2010 Commits

Author SHA1 Message Date
CrazyCat
af8890e8f6 [tree-wide] finally take no_llseek out
no_llseek had been defined to NULL two years ago, in commit 868941b
("fs: remove no_llseek")

To quote that commit,

  At -rc1 we'll need do a mechanical removal of no_llseek -

  git grep -l -w no_llseek | grep -v porting.rst | while read i; do
    sed -i '/\<no_llseek\>/d' $i
  done

  would do it.

Unfortunately, that hadn't been done.  Linus, could you do that now, so
that we could finally put that thing to rest? All instances are of the
form
    .llseek = no_llseek,
so it's obviously safe.
2024-12-11 18:00:46 +02:00
Linus Torvalds
c6b0271053 Merge tag 'fs_for_v6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
Pull misc filesystem updates from Jan Kara:

 - Rewrite kmap_local() handling in ext2

 - Convert ext2 direct IO path to iomap (with some infrastructure tweaks
   associated with that)

 - Convert two boilerplate licenses in udf to SPDX identifiers

 - Other small udf, ext2, and quota fixes and cleanups

* tag 'fs_for_v6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  udf: Fix uninitialized array access for some pathnames
  ext2: Drop fragment support
  quota: fix warning in dqgrab()
  quota: Properly disable quotas when add_dquot_ref() fails
  fs: udf: udftime: Replace LGPL boilerplate with SPDX identifier
  fs: udf: Replace GPL 2.0 boilerplate license notice with SPDX identifier
  fs: Drop wait_unfrozen wait queue
  ext2_find_entry()/ext2_dotdot(): callers don't need page_addr anymore
  ext2_{set_link,delete_entry}(): don't bother with page_addr
  ext2_put_page(): accept any pointer within the page
  ext2_get_page(): saner type
  ext2: use offset_in_page() instead of open-coding it as subtraction
  ext2_rename(): set_link and delete_entry may fail
  ext2: Add direct-io trace points
  ext2: Move direct-io to use iomap
  ext2: Use generic_buffers_fsync() implementation
  ext4: Use generic_buffers_fsync_noflush() implementation
  fs/buffer.c: Add generic_buffers_fsync*() implementation
  ext2/dax: Fix ext2_setsize when len is page aligned
2023-06-29 13:39:51 -07:00
Linus Torvalds
3a8a670eee Merge tag 'net-next-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
Pull networking changes from Jakub Kicinski:
 "WiFi 7 and sendpage changes are the biggest pieces of work for this
  release. The latter will definitely require fixes but I think that we
  got it to a reasonable point.

  Core:

   - Rework the sendpage & splice implementations

     Instead of feeding data into sockets page by page extend sendmsg
     handlers to support taking a reference on the data, controlled by a
     new flag called MSG_SPLICE_PAGES

     Rework the handling of unexpected-end-of-file to invoke an
     additional callback instead of trying to predict what the right
     combination of MORE/NOTLAST flags is

     Remove the MSG_SENDPAGE_NOTLAST flag completely

   - Implement SCM_PIDFD, a new type of CMSG type analogous to
     SCM_CREDENTIALS, but it contains pidfd instead of plain pid

   - Enable socket busy polling with CONFIG_RT

   - Improve reliability and efficiency of reporting for ref_tracker

   - Auto-generate a user space C library for various Netlink families

  Protocols:

   - Allow TCP to shrink the advertised window when necessary, prevent
     sk_rcvbuf auto-tuning from growing the window all the way up to
     tcp_rmem[2]

   - Use per-VMA locking for "page-flipping" TCP receive zerocopy

   - Prepare TCP for device-to-device data transfers, by making sure
     that payloads are always attached to skbs as page frags

   - Make the backoff time for the first N TCP SYN retransmissions
     linear. Exponential backoff is unnecessarily conservative

   - Create a new MPTCP getsockopt to retrieve all info
     (MPTCP_FULL_INFO)

   - Avoid waking up applications using TLS sockets until we have a full
     record

   - Allow using kernel memory for protocol ioctl callbacks, paving the
     way to issuing ioctls over io_uring

   - Add nolocalbypass option to VxLAN, forcing packets to be fully
     encapsulated even if they are destined for a local IP address

   - Make TCPv4 use consistent hash in TIME_WAIT and SYN_RECV. Ensure
     in-kernel ECMP implementation (e.g. Open vSwitch) select the same
     link for all packets. Support L4 symmetric hashing in Open vSwitch

   - PPPoE: make number of hash bits configurable

   - Allow DNS to be overwritten by DHCPACK in the in-kernel DHCP client
     (ipconfig)

   - Add layer 2 miss indication and filtering, allowing higher layers
     (e.g. ACL filters) to make forwarding decisions based on whether
     packet matched forwarding state in lower devices (bridge)

   - Support matching on Connectivity Fault Management (CFM) packets

   - Hide the "link becomes ready" IPv6 messages by demoting their
     printk level to debug

   - HSR: don't enable promiscuous mode if device offloads the proto

   - Support active scanning in IEEE 802.15.4

   - Continue work on Multi-Link Operation for WiFi 7

  BPF:

   - Add precision propagation for subprogs and callbacks. This allows
     maintaining verification efficiency when subprograms are used, or
     in fact passing the verifier at all for complex programs,
     especially those using open-coded iterators

   - Improve BPF's {g,s}setsockopt() length handling. Previously BPF
     assumed the length is always equal to the amount of written data.
     But some protos allow passing a NULL buffer to discover what the
     output buffer *should* be, without writing anything

   - Accept dynptr memory as memory arguments passed to helpers

   - Add routing table ID to bpf_fib_lookup BPF helper

   - Support O_PATH FDs in BPF_OBJ_PIN and BPF_OBJ_GET commands

   - Drop bpf_capable() check in BPF_MAP_FREEZE command (used to mark
     maps as read-only)

   - Show target_{obj,btf}_id in tracing link fdinfo

   - Addition of several new kfuncs (most of the names are
     self-explanatory):
      - Add a set of new dynptr kfuncs: bpf_dynptr_adjust(),
        bpf_dynptr_is_null(), bpf_dynptr_is_rdonly(), bpf_dynptr_size()
        and bpf_dynptr_clone().
      - bpf_task_under_cgroup()
      - bpf_sock_destroy() - force closing sockets
      - bpf_cpumask_first_and(), rework bpf_cpumask_any*() kfuncs

  Netfilter:

   - Relax set/map validation checks in nf_tables. Allow checking
     presence of an entry in a map without using the value

   - Increase ip_vs_conn_tab_bits range for 64BIT builds

   - Allow updating size of a set

   - Improve NAT tuple selection when connection is closing

  Driver API:

   - Integrate netdev with LED subsystem, to allow configuring HW
     "offloaded" blinking of LEDs based on link state and activity
     (i.e. packets coming in and out)

   - Support configuring rate selection pins of SFP modules

   - Factor Clause 73 auto-negotiation code out of the drivers, provide
     common helper routines

   - Add more fool-proof helpers for managing lifetime of MDIO devices
     associated with the PCS layer

   - Allow drivers to report advanced statistics related to Time Aware
     scheduler offload (taprio)

   - Allow opting out of VF statistics in link dump, to allow more VFs
     to fit into the message

   - Split devlink instance and devlink port operations

  New hardware / drivers:

   - Ethernet:
      - Synopsys EMAC4 IP support (stmmac)
      - Marvell 88E6361 8 port (5x1GE + 3x2.5GE) switches
      - Marvell 88E6250 7 port switches
      - Microchip LAN8650/1 Rev.B0 PHYs
      - MediaTek MT7981/MT7988 built-in 1GE PHY driver

   - WiFi:
      - Realtek RTL8192FU, 2.4 GHz, b/g/n mode, 2T2R, 300 Mbps
      - Realtek RTL8723DS (SDIO variant)
      - Realtek RTL8851BE

   - CAN:
      - Fintek F81604

  Drivers:

   - Ethernet NICs:
      - Intel (100G, ice):
         - support dynamic interrupt allocation
         - use meta data match instead of VF MAC addr on slow-path
      - nVidia/Mellanox:
         - extend link aggregation to handle 4, rather than just 2 ports
         - spawn sub-functions without any features by default
      - OcteonTX2:
         - support HTB (Tx scheduling/QoS) offload
         - make RSS hash generation configurable
         - support selecting Rx queue using TC filters
      - Wangxun (ngbe/txgbe):
         - add basic Tx/Rx packet offloads
         - add phylink support (SFP/PCS control)
      - Freescale/NXP (enetc):
         - report TAPRIO packet statistics
      - Solarflare/AMD:
         - support matching on IP ToS and UDP source port of outer
           header
         - VxLAN and GENEVE tunnel encapsulation over IPv4 or IPv6
         - add devlink dev info support for EF10

   - Virtual NICs:
      - Microsoft vNIC:
         - size the Rx indirection table based on requested
           configuration
         - support VLAN tagging
      - Amazon vNIC:
         - try to reuse Rx buffers if not fully consumed, useful for ARM
           servers running with 16kB pages
      - Google vNIC:
         - support TCP segmentation of >64kB frames

   - Ethernet embedded switches:
      - Marvell (mv88e6xxx):
         - enable USXGMII (88E6191X)
      - Microchip:
         - lan966x: add support for Egress Stage 0 ACL engine
         - lan966x: support mapping packet priority to internal switch
           priority (based on PCP or DSCP)

   - Ethernet PHYs:
      - Broadcom PHYs:
         - support for Wake-on-LAN for BCM54210E/B50212E
         - report LPI counter
      - Microsemi PHYs: support RGMII delay configuration (VSC85xx)
      - Micrel PHYs: receive timestamp in the frame (LAN8841)
      - Realtek PHYs: support optional external PHY clock
      - Altera TSE PCS: merge the driver into Lynx PCS which it is a
        variant of

   - CAN: Kvaser PCIEcan:
      - support packet timestamping

   - WiFi:
      - Intel (iwlwifi):
         - major update for new firmware and Multi-Link Operation (MLO)
         - configuration rework to drop test devices and split the
           different families
         - support for segmented PNVM images and power tables
         - new vendor entries for PPAG (platform antenna gain) feature
      - Qualcomm 802.11ax (ath11k):
         - Multiple Basic Service Set Identifier (MBSSID) and Enhanced
           MBSSID Advertisement (EMA) support in AP mode
         - support factory test mode
      - RealTek (rtw89):
         - add RSSI based antenna diversity
         - support U-NII-4 channels on 5 GHz band
      - RealTek (rtl8xxxu):
         - AP mode support for 8188f
         - support USB RX aggregation for the newer chips"

* tag 'net-next-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1602 commits)
  net: scm: introduce and use scm_recv_unix helper
  af_unix: Skip SCM_PIDFD if scm->pid is NULL.
  net: lan743x: Simplify comparison
  netlink: Add __sock_i_ino() for __netlink_diag_dump().
  net: dsa: avoid suspicious RCU usage for synced VLAN-aware MAC addresses
  Revert "af_unix: Call scm_recv() only after scm_set_cred()."
  phylink: ReST-ify the phylink_pcs_neg_mode() kdoc
  libceph: Partially revert changes to support MSG_SPLICE_PAGES
  net: phy: mscc: fix packet loss due to RGMII delays
  net: mana: use vmalloc_array and vcalloc
  net: enetc: use vmalloc_array and vcalloc
  ionic: use vmalloc_array and vcalloc
  pds_core: use vmalloc_array and vcalloc
  gve: use vmalloc_array and vcalloc
  octeon_ep: use vmalloc_array and vcalloc
  net: usb: qmi_wwan: add u-blox 0x1312 composition
  perf trace: fix MSG_SPLICE_PAGES build error
  ipvlan: Fix return value of ipvlan_queue_xmit()
  netfilter: nf_tables: fix underflow in chain reference counter
  netfilter: nf_tables: unbind non-anonymous set if rule construction fails
  ...
2023-06-28 16:43:10 -07:00
Linus Torvalds
6e17c6de3d Merge tag 'mm-stable-2023-06-24-19-15' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull mm updates from Andrew Morton:

 - Yosry Ahmed brought back some cgroup v1 stats in OOM logs

 - Yosry has also eliminated cgroup's atomic rstat flushing

 - Nhat Pham adds the new cachestat() syscall. It provides userspace
   with the ability to query pagecache status - a similar concept to
   mincore() but more powerful and with improved usability

 - Mel Gorman provides more optimizations for compaction, reducing the
   prevalence of page rescanning

 - Lorenzo Stoakes has done some maintanance work on the
   get_user_pages() interface

 - Liam Howlett continues with cleanups and maintenance work to the
   maple tree code. Peng Zhang also does some work on maple tree

 - Johannes Weiner has done some cleanup work on the compaction code

 - David Hildenbrand has contributed additional selftests for
   get_user_pages()

 - Thomas Gleixner has contributed some maintenance and optimization
   work for the vmalloc code

 - Baolin Wang has provided some compaction cleanups,

 - SeongJae Park continues maintenance work on the DAMON code

 - Huang Ying has done some maintenance on the swap code's usage of
   device refcounting

 - Christoph Hellwig has some cleanups for the filemap/directio code

 - Ryan Roberts provides two patch series which yield some
   rationalization of the kernel's access to pte entries - use the
   provided APIs rather than open-coding accesses

 - Lorenzo Stoakes has some fixes to the interaction between pagecache
   and directio access to file mappings

 - John Hubbard has a series of fixes to the MM selftesting code

 - ZhangPeng continues the folio conversion campaign

 - Hugh Dickins has been working on the pagetable handling code, mainly
   with a view to reducing the load on the mmap_lock

 - Catalin Marinas has reduced the arm64 kmalloc() minimum alignment
   from 128 to 8

 - Domenico Cerasuolo has improved the zswap reclaim mechanism by
   reorganizing the LRU management

 - Matthew Wilcox provides some fixups to make gfs2 work better with the
   buffer_head code

 - Vishal Moola also has done some folio conversion work

 - Matthew Wilcox has removed the remnants of the pagevec code - their
   functionality is migrated over to struct folio_batch

* tag 'mm-stable-2023-06-24-19-15' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (380 commits)
  mm/hugetlb: remove hugetlb_set_page_subpool()
  mm: nommu: correct the range of mmap_sem_read_lock in task_mem()
  hugetlb: revert use of page_cache_next_miss()
  Revert "page cache: fix page_cache_next/prev_miss off by one"
  mm/vmscan: fix root proactive reclaim unthrottling unbalanced node
  mm: memcg: rename and document global_reclaim()
  mm: kill [add|del]_page_to_lru_list()
  mm: compaction: convert to use a folio in isolate_migratepages_block()
  mm: zswap: fix double invalidate with exclusive loads
  mm: remove unnecessary pagevec includes
  mm: remove references to pagevec
  mm: rename invalidate_mapping_pagevec to mapping_try_invalidate
  mm: remove struct pagevec
  net: convert sunrpc from pagevec to folio_batch
  i915: convert i915_gpu_error to use a folio_batch
  pagevec: rename fbatch_count()
  mm: remove check_move_unevictable_pages()
  drm: convert drm_gem_put_pages() to use a folio_batch
  i915: convert shmem_sg_free_table() to use a folio_batch
  scatterlist: add sg_set_folio()
  ...
2023-06-28 10:28:11 -07:00
Linus Torvalds
a0433f8cae Merge tag 'for-6.5/block-2023-06-23' of git://git.kernel.dk/linux
Pull block updates from Jens Axboe:

 - NVMe pull request via Keith:
      - Various cleanups all around (Irvin, Chaitanya, Christophe)
      - Better struct packing (Christophe JAILLET)
      - Reduce controller error logs for optional commands (Keith)
      - Support for >=64KiB block sizes (Daniel Gomez)
      - Fabrics fixes and code organization (Max, Chaitanya, Daniel
        Wagner)

 - bcache updates via Coly:
      - Fix a race at init time (Mingzhe Zou)
      - Misc fixes and cleanups (Andrea, Thomas, Zheng, Ye)

 - use page pinning in the block layer for dio (David)

 - convert old block dio code to page pinning (David, Christoph)

 - cleanups for pktcdvd (Andy)

 - cleanups for rnbd (Guoqing)

 - use the unchecked __bio_add_page() for the initial single page
   additions (Johannes)

 - fix overflows in the Amiga partition handling code (Michael)

 - improve mq-deadline zoned device support (Bart)

 - keep passthrough requests out of the IO schedulers (Christoph, Ming)

 - improve support for flush requests, making them less special to deal
   with (Christoph)

 - add bdev holder ops and shutdown methods (Christoph)

 - fix the name_to_dev_t() situation and use cases (Christoph)

 - decouple the block open flags from fmode_t (Christoph)

 - ublk updates and cleanups, including adding user copy support (Ming)

 - BFQ sanity checking (Bart)

 - convert brd from radix to xarray (Pankaj)

 - constify various structures (Thomas, Ivan)

 - more fine grained persistent reservation ioctl capability checks
   (Jingbo)

 - misc fixes and cleanups (Arnd, Azeem, Demi, Ed, Hengqi, Hou, Jan,
   Jordy, Li, Min, Yu, Zhong, Waiman)

* tag 'for-6.5/block-2023-06-23' of git://git.kernel.dk/linux: (266 commits)
  scsi/sg: don't grab scsi host module reference
  ext4: Fix warning in blkdev_put()
  block: don't return -EINVAL for not found names in devt_from_devname
  cdrom: Fix spectre-v1 gadget
  block: Improve kernel-doc headers
  blk-mq: don't insert passthrough request into sw queue
  bsg: make bsg_class a static const structure
  ublk: make ublk_chr_class a static const structure
  aoe: make aoe_class a static const structure
  block/rnbd: make all 'class' structures const
  block: fix the exclusive open mask in disk_scan_partitions
  block: add overflow checks for Amiga partition support
  block: change all __u32 annotations to __be32 in affs_hardblocks.h
  block: fix signed int overflow in Amiga partition support
  block: add capacity validation in bdev_add_partition()
  block: fine-granular CAP_SYS_ADMIN for Persistent Reservation
  block: disallow Persistent Reservation on partitions
  reiserfs: fix blkdev_put() warning from release_journal_dev()
  block: fix wrong mode for blkdev_get_by_dev() from disk_scan_partitions()
  block: document the holder argument to blkdev_get_by_path
  ...
2023-06-26 12:47:20 -07:00
Linus Torvalds
3eccc0c886 Merge tag 'for-6.5/splice-2023-06-23' of git://git.kernel.dk/linux
Pull splice updates from Jens Axboe:
 "This kills off ITER_PIPE to avoid a race between truncate,
  iov_iter_revert() on the pipe and an as-yet incomplete DMA to a bio
  with unpinned/unref'ed pages from an O_DIRECT splice read. This causes
  memory corruption.

  Instead, we either use (a) filemap_splice_read(), which invokes the
  buffered file reading code and splices from the pagecache into the
  pipe; (b) copy_splice_read(), which bulk-allocates a buffer, reads
  into it and then pushes the filled pages into the pipe; or (c) handle
  it in filesystem-specific code.

  Summary:

   - Rename direct_splice_read() to copy_splice_read()

   - Simplify the calculations for the number of pages to be reclaimed
     in copy_splice_read()

   - Turn do_splice_to() into a helper, vfs_splice_read(), so that it
     can be used by overlayfs and coda to perform the checks on the
     lower fs

   - Make vfs_splice_read() jump to copy_splice_read() to handle
     direct-I/O and DAX

   - Provide shmem with its own splice_read to handle non-existent pages
     in the pagecache. We don't want a ->read_folio() as we don't want
     to populate holes, but filemap_get_pages() requires it

   - Provide overlayfs with its own splice_read to call down to a lower
     layer as overlayfs doesn't provide ->read_folio()

   - Provide coda with its own splice_read to call down to a lower layer
     as coda doesn't provide ->read_folio()

   - Direct ->splice_read to copy_splice_read() in tty, procfs, kernfs
     and random files as they just copy to the output buffer and don't
     splice pages

   - Provide wrappers for afs, ceph, ecryptfs, ext4, f2fs, nfs, ntfs3,
     ocfs2, orangefs, xfs and zonefs to do locking and/or revalidation

   - Make cifs use filemap_splice_read()

   - Replace pointers to generic_file_splice_read() with pointers to
     filemap_splice_read() as DIO and DAX are handled in the caller;
     filesystems can still provide their own alternate ->splice_read()
     op

   - Remove generic_file_splice_read()

   - Remove ITER_PIPE and its paraphernalia as generic_file_splice_read
     was the only user"

* tag 'for-6.5/splice-2023-06-23' of git://git.kernel.dk/linux: (31 commits)
  splice: kdoc for filemap_splice_read() and copy_splice_read()
  iov_iter: Kill ITER_PIPE
  splice: Remove generic_file_splice_read()
  splice: Use filemap_splice_read() instead of generic_file_splice_read()
  cifs: Use filemap_splice_read()
  trace: Convert trace/seq to use copy_splice_read()
  zonefs: Provide a splice-read wrapper
  xfs: Provide a splice-read wrapper
  orangefs: Provide a splice-read wrapper
  ocfs2: Provide a splice-read wrapper
  ntfs3: Provide a splice-read wrapper
  nfs: Provide a splice-read wrapper
  f2fs: Provide a splice-read wrapper
  ext4: Provide a splice-read wrapper
  ecryptfs: Provide a splice-read wrapper
  ceph: Provide a splice-read wrapper
  afs: Provide a splice-read wrapper
  9p: Add splice_read wrapper
  net: Make sock_splice_read() use copy_splice_read() by default
  tty, proc, kernfs, random: Use copy_splice_read()
  ...
2023-06-26 11:52:12 -07:00
Linus Torvalds
1f2300a738 Merge tag 'v6.5/vfs.file' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs file handling updates from Christian Brauner:
 "This contains Amir's work to fix a long-standing problem where an
  unprivileged overlayfs mount can be used to avoid fanotify permission
  events that were requested for an inode or superblock on the
  underlying filesystem.

  Some background about files opened in overlayfs. If a file is opened
  in overlayfs @file->f_path will refer to a "fake" path. What this
  means is that while @file->f_inode will refer to inode of the
  underlying layer, @file->f_path refers to an overlayfs
  {dentry,vfsmount} pair. The reasons for doing this are out of scope
  here but it is the reason why the vfs has been providing the
  open_with_fake_path() helper for overlayfs for very long time now. So
  nothing new here.

  This is for sure not very elegant and everyone including the overlayfs
  maintainers agree. Improving this significantly would involve more
  fragile and potentially rather invasive changes.

  In various codepaths access to the path of the underlying filesystem
  is needed for such hybrid file. The best example is fsnotify where
  this becomes security relevant. Passing the overlayfs
  @file->f_path->dentry will cause fsnotify to skip generating fsnotify
  events registered on the underlying inode or superblock.

  To fix this we extend the vfs provided open_with_fake_path() concept
  for overlayfs to create a backing file container that holds the real
  path and to expose a helper that can be used by relevant callers to
  get access to the path of the underlying filesystem through the new
  file_real_path() helper. This pattern is similar to what we do in
  d_real() and d_real_inode().

  The first beneficiary is fsnotify and fixes the security sensitive
  problem mentioned above.

  There's a couple of nice cleanups included as well.

  Over time, the old open_with_fake_path() helper added specifically for
  overlayfs a long time ago started to get used in other places such as
  cachefiles. Even though cachefiles have nothing to do with hybrid
  files.

  The only reason cachefiles used that concept was that files opened
  with open_with_fake_path() aren't charged against the caller's open
  file limit by raising FMODE_NOACCOUNT. It's just mere coincidence that
  both overlayfs and cachefiles need to ensure to not overcharge the
  caller for their internal open calls.

  So this work disentangles FMODE_NOACCOUNT use cases and backing file
  use-cases by adding the FMODE_BACKING flag which indicates that the
  file can be used to retrieve the backing file of another filesystem.
  (Fyi, Jens will be sending you a really nice cleanup from Christoph
  that gets rid of 3 FMODE_* flags otherwise this would be the last
  fmode_t bit we'd be using.)

  So now overlayfs becomes the sole user of the renamed
  open_with_fake_path() helper which is now named backing_file_open().
  For internal kernel users such as cachefiles that are only interested
  in FMODE_NOACCOUNT but not in FMODE_BACKING we add a new
  kernel_file_open() helper which opens a file without being charged
  against the caller's open file limit. All new helpers are properly
  documented and clearly annotated to mention their special uses.

  We also rename vfs_tmpfile_open() to kernel_tmpfile_open() to clearly
  distinguish it from vfs_tmpfile() and align it the other kernel_*()
  internal helpers"

* tag 'v6.5/vfs.file' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  ovl: enable fsnotify events on underlying real files
  fs: use backing_file container for internal files with "fake" f_path
  fs: move kmem_cache_zalloc() into alloc_empty_file*() helpers
  fs: use a helper for opening kernel internal files
  fs: rename {vfs,kernel}_tmpfile_open()
2023-06-26 10:14:36 -07:00
Linus Torvalds
64bf6ae93e Merge tag 'v6.5/vfs.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull misc vfs updates from Christian Brauner:
 "Miscellaneous features, cleanups, and fixes for vfs and individual fs

  Features:

   - Use mode 0600 for file created by cachefilesd so it can be run by
     unprivileged users. This aligns them with directories which are
     already created with mode 0700 by cachefilesd

   - Reorder a few members in struct file to prevent some false sharing
     scenarios

   - Indicate that an eventfd is used a semaphore in the eventfd's
     fdinfo procfs file

   - Add a missing uapi header for eventfd exposing relevant uapi
     defines

   - Let the VFS protect transitions of a superblock from read-only to
     read-write in addition to the protection it already provides for
     transitions from read-write to read-only. Protecting read-only to
     read-write transitions allows filesystems such as ext4 to perform
     internal writes, keeping writers away until the transition is
     completed

  Cleanups:

   - Arnd removed the architecture specific arch_report_meminfo()
     prototypes and added a generic one into procfs.h. Note, we got a
     report about a warning in amdpgpu codepaths that suggested this was
     bisectable to this change but we concluded it was a false positive

   - Remove unused parameters from split_fs_names()

   - Rename put_and_unmap_page() to unmap_and_put_page() to let the name
     reflect the order of the cleanup operation that has to unmap before
     the actual put

   - Unexport buffer_check_dirty_writeback() as it is not used outside
     of block device aops

   - Stop allocating aio rings from highmem

   - Protecting read-{only,write} transitions in the VFS used open-coded
     barriers in various places. Replace them with proper little helpers
     and document both the helpers and all barrier interactions involved
     when transitioning between read-{only,write} states

   - Use flexible array members in old readdir codepaths

  Fixes:

   - Use the correct type __poll_t for epoll and eventfd

   - Replace all deprecated strlcpy() invocations, whose return value
     isn't checked with an equivalent strscpy() call

   - Fix some kernel-doc warnings in fs/open.c

   - Reduce the stack usage in jffs2's xattr codepaths finally getting
     rid of this: fs/jffs2/xattr.c:887:1: error: the frame size of 1088
     bytes is larger than 1024 bytes [-Werror=frame-larger-than=]
     royally annoying compilation warning

   - Use __FMODE_NONOTIFY instead of FMODE_NONOTIFY where an int and not
     fmode_t is required to avoid fmode_t to integer degradation
     warnings

   - Create coredumps with O_WRONLY instead of O_RDWR. There's a long
     explanation in that commit how O_RDWR is actually a bug which we
     found out with the help of Linus and git archeology

   - Fix "no previous prototype" warnings in the pipe codepaths

   - Add overflow calculations for remap_verify_area() as a signed
     addition overflow could be triggered in xfstests

   - Fix a null pointer dereference in sysv

   - Use an unsigned variable for length calculations in jfs avoiding
     compilation warnings with gcc 13

   - Fix a dangling pipe pointer in the watch queue codepath

   - The legacy mount option parser provided as a fallback by the VFS
     for filesystems not yet converted to the new mount api did prefix
     the generated mount option string with a leading ',' causing issues
     for some filesystems

   - Fix a repeated word in a comment in fs.h

   - autofs: Update the ctime when mtime is updated as mandated by
     POSIX"

* tag 'v6.5/vfs.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (27 commits)
  readdir: Replace one-element arrays with flexible-array members
  fs: Provide helpers for manipulating sb->s_readonly_remount
  fs: Protect reconfiguration of sb read-write from racing writes
  eventfd: add a uapi header for eventfd userspace APIs
  autofs: set ctime as well when mtime changes on a dir
  eventfd: show the EFD_SEMAPHORE flag in fdinfo
  fs/aio: Stop allocating aio rings from HIGHMEM
  fs: Fix comment typo
  fs: unexport buffer_check_dirty_writeback
  fs: avoid empty option when generating legacy mount string
  watch_queue: prevent dangling pipe pointer
  fs.h: Optimize file struct to prevent false sharing
  highmem: Rename put_and_unmap_page() to unmap_and_put_page()
  cachefiles: Allow the cache to be non-root
  init: remove unused names parameter in split_fs_names()
  jfs: Use unsigned variable for length calculations
  fs/sysv: Null check to prevent null-ptr-deref bug
  fs: use UB-safe check for signed addition overflow in remap_verify_area
  procfs: consolidate arch_report_meminfo declaration
  fs: pipe: reveal missing function protoypes
  ...
2023-06-26 09:50:21 -07:00
Andrew Morton
63773d2b59 Merge mm-hotfixes-stable into mm-stable to pick up depended-upon changes. 2023-06-23 16:58:19 -07:00
Jan Kara
d7439fb1f4 fs: Provide helpers for manipulating sb->s_readonly_remount
Provide helpers to set and clear sb->s_readonly_remount including
appropriate memory barriers. Also use this opportunity to document what
the barriers pair with and why they are needed.

Suggested-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Message-Id: <20230620112832.5158-1-jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-06-20 13:48:01 +02:00
Amir Goldstein
62d53c4a1d fs: use backing_file container for internal files with "fake" f_path
Overlayfs uses open_with_fake_path() to allocate internal kernel files,
with a "fake" path - whose f_path is not on the same fs as f_inode.

Allocate a container struct backing_file for those internal files, that
is used to hold the "fake" ovl path along with the real path.

backing_file_real_path() can be used to access the stored real path.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Message-Id: <20230615112229.2143178-5-amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-06-19 18:16:38 +02:00
Amir Goldstein
cbb0b9d4bb fs: use a helper for opening kernel internal files
cachefiles uses kernel_open_tmpfile() to open kernel internal tmpfile
without accounting for nr_files.

cachefiles uses open_with_fake_path() for the same reason without the
need for a fake path.

Fork open_with_fake_path() to kernel_file_open() which only does the
noaccount part and use it in cachefiles.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Message-Id: <20230615112229.2143178-3-amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-06-19 18:11:58 +02:00
Amir Goldstein
d56e0ddb8f fs: rename {vfs,kernel}_tmpfile_open()
Overlayfs and cachefiles use vfs_open_tmpfile() to open a tmpfile
without accounting for nr_files.

Rename this helper to kernel_tmpfile_open() to better reflect this
helper is used for kernel internal users.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Message-Id: <20230615112229.2143178-2-amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-06-19 18:09:09 +02:00
David Howells
a3bbdc52c3 Remove file->f_op->sendpage
Remove file->f_op->sendpage as splicing to a socket now calls sendmsg
rather than sendpage.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jens Axboe <axboe@kernel.dk>
cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-12 21:13:23 -07:00
Christoph Hellwig
0733ad8002 fs: remove the now unused FMODE_* flags
FMODE_NDELAY, FMODE_EXCL and FMODE_WRITE_IOCTL were only used for
block internal purposed and are now entirely unused, so remove them.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/r/20230608110258.189493-31-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-06-12 08:04:05 -06:00
Christoph Hellwig
81b1fb7d17 fs: remove sb->s_mode
There is no real need to store the open mode in the super_block now.
It is only used by f2fs, which can easily recalculate it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/r/20230608110258.189493-18-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-06-12 08:04:04 -06:00
Mao Zhu
b6334e2cd4 fs: Fix comment typo
Delete duplicated word in comment.

Signed-off-by: Mao Zhu <zhumao001@208suo.com>
Message-Id: <20230611123314.5282-1-dengshaomin@cdjrlc.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-06-12 10:35:08 +02:00
Christoph Hellwig
44fff0fa08 fs: factor out a direct_write_fallback helper
Add a helper dealing with handling the syncing of a buffered write
fallback for direct I/O.

Link: https://lkml.kernel.org/r/20230601145904.1385409-10-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Anna Schumaker <anna@kernel.org>
Cc: Chao Yu <chao@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09 16:25:53 -07:00
Christoph Hellwig
c402a9a943 filemap: add a kiocb_invalidate_post_direct_write helper
Add a helper to invalidate page cache after a dio write.

Link: https://lkml.kernel.org/r/20230601145904.1385409-7-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Anna Schumaker <anna@kernel.org>
Cc: Chao Yu <chao@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09 16:25:53 -07:00
David Howells
2bfc668509 splice, net: Add a splice_eof op to file-ops and socket-ops
Add an optional method, ->splice_eof(), to allow splice to indicate the
premature termination of a splice to struct file_operations and struct
proto_ops.

This is called if sendfile() or splice() encounters all of the following
conditions inside splice_direct_to_actor():

 (1) the user did not set SPLICE_F_MORE (splice only), and

 (2) an EOF condition occurred (->splice_read() returned 0), and

 (3) we haven't read enough to fulfill the request (ie. len > 0 still), and

 (4) we have already spliced at least one byte.

A further patch will modify the behaviour of SPLICE_F_MORE to always be
passed to the actor if either the user set it or we haven't yet read
sufficient data to fulfill the request.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/CAHk-=wh=V579PDYvkpnTobCLGczbgxpMgGmmhqiTyE34Cpi5Gg@mail.gmail.com/
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
cc: Jens Axboe <axboe@kernel.dk>
cc: Christoph Hellwig <hch@lst.de>
cc: Al Viro <viro@zeniv.linux.org.uk>
cc: Matthew Wilcox <willy@infradead.org>
cc: Jan Kara <jack@suse.cz>
cc: Jeff Layton <jlayton@kernel.org>
cc: David Hildenbrand <david@redhat.com>
cc: Christian Brauner <brauner@kernel.org>
cc: Chuck Lever <chuck.lever@oracle.com>
cc: Boris Pismenny <borisp@nvidia.com>
cc: John Fastabend <john.fastabend@gmail.com>
cc: linux-mm@kvack.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-08 19:40:30 -07:00
David Howells
2dc334f1a6 splice, net: Use sendmsg(MSG_SPLICE_PAGES) rather than ->sendpage()
Replace generic_splice_sendpage() + splice_from_pipe + pipe_to_sendpage()
with a net-specific handler, splice_to_socket(), that calls sendmsg() with
MSG_SPLICE_PAGES set instead of calling ->sendpage().

MSG_MORE is used to indicate if the sendmsg() is expected to be followed
with more data.

This allows multiple pipe-buffer pages to be passed in a single call in a
BVEC iterator, allowing the processing to be pushed down to a loop in the
protocol driver.  This helps pave the way for passing multipage folios down
too.

Protocols that haven't been converted to handle MSG_SPLICE_PAGES yet should
just ignore it and do a normal sendmsg() for now - although that may be a
bit slower as it may copy everything.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
cc: Jens Axboe <axboe@kernel.dk>
cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-08 19:40:30 -07:00
Christoph Hellwig
87efb39075 fs: add a method to shut down the file system
Add a new ->shutdown super operation that can be used to tell the file
system to shut down, and call it from newly created holder ops when the
block device under a file system shuts down.

This only covers the main block device for "simple" file systems using
get_tree_bdev / mount_bdev.  File systems their own get_tree method
or opening additional devices will need to set up their own
blk_holder_ops.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Link: https://lore.kernel.org/r/20230601094459.1350643-12-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-06-05 10:53:04 -06:00
chenzhiyin
a7bc2e8ddf fs.h: Optimize file struct to prevent false sharing
In the syscall test of UnixBench, performance regression occurred due
to false sharing.

The lock and atomic members, including file::f_lock, file::f_count and
file::f_pos_lock are highly contended and frequently updated in the
high-concurrency test scenarios. perf c2c indentified one affected
read access, file::f_op.
To prevent false sharing, the layout of file struct is changed as
following
(A) f_lock, f_count and f_pos_lock are put together to share the same
cache line.
(B) The read mostly members, including f_path, f_inode, f_op are put
into a separate cache line.
(C) f_mode is put together with f_count, since they are used frequently
 at the same time.
Due to '__randomize_layout' attribute of file struct, the updated layout
only can be effective when CONFIG_RANDSTRUCT_NONE is 'y'.

The optimization has been validated in the syscall test of UnixBench.
performance gain is 30~50%. Furthermore, to confirm the optimization
effectiveness on the other codes path, the results of fsdisk, fsbuffer
and fstime are also shown.

Here are the detailed test results of unixbench.

Command: numactl -C 3-18 ./Run -c 16 syscall fsbuffer fstime fsdisk

Without Patch
------------------------------------------------------------------------
File Copy 1024 bufsize 2000 maxblocks   875052.1 KBps  (30.0 s, 2 samples)
File Copy 256 bufsize 500 maxblocks     235484.0 KBps  (30.0 s, 2 samples)
File Copy 4096 bufsize 8000 maxblocks  2815153.5 KBps  (30.0 s, 2 samples)
System Call Overhead                   5772268.3 lps   (10.0 s, 7 samples)

System Benchmarks Partial Index         BASELINE       RESULT    INDEX
File Copy 1024 bufsize 2000 maxblocks     3960.0     875052.1   2209.7
File Copy 256 bufsize 500 maxblocks       1655.0     235484.0   1422.9
File Copy 4096 bufsize 8000 maxblocks     5800.0    2815153.5   4853.7
System Call Overhead                     15000.0    5772268.3   3848.2
                                                              ========
System Benchmarks Index Score (Partial Only)                    2768.3

With Patch
------------------------------------------------------------------------
File Copy 1024 bufsize 2000 maxblocks  1009977.2 KBps  (30.0 s, 2 samples)
File Copy 256 bufsize 500 maxblocks     264765.9 KBps  (30.0 s, 2 samples)
File Copy 4096 bufsize 8000 maxblocks  3052236.0 KBps  (30.0 s, 2 samples)
System Call Overhead                   8237404.4 lps   (10.0 s, 7 samples)

System Benchmarks Partial Index         BASELINE       RESULT    INDEX
File Copy 1024 bufsize 2000 maxblocks     3960.0    1009977.2   2550.4
File Copy 256 bufsize 500 maxblocks       1655.0     264765.9   1599.8
File Copy 4096 bufsize 8000 maxblocks     5800.0    3052236.0   5262.5
System Call Overhead                     15000.0    8237404.4   5491.6
                                                              ========
System Benchmarks Index Score (Partial Only)                    3295.3

Signed-off-by: chenzhiyin <zhiyin.chen@intel.com>
Message-Id: <20230601092400.27162-1-zhiyin.chen@intel.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-06-05 14:54:48 +02:00
Jan Kara
576215cffd fs: Drop wait_unfrozen wait queue
wait_unfrozen waitqueue is used only in quota code to wait for
filesystem to become unfrozen. In that place we can just use
sb_start_write() - sb_end_write() pair to achieve the same. So just
remove the waitqueue.

Reviewed-by: Christian Brauner <brauner@kernel.org>
Message-Id: <20230525141710.7595-1-jack@suse.cz>
Signed-off-by: Jan Kara <jack@suse.cz>
2023-05-30 15:36:40 +02:00
Linus Torvalds
ac2263b588 Revert "module: error out early on concurrent load of the same module file"
This reverts commit 9828ed3f69.

Sadly, it does seem to cause failures to load modules. Johan Hovold reports:

 "This change breaks module loading during boot on the Lenovo Thinkpad
  X13s (aarch64).

  Specifically it results in indefinite probe deferral of the display
  and USB (ethernet) which makes it a pain to debug. Typing in the dark
  to acquire some logs reveals that other modules are missing as well"

Since this was applied late as a "let's try this", I'm reverting it
asap, and we can try to figure out what goes wrong later.  The excessive
parallel module loading problem is annoying, but not noticeable in
normal situations, and this was only meant as an optimistic workaround
for a user-space bug.

One possible solution may be to do the optimistic exclusive open first,
and then use a lock to serialize loading if that fails.

Reported-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/lkml/ZHRpH-JXAxA6DnzR@hovoldconsulting.com/
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-05-29 06:40:33 -04:00
Linus Torvalds
9828ed3f69 module: error out early on concurrent load of the same module file
It turns out that udev under certain circumstances will concurrently try
to load the same modules over-and-over excessively.  This isn't a kernel
bug, but it ends up affecting the kernel, to the point that under
certain circumstances we can fail to boot, because the kernel uses a lot
of memory to read all the module data all at once.

Note that it isn't a memory leak, it's just basically a thundering herd
problem happening at bootup with a lot of CPUs, with the worst cases
then being pretty bad.

Admittedly the worst situations are somewhat contrived: lots and lots of
CPUs, not a lot of memory, and KASAN enabled to make it all slower and
as such (unintentionally) exacerbate the problem.

Luis explains: [1]

 "My best assessment of the situation is that each CPU in udev ends up
  triggering a load of duplicate set of modules, not just one, but *a
  lot*. Not sure what heuristics udev uses to load a set of modules per
  CPU."

Petr Pavlu chimes in: [2]

 "My understanding is that udev workers are forked. An initial kmod
  context is created by the main udevd process but no sharing happens
  after the fork. It means that the mentioned memory pool logic doesn't
  really kick in.

  Multiple parallel load requests come from multiple udev workers, for
  instance, each handling an udev event for one CPU device and making
  the exactly same requests as all others are doing at the same time.

  The optimization idea would be to recognize these duplicate requests
  at the udevd/kmod level and converge them"

Note that module loading has tried to mitigate this issue before, see
for example commit 064f4536d1 ("module: avoid allocation if module is
already present and ready"), which has a few ASCII graphs on memory use
due to this same issue.

However, while that noticed that the module was already loaded, and
exited with an error early before spending any more time on setting up
the module, it didn't handle the case of multiple concurrent module
loads all being active - but not complete - at the same time.

Yes, one of them will eventually win the race and finalize its copy, and
the others will then notice that the module already exists and error
out, but while this all happens, we have tons of unnecessary concurrent
work being done.

Again, the real fix is for udev to not do that (maybe it should use
threads instead of fork, and have actual shared data structures and not
cause duplicate work). That real fix is apparently not trivial.

But it turns out that the kernel already has a pretty good model for
dealing with concurrent access to the same file: the i_writecount of the
inode.

In fact, the module loading already indirectly uses 'i_writecount' ,
because 'kernel_file_read()' will in fact do

	ret = deny_write_access(file);
	if (ret)
		return ret;
	...
	allow_write_access(file);

around the read of the file data.  We do not allow concurrent writes to
the file, and return -ETXTBUSY if the file was open for writing at the
same time as the module data is loaded from it.

And the solution to the reader concurrency problem is to simply extend
this "no concurrent writers" logic to simply be "exclusive access".

Note that "exclusive" in this context isn't really some absolute thing:
it's only exclusion from writers and from other "special readers" that
do this writer denial.  So we simply introduce a variation of that
"deny_write_access()" logic that not only denies write access, but also
requires that this is the _only_ such access that denies write access.

Which means that you can't start loading a module that is already being
loaded as a module by somebody else, or you will get the same -ETXTBSY
error that you would get if there were writers around.

[ It also means that you can't try to load a currently executing
  executable as a module, for the same reason: executables do that same
  "deny_write_access()" thing, and that's obviously where the whole
  ETXTBSY logic traditionally came from.

  This is not a problem for kernel modules, since the set of normal
  executable files and kernel module files is entirely disjoint. ]

This new function is called "exclusive_deny_write_access()", and the
implementation is trivial, in that it's just an atomic decrement of
i_writecount if it was 0 before.

To use that new exclusivity check, all we then do is wrap the module
loading with that exclusive_deny_write_access()() / allow_write_access()
pair.  The actual patch is a bit bigger than that, because we want to
surround not just the "load file data" part, but the whole module setup,
to get maximum exclusion.

So this ends up splitting up "finit_module()" into a few helper
functions to make it all very clear and legible.

In Luis' test-case (bringing up 255 vcpu's in a virtual machine [3]),
the "wasted vmalloc" space (ie module data read into a vmalloc'ed area
in order to be loaded as a module, but then discarded because somebody
else loaded the same module instead) dropped from 1.8GiB to 474kB.  Yes,
that's gigabytes to kilobytes.

It doesn't drop completely to zero, because even with this change, you
can still end up having completely serial pointless module loads, where
one udev process has loaded a module fully (and thus the kernel has
released that exclusive lock on the module file), and then another udev
process tries to load the same module again.

So while we cannot fully get rid of the fundamental bug in user space,
we _can_ get rid of the excessive concurrent thundering herd effect.

A couple of final side notes on this all:

 - This tweak only affects the "finit_module()" system call, which gives
   the kernel a file descriptor with the module data.

   You can also just feed the module data as raw data from user space
   with "init_module()" (note the lack of 'f' at the beginning), and
   obviously for that case we do _not_ have any "exclusive read" logic.

   So if you absolutely want to do things wrong in user space, and try
   to load the same module multiple times, and error out only later when
   the kernel ends up saying "you can't load the same module name
   twice", you can still do that.

   And in fact, some distros will do exactly that, because they will
   uncompress the kernel module data in user space before feeding it to
   the kernel (mainly because they haven't started using the new kernel
   side decompression yet).

   So this is not some absolute "you can't do concurrent loads of the
   same module". It's literally just a very simple heuristic that will
   catch it early in case you try to load the exact same module file at
   the same time, and in that case avoid a potentially nasty situation.

 - There is another user of "deny_write_access()": the verity code that
   enables fs-verity on a file (the FS_IOC_ENABLE_VERITY ioctl).

   If you use fs-verity and you care about verifying the kernel modules
   (which does make sense), you should do it *before* loading said
   kernel module. That may sound obvious, but now the implementation
   basically requires it. Because if you try to do it concurrently, the
   kernel may refuse to load the module file that is being set up by the
   fs-verity code.

 - This all will obviously mean that if you insist on loading the same
   module in parallel, only one module load will succeed, and the others
   will return with an error.

   That was true before too, but what is different is that the -ETXTBSY
   error can be returned *before* the success case of another process
   fully loading and instantiating the module.

   Again, that might sound obvious, and it is indeed the whole point of
   the whole change: we are much quicker to notice the whole "you're
   already in the process of loading this module".

   So it's very much intentional, but it does mean that if you just
   spray the kernel with "finit_module()", and expect that the module is
   immediately loaded afterwards without checking the return value, you
   are doing something horribly horribly wrong.

   I'd like to say that that would never happen, but the whole _reason_
   for this commit is that udev is currently doing something horribly
   horribly wrong, so ...

Link: https://lore.kernel.org/all/ZEGopJ8VAYnE7LQ2@bombadil.infradead.org/ [1]
Link: https://lore.kernel.org/all/23bd0ce6-ef78-1cd8-1f21-0e706a00424a@suse.com/ [2]
Link: https://lore.kernel.org/lkml/ZG%2Fa+nrt4%2FAAUi5z@bombadil.infradead.org/ [3]
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Petr Pavlu <petr.pavlu@suse.com>
Tested-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-05-25 17:07:57 -07:00
David Howells
c6585011bc splice: Remove generic_file_splice_read()
Remove generic_file_splice_read() as it has been replaced with calls to
filemap_splice_read() and copy_splice_read().

With this, ITER_PIPE is no longer used.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christian Brauner <brauner@kernel.org>
cc: Jens Axboe <axboe@kernel.dk>
cc: Steve French <smfrench@gmail.com>
cc: Al Viro <viro@zeniv.linux.org.uk>
cc: David Hildenbrand <david@redhat.com>
cc: John Hubbard <jhubbard@nvidia.com>
cc: linux-mm@kvack.org
cc: linux-block@vger.kernel.org
cc: linux-cifs@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/20230522135018.2742245-30-dhowells@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-05-24 08:42:17 -06:00
David Howells
69df79a451 splice: Rename direct_splice_read() to copy_splice_read()
Rename direct_splice_read() to copy_splice_read() to better reflect as to
what it does.

Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christian Brauner <brauner@kernel.org>
cc: Steve French <sfrench@samba.org>
cc: Jens Axboe <axboe@kernel.dk>
cc: Al Viro <viro@zeniv.linux.org.uk>
cc: linux-cifs@vger.kernel.org
cc: linux-mm@kvack.org
cc: linux-block@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/20230522135018.2742245-4-dhowells@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-05-24 08:42:15 -06:00
Hao Ge
f15afbd34d fs: fix undefined behavior in bit shift for SB_NOUSER
Shifting signed 32-bit value by 31 bits is undefined, so changing
significant bit to unsigned. It was spotted by UBSAN.

So let's just fix this by using the BIT() helper for all SB_* flags.

Fixes: e462ec50cb ("VFS: Differentiate mount flags (MS_*) from internal superblock flags")
Signed-off-by: Hao Ge <gehao@kylinos.cn>
Message-Id: <20230424051835.374204-1-gehao@kylinos.cn>
[brauner@kernel.org: use BIT() for all SB_* flags]
Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-05-17 15:25:18 +02:00
Linus Torvalds
bedf149527 Merge tag 'iomap-6.4-merge-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull iomap updates from Darrick Wong:
 "The only changes for this cycle are the addition of tracepoints to the
  iomap directio code so that Ritesh (who is working on porting ext2 to
  iomap) can observe the io flows more easily.

  Summary:

   - Remove an unused symbol

   - Add tracepoints for the directio code"

* tag 'iomap-6.4-merge-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  iomap: Add DIO tracepoints
  iomap: Remove IOMAP_DIO_NOSYNC unused dio flag
  fs.h: Add TRACE_IOCB_STRINGS for use in trace points
2023-04-29 10:35:48 -07:00
Linus Torvalds
5b9a7bb72f Merge tag 'for-6.4/io_uring-2023-04-21' of git://git.kernel.dk/linux
Pull io_uring updates from Jens Axboe:

 - Cleanup of the io-wq per-node mapping, notably getting rid of it so
   we just have a single io_wq entry per ring (Breno)

 - Followup to the above, move accounting to io_wq as well and
   completely drop struct io_wqe (Gabriel)

 - Enable KASAN for the internal io_uring caches (Breno)

 - Add support for multishot timeouts. Some applications use timeouts to
   wake someone waiting on completion entries, and this makes it a bit
   easier to just have a recurring timer rather than needing to rearm it
   every time (David)

 - Support archs that have shared cache coloring between userspace and
   the kernel, and hence have strict address requirements for mmap'ing
   the ring into userspace. This should only be parisc/hppa. (Helge, me)

 - XFS has supported O_DIRECT writes without needing to lock the inode
   exclusively for a long time, and ext4 now supports it as well. This
   is true for the common cases of not extending the file size. Flag the
   fs as having that feature, and utilize that to avoid serializing
   those writes in io_uring (me)

 - Enable completion batching for uring commands (me)

 - Revert patch adding io_uring restriction to what can be GUP mapped or
   not. This does not belong in io_uring, as io_uring isn't really
   special in this regard. Since this is also getting in the way of
   cleanups and improvements to the GUP code, get rid of if (me)

 - A few series greatly reducing the complexity of registered resources,
   like buffers or files. Not only does this clean up the code a lot,
   the simplified code is also a LOT more efficient (Pavel)

 - Series optimizing how we wait for events and run task_work related to
   it (Pavel)

 - Fixes for file/buffer unregistration with DEFER_TASKRUN (Pavel)

 - Misc cleanups and improvements (Pavel, me)

* tag 'for-6.4/io_uring-2023-04-21' of git://git.kernel.dk/linux: (71 commits)
  Revert "io_uring/rsrc: disallow multi-source reg buffers"
  io_uring: add support for multishot timeouts
  io_uring/rsrc: disassociate nodes and rsrc_data
  io_uring/rsrc: devirtualise rsrc put callbacks
  io_uring/rsrc: pass node to io_rsrc_put_work()
  io_uring/rsrc: inline io_rsrc_put_work()
  io_uring/rsrc: add empty flag in rsrc_node
  io_uring/rsrc: merge nodes and io_rsrc_put
  io_uring/rsrc: infer node from ctx on io_queue_rsrc_removal
  io_uring/rsrc: remove unused io_rsrc_node::llist
  io_uring/rsrc: refactor io_queue_rsrc_removal
  io_uring/rsrc: simplify single file node switching
  io_uring/rsrc: clean up __io_sqe_buffers_update()
  io_uring/rsrc: inline switch_start fast path
  io_uring/rsrc: remove rsrc_data refs
  io_uring/rsrc: fix DEFER_TASKRUN rsrc quiesce
  io_uring/rsrc: use wq for quiescing
  io_uring/rsrc: refactor io_rsrc_ref_quiesce
  io_uring/rsrc: remove io_rsrc_node::done
  io_uring/rsrc: use nospec'ed indexes
  ...
2023-04-26 12:40:31 -07:00
Linus Torvalds
11b32219cb Merge tag 'pull-old-dio' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull legacy dio cleanup from Al Viro.

* tag 'pull-old-dio' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  __blockdev_direct_IO(): get rid of submit_io callback
2023-04-24 19:28:49 -07:00
Ritesh Harjani (IBM)
f6c73a1113 fs.h: Add TRACE_IOCB_STRINGS for use in trace points
Add TRACE_IOCB_STRINGS macro which can be used in the trace point patch to
print different flag values with meaningful string output.

Tested-by: Disha Goel <disgoel@linux.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
[djwong: line up strings all prettylike]
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2023-04-21 08:52:42 -07:00
Jens Axboe
d8aeb44a9a fs: add FMODE_DIO_PARALLEL_WRITE flag
Some filesystems support multiple threads writing to the same file with
O_DIRECT without requiring exclusive access to it. io_uring can use this
hint to avoid serializing dio writes to this inode, instead allowing them
to run in parallel.

XFS and ext4 both fall into this category, so set the flag for both of
them.

Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-03 07:14:20 -06:00
Christian Brauner
4f704d9a83 nfs: use vfs setgid helper
We've aligned setgid behavior over multiple kernel releases. The details
can be found in the following two merge messages:
cf619f8919 ("Merge tag 'fs.ovl.setgid.v6.2')
426b4ca2d6 ("Merge tag 'fs.setgid.v6.0')
Consistent setgid stripping behavior is now encapsulated in the
setattr_should_drop_sgid() helper which is used by all filesystems that
strip setgid bits outside of vfs proper. Switch nfs to rely on this
helper as well. Without this patch the setgid stripping tests in
xfstests will fail.

Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Message-Id: <20230313-fs-nfs-setgid-v2-1-9a59f436cfc0@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-03-30 08:51:48 +02:00
Al Viro
0aaf08de84 __blockdev_direct_IO(): get rid of submit_io callback
always NULL...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2023-03-05 20:27:41 -05:00
Linus Torvalds
3822a7c409 Merge tag 'mm-stable-2023-02-20-13-37' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:

 - Daniel Verkamp has contributed a memfd series ("mm/memfd: add
   F_SEAL_EXEC") which permits the setting of the memfd execute bit at
   memfd creation time, with the option of sealing the state of the X
   bit.

 - Peter Xu adds a patch series ("mm/hugetlb: Make huge_pte_offset()
   thread-safe for pmd unshare") which addresses a rare race condition
   related to PMD unsharing.

 - Several folioification patch serieses from Matthew Wilcox, Vishal
   Moola, Sidhartha Kumar and Lorenzo Stoakes

 - Johannes Weiner has a series ("mm: push down lock_page_memcg()")
   which does perform some memcg maintenance and cleanup work.

 - SeongJae Park has added DAMOS filtering to DAMON, with the series
   "mm/damon/core: implement damos filter".

   These filters provide users with finer-grained control over DAMOS's
   actions. SeongJae has also done some DAMON cleanup work.

 - Kairui Song adds a series ("Clean up and fixes for swap").

 - Vernon Yang contributed the series "Clean up and refinement for maple
   tree".

 - Yu Zhao has contributed the "mm: multi-gen LRU: memcg LRU" series. It
   adds to MGLRU an LRU of memcgs, to improve the scalability of global
   reclaim.

 - David Hildenbrand has added some userfaultfd cleanup work in the
   series "mm: uffd-wp + change_protection() cleanups".

 - Christoph Hellwig has removed the generic_writepages() library
   function in the series "remove generic_writepages".

 - Baolin Wang has performed some maintenance on the compaction code in
   his series "Some small improvements for compaction".

 - Sidhartha Kumar is doing some maintenance work on struct page in his
   series "Get rid of tail page fields".

 - David Hildenbrand contributed some cleanup, bugfixing and
   generalization of pte management and of pte debugging in his series
   "mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures with
   swap PTEs".

 - Mel Gorman and Neil Brown have removed the __GFP_ATOMIC allocation
   flag in the series "Discard __GFP_ATOMIC".

 - Sergey Senozhatsky has improved zsmalloc's memory utilization with
   his series "zsmalloc: make zspage chain size configurable".

 - Joey Gouly has added prctl() support for prohibiting the creation of
   writeable+executable mappings.

   The previous BPF-based approach had shortcomings. See "mm: In-kernel
   support for memory-deny-write-execute (MDWE)".

 - Waiman Long did some kmemleak cleanup and bugfixing in the series
   "mm/kmemleak: Simplify kmemleak_cond_resched() & fix UAF".

 - T.J. Alumbaugh has contributed some MGLRU cleanup work in his series
   "mm: multi-gen LRU: improve".

 - Jiaqi Yan has provided some enhancements to our memory error
   statistics reporting, mainly by presenting the statistics on a
   per-node basis. See the series "Introduce per NUMA node memory error
   statistics".

 - Mel Gorman has a second and hopefully final shot at fixing a CPU-hog
   regression in compaction via his series "Fix excessive CPU usage
   during compaction".

 - Christoph Hellwig does some vmalloc maintenance work in the series
   "cleanup vfree and vunmap".

 - Christoph Hellwig has removed block_device_operations.rw_page() in
   ths series "remove ->rw_page".

 - We get some maple_tree improvements and cleanups in Liam Howlett's
   series "VMA tree type safety and remove __vma_adjust()".

 - Suren Baghdasaryan has done some work on the maintainability of our
   vm_flags handling in the series "introduce vm_flags modifier
   functions".

 - Some pagemap cleanup and generalization work in Mike Rapoport's
   series "mm, arch: add generic implementation of pfn_valid() for
   FLATMEM" and "fixups for generic implementation of pfn_valid()"

 - Baoquan He has done some work to make /proc/vmallocinfo and
   /proc/kcore better represent the real state of things in his series
   "mm/vmalloc.c: allow vread() to read out vm_map_ram areas".

 - Jason Gunthorpe rationalized the GUP system's interface to the rest
   of the kernel in the series "Simplify the external interface for
   GUP".

 - SeongJae Park wishes to migrate people from DAMON's debugfs interface
   over to its sysfs interface. To support this, we'll temporarily be
   printing warnings when people use the debugfs interface. See the
   series "mm/damon: deprecate DAMON debugfs interface".

 - Andrey Konovalov provided the accurately named "lib/stackdepot: fixes
   and clean-ups" series.

 - Huang Ying has provided a dramatic reduction in migration's TLB flush
   IPI rates with the series "migrate_pages(): batch TLB flushing".

 - Arnd Bergmann has some objtool fixups in "objtool warning fixes".

* tag 'mm-stable-2023-02-20-13-37' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (505 commits)
  include/linux/migrate.h: remove unneeded externs
  mm/memory_hotplug: cleanup return value handing in do_migrate_range()
  mm/uffd: fix comment in handling pte markers
  mm: change to return bool for isolate_movable_page()
  mm: hugetlb: change to return bool for isolate_hugetlb()
  mm: change to return bool for isolate_lru_page()
  mm: change to return bool for folio_isolate_lru()
  objtool: add UACCESS exceptions for __tsan_volatile_read/write
  kmsan: disable ftrace in kmsan core code
  kasan: mark addr_has_metadata __always_inline
  mm: memcontrol: rename memcg_kmem_enabled()
  sh: initialize max_mapnr
  m68k/nommu: add missing definition of ARCH_PFN_OFFSET
  mm: percpu: fix incorrect size in pcpu_obj_full_size()
  maple_tree: reduce stack usage with gcc-9 and earlier
  mm: page_alloc: call panic() when memoryless node allocation fails
  mm: multi-gen LRU: avoid futile retries
  migrate_pages: move THP/hugetlb migration support check to simplify code
  migrate_pages: batch flushing TLB
  migrate_pages: share more code between _unmap and _move
  ...
2023-02-23 17:09:35 -08:00
Linus Torvalds
307e14c039 Merge tag '6.3-rc-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6
Pull cifs client updates from Steve French:
 "The largest subset of this is from David Howells et al: making the
  cifs/smb3 driver pass iov_iters down to the lowest layers, directly to
  the network transport rather than passing lists of pages around,
  helping multiple areas:

   - Pin user pages, thereby fixing the race between concurrent DIO read
     and fork, where the pages containing the DIO read buffer may end up
     belonging to the child process and not the parent - with the result
     that the parent might not see the retrieved data.

   - cifs shouldn't take refs on pages extracted from non-user-backed
     iterators (eg. KVEC). With these changes, cifs will apply the
     appropriate cleanup.

   - Making it easier to transition to using folios in cifs rather than
     pages by dealing with them through BVEC and XARRAY iterators.

   - Allowing cifs to use the new splice function

  The remainder are:

   - fixes for stable, including various fixes for uninitialized memory,
     wrong length field causing mount issue to very old servers,
     important directory lease fixes and reconnect fixes

   - cleanups (unused code removal, change one element array usage, and
     a change form strtobool to kstrtobool, and Kconfig cleanups)

   - SMBDIRECT (RDMA) fixes including iov_iter integration and UAF fixes

   - reconnect fixes

   - multichannel fixes, including improving channel allocation (to
     least used channel)

   - remove the last use of lock_page_killable by moving to
     folio_lock_killable"

* tag '6.3-rc-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6: (46 commits)
  update internal module version number for cifs.ko
  cifs: update ip_addr for ses only for primary chan setup
  cifs: use tcon allocation functions even for dummy tcon
  cifs: use the least loaded channel for sending requests
  cifs: DIO to/from KVEC-type iterators should now work
  cifs: Remove unused code
  cifs: Build the RDMA SGE list directly from an iterator
  cifs: Change the I/O paths to use an iterator rather than a page list
  cifs: Add a function to read into an iter from a socket
  cifs: Add some helper functions
  cifs: Add a function to Hash the contents of an iterator
  cifs: Add a function to build an RDMA SGE list from an iterator
  netfs: Add a function to extract an iterator into a scatterlist
  netfs: Add a function to extract a UBUF or IOVEC into a BVEC iterator
  cifs: Implement splice_read to pass down ITER_BVEC not ITER_PIPE
  splice: Export filemap/direct_splice_read()
  iov_iter: Add a function to extract a page list from an iterator
  iov_iter: Define flags to qualify page extraction.
  splice: Add a func to do a splice from an O_DIRECT file without ITER_PIPE
  splice: Add a func to do a splice from a buffered file without ITER_PIPE
  ...
2023-02-22 17:12:44 -08:00
David Howells
33b3b04154 splice: Add a func to do a splice from an O_DIRECT file without ITER_PIPE
Implement a function, direct_file_splice(), that deals with this by using
an ITER_BVEC iterator instead of an ITER_PIPE iterator as the former won't
free its buffers when reverted.  The function bulk allocates all the
buffers it thinks it is going to use in advance, does the read
synchronously and only then trims the buffer down.  The pages we did use
get pushed into the pipe.

This fixes a problem with the upcoming iov_iter_extract_pages() function,
whereby pages extracted from a non-user-backed iterator such as ITER_PIPE
aren't pinned.  __iomap_dio_rw(), however, calls iov_iter_revert() to
shorten the iterator to just the bufferage it is going to use - which has
the side-effect of freeing the excess pipe buffers, even though they're
attached to a bio and may get written to by DMA (thanks to Hillf Danton for
spotting this[1]).

This then causes memory corruption that is particularly noticeable when the
syzbot test[2] is run.  The test boils down to:

	out = creat(argv[1], 0666);
	ftruncate(out, 0x800);
	lseek(out, 0x200, SEEK_SET);
	in = open(argv[1], O_RDONLY | O_DIRECT | O_NOFOLLOW);
	sendfile(out, in, NULL, 0x1dd00);

run repeatedly in parallel.  What I think is happening is that ftruncate()
occasionally shortens the DIO read that's about to be made by sendfile's
splice core by reducing i_size.

This should be more efficient for DIO read by virtue of doing a bulk page
allocation, but slightly less efficient by ignoring any partial page in the
pipe.

Reported-by: syzbot+a440341a59e3b7142895@syzkaller.appspotmail.com
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
cc: Christoph Hellwig <hch@lst.de>
cc: Al Viro <viro@zeniv.linux.org.uk>
cc: David Hildenbrand <david@redhat.com>
cc: John Hubbard <jhubbard@nvidia.com>
cc: linux-mm@kvack.org
cc: linux-block@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/20230207094731.1390-1-hdanton@sina.com/ [1]
Link: https://lore.kernel.org/r/000000000000b0b3c005f3a09383@google.com/ [2]
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-02-20 17:25:43 -06:00
David Howells
07073eb01c splice: Add a func to do a splice from a buffered file without ITER_PIPE
Provide a function to do splice read from a buffered file, pulling the
folios out of the pagecache directly by calling filemap_get_pages() to do
any required reading and then pasting the returned folios into the pipe.

A helper function is provided to do the actual folio pasting and will
handle multipage folios by splicing as many of the relevant subpages as
will fit into the pipe.

The code is loosely based on filemap_read() and might belong in
mm/filemap.c with that as it needs to use filemap_get_pages().

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
cc: Christoph Hellwig <hch@lst.de>
cc: Al Viro <viro@zeniv.linux.org.uk>
cc: David Hildenbrand <david@redhat.com>
cc: John Hubbard <jhubbard@nvidia.com>
cc: linux-mm@kvack.org
cc: linux-block@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
2023-02-20 17:25:43 -06:00
Linus Torvalds
05e6295f7b Merge tag 'fs.idmapped.v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping
Pull vfs idmapping updates from Christian Brauner:

 - Last cycle we introduced the dedicated struct mnt_idmap type for
   mount idmapping and the required infrastucture in 256c8aed2b ("fs:
   introduce dedicated idmap type for mounts"). As promised in last
   cycle's pull request message this converts everything to rely on
   struct mnt_idmap.

   Currently we still pass around the plain namespace that was attached
   to a mount. This is in general pretty convenient but it makes it easy
   to conflate namespaces that are relevant on the filesystem with
   namespaces that are relevant on the mount level. Especially for
   non-vfs developers without detailed knowledge in this area this was a
   potential source for bugs.

   This finishes the conversion. Instead of passing the plain namespace
   around this updates all places that currently take a pointer to a
   mnt_userns with a pointer to struct mnt_idmap.

   Now that the conversion is done all helpers down to the really
   low-level helpers only accept a struct mnt_idmap argument instead of
   two namespace arguments.

   Conflating mount and other idmappings will now cause the compiler to
   complain loudly thus eliminating the possibility of any bugs. This
   makes it impossible for filesystem developers to mix up mount and
   filesystem idmappings as they are two distinct types and require
   distinct helpers that cannot be used interchangeably.

   Everything associated with struct mnt_idmap is moved into a single
   separate file. With that change no code can poke around in struct
   mnt_idmap. It can only be interacted with through dedicated helpers.
   That means all filesystems are and all of the vfs is completely
   oblivious to the actual implementation of idmappings.

   We are now also able to extend struct mnt_idmap as we see fit. For
   example, we can decouple it completely from namespaces for users that
   don't require or don't want to use them at all. We can also extend
   the concept of idmappings so we can cover filesystem specific
   requirements.

   In combination with the vfs{g,u}id_t work we finished in v6.2 this
   makes this feature substantially more robust and thus difficult to
   implement wrong by a given filesystem and also protects the vfs.

 - Enable idmapped mounts for tmpfs and fulfill a longstanding request.

   A long-standing request from users had been to make it possible to
   create idmapped mounts for tmpfs. For example, to share the host's
   tmpfs mount between multiple sandboxes. This is a prerequisite for
   some advanced Kubernetes cases. Systemd also has a range of use-cases
   to increase service isolation. And there are more users of this.

   However, with all of the other work going on this was way down on the
   priority list but luckily someone other than ourselves picked this
   up.

   As usual the patch is tiny as all the infrastructure work had been
   done multiple kernel releases ago. In addition to all the tests that
   we already have I requested that Rodrigo add a dedicated tmpfs
   testsuite for idmapped mounts to xfstests. It is to be included into
   xfstests during the v6.3 development cycle. This should add a slew of
   additional tests.

* tag 'fs.idmapped.v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping: (26 commits)
  shmem: support idmapped mounts for tmpfs
  fs: move mnt_idmap
  fs: port vfs{g,u}id helpers to mnt_idmap
  fs: port fs{g,u}id helpers to mnt_idmap
  fs: port i_{g,u}id_into_vfs{g,u}id() to mnt_idmap
  fs: port i_{g,u}id_{needs_}update() to mnt_idmap
  quota: port to mnt_idmap
  fs: port privilege checking helpers to mnt_idmap
  fs: port inode_owner_or_capable() to mnt_idmap
  fs: port inode_init_owner() to mnt_idmap
  fs: port acl to mnt_idmap
  fs: port xattr to mnt_idmap
  fs: port ->permission() to pass mnt_idmap
  fs: port ->fileattr_set() to pass mnt_idmap
  fs: port ->set_acl() to pass mnt_idmap
  fs: port ->get_acl() to pass mnt_idmap
  fs: port ->tmpfile() to pass mnt_idmap
  fs: port ->rename() to pass mnt_idmap
  fs: port ->mknod() to pass mnt_idmap
  fs: port ->mkdir() to pass mnt_idmap
  ...
2023-02-20 11:53:11 -08:00
Christian Brauner
4d7ca40901 fs: port vfs{g,u}id helpers to mnt_idmap
Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-19 09:24:30 +01:00
Christian Brauner
c14329d39f fs: port fs{g,u}id helpers to mnt_idmap
Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-19 09:24:30 +01:00
Christian Brauner
e67fe63341 fs: port i_{g,u}id_into_vfs{g,u}id() to mnt_idmap
Convert to struct mnt_idmap.
Remove legacy file_mnt_user_ns() and mnt_user_ns().

Last cycle we merged the necessary infrastructure in
256c8aed2b ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-19 09:24:29 +01:00
Christian Brauner
0dbe12f2e4 fs: port i_{g,u}id_{needs_}update() to mnt_idmap
Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-19 09:24:29 +01:00
Christian Brauner
9452e93e6d fs: port privilege checking helpers to mnt_idmap
Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-19 09:24:29 +01:00
Christian Brauner
01beba7957 fs: port inode_owner_or_capable() to mnt_idmap
Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-19 09:24:29 +01:00
Christian Brauner
f2d40141d5 fs: port inode_init_owner() to mnt_idmap
Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-19 09:24:28 +01:00
Christian Brauner
4609e1f18e fs: port ->permission() to pass mnt_idmap
Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-19 09:24:28 +01:00
Christian Brauner
8782a9aea3 fs: port ->fileattr_set() to pass mnt_idmap
Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-19 09:24:27 +01:00