netfs: Remove unnecessary references to pages

These places should all use folios instead of pages.

Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
Link: https://lore.kernel.org/r/20241

netfs: Remove unnecessary references to pages

These places should all use folios instead of pages.

Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Christian Brauner <[email protected]>

show more ...

netfs: Fix a few minor bugs in netfs_page_mkwrite()

We can't return with VM_FAULT_SIGBUS | VM_FAULT_LOCKED; the core
code will not unlock the folio in this instance. Introduce a new
"unlock" error

netfs: Fix a few minor bugs in netfs_page_mkwrite()

We can't return with VM_FAULT_SIGBUS | VM_FAULT_LOCKED; the core
code will not unlock the folio in this instance. Introduce a new
"unlock" error exit to handle this case. Use it to handle
the "folio is truncated" check, and change the "writeback interrupted
by a fatal signal" to do a NOPAGE exit instead of letting the core
code install the folio currently under writeback before killing the
process.

Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Christian Brauner <[email protected]>

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netfs, cifs: Fix mtime/ctime update for mmapped writes

The cifs flag CIFS_INO_MODIFIED_ATTR, which indicates that the mtime and
ctime need to be written back on close, got taken over by netfs as
NET

netfs, cifs: Fix mtime/ctime update for mmapped writes

The cifs flag CIFS_INO_MODIFIED_ATTR, which indicates that the mtime and
ctime need to be written back on close, got taken over by netfs as
NETFS_ICTX_MODIFIED_ATTR to avoid the need to call a function pointer to
set it.

The flag gets set correctly on buffered writes, but doesn't get set by
netfs_page_mkwrite(), leading to occasional failures in generic/080 and
generic/215.

Fix this by setting the flag in netfs_page_mkwrite().

Fixes: 73425800ac94 ("netfs, cifs: Move CIFS_INO_MODIFIED_ATTR to netfs_inode")
Reported-by: kernel test robot <[email protected]>
Closes: https://lore.kernel.org/oe-lkp/[email protected]
Signed-off-by: David Howells <[email protected]>
Reviewed-by: Paulo Alcantara (Red Hat) <[email protected]>
cc: Jeff Layton <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
Signed-off-by: Steve French <[email protected]>

show more ...

netfs, cifs: Move CIFS_INO_MODIFIED_ATTR to netfs_inode

Move CIFS_INO_MODIFIED_ATTR to netfs_inode as NETFS_ICTX_MODIFIED_ATTR and
then make netfs_perform_write() set it. This means that cifs doesn

netfs, cifs: Move CIFS_INO_MODIFIED_ATTR to netfs_inode

Move CIFS_INO_MODIFIED_ATTR to netfs_inode as NETFS_ICTX_MODIFIED_ATTR and
then make netfs_perform_write() set it. This means that cifs doesn't need
to implement the ->post_modify() hook.

Signed-off-by: David Howells <[email protected]>
cc: Jeff Layton <[email protected]>
cc: Steve French <[email protected]>
cc: Paulo Alcantara <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]/ # v2
Signed-off-by: Christian Brauner <[email protected]>

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netfs: Reduce number of conditional branches in netfs_perform_write()

Reduce the number of conditional branches in netfs_perform_write() by
merging in netfs_how_to_modify() and then creating a separ

netfs: Reduce number of conditional branches in netfs_perform_write()

Reduce the number of conditional branches in netfs_perform_write() by
merging in netfs_how_to_modify() and then creating a separate if-statement
for each way we might modify a folio. Note that this means replicating the
data copy in each path.

Signed-off-by: David Howells <[email protected]>
cc: Jeff Layton <[email protected]>
cc: [email protected]
cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]/ # v2
Signed-off-by: Christian Brauner <[email protected]>

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netfs: Fault in smaller chunks for non-large folio mappings

As in commit 4e527d5841e2 ("iomap: fault in smaller chunks for non-large
folio mappings"), we can see a performance loss for filesystems
w

netfs: Fault in smaller chunks for non-large folio mappings

As in commit 4e527d5841e2 ("iomap: fault in smaller chunks for non-large
folio mappings"), we can see a performance loss for filesystems
which have not yet been converted to large folios.

Fixes: c38f4e96e605 ("netfs: Provide func to copy data to pagecache for buffered write")
Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Jeff Layton <[email protected]>
Signed-off-by: Christian Brauner <[email protected]>

show more ...

netfs: Revert "netfs: Switch debug logging to pr_debug()"

Revert commit 163eae0fb0d4c610c59a8de38040f8e12f89fd43 to get back the
original operation of the debugging macros.

Signed-off-by: David How

netfs: Revert "netfs: Switch debug logging to pr_debug()"

Revert commit 163eae0fb0d4c610c59a8de38040f8e12f89fd43 to get back the
original operation of the debugging macros.

Signed-off-by: David Howells <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Link: https://lore.kernel.org/r/[email protected]
cc: Uwe Kleine-König <[email protected]>
cc: Christian Brauner <[email protected]>
cc: Jeff Layton <[email protected]>
cc: [email protected]
cc: [email protected]
Signed-off-by: Christian Brauner <[email protected]>

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netfs: drop usage of folio_file_pos

folio_file_pos is only needed for mixed usage of page cache and swap
cache, for pure page cache usage, the caller can just use folio_pos
instead.

It can't be a s

netfs: drop usage of folio_file_pos

folio_file_pos is only needed for mixed usage of page cache and swap
cache, for pure page cache usage, the caller can just use folio_pos
instead.

It can't be a swap cache page here. Swap mapping may only call into fs
through swap_rw and that is not supported for netfs. So just drop it and
use folio_pos instead.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Kairui Song <[email protected]>
Cc: David Howells <[email protected]>
Cc: Jeff Layton <[email protected]>
Cc: Anna Schumaker <[email protected]>
Cc: Barry Song <[email protected]>
Cc: Chao Yu <[email protected]>
Cc: Chris Li <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: "Huang, Ying" <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Ilya Dryomov <[email protected]>
Cc: Jaegeuk Kim <[email protected]>
Cc: Marc Dionne <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: NeilBrown <[email protected]>
Cc: Ryan Roberts <[email protected]>
Cc: Ryusuke Konishi <[email protected]>
Cc: Trond Myklebust <[email protected]>
Cc: Xiubo Li <[email protected]>
Cc: Yosry Ahmed <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

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netfs: Fix netfs_page_mkwrite() to flush conflicting data, not wait

Fix netfs_page_mkwrite() to use filemap_fdatawrite_range(), not
filemap_fdatawait_range() to flush conflicting data.

Fixes: 102a7

netfs: Fix netfs_page_mkwrite() to flush conflicting data, not wait

Fix netfs_page_mkwrite() to use filemap_fdatawrite_range(), not
filemap_fdatawait_range() to flush conflicting data.

Fixes: 102a7e2c598c ("netfs: Allow buffered shared-writeable mmap through netfs_page_mkwrite()")
Signed-off-by: David Howells <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
cc: Matthew Wilcox <[email protected]>
cc: Jeff Layton <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
cc: [email protected]
cc: [email protected]
cc: [email protected]
Signed-off-by: Christian Brauner <[email protected]>

show more ...

netfs: Fix netfs_page_mkwrite() to check folio->mapping is valid

Fix netfs_page_mkwrite() to check that folio->mapping is valid once it has
taken the folio lock (as filemap_page_mkwrite() does). Wi

netfs: Fix netfs_page_mkwrite() to check folio->mapping is valid

Fix netfs_page_mkwrite() to check that folio->mapping is valid once it has
taken the folio lock (as filemap_page_mkwrite() does). Without this,
generic/247 occasionally oopses with something like the following:

BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page

RIP: 0010:trace_event_raw_event_netfs_folio+0x61/0xc0
...
Call Trace:
<TASK>
? __die_body+0x1a/0x60
? page_fault_oops+0x6e/0xa0
? exc_page_fault+0xc2/0xe0
? asm_exc_page_fault+0x22/0x30
? trace_event_raw_event_netfs_folio+0x61/0xc0
trace_netfs_folio+0x39/0x40
netfs_page_mkwrite+0x14c/0x1d0
do_page_mkwrite+0x50/0x90
do_pte_missing+0x184/0x200
__handle_mm_fault+0x42d/0x500
handle_mm_fault+0x121/0x1f0
do_user_addr_fault+0x23e/0x3c0
exc_page_fault+0xc2/0xe0
asm_exc_page_fault+0x22/0x30

This is due to the invalidate_inode_pages2_range() issued at the end of the
DIO write interfering with the mmap'd writes.

Fixes: 102a7e2c598c ("netfs: Allow buffered shared-writeable mmap through netfs_page_mkwrite()")
Signed-off-by: David Howells <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Jeff Layton <[email protected]>
cc: Matthew Wilcox <[email protected]>
cc: Jeff Layton <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
cc: [email protected]
cc: [email protected]
cc: [email protected]
Signed-off-by: Christian Brauner <[email protected]>

show more ...

netfs: Switch debug logging to pr_debug()

Instead of inventing a custom way to conditionally enable debugging,
just make use of pr_debug(), which also has dynamic debugging facilities
and is more li

netfs: Switch debug logging to pr_debug()

Instead of inventing a custom way to conditionally enable debugging,
just make use of pr_debug(), which also has dynamic debugging facilities
and is more likely known to someone who hunts a problem in the netfs
code. Also drop the module parameter netfs_debug which didn't have any
effect without further source changes. (The variable netfs_debug was
only used in #ifdef blocks for cpp vars that don't exist; Note that
CONFIG_NETFS_DEBUG isn't settable via kconfig, a variable with that name
never existed in the mainline and is probably just taken over (and
renamed) from similar custom debug logging implementations.)

Signed-off-by: Uwe Kleine-König <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Christian Brauner <[email protected]>

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netfs: Fix setting of BDP_ASYNC from iocb flags

Fix netfs_perform_write() to set BDP_ASYNC if IOCB_NOWAIT is set rather
than if IOCB_SYNC is not set. It reflects asynchronicity in the sense of
not

netfs: Fix setting of BDP_ASYNC from iocb flags

Fix netfs_perform_write() to set BDP_ASYNC if IOCB_NOWAIT is set rather
than if IOCB_SYNC is not set. It reflects asynchronicity in the sense of
not waiting rather than synchronicity in the sense of not returning until
the op is complete.

Without this, generic/590 fails on cifs in strict caching mode with a
complaint that one of the writes fails with EAGAIN. The test can be
distilled down to:

mount -t cifs /my/share /mnt -ostuff
xfs_io -i -c 'falloc 0 8191M -c fsync -f /mnt/file
xfs_io -i -c 'pwrite -b 1M -W 0 8191M' /mnt/file

Fixes: c38f4e96e605 ("netfs: Provide func to copy data to pagecache for buffered write")
Signed-off-by: David Howells <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Jens Axboe <[email protected]>
cc: Jeff Layton <[email protected]>
cc: Enzo Matsumiya <[email protected]>
cc: Jens Axboe <[email protected]>
cc: Matthew Wilcox <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
cc: [email protected]
cc: [email protected]
Signed-off-by: Christian Brauner <[email protected]>

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cifs: Implement netfslib hooks

Provide implementation of the netfslib hooks that will be used by netfslib
to ask cifs to set up and perform operations. Of particular note are

(*) cifs_clamp_lengt

cifs: Implement netfslib hooks

Provide implementation of the netfslib hooks that will be used by netfslib
to ask cifs to set up and perform operations. Of particular note are

(*) cifs_clamp_length() - This is used to negotiate the size of the next
subrequest in a read request, taking into account the credit available
and the rsize. The credits are attached to the subrequest.

(*) cifs_req_issue_read() - This is used to issue a subrequest that has
been set up and clamped.

(*) cifs_prepare_write() - This prepares to fill a subrequest by picking a
channel, reopening the file and requesting credits so that we can set
the maximum size of the subrequest and also sets the maximum number of
segments if we're doing RDMA.

(*) cifs_issue_write() - This releases any unneeded credits and issues an
asynchronous data write for the contiguous slice of file covered by
the subrequest. This should possibly be folded in to all
->async_writev() ops and that called directly.

(*) cifs_begin_writeback() - This gets the cached writable handle through
which we do writeback (this does not affect writethrough, unbuffered
or direct writes).

At this point, cifs is not wired up to actually *use* netfslib; that will
be done in a subsequent patch.

Signed-off-by: David Howells <[email protected]>
cc: Steve French <[email protected]>
cc: Shyam Prasad N <[email protected]>
cc: Rohith Surabattula <[email protected]>
cc: Jeff Layton <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
cc: [email protected]

show more ...

netfs: Miscellaneous tidy ups

Do a couple of miscellaneous tidy ups:

(1) Add a qualifier into a file banner comment.

(2) Put the writeback folio traces back into alphabetical order.

(3) Remove

netfs: Miscellaneous tidy ups

Do a couple of miscellaneous tidy ups:

(1) Add a qualifier into a file banner comment.

(2) Put the writeback folio traces back into alphabetical order.

(3) Remove some unused folio traces.

Signed-off-by: David Howells <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
cc: [email protected]
cc: [email protected]

show more ...

netfs: Remove the old writeback code

Remove the old writeback code.

Signed-off-by: David Howells <[email protected]>
cc: Jeff Layton <[email protected]>
cc: Eric Van Hensbergen <[email protected]

netfs: Remove the old writeback code

Remove the old writeback code.

Signed-off-by: David Howells <[email protected]>
cc: Jeff Layton <[email protected]>
cc: Eric Van Hensbergen <[email protected]>
cc: Latchesar Ionkov <[email protected]>
cc: Dominique Martinet <[email protected]>
cc: Christian Schoenebeck <[email protected]>
cc: Marc Dionne <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
cc: [email protected]

show more ...

netfs: Cut over to using new writeback code

Cut over to using the new writeback code. The old code is #ifdef'd out or
otherwise removed from compilation to avoid conflicts and will be removed
in a

netfs: Cut over to using new writeback code

Cut over to using the new writeback code. The old code is #ifdef'd out or
otherwise removed from compilation to avoid conflicts and will be removed
in a future patch.

Signed-off-by: David Howells <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
cc: Eric Van Hensbergen <[email protected]>
cc: Latchesar Ionkov <[email protected]>
cc: Dominique Martinet <[email protected]>
cc: Christian Schoenebeck <[email protected]>
cc: Marc Dionne <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
cc: [email protected]

show more ...

netfs: Add some write-side stats and clean up some stat names

Add some write-side stats to count buffered writes, buffered writethrough,
and writepages calls.

Whilst we're at it, clean up the namin

netfs: Add some write-side stats and clean up some stat names

Add some write-side stats to count buffered writes, buffered writethrough,
and writepages calls.

Whilst we're at it, clean up the naming on some of the existing stats
counters and organise the output into two sets.

Signed-off-by: David Howells <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
cc: [email protected]
cc: [email protected]

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netfs: New writeback implementation

The current netfslib writeback implementation creates writeback requests of
contiguous folio data and then separately tiles subrequests over the space
twice, once

netfs: New writeback implementation

The current netfslib writeback implementation creates writeback requests of
contiguous folio data and then separately tiles subrequests over the space
twice, once for the server and once for the cache. This creates a few
issues:

(1) Every time there's a discontiguity or a change between writing to only
one destination or writing to both, it must create a new request.
This makes it harder to do vectored writes.

(2) The folios don't have the writeback mark removed until the end of the
request - and a request could be hundreds of megabytes.

(3) In future, I want to support a larger cache granularity, which will
require aggregation of some folios that contain unmodified data (which
only need to go to the cache) and some which contain modifications
(which need to be uploaded and stored to the cache) - but, currently,
these are treated as discontiguous.

There's also a move to get everyone to use writeback_iter() to extract
writable folios from the pagecache. That said, currently writeback_iter()
has some issues that make it less than ideal:

(1) there's no way to cancel the iteration, even if you find a "temporary"
error that means the current folio and all subsequent folios are going
to fail;

(2) there's no way to filter the folios being written back - something
that will impact Ceph with it's ordered snap system;

(3) and if you get a folio you can't immediately deal with (say you need
to flush the preceding writes), you are left with a folio hanging in
the locked state for the duration, when really we should unlock it and
relock it later.

In this new implementation, I use writeback_iter() to pump folios,
progressively creating two parallel, but separate streams and cleaning up
the finished folios as the subrequests complete. Either or both streams
can contain gaps, and the subrequests in each stream can be of variable
size, don't need to align with each other and don't need to align with the
folios.

Indeed, subrequests can cross folio boundaries, may cover several folios or
a folio may be spanned by multiple folios, e.g.:

+---+---+-----+-----+---+----------+
Folios: | | | | | | |
+---+---+-----+-----+---+----------+

+------+------+ +----+----+
Upload: | | |.....| | |
+------+------+ +----+----+

+------+------+------+------+------+
Cache: | | | | | |
+------+------+------+------+------+

The progressive subrequest construction permits the algorithm to be
preparing both the next upload to the server and the next write to the
cache whilst the previous ones are already in progress. Throttling can be
applied to control the rate of production of subrequests - and, in any
case, we probably want to write them to the server in ascending order,
particularly if the file will be extended.

Content crypto can also be prepared at the same time as the subrequests and
run asynchronously, with the prepped requests being stalled until the
crypto catches up with them. This might also be useful for transport
crypto, but that happens at a lower layer, so probably would be harder to
pull off.

The algorithm is split into three parts:

(1) The issuer. This walks through the data, packaging it up, encrypting
it and creating subrequests. The part of this that generates
subrequests only deals with file positions and spans and so is usable
for DIO/unbuffered writes as well as buffered writes.

(2) The collector. This asynchronously collects completed subrequests,
unlocks folios, frees crypto buffers and performs any retries. This
runs in a work queue so that the issuer can return to the caller for
writeback (so that the VM can have its kswapd thread back) or async
writes.

(3) The retryer. This pauses the issuer, waits for all outstanding
subrequests to complete and then goes through the failed subrequests
to reissue them. This may involve reprepping them (with cifs, the
credits must be renegotiated, and a subrequest may need splitting),
and doing RMW for content crypto if there's a conflicting change on
the server.

[!] Note that some of the functions are prefixed with "new_" to avoid
clashes with existing functions. These will be renamed in a later patch
that cuts over to the new algorithm.

Signed-off-by: David Howells <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
cc: Eric Van Hensbergen <[email protected]>
cc: Latchesar Ionkov <[email protected]>
cc: Dominique Martinet <[email protected]>
cc: Christian Schoenebeck <[email protected]>
cc: Marc Dionne <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
cc: [email protected]

show more ...

netfs: Switch to using unsigned long long rather than loff_t

Switch to using unsigned long long rather than loff_t in netfslib to avoid
problems with the sign flipping in the maths when we're dealin

netfs: Switch to using unsigned long long rather than loff_t

Switch to using unsigned long long rather than loff_t in netfslib to avoid
problems with the sign flipping in the maths when we're dealing with the
byte at position 0x7fffffffffffffff.

Signed-off-by: David Howells <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
cc: Ilya Dryomov <[email protected]>
cc: Xiubo Li <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]

show more ...

netfs: Remove ->launder_folio() support

Remove support for ->launder_folio() from netfslib and expect filesystems
to use filemap_invalidate_inode() instead. netfs_launder_folio() can then
be got ri

netfs: Remove ->launder_folio() support

Remove support for ->launder_folio() from netfslib and expect filesystems
to use filemap_invalidate_inode() instead. netfs_launder_folio() can then
be got rid of.

Signed-off-by: David Howells <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
cc: Eric Van Hensbergen <[email protected]>
cc: Latchesar Ionkov <[email protected]>
cc: Dominique Martinet <[email protected]>
cc: Christian Schoenebeck <[email protected]>
cc: David Howells <[email protected]>
cc: Marc Dionne <[email protected]>
cc: Steve French <[email protected]>
cc: Matthew Wilcox <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
cc: [email protected]
cc: [email protected]
cc: [email protected]
cc: [email protected]
cc: [email protected]

show more ...

netfs: Replace PG_fscache by setting folio->private and marking dirty

When dirty data is being written to the cache, setting/waiting on/clearing
the fscache flag is always done in tandem with settin

netfs: Replace PG_fscache by setting folio->private and marking dirty

When dirty data is being written to the cache, setting/waiting on/clearing
the fscache flag is always done in tandem with setting/waiting on/clearing
the writeback flag. The netfslib buffered write routines wait on and set
both flags and the write request cleanup clears both flags, so the fscache
flag is almost superfluous.

The reason it isn't superfluous is because the fscache flag is also used to
indicate that data just read from the server is being written to the cache.
The flag is used to prevent a race involving overlapping direct-I/O writes
to the cache.

Change this to indicate that a page is in need of being copied to the cache
by placing a magic value in folio->private and marking the folios dirty.
Then when the writeback code sees a folio marked in this way, it only
writes it to the cache and not to the server.

If a folio that has this magic value set is modified, the value is just
replaced and the folio will then be uplodaded too.

With this, PG_fscache is no longer required by the netfslib core, 9p and
afs.

Ceph and nfs, however, still need to use the old PG_fscache-based tracking.
To deal with this, a flag, NETFS_ICTX_USE_PGPRIV2, now has to be set on the
flags in the netfs_inode struct for those filesystems. This reenables the
use of PG_fscache in that inode. 9p and afs use the netfslib write helpers
so get switched over; cifs, for the moment, does page-by-page manual access
to the cache, so doesn't use PG_fscache and is unaffected.

Signed-off-by: David Howells <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
cc: Matthew Wilcox (Oracle) <[email protected]>
cc: Eric Van Hensbergen <[email protected]>
cc: Latchesar Ionkov <[email protected]>
cc: Dominique Martinet <[email protected]>
cc: Christian Schoenebeck <[email protected]>
cc: Marc Dionne <[email protected]>
cc: Ilya Dryomov <[email protected]>
cc: Xiubo Li <[email protected]>
cc: Steve French <[email protected]>
cc: Paulo Alcantara <[email protected]>
cc: Ronnie Sahlberg <[email protected]>
cc: Shyam Prasad N <[email protected]>
cc: Tom Talpey <[email protected]>
cc: Bharath SM <[email protected]>
cc: Trond Myklebust <[email protected]>
cc: Anna Schumaker <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
cc: [email protected]
cc: [email protected]
cc: [email protected]
cc: [email protected]
cc: [email protected]

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netfs: Update i_blocks when write committed to pagecache

Update i_blocks when i_size is updated when we finish making a write to the
pagecache to reflect the amount of space we think will be consume

netfs: Update i_blocks when write committed to pagecache

Update i_blocks when i_size is updated when we finish making a write to the
pagecache to reflect the amount of space we think will be consumed.

This maintains cifs commit dbfdff402d89854126658376cbcb08363194d3cd ("smb3:
update allocation size more accurately on write completion") which would
otherwise be removed by the cifs part of the netfs writeback rewrite.

Signed-off-by: David Howells <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
cc: Steve French <[email protected]>
cc: Shyam Prasad N <[email protected]>
cc: Rohith Surabattula <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
cc: [email protected]

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netfs: Fix the pre-flush when appending to a file in writethrough mode

In netfs_perform_write(), when the file is marked NETFS_ICTX_WRITETHROUGH
or O_*SYNC or RWF_*SYNC was specified, write-through

netfs: Fix the pre-flush when appending to a file in writethrough mode

In netfs_perform_write(), when the file is marked NETFS_ICTX_WRITETHROUGH
or O_*SYNC or RWF_*SYNC was specified, write-through caching is performed
on a buffered file. When setting up for write-through, we flush any
conflicting writes in the region and wait for the write to complete,
failing if there's a write error to return.

The issue arises if we're writing at or above the EOF position because we
skip the flush and - more importantly - the wait. This becomes a problem
if there's a partial folio at the end of the file that is being written out
and we want to make a write to it too. Both the already-running write and
the write we start both want to clear the writeback mark, but whoever is
second causes a warning looking something like:

------------[ cut here ]------------
R=00000012: folio 11 is not under writeback
WARNING: CPU: 34 PID: 654 at fs/netfs/write_collect.c:105
...
CPU: 34 PID: 654 Comm: kworker/u386:27 Tainted: G S ...
...
Workqueue: events_unbound netfs_write_collection_worker
...
RIP: 0010:netfs_writeback_lookup_folio

Fix this by making the flush-and-wait unconditional. It will do nothing if
there are no folios in the pagecache and will return quickly if there are
no folios in the region specified.

Further, move the WBC attachment above the flush call as the flush is going
to attach a WBC and detach it again if it is not present - and since we
need one anyway we might as well share it.

Fixes: 41d8e7673a77 ("netfs: Implement a write-through caching option")
Reported-by: kernel test robot <[email protected]>
Closes: https://lore.kernel.org/oe-lkp/[email protected]
Signed-off-by: David Howells <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Jeffrey Layton <[email protected]>
cc: Eric Van Hensbergen <[email protected]>
cc: Latchesar Ionkov <[email protected]>
cc: Dominique Martinet <[email protected]>
cc: Christian Schoenebeck <[email protected]>
cc: Marc Dionne <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
cc: [email protected]
cc: [email protected]
cc: [email protected]
Signed-off-by: Christian Brauner <[email protected]>

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netfs: Fix writethrough-mode error handling

Fix the error return in netfs_perform_write() acting in writethrough-mode
to return any cached error in the case that netfs_end_writethrough()
returns 0.

netfs: Fix writethrough-mode error handling

Fix the error return in netfs_perform_write() acting in writethrough-mode
to return any cached error in the case that netfs_end_writethrough()
returns 0.

This can affect the use of O_SYNC/O_DSYNC/RWF_SYNC/RWF_DSYNC in 9p and afs.

Fixes: 41d8e7673a77 ("netfs: Implement a write-through caching option")
Signed-off-by: David Howells <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Jeff Layton <[email protected]>
cc: Eric Van Hensbergen <[email protected]>
cc: Latchesar Ionkov <[email protected]>
cc: Dominique Martinet <[email protected]>
cc: Christian Schoenebeck <[email protected]>
cc: Marc Dionne <[email protected]>
cc: [email protected]
cc: [email protected]
cc: [email protected]
cc: [email protected]
Signed-off-by: Christian Brauner <[email protected]>

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netfs: Fix missing zero-length check in unbuffered write

Fix netfs_unbuffered_write_iter() to return immediately if
generic_write_checks() returns 0, indicating there's nothing to write.
Note that n

netfs: Fix missing zero-length check in unbuffered write

Fix netfs_unbuffered_write_iter() to return immediately if
generic_write_checks() returns 0, indicating there's nothing to write.
Note that netfs_file_write_iter() already does this.

Also, whilst we're at it, put in checks for the size being zero before we
even take the locks. Note that generic_write_checks() can still reduce the
size to zero, so we still need that check.

Without this, a warning similar to the following is logged to dmesg:

netfs: Zero-sized write [R=1b6da]

and the syscall fails with EIO, e.g.:

/sbin/ldconfig.real: Writing of cache extension data failed: Input/output error

This can be reproduced on 9p by:

xfs_io -f -c 'pwrite 0 0' /xfstest.test/foo

Fixes: 153a9961b551 ("netfs: Implement unbuffered/DIO write support")
Reported-by: Eric Van Hensbergen <[email protected]>
Link: https://lore.kernel.org/r/ZbQUU6QKmIftKsmo@FV7GG9FTHL/
Signed-off-by: David Howells <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Tested-by: Dominique Martinet <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
cc: Dominique Martinet <[email protected]>
cc: Jeff Layton <[email protected]>
cc: <[email protected]>
cc: <[email protected]>
cc: <[email protected]>
cc: <[email protected]>
Signed-off-by: Christian Brauner <[email protected]>

show more ...