: Jeff Layton <jlayton@kernel.org>
Tested-by: Dave Wysochanski <dwysocha@redhat.com>
Tested-By: Marc Dionne <marc.dionne@auristor.com>
cc: Matthew Wilcox <willy@infradead.org>
cc: linux-mm@kvack.org
cc: linux-cachefs@redhat.com
cc: linux-afs@lists.infradead.org
cc: linux-nfs@vger.kernel.org
cc: linux-cifs@vger.kernel.org
cc: ceph-devel@vger.kernel.org
cc: v9fs-developer@lists.sourceforge.net
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/161118139247.1232039.10556850937548511068.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/161161034669.2537118.2761232524997091480.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/161340397101.1303470.17581910581108378458.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/161539539959.286939.6794352576462965914.stgit@warthog.procyon.org.uk/ # v4
Link: https://lore.kernel.org/r/161653797700.2770958.5801990354413178228.stgit@warthog.procyon.org.uk/ # v5
Link: https://lore.kernel.org/r/161789079281.6155.17141344853277186500.stgit@warthog.procyon.org.uk/ # v6
2021-04-23 10:14:32 +01:00
David Howells
3d3c950467
netfs: Provide readahead and readpage netfs helpers
...
Add a pair of helper functions:
(*) netfs_readahead()
(*) netfs_readpage()
to do the work of handling a readahead or a readpage, where the page(s)
that form part of the request may be split between the local cache, the
server or just require clearing, and may be single pages and transparent
huge pages. This is all handled within the helper.
Note that while both will read from the cache if there is data present,
only netfs_readahead() will expand the request beyond what it was asked to
do, and only netfs_readahead() will write back to the cache.
netfs_readpage(), on the other hand, is synchronous and only fetches the
page (which might be a THP) it is asked for.
The netfs gives the helper parameters from the VM, the cache cookie it
wants to use (or NULL) and a table of operations (only one of which is
mandatory):
(*) expand_readahead() [optional]
Called to allow the netfs to request an expansion of a readahead
request to meet its own alignment requirements. This is done by
changing rreq->start and rreq->len.
(*) clamp_length() [optional]
Called to allow the netfs to cut down a subrequest to meet its own
boundary requirements. If it does this, the helper will generate
additional subrequests until the full request is satisfied.
(*) is_still_valid() [optional]
Called to find out if the data just read from the cache has been
invalidated and must be reread from the server.
(*) issue_op() [required]
Called to ask the netfs to issue a read to the server. The subrequest
describes the read. The read request holds information about the file
being accessed.
The netfs can cache information in rreq->netfs_priv.
Upon completion, the netfs should set the error, transferred and can
also set FSCACHE_SREQ_CLEAR_TAIL and then call
fscache_subreq_terminated().
(*) done() [optional]
Called after the pages have been unlocked. The read request is still
pinning the file and mapping and may still be pinning pages with
PG_fscache. rreq->error indicates any error that has been
accumulated.
(*) cleanup() [optional]
Called when the helper is disposing of a finished read request. This
allows the netfs to clear rreq->netfs_priv.
Netfs support is enabled with CONFIG_NETFS_SUPPORT=y. It will be built
even if CONFIG_FSCACHE=n and in this case much of it should be optimised
away, allowing the filesystem to use it even when caching is disabled.
Changes:
v5:
- Comment why netfs_readahead() is putting pages[2].
- Use page_file_mapping() rather than page->mapping[2].
- Use page_index() rather than page->index[2].
- Use set_page_fscache()[3] rather then SetPageFsCache() as this takes an
appropriate ref too[4].
v4:
- Folded in a kerneldoc comment fix.
- Folded in a fix for the error handling in the case that ENOMEM occurs.
- Added flag to netfs_subreq_terminated() to indicate that the caller may
have been running async and stuff that might sleep needs punting to a
workqueue (can't use in_softirq()[1]).
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-and-tested-by: Jeff Layton <jlayton@kernel.org>
Tested-by: Dave Wysochanski <dwysocha@redhat.com>
Tested-By: Marc Dionne <marc.dionne@auristor.com>
cc: Matthew Wilcox <willy@infradead.org>
cc: linux-mm@kvack.org
cc: linux-cachefs@redhat.com
cc: linux-afs@lists.infradead.org
cc: linux-nfs@vger.kernel.org
cc: linux-cifs@vger.kernel.org
cc: ceph-devel@vger.kernel.org
cc: v9fs-developer@lists.sourceforge.net
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/20210216084230.GA23669@lst.de/ [1]
Link: https://lore.kernel.org/r/20210321014202.GF3420@casper.infradead.org/ [2]
Link: https://lore.kernel.org/r/2499407.1616505440@warthog.procyon.org.uk/ [3]
Link: https://lore.kernel.org/r/CAHk-=wh+2gbF7XEjYc=HV9w_2uVzVf7vs60BPz0gFA=+pUm3ww@mail.gmail.com/ [4]
Link: https://lore.kernel.org/r/160588497406.3465195.18003475695899726222.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/161118136849.1232039.8923686136144228724.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/161161032290.2537118.13400578415247339173.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/161340394873.1303470.6237319335883242536.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/161539537375.286939.16642940088716990995.stgit@warthog.procyon.org.uk/ # v4
Link: https://lore.kernel.org/r/161653795430.2770958.4947584573720000554.stgit@warthog.procyon.org.uk/ # v5
Link: https://lore.kernel.org/r/161789076581.6155.6745849361504760209.stgit@warthog.procyon.org.uk/ # v6
2021-04-23 10:14:32 +01:00
