kernel.git/fs/netfs/buffered_read.c, branch linux-6.10.y

netfs, ceph: Revert "netfs: Remove deprecated use of PG_private_2 as a second writeback flag"

2024-08-29T15:35:34Z

commit 8e5ced7804cb9184c4a23f8054551240562a8eda upstream. This reverts commit ae678317b95e760607c7b20b97c9cd4ca9ed6e1a. Revert the patch that removes the deprecated use of PG_private_2 in netfslib for the moment as Ceph is actually still using this to track data copied to the cache. Fixes: ae678317b95e ("netfs: Remove deprecated use of PG_private_2 as a second writeback flag") Reported-by: Max Kellermann Signed-off-by: David Howells cc: Ilya Dryomov cc: Xiubo Li cc: Jeff Layton cc: Matthew Wilcox cc: ceph-devel@vger.kernel.org cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org cc: linux-mm@kvack.org https: //lore.kernel.org/r/3575457.1722355300@warthog.procyon.org.uk Signed-off-by: Christian Brauner Signed-off-by: Greg Kroah-Hartman

netfs: Switch debug logging to pr_debug()

2024-06-12T12:25:41Z

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 Link: https://lore.kernel.org/r/20240608151352.22860-2-ukleinek@kernel.org Signed-off-by: Christian Brauner

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

2024-05-01T17:07:36Z

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 Reviewed-by: Jeff Layton cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org

netfs: Switch to using unsigned long long rather than loff_t

2024-05-01T17:07:35Z

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 Reviewed-by: Jeff Layton cc: Ilya Dryomov cc: Xiubo Li cc: netfs@lists.linux.dev cc: ceph-devel@vger.kernel.org cc: linux-fsdevel@vger.kernel.org

netfs: Remove deprecated use of PG_private_2 as a second writeback flag

2024-04-29T14:01:43Z

Remove the deprecated use of PG_private_2 in netfslib. Signed-off-by: David Howells Reviewed-by: Jeff Layton cc: Matthew Wilcox (Oracle) cc: linux-cachefs@redhat.com cc: linux-fsdevel@vger.kernel.org cc: linux-mm@kvack.org

mm: Remove the PG_fscache alias for PG_private_2

2024-04-29T14:01:42Z

Remove the PG_fscache alias for PG_private_2 and use the latter directly. Use of this flag for marking pages undergoing writing to the cache should be considered deprecated and the folios should be marked dirty instead and the write done in ->writepages(). Note that PG_private_2 itself should be considered deprecated and up for future removal by the MM folks too. Signed-off-by: David Howells Reviewed-by: Jeff Layton cc: Matthew Wilcox (Oracle) cc: Ilya Dryomov cc: Xiubo Li cc: Steve French cc: Paulo Alcantara cc: Ronnie Sahlberg cc: Shyam Prasad N cc: Tom Talpey cc: Bharath SM cc: Trond Myklebust cc: Anna Schumaker cc: netfs@lists.linux.dev cc: ceph-devel@vger.kernel.org cc: linux-cifs@vger.kernel.org cc: linux-nfs@vger.kernel.org cc: linux-fsdevel@vger.kernel.org cc: linux-mm@kvack.org

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

2024-04-29T14:01:42Z

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 Reviewed-by: Jeff Layton cc: Matthew Wilcox (Oracle) cc: Eric Van Hensbergen cc: Latchesar Ionkov cc: Dominique Martinet cc: Christian Schoenebeck cc: Marc Dionne cc: Ilya Dryomov cc: Xiubo Li cc: Steve French cc: Paulo Alcantara cc: Ronnie Sahlberg cc: Shyam Prasad N cc: Tom Talpey cc: Bharath SM cc: Trond Myklebust cc: Anna Schumaker cc: netfs@lists.linux.dev cc: v9fs@lists.linux.dev cc: linux-afs@lists.infradead.org cc: ceph-devel@vger.kernel.org cc: linux-cifs@vger.kernel.org cc: linux-nfs@vger.kernel.org cc: linux-fsdevel@vger.kernel.org cc: linux-mm@kvack.org

netfs: Don't use certain unnecessary folio_*() functions

2024-01-22T21:56:11Z

Filesystems should use folio->index and folio->mapping, instead of folio_index(folio), folio_mapping() and folio_file_mapping() since they know that it's in the pagecache. Change this automagically with: perl -p -i -e 's/folio_mapping[(]([^)]*)[)]/\1->mapping/g' fs/netfs/*.c perl -p -i -e 's/folio_file_mapping[(]([^)]*)[)]/\1->mapping/g' fs/netfs/*.c perl -p -i -e 's/folio_index[(]([^)]*)[)]/\1->index/g' fs/netfs/*.c Reported-by: Matthew Wilcox Signed-off-by: David Howells cc: Jeff Layton cc: linux-afs@lists.infradead.org cc: linux-cachefs@redhat.com cc: linux-cifs@vger.kernel.org cc: linux-erofs@lists.ozlabs.org cc: linux-fsdevel@vger.kernel.org

netfs: Provide netfs_file_read_iter()

2023-12-28T09:45:25Z

Provide a top-level-ish function that can be pointed to directly by ->read_iter file op. Signed-off-by: David Howells Reviewed-by: Jeff Layton cc: linux-cachefs@redhat.com cc: linux-fsdevel@vger.kernel.org cc: linux-mm@kvack.org

netfs: Make netfs_read_folio() handle streaming-write pages

2023-12-28T09:45:22Z

netfs_read_folio() needs to handle partially-valid pages that are marked dirty, but not uptodate in the event that someone tries to read a page was used to cache data by a streaming write. In such a case, make netfs_read_folio() set up a bvec iterator that points to the parts of the folio that need filling and to a sink page for the data that should be discarded and use that instead of i_pages as the iterator to be written to. This requires netfs_rreq_unlock_folios() to convert the page into a normal dirty uptodate page, getting rid of the partial write record and bumping the group pointer over to folio->private. Signed-off-by: David Howells Reviewed-by: Jeff Layton cc: linux-cachefs@redhat.com cc: linux-fsdevel@vger.kernel.org cc: linux-mm@kvack.org