kernel.git/fs/afs/super.c, branch linux-6.15.y

afs: Drop the net parameter from afs_unuse_cell()

2025-03-10T09:47:15Z

Remove the redundant net parameter to afs_unuse_cell() as cell->net can be used instead. Signed-off-by: David Howells cc: Marc Dionne cc: linux-afs@lists.infradead.org cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/20250224234154.2014840-12-dhowells@redhat.com/ # v1 Link: https://lore.kernel.org/r/20250310094206.801057-8-dhowells@redhat.com/ # v4

afs: Make afs_lookup_cell() take a trace note

2025-03-10T09:47:15Z

Pass a note to be added to the afs_cell tracepoint to afs_lookup_cell() so that different callers can be distinguished. Signed-off-by: David Howells cc: Marc Dionne cc: linux-afs@lists.infradead.org cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/20250224234154.2014840-11-dhowells@redhat.com/ # v1 Link: https://lore.kernel.org/r/20250310094206.801057-7-dhowells@redhat.com/ # v4

afs: Change dynroot to create contents on demand

2025-03-10T09:47:15Z

Change the AFS dynamic root to do things differently: (1) Rather than having the creation of cell records create inodes and dentries for cell mountpoints, create them on demand during lookup. This simplifies cell management and locking as we no longer have to create these objects in advance *and* on speculative lookup by the user for a cell that isn't precreated. (2) Rather than using the libfs dentry-based readdir (the dentries now no longer exist until accessed from (1)), have readdir generate the contents by reading the list of cells. The @cell symlinks get pushed in positions 2 and 3 if rootcell has been configured. (3) Make the @cell symlink dentries persist for the life of the superblock or until reclaimed, but make cell mountpoints disappear immediately if unused. It's not perfect as someone doing an "ls -l /afs" may create a whole bunch of dentries which will be garbage collected immediately. But any dentry that gets automounted will be pinned by the mount, so it shouldn't be too bad. (4) Allocate the inode numbers for the cell mountpoints from an IDR to prevent duplicates appearing in the event it cycles round. The number allocated from the IDR is doubled to provide two inode numbers - one for the normal cell name (RO) and one for the dotted cell name (RW). Signed-off-by: David Howells cc: Marc Dionne cc: linux-afs@lists.infradead.org cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/20250224234154.2014840-8-dhowells@redhat.com/ # v1 Link: https://lore.kernel.org/r/20250310094206.801057-4-dhowells@redhat.com/ # v4

afs: Remove the "autocell" mount option

2025-03-10T09:47:05Z

Remove the "autocell" mount option. It was an attempt to do automounting of arbitrary cells based on what the user looked up but within the root directory of a mounted volume. This isn't really the right thing to do, and using the "dyn" mount option to get the dynamic root is the right way to do it. The kafs-client package uses "-o dyn" when mounting /afs, so it should be safe to drop "-o autocell". Signed-off-by: David Howells cc: Marc Dionne cc: linux-afs@lists.infradead.org cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/20250224234154.2014840-7-dhowells@redhat.com/ # v1 Link: https://lore.kernel.org/r/20250310094206.801057-3-dhowells@redhat.com/ # v4

afs: Use netfslib for directories

2024-12-20T21:34:07Z

In the AFS ecosystem, directories are just a special type of file that is downloaded and parsed locally. Download is done by the same mechanism as ordinary files and the data can be cached. There is one important semantic restriction on directories over files: the client must download the entire directory in one go because, for example, the server could fabricate the contents of the blob on the fly with each download and give a different image each time. So that we can cache the directory download, switch AFS directory support over to using the netfslib single-object API, thereby allowing directory content to be stored in the local cache. To make this work, the following changes are made: (1) A directory's contents are now stored in a folio_queue chain attached to the afs_vnode (inode) struct rather than its associated pagecache, though multipage folios are still used to hold the data. The folio queue is discarded when the directory inode is evicted. This also helps with the phasing out of ITER_XARRAY. (2) Various directory operations are made to use and unuse the cache cookie. (3) The content checking, content dumping and content iteration are now performed with a standard iov_iter iterator over the contents of the folio queue. (4) Iteration and modification must be done with the vnode's validate_lock held. In conjunction with (1), this means that the iteration can be done without the need to lock pages or take extra refs on them, unlike when accessing ->i_pages. (5) Convert to using netfs_read_single() to read data. (6) Provide a ->writepages() to call netfs_writeback_single() to save the data to the cache according to the VM's scheduling whilst holding the validate_lock read-locked as (4). (7) Change local directory image editing functions: (a) Provide a function to get a specific block by number from the folio_queue as we can no longer use the i_pages xarray to locate folios by index. This uses a cursor to remember the current position as we need to iterate through the directory contents. The block is kmapped before being returned. (b) Make the function in (a) extend the directory by an extra folio if we run out of space. (c) Raise the check of the block free space counter, for those blocks that have one, higher in the function to eliminate a call to get a block. (d) Remove the page unlocking and putting done during the editing loops. This is no longer necessary as the folio_queue holds the references and the pages are no longer in the pagecache. (e) Mark the inode dirty and pin the cache usage till writeback at the end of a successful edit. (8) Don't set the large_folios flag on the inode as we do the allocation ourselves rather than the VM doing it automatically. (9) Mark the inode as being a single object that isn't uploaded to the server. (10) Enable caching on directories. (11) Only set the upload key for writeback for regular files. Notes: (*) We keep the ->release_folio(), ->invalidate_folio() and ->migrate_folio() ops as we set the mapping pointer on the folio. Signed-off-by: David Howells Link: https://lore.kernel.org/r/20241216204124.3752367-22-dhowells@redhat.com cc: Marc Dionne cc: Jeff Layton cc: linux-afs@lists.infradead.org cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner

afs: Don't use mutex for I/O operation lock

2024-12-20T21:34:04Z

Don't use the standard mutex for the I/O operation lock, but rather implement our own as the standard mutex must be released in the same thread as locked it. This is a problem when it comes to doing async FetchData where the lock will be dropped from the workqueue that processed the incoming data and not from the issuing thread. Signed-off-by: David Howells Link: https://lore.kernel.org/r/20241216204124.3752367-12-dhowells@redhat.com cc: Marc Dionne cc: linux-afs@lists.infradead.org Signed-off-by: Christian Brauner

Merge tag 'vfs-6.8.netfs' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs

2024-01-19T17:10:23Z

Pull netfs updates from Christian Brauner: "This extends the netfs helper library that network filesystems can use to replace their own implementations. Both afs and 9p are ported. cifs is ready as well but the patches are way bigger and will be routed separately once this is merged. That will remove lots of code as well. The overal goal is to get high-level I/O and knowledge of the page cache and ouf of the filesystem drivers. This includes knowledge about the existence of pages and folios The pull request converts afs and 9p. This removes about 800 lines of code from afs and 300 from 9p. For 9p it is now possible to do writes in larger than a page chunks. Additionally, multipage folio support can be turned on for 9p. Separate patches exist for cifs removing another 2000+ lines. I've included detailed information in the individual pulls I took. Summary: - Add NFS-style (and Ceph-style) locking around DIO vs buffered I/O calls to prevent these from happening at the same time. - Support for direct and unbuffered I/O. - Support for write-through caching in the page cache. - O_*SYNC and RWF_*SYNC writes use write-through rather than writing to the page cache and then flushing afterwards. - Support for write-streaming. - Support for write grouping. - Skip reads for which the server could only return zeros or EOF. - The fscache module is now part of the netfs library and the corresponding maintainer entry is updated. - Some helpers from the fscache subsystem are renamed to mark them as belonging to the netfs library. - Follow-up fixes for the netfs library. - Follow-up fixes for the 9p conversion" * tag 'vfs-6.8.netfs' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs: (50 commits) netfs: Fix wrong #ifdef hiding wait cachefiles: Fix signed/unsigned mixup netfs: Fix the loop that unmarks folios after writing to the cache netfs: Fix interaction between write-streaming and cachefiles culling netfs: Count DIO writes netfs: Mark netfs_unbuffered_write_iter_locked() static netfs: Fix proc/fs/fscache symlink to point to "netfs" not "../netfs" netfs: Rearrange netfs_io_subrequest to put request pointer first 9p: Use length of data written to the server in preference to error 9p: Do a couple of cleanups 9p: Fix initialisation of netfs_inode for 9p cachefiles: Fix __cachefiles_prepare_write() 9p: Use netfslib read/write_iter afs: Use the netfs write helpers netfs: Export the netfs_sreq tracepoint netfs: Optimise away reads above the point at which there can be no data netfs: Implement a write-through caching option netfs: Provide a launder_folio implementation netfs: Provide a writepages implementation netfs, cachefiles: Pass upper bound length to allow expansion ...

afs: Defer volume record destruction to a workqueue

2024-01-01T16:37:27Z

Defer volume record destruction to a workqueue so that afs_put_volume() isn't going to run the destruction process in the callback workqueue whilst the server is holding up other clients whilst waiting for us to reply to a CB.CallBack notification RPC. Signed-off-by: David Howells cc: Marc Dionne cc: linux-afs@lists.infradead.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

afs: Mark a superblock for an R/O or Backup volume as SB_RDONLY

2023-11-24T14:52:24Z

Mark a superblock that is for for an R/O or Backup volume as SB_RDONLY when mounting it. Signed-off-by: David Howells cc: Marc Dionne cc: linux-afs@lists.infradead.org