wireguard-linux/fs/ceph/inode.c, branch update-toolchain

netfs: Fix handling of USE_PGPRIV2 and WRITE_TO_CACHE flags

2024-08-12T20:03:27Z

The NETFS_RREQ_USE_PGPRIV2 and NETFS_RREQ_WRITE_TO_CACHE flags aren't used correctly. The problem is that we try to set them up in the request initialisation, but we the cache may be in the process of setting up still, and so the state may not be correct. Further, we secondarily sample the cache state and make contradictory decisions later. The issue arises because we set up the cache resources, which allows the cache's ->prepare_read() to switch on NETFS_SREQ_COPY_TO_CACHE - which triggers cache writing even if we didn't set the flags when allocating. Fix this in the following way: (1) Drop NETFS_ICTX_USE_PGPRIV2 and instead set NETFS_RREQ_USE_PGPRIV2 in ->init_request() rather than trying to juggle that in netfs_alloc_request(). (2) Repurpose NETFS_RREQ_USE_PGPRIV2 to merely indicate that if caching is to be done, then PG_private_2 is to be used rather than only setting it if we decide to cache and then having netfs_rreq_unlock_folios() set the non-PG_private_2 writeback-to-cache if it wasn't set. (3) Split netfs_rreq_unlock_folios() into two functions, one of which contains the deprecated code for using PG_private_2 to avoid accidentally doing the writeback path - and always use it if USE_PGPRIV2 is set. (4) As NETFS_ICTX_USE_PGPRIV2 is removed, make netfs_write_begin() always wait for PG_private_2. This function is deprecated and only used by ceph anyway, and so label it so. (5) Drop the NETFS_RREQ_WRITE_TO_CACHE flag and use fscache_operation_valid() on the cache_resources instead. This has the advantage of picking up the result of netfs_begin_cache_read() and fscache_begin_write_operation() - which are called after the object is initialised and will wait for the cache to come to a usable state. Just reverting ae678317b95e[1] isn't a sufficient fix, so this need to be applied on top of that. Without this as well, things like: rcu: INFO: rcu_sched detected expedited stalls on CPUs/tasks: { and: WARNING: CPU: 13 PID: 3621 at fs/ceph/caps.c:3386 may happen, along with some UAFs due to PG_private_2 not getting used to wait on writeback completion. Fixes: 2ff1e97587f4 ("netfs: Replace PG_fscache by setting folio->private and marking dirty") Reported-by: Max Kellermann Signed-off-by: David Howells cc: Ilya Dryomov cc: Xiubo Li cc: Hristo Venev 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 Link: https://lore.kernel.org/r/3575457.1722355300@warthog.procyon.org.uk/ [1] Link: https://lore.kernel.org/r/1173209.1723152682@warthog.procyon.org.uk Signed-off-by: Christian Brauner

ceph: drop usage of page_index

2024-07-04T02:29:55Z

page_index is needed for mixed usage of page cache and swap cache, for pure page cache usage, the caller can just use page->index instead. It can't be a swap cache page here, so just drop it. Link: https://lkml.kernel.org/r/20240521175854.96038-4-ryncsn@gmail.com Signed-off-by: Kairui Song Cc: Xiubo Li Cc: Ilya Dryomov Cc: Jeff Layton Cc: Anna Schumaker Cc: Barry Song Cc: Chao Yu Cc: Chris Li Cc: David Hildenbrand Cc: David Howells Cc: "Huang, Ying" Cc: Hugh Dickins Cc: Jaegeuk Kim Cc: Marc Dionne Cc: Matthew Wilcox (Oracle) Cc: Minchan Kim Cc: NeilBrown Cc: Ryan Roberts Cc: Ryusuke Konishi Cc: Trond Myklebust Cc: Yosry Ahmed Signed-off-by: Andrew Morton

Merge tag 'ceph-for-6.10-rc1' of https://github.com/ceph/ceph-client

2024-05-25T21:23:58Z

Pull ceph updates from Ilya Dryomov: "A series from Xiubo that adds support for additional access checks based on MDS auth caps which were recently made available to clients. This is needed to prevent scenarios where the MDS quietly discards updates that a UID-restricted client previously (wrongfully) acked to the user. Other than that, just a documentation fixup" * tag 'ceph-for-6.10-rc1' of https://github.com/ceph/ceph-client: doc: ceph: update userspace command to get CephFS metadata ceph: add CEPHFS_FEATURE_MDS_AUTH_CAPS_CHECK feature bit ceph: check the cephx mds auth access for async dirop ceph: check the cephx mds auth access for open ceph: check the cephx mds auth access for setattr ceph: add ceph_mds_check_access() helper ceph: save cap_auths in MDS client when session is opened

ceph: check the cephx mds auth access for setattr

2024-05-23T08:35:47Z

If we hit any failre just try to force it to do the sync setattr. Link: https://tracker.ceph.com/issues/61333 Signed-off-by: Xiubo Li Reviewed-by: Milind Changire Signed-off-by: Ilya Dryomov

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

ceph: always set initial i_blkbits to CEPH_FSCRYPT_BLOCK_SHIFT

2024-02-07T13:43:29Z

The fscrypt code will use i_blkbits to setup ci_data_unit_bits when allocating the new inode, but ceph will initiate i_blkbits ater when filling the inode, which is too late. Since ci_data_unit_bits will only be used by the fscrypt framework so initiating i_blkbits with CEPH_FSCRYPT_BLOCK_SHIFT is safe. Link: https://tracker.ceph.com/issues/64035 Fixes: 5b1188847180 ("fscrypt: support crypto data unit size less than filesystem block size") Signed-off-by: Xiubo Li Reviewed-by: Eric Biggers Signed-off-by: Ilya Dryomov

netfs: Optimise away reads above the point at which there can be no data

2023-12-28T09:45:27Z

Track the file position above which the server is not expected to have any data (the "zero point") and preemptively assume that we can satisfy requests by filling them with zeroes locally rather than attempting to download them if they're over that line - even if we've written data back to the server. Assume that any data that was written back above that position is held in the local cache. Note that we have to split requests that straddle the line. Make use of this to optimise away some reads from the server. We need to set the zero point in the following circumstances: (1) When we see an extant remote inode and have no cache for it, we set the zero_point to i_size. (2) On local inode creation, we set zero_point to 0. (3) On local truncation down, we reduce zero_point to the new i_size if the new i_size is lower. (4) On local truncation up, we don't change zero_point. (5) On local modification, we don't change zero_point. (6) On remote invalidation, we set zero_point to the new i_size. (7) If stored data is discarded from the pagecache or culled from fscache, we must set zero_point above that if the data also got written to the server. (8) If dirty data is written back to the server, but not fscache, we must set zero_point above that. (9) If a direct I/O write is made, set zero_point above that. Assuming the above, any read from the server at or above the zero_point position will return all zeroes. The zero_point value can be stored in the cache, provided the above rules are applied to it by any code that culls part of the local cache. Signed-off-by: David Howells cc: Jeff Layton cc: linux-cachefs@redhat.com cc: linux-fsdevel@vger.kernel.org cc: linux-mm@kvack.org

netfs: Move pinning-for-writeback from fscache to netfs

2023-12-24T15:08:49Z

Move the resource pinning-for-writeback from fscache code to netfslib code. This is used to keep a cache backing object pinned whilst we have dirty pages on the netfs inode in the pagecache such that VM writeback will be able to reach it. Whilst we're at it, switch the parameters of netfs_unpin_writeback() to match ->write_inode() so that it can be used for that directly. Note that this mechanism could be more generically useful than that for network filesystems. Quite often they have to keep around other resources (e.g. authentication tokens or network connections) until the writeback is complete. 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

Merge tag 'ceph-for-6.7-rc1' of https://github.com/ceph/ceph-client

2023-11-10T17:52:56Z

Pull ceph updates from Ilya Dryomov: - support for idmapped mounts in CephFS (Christian Brauner, Alexander Mikhalitsyn). The series was originally developed by Christian and later picked up and brought over the finish line by Alexander, who also contributed an enabler on the MDS side (separate owner_{u,g}id fields on the wire). The required exports for mnt_idmap_{get,put}() in VFS have been acked by Christian and received no objection from Christoph. - a churny change in CephFS logging to include cluster and client identifiers in log and debug messages (Xiubo Li). This would help in scenarios with dozens of CephFS mounts on the same node which are getting increasingly common, especially in the Kubernetes world. * tag 'ceph-for-6.7-rc1' of https://github.com/ceph/ceph-client: ceph: allow idmapped mounts ceph: allow idmapped atomic_open inode op ceph: allow idmapped set_acl inode op ceph: allow idmapped setattr inode op ceph: pass idmap to __ceph_setattr ceph: allow idmapped permission inode op ceph: allow idmapped getattr inode op ceph: pass an idmapping to mknod/symlink/mkdir ceph: add enable_unsafe_idmap module parameter ceph: handle idmapped mounts in create_request_message() ceph: stash idmapping in mdsc request fs: export mnt_idmap_get/mnt_idmap_put libceph, ceph: move mdsmap.h to fs/ceph ceph: print cluster fsid and client global_id in all debug logs ceph: rename _to_client() to _to_fs_client() ceph: pass the mdsc to several helpers libceph: add doutc and *_client debug macros support

ceph: allow idmapped setattr inode op

2023-11-03T22:28:34Z

Enable __ceph_setattr() to handle idmapped mounts. This is just a matter of passing down the mount's idmapping. [ aleksandr.mikhalitsyn: adapted to b27c82e12965 ("attr: port attribute changes to new types") ] Signed-off-by: Christian Brauner Signed-off-by: Alexander Mikhalitsyn Reviewed-by: Xiubo Li Signed-off-by: Ilya Dryomov