Merge patch series "netfs: Miscellaneous fixes"

David Howells <dhowells@redhat.com> says:

Here are the outstanding miscellaneous fixes for netfslib gathered together
and with some fixes-to-fixes folded down and one rearrangement.  Various
Sashiko review comments[1][2][3][4][5] are addressed:

 (1) Fix subrequest cancellation cleanup in DIO read and single-read.

 (2) Fix missing locking around retry adding new subrequests.

 (3) Fix read and write result collection to use barriering correctly to
     access a request's subrequest lists without taking a lock.

     This adds list_add_tail_release() and
     list_first_entry_or_null_acquire() to appropriate incorporate
     barriering into some list functions.

 (4) Fix netfs_read_to_pagecache() to pause on subrequest I/O failure.

 (5) Fix the potential for 64-bit tearing on a 32-bit machine when reading
     netfs_inode->remote_i_size and ->zero_point by using much the same
     mechanism as is used for ->i_size.

 (6) Fix the calculation of zero_point in netfs_release_folio() to limit it
     to ->remote_i_size, not ->i_size.

 (7) Fix triggering of a VM_BUG_ON_FOLIO() in netfs_write_begin().

 (8) Fix a potentially uninitialised error value in
     netfs_extract_user_iter().

 (9) Fix error handling in netfs_extract_user_iter().

(10) Fix overrun checking in netfs_extract_user_iter().

(11) Fix netfs_invalidate_folio() to clear the folio dirty bit if all dirty
     data removed.

(12) Defer the emission of trace_netfs_folio() in netfs_perform_write().
     This allows the next patch to emit the correct traces.

(13) Fix the handling of a partially failed copy (ie. EFAULT) into a
     streaming write folio.  Also remove the netfs_folio if a streaming
     write folio is entirely overwritten.

(14) Fix a potential deadlock in writethrough writing.

(15) Fix netfs_read_gaps() to remove the netfs_folio from a filled folio.

(16) Fix netfs_perform_write() to not disable streaming writes when writing
     to an fd that's open O_RDWR.

(17) Fix an early put of the sink page used in netfs_read_gaps(), before
     the request has completed.

(18) Fix request leak in netfs_write_begin() error handling.

(19) Fix a potential UAF in netfs_unlock_abandoned_read_pages() due to
     trying to check index of each folio we're abandoning to see if that
     folio is actually owned by the caller (in which case, we're not
     actually allowed to dereference it).

(20) Fix incorrect adjustment of dirty region when partially invalidating a
     streaming write folio.

(21) Fix the handling of folio->private in netfs_perform_write() and the
     attached netfs_folio and/or group when a streaming write folio is
     modified.

(22) Fix netfs_read_folio() to wait on writeback first (it holds the folio
     lock) otherwise we aren't allowed to look at the netfs_folio struct as
     that could be modified at any time by the writeback collector.

(23) Fix write skipping in dir/symlink writepages.

(24) Fix the locking used by afs_get_link().

[1] https://sashiko.dev/#/patchset/20260414082004.3756080-1-dhowells%40redhat.com
[2] https://sashiko.dev/#/patchset/20260326104544.509518-1-dhowells%40redhat.com
[3] https://sashiko.dev/#/patchset/20260425125426.3855807-1-dhowells%40redhat.com
[4] https://sashiko.dev/#/patchset/20260427154639.180684-1-dhowells%40redhat.com
[5] https://sashiko.dev/#/patchset/20260428131756.922303-1-dhowells%40redhat.com

* patches from https://patch.msgid.link/20260512123404.719402-1-dhowells@redhat.com: (24 commits)
  afs: Fix the locking used by afs_get_link()
  netfs, afs: Fix write skipping in dir/link writepages
  netfs: Fix netfs_read_folio() to wait on writeback
  netfs: Fix folio->private handling in netfs_perform_write()
  netfs: Fix partial invalidation of streaming-write folio
  netfs: Fix potential UAF in netfs_unlock_abandoned_read_pages()
  netfs: Fix leak of request in netfs_write_begin() error handling
  netfs: Fix early put of sink folio in netfs_read_gaps()
  netfs: Fix write streaming disablement if fd open O_RDWR
  netfs: Fix read-gaps to remove netfs_folio from filled folio
  netfs: Fix potential deadlock in write-through mode
  netfs: Fix streaming write being overwritten
  netfs: Defer the emission of trace_netfs_folio()
  netfs: Fix netfs_invalidate_folio() to clear dirty bit if all changes gone
  netfs: Fix overrun check in netfs_extract_user_iter()
  netfs: fix error handling in netfs_extract_user_iter()
  netfs: Fix potential uninitialised var in netfs_extract_user_iter()
  netfs: fix VM_BUG_ON_FOLIO() issue in netfs_write_begin() call
  netfs: Fix zeropoint update where i_size > remote_i_size
  netfs: Fix potential for tearing in ->remote_i_size and ->zero_point
  ...

Link: https://patch.msgid.link/20260512123404.719402-1-dhowells@redhat.com
Signed-off-by: Christian Brauner <brauner@kernel.org>