The pages in the file mapping maybe reclaimed and reused by other
subsystems and the page->private maybe used as flags field or
something else, if later that pages are used by page caches again
the page->private maybe not cleared as expected.

Here will check the PG_private bit instead of the folio->private.

Cc: stable@vger.kernel.org
URL: https://tracker.ceph.com/issues/55421
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Luis Henriques <lhenriques@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Currently when we create a file, we spin up an xattr buffer to send
along with the create request. If we end up doing an async create
however, then we currently pass down a zero-length xattr buffer.

Fix the code to send down the xattr buffer in req->r_pagelist. If the
xattrs span more than a page, however give up and don't try to do an
async create.

Cc: stable@vger.kernel.org
URL: https://bugzilla.redhat.com/show_bug.cgi?id=2063929
Fixes: 9a8d03ca2e2c ("ceph: attempt to do async create when possible")
Reported-by: John Fortin <fortinj66@gmail.com>
Reported-by: Sri Ramanujam <sri@ramanujam.io>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

The request will be inserted into the ci->i_unsafe_dirops before
assigning the req->r_session, so it's possible that we will hit
NULL pointer dereference bug here.

Cc: stable@vger.kernel.org
URL: https://tracker.ceph.com/issues/55327
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Tested-by: Aaron Tomlin <atomlin@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Once the session is opened the s->s_ttl will be set, and when receiving
a new mdsmap and the MDS map is changed, it will be possibly will close
some sessions and open new ones. And then some sessions will be in
CLOSING state evening without unmounting.

URL: https://tracker.ceph.com/issues/54979
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

ceph_add_cap says in its function documentation that the caller should
hold the read lock on the session snap_rwsem. Furthermore, not only
ceph_add_cap needs that lock, when it calls to ceph_lookup_snap_realm it
eventually calls ceph_get_snap_realm which states via lockdep that
snap_rwsem needs to be held. handle_cap_export calls ceph_add_cap
without that mdsc->snap_rwsem held. Thus, since ceph_get_snap_realm
and ceph_add_cap both need the lock, the common place to acquire that
lock is inside handle_cap_export.

Signed-off-by: Niels Dossche <dossche.niels@gmail.com>
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Pull more filesystem folio updates from Matthew Wilcox:
 "A mixture of odd changes that didn't quite make it into the original
  pull and fixes for things that did. Also the readpages changes had to
  wait for the NFS tree to be pulled first.

   - Remove ->readpages infrastructure

   - Remove AOP_FLAG_CONT_EXPAND

   - Move read_descriptor_t to networking code

   - Pass the iocb to generic_perform_write

   - Minor updates to iomap, btrfs, ext4, f2fs, ntfs"

* tag 'folio-5.18d' of git://git.infradead.org/users/willy/pagecache:
  btrfs: Remove a use of PAGE_SIZE in btrfs_invalidate_folio()
  ntfs: Correct mark_ntfs_record_dirty() folio conversion
  f2fs: Get the superblock from the mapping instead of the page
  f2fs: Correct f2fs_dirty_data_folio() conversion
  ext4: Correct ext4_journalled_dirty_folio() conversion
  filemap: Remove AOP_FLAG_CONT_EXPAND
  fs: Pass an iocb to generic_perform_write()
  fs, net: Move read_descriptor_t to net.h
  fs: Remove read_actor_t
  iomap: Simplify is_partially_uptodate a little
  readahead: Update comments
  mm: remove the skip_page argument to read_pages
  mm: remove the pages argument to read_pages
  fs: Remove ->readpages address space operation
  readahead: Remove read_cache_pages()

We can extract both the file pointer and the pos from the iocb.
This simplifies each caller as well as allowing generic_perform_write()
to see more of the iocb contents in the future.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>

Pull netfs updates from David Howells:
 "Netfs prep for write helpers.

  Having had a go at implementing write helpers and content encryption
  support in netfslib, it seems that the netfs_read_{,sub}request
  structs and the equivalent write request structs were almost the same
  and so should be merged, thereby requiring only one set of
  alloc/get/put functions and a common set of tracepoints.

  Merging the structs also has the advantage that if a bounce buffer is
  added to the request struct, a read operation can be performed to fill
  the bounce buffer, the contents of the buffer can be modified and then
  a write operation can be performed on it to send the data wherever it
  needs to go using the same request structure all the way through. The
  I/O handlers would then transparently perform any required crypto.
  This should make it easier to perform RMW cycles if needed.

  The potentially common functions and structs, however, by their names
  all proclaim themselves to be associated with the read side of things.

  The bulk of these changes alter this in the following ways:

   - Rename struct netfs_read_{,sub}request to netfs_io_{,sub}request.

   - Rename some enums, members and flags to make them more appropriate.

   - Adjust some comments to match.

   - Drop "read"/"rreq" from the names of common functions. For
     instance, netfs_get_read_request() becomes netfs_get_request().

   - The ->init_rreq() and ->issue_op() methods become ->init_request()
     and ->issue_read(). I've kept the latter as a read-specific
     function and in another branch added an ->issue_write() method.

  The driver source is then reorganised into a number of files:

        fs/netfs/buffered_read.c        Create read reqs to the pagecache
        fs/netfs/io.c                   Dispatchers for read and write reqs
        fs/netfs/main.c                 Some general miscellaneous bits
        fs/netfs/objects.c              Alloc, get and put functions
        fs/netfs/stats.c                Optional procfs statistics.

  and future development can be fitted into this scheme, e.g.:

        fs/netfs/buffered_write.c       Modify the pagecache
        fs/netfs/buffered_flush.c       Writeback from the pagecache
        fs/netfs/direct_read.c          DIO read support
        fs/netfs/direct_write.c         DIO write support
        fs/netfs/unbuffered_write.c     Write modifications directly back

  Beyond the above changes, there are also some changes that affect how
  things work:

   - Make fscache_end_operation() generally available.

   - In the netfs tracing header, generate enums from the symbol ->
     string mapping tables rather than manually coding them.

   - Add a struct for filesystems that uses netfslib to put into their
     inode wrapper structs to hold extra state that netfslib is
     interested in, such as the fscache cookie. This allows netfslib
     functions to be set in filesystem operation tables and jumped to
     directly without having to have a filesystem wrapper.

   - Add a member to the struct added above to track the remote inode
     length as that may differ if local modifications are buffered. We
     may need to supply an appropriate EOF pointer when storing data (in
     AFS for example).

   - Pass extra information to netfs_alloc_request() so that the
     ->init_request() hook can access it and retain information to
     indicate the origin of the operation.

   - Make the ->init_request() hook return an error, thereby allowing a
     filesystem that isn't allowed to cache an inode (ceph or cifs, for
     example) to skip readahead.

   - Switch to using refcount_t for subrequests and add tracepoints to
     log refcount changes for the request and subrequest structs.

   - Add a function to consolidate dispatching a read request. Similar
     code is used in three places and another couple are likely to be
     added in the future"

Link: https://lore.kernel.org/all/2639515.1648483225@warthog.procyon.org.uk/

* tag 'netfs-prep-20220318' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  afs: Maintain netfs_i_context::remote_i_size
  netfs: Keep track of the actual remote file size
  netfs: Split some core bits out into their own file
  netfs: Split fs/netfs/read_helper.c
  netfs: Rename read_helper.c to io.c
  netfs: Prepare to split read_helper.c
  netfs: Add a function to consolidate beginning a read
  netfs: Add a netfs inode context
  ceph: Make ceph_init_request() check caps on readahead
  netfs: Change ->init_request() to return an error code
  netfs: Refactor arguments for netfs_alloc_read_request
  netfs: Adjust the netfs_failure tracepoint to indicate non-subreq lines
  netfs: Trace refcounting on the netfs_io_subrequest struct
  netfs: Trace refcounting on the netfs_io_request struct
  netfs: Adjust the netfs_rreq tracepoint slightly
  netfs: Split netfs_io_* object handling out
  netfs: Finish off rename of netfs_read_request to netfs_io_request
  netfs: Rename netfs_read_*request to netfs_io_*request
  netfs: Generate enums from trace symbol mapping lists
  fscache: export fscache_end_operation()

Pull ceph updates from Ilya Dryomov:
 "The highlights are:

   - several changes to how snap context and snap realms are tracked
     (Xiubo Li). In particular, this should resolve a long-standing
     issue of high kworker CPU usage and various stalls caused by
     needless iteration over all inodes in the snap realm.

   - async create fixes to address hangs in some edge cases (Jeff
     Layton)

   - support for getvxattr MDS op for querying server-side xattrs, such
     as file/directory layouts and ephemeral pins (Milind Changire)

   - average latency is now maintained for all metrics (Venky Shankar)

   - some tweaks around handling inline data to make it fit better with
     netfs helper library (David Howells)

  Also a couple of memory leaks got plugged along with a few assorted
  fixups. Last but not least, Xiubo has stepped up to serve as a CephFS
  co-maintainer"

* tag 'ceph-for-5.18-rc1' of https://github.com/ceph/ceph-client: (27 commits)
  ceph: fix memory leak in ceph_readdir when note_last_dentry returns error
  ceph: uninitialized variable in debug output
  ceph: use tracked average r/w/m latencies to display metrics in debugfs
  ceph: include average/stdev r/w/m latency in mds metrics
  ceph: track average r/w/m latency
  ceph: use ktime_to_timespec64() rather than jiffies_to_timespec64()
  ceph: assign the ci only when the inode isn't NULL
  ceph: fix inode reference leakage in ceph_get_snapdir()
  ceph: misc fix for code style and logs
  ceph: allocate capsnap memory outside of ceph_queue_cap_snap()
  ceph: do not release the global snaprealm until unmounting
  ceph: remove incorrect and unused CEPH_INO_DOTDOT macro
  MAINTAINERS: add Xiubo Li as cephfs co-maintainer
  ceph: eliminate the recursion when rebuilding the snap context
  ceph: do not update snapshot context when there is no new snapshot
  ceph: zero the dir_entries memory when allocating it
  ceph: move to a dedicated slabcache for ceph_cap_snap
  ceph: add getvxattr op
  libceph: drop else branches in prepare_read_data{,_cont}
  ceph: fix comments mentioning i_mutex
  ...

Pull filesystem folio updates from Matthew Wilcox:
 "Primarily this series converts some of the address_space operations to
  take a folio instead of a page.

  Notably:

   - a_ops->is_partially_uptodate() takes a folio instead of a page and
     changes the type of the 'from' and 'count' arguments to make it
     obvious they're bytes.

   - a_ops->invalidatepage() becomes ->invalidate_folio() and has a
     similar type change.

   - a_ops->launder_page() becomes ->launder_folio()

   - a_ops->set_page_dirty() becomes ->dirty_folio() and adds the
     address_space as an argument.

  There are a couple of other misc changes up front that weren't worth
  separating into their own pull request"

* tag 'folio-5.18b' of git://git.infradead.org/users/willy/pagecache: (53 commits)
  fs: Remove aops ->set_page_dirty
  fb_defio: Use noop_dirty_folio()
  fs: Convert __set_page_dirty_no_writeback to noop_dirty_folio
  fs: Convert __set_page_dirty_buffers to block_dirty_folio
  nilfs: Convert nilfs_set_page_dirty() to nilfs_dirty_folio()
  mm: Convert swap_set_page_dirty() to swap_dirty_folio()
  ubifs: Convert ubifs_set_page_dirty to ubifs_dirty_folio
  f2fs: Convert f2fs_set_node_page_dirty to f2fs_dirty_node_folio
  f2fs: Convert f2fs_set_data_page_dirty to f2fs_dirty_data_folio
  f2fs: Convert f2fs_set_meta_page_dirty to f2fs_dirty_meta_folio
  afs: Convert afs_dir_set_page_dirty() to afs_dir_dirty_folio()
  btrfs: Convert extent_range_redirty_for_io() to use folios
  fs: Convert trivial uses of __set_page_dirty_nobuffers to filemap_dirty_folio
  btrfs: Convert from set_page_dirty to dirty_folio
  fscache: Convert fscache_set_page_dirty() to fscache_dirty_folio()
  fs: Add aops->dirty_folio
  fs: Remove aops->launder_page
  orangefs: Convert launder_page to launder_folio
  nfs: Convert from launder_page to launder_folio
  fuse: Convert from launder_page to launder_folio
  ...