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2023-10-09iov_iter, net: Move hash_and_copy_to_iter() to net/David Howells1-3/+0
Move hash_and_copy_to_iter() to be with its only caller in networking code. Signed-off-by: David Howells <dhowells@redhat.com> Link: https://lore.kernel.org/r/20230925120309.1731676-13-dhowells@redhat.com cc: Alexander Viro <viro@zeniv.linux.org.uk> cc: Jens Axboe <axboe@kernel.dk> cc: Christoph Hellwig <hch@lst.de> cc: Christian Brauner <christian@brauner.io> cc: Matthew Wilcox <willy@infradead.org> cc: Linus Torvalds <torvalds@linux-foundation.org> cc: David Laight <David.Laight@ACULAB.COM> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-block@vger.kernel.org cc: linux-fsdevel@vger.kernel.org cc: linux-mm@kvack.org cc: netdev@vger.kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-09iov_iter, net: Move csum_and_copy_to/from_iter() to net/David Howells1-18/+0
Move csum_and_copy_to/from_iter() to net code now that the iteration framework can be #included. Signed-off-by: David Howells <dhowells@redhat.com> Link: https://lore.kernel.org/r/20230925120309.1731676-10-dhowells@redhat.com cc: Alexander Viro <viro@zeniv.linux.org.uk> cc: Jens Axboe <axboe@kernel.dk> cc: Christoph Hellwig <hch@lst.de> cc: Christian Brauner <christian@brauner.io> cc: Matthew Wilcox <willy@infradead.org> cc: Linus Torvalds <torvalds@linux-foundation.org> cc: David Laight <David.Laight@ACULAB.COM> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-block@vger.kernel.org cc: linux-fsdevel@vger.kernel.org cc: linux-mm@kvack.org cc: netdev@vger.kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-09-25iov_iter: Derive user-backedness from the iterator typeDavid Howells1-3/+1
Use the iterator type to determine whether an iterator is user-backed or not rather than using a special flag for it. Now that ITER_UBUF and ITER_IOVEC are 0 and 1, they can be checked with a single comparison. Signed-off-by: David Howells <dhowells@redhat.com> Link: https://lore.kernel.org/r/20230925120309.1731676-7-dhowells@redhat.com cc: Alexander Viro <viro@zeniv.linux.org.uk> cc: Jens Axboe <axboe@kernel.dk> cc: Christoph Hellwig <hch@lst.de> cc: Christian Brauner <christian@brauner.io> cc: Matthew Wilcox <willy@infradead.org> cc: Linus Torvalds <torvalds@linux-foundation.org> cc: David Laight <David.Laight@ACULAB.COM> cc: linux-block@vger.kernel.org cc: linux-fsdevel@vger.kernel.org cc: linux-mm@kvack.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-09-25iov_iter: Renumber ITER_* constantsDavid Howells1-2/+2
Renumber the ITER_* iterator-type constants to put things in the same order as in the iteration functions and to group user-backed iterators at the bottom. Signed-off-by: David Howells <dhowells@redhat.com> Link: https://lore.kernel.org/r/20230925120309.1731676-6-dhowells@redhat.com cc: Alexander Viro <viro@zeniv.linux.org.uk> cc: Jens Axboe <axboe@kernel.dk> cc: Christoph Hellwig <hch@lst.de> cc: Christian Brauner <christian@brauner.io> cc: Matthew Wilcox <willy@infradead.org> cc: Linus Torvalds <torvalds@linux-foundation.org> cc: David Laight <David.Laight@ACULAB.COM> cc: linux-block@vger.kernel.org cc: linux-fsdevel@vger.kernel.org cc: linux-mm@kvack.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-09-25iov_iter: Remove last_offset from iov_iter as it was for ITER_PIPEDavid Howells1-4/+1
Now that ITER_PIPE has been removed, iov_iter::last_offset is no longer used, so remove it. Signed-off-by: David Howells <dhowells@redhat.com> Link: https://lore.kernel.org/r/20230925120309.1731676-2-dhowells@redhat.com cc: Alexander Viro <viro@zeniv.linux.org.uk> cc: Jens Axboe <axboe@kernel.dk> cc: Christoph Hellwig <hch@lst.de> cc: Christian Brauner <christian@brauner.io> cc: Matthew Wilcox <willy@infradead.org> cc: Linus Torvalds <torvalds@linux-foundation.org> cc: David Laight <David.Laight@ACULAB.COM> cc: linux-block@vger.kernel.org cc: linux-fsdevel@vger.kernel.org cc: linux-mm@kvack.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-07-24iov_iter: Add copy_folio_from_iter_atomic()Matthew Wilcox (Oracle)1-1/+8
Add a folio wrapper around copy_page_from_iter_atomic(). Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2023-06-28Merge tag 'net-next-6.5' of ↵Linus Torvalds1-0/+5
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 ...
2023-06-16iov_iter: remove iov_iter_get_pages and iov_iter_get_pages_allocChristoph Hellwig1-6/+0
Now that the direct I/O helpers have switched to use iov_iter_extract_pages, these helpers are unused. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Christian Brauner <brauner@kernel.org> Reviewed-by: David Howells <dhowells@redhat.com> Link: https://lore.kernel.org/r/20230614140341.521331-5-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-06-08Move netfs_extract_iter_to_sg() to lib/scatterlist.cDavid Howells1-0/+5
Move netfs_extract_iter_to_sg() to lib/scatterlist.c as it's going to be used by more than just network filesystems (AF_ALG, for example). Signed-off-by: David Howells <dhowells@redhat.com> cc: Jeff Layton <jlayton@kernel.org> cc: Steve French <sfrench@samba.org> cc: Shyam Prasad N <nspmangalore@gmail.com> cc: Rohith Surabattula <rohiths.msft@gmail.com> cc: Jens Axboe <axboe@kernel.dk> cc: Herbert Xu <herbert@gondor.apana.org.au> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: Matthew Wilcox <willy@infradead.org> cc: linux-crypto@vger.kernel.org cc: linux-cachefs@redhat.com cc: linux-cifs@vger.kernel.org cc: linux-fsdevel@vger.kernel.org cc: netdev@vger.kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-05-24iov_iter: Kill ITER_PIPEDavid Howells1-14/+0
The ITER_PIPE-type iterator was only used by generic_file_splice_read() and that has been replaced and removed. This leaves ITER_PIPE unused - so remove it too. 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: 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/20230522135018.2742245-31-dhowells@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-05-02mm: hwpoison: coredump: support recovery from dump_user_range()Kefeng Wang1-0/+16
dump_user_range() is used to copy the user page to a coredump file, but if a hardware memory error occurred during copy, which called from __kernel_write_iter() in dump_user_range(), it crashes, CPU: 112 PID: 7014 Comm: mca-recover Not tainted 6.3.0-rc2 #425 pc : __memcpy+0x110/0x260 lr : _copy_from_iter+0x3bc/0x4c8 ... Call trace: __memcpy+0x110/0x260 copy_page_from_iter+0xcc/0x130 pipe_write+0x164/0x6d8 __kernel_write_iter+0x9c/0x210 dump_user_range+0xc8/0x1d8 elf_core_dump+0x308/0x368 do_coredump+0x2e8/0xa40 get_signal+0x59c/0x788 do_signal+0x118/0x1f8 do_notify_resume+0xf0/0x280 el0_da+0x130/0x138 el0t_64_sync_handler+0x68/0xc0 el0t_64_sync+0x188/0x190 Generally, the '->write_iter' of file ops will use copy_page_from_iter() and copy_page_from_iter_atomic(), change memcpy() to copy_mc_to_kernel() in both of them to handle #MC during source read, which stop coredump processing and kill the task instead of kernel panic, but the source address may not always a user address, so introduce a new copy_mc flag in struct iov_iter{} to indicate that the iter could do a safe memory copy, also introduce the helpers to set/cleck the flag, for now, it's only used in coredump's dump_user_range(), but it could expand to any other scenarios to fix the similar issue. Link: https://lkml.kernel.org/r/20230417045323.11054-1-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Tong Tiangen <tongtiangen@huawei.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-27Merge tag 'mm-stable-2023-04-27-15-30' of ↵Linus Torvalds1-0/+2
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of switching from a user process to a kernel thread. - More folio conversions from Kefeng Wang, Zhang Peng and Pankaj Raghav. - zsmalloc performance improvements from Sergey Senozhatsky. - Yue Zhao has found and fixed some data race issues around the alteration of memcg userspace tunables. - VFS rationalizations from Christoph Hellwig: - removal of most of the callers of write_one_page() - make __filemap_get_folio()'s return value more useful - Luis Chamberlain has changed tmpfs so it no longer requires swap backing. Use `mount -o noswap'. - Qi Zheng has made the slab shrinkers operate locklessly, providing some scalability benefits. - Keith Busch has improved dmapool's performance, making part of its operations O(1) rather than O(n). - Peter Xu adds the UFFD_FEATURE_WP_UNPOPULATED feature to userfaultd, permitting userspace to wr-protect anon memory unpopulated ptes. - Kirill Shutemov has changed MAX_ORDER's meaning to be inclusive rather than exclusive, and has fixed a bunch of errors which were caused by its unintuitive meaning. - Axel Rasmussen give userfaultfd the UFFDIO_CONTINUE_MODE_WP feature, which causes minor faults to install a write-protected pte. - Vlastimil Babka has done some maintenance work on vma_merge(): cleanups to the kernel code and improvements to our userspace test harness. - Cleanups to do_fault_around() by Lorenzo Stoakes. - Mike Rapoport has moved a lot of initialization code out of various mm/ files and into mm/mm_init.c. - Lorenzo Stoakes removd vmf_insert_mixed_prot(), which was added for DRM, but DRM doesn't use it any more. - Lorenzo has also coverted read_kcore() and vread() to use iterators and has thereby removed the use of bounce buffers in some cases. - Lorenzo has also contributed further cleanups of vma_merge(). - Chaitanya Prakash provides some fixes to the mmap selftesting code. - Matthew Wilcox changes xfs and afs so they no longer take sleeping locks in ->map_page(), a step towards RCUification of pagefaults. - Suren Baghdasaryan has improved mmap_lock scalability by switching to per-VMA locking. - Frederic Weisbecker has reworked the percpu cache draining so that it no longer causes latency glitches on cpu isolated workloads. - Mike Rapoport cleans up and corrects the ARCH_FORCE_MAX_ORDER Kconfig logic. - Liu Shixin has changed zswap's initialization so we no longer waste a chunk of memory if zswap is not being used. - Yosry Ahmed has improved the performance of memcg statistics flushing. - David Stevens has fixed several issues involving khugepaged, userfaultfd and shmem. - Christoph Hellwig has provided some cleanup work to zram's IO-related code paths. - David Hildenbrand has fixed up some issues in the selftest code's testing of our pte state changing. - Pankaj Raghav has made page_endio() unneeded and has removed it. - Peter Xu contributed some rationalizations of the userfaultfd selftests. - Yosry Ahmed has fixed an issue around memcg's page recalim accounting. - Chaitanya Prakash has fixed some arm-related issues in the selftests/mm code. - Longlong Xia has improved the way in which KSM handles hwpoisoned pages. - Peter Xu fixes a few issues with uffd-wp at fork() time. - Stefan Roesch has changed KSM so that it may now be used on a per-process and per-cgroup basis. * tag 'mm-stable-2023-04-27-15-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (369 commits) mm,unmap: avoid flushing TLB in batch if PTE is inaccessible shmem: restrict noswap option to initial user namespace mm/khugepaged: fix conflicting mods to collapse_file() sparse: remove unnecessary 0 values from rc mm: move 'mmap_min_addr' logic from callers into vm_unmapped_area() hugetlb: pte_alloc_huge() to replace huge pte_alloc_map() maple_tree: fix allocation in mas_sparse_area() mm: do not increment pgfault stats when page fault handler retries zsmalloc: allow only one active pool compaction context selftests/mm: add new selftests for KSM mm: add new KSM process and sysfs knobs mm: add new api to enable ksm per process mm: shrinkers: fix debugfs file permissions mm: don't check VMA write permissions if the PTE/PMD indicates write permissions migrate_pages_batch: fix statistics for longterm pin retry userfaultfd: use helper function range_in_vma() lib/show_mem.c: use for_each_populated_zone() simplify code mm: correct arg in reclaim_pages()/reclaim_clean_pages_from_list() fs/buffer: convert create_page_buffers to folio_create_buffers fs/buffer: add folio_create_empty_buffers helper ...
2023-04-05iov_iter: add copy_page_to_iter_nofault()Lorenzo Stoakes1-0/+2
Provide a means to copy a page to user space from an iterator, aborting if a page fault would occur. This supports compound pages, but may be passed a tail page with an offset extending further into the compound page, so we cannot pass a folio. This allows for this function to be called from atomic context and _try_ to user pages if they are faulted in, aborting if not. The function does not use _copy_to_iter() in order to not specify might_fault(), this is similar to copy_page_from_iter_atomic(). This is being added in order that an iteratable form of vread() can be implemented while holding spinlocks. Link: https://lkml.kernel.org/r/19734729defb0f498a76bdec1bef3ac48a3af3e8.1679511146.git.lstoakes@gmail.com Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com> Reviewed-by: Baoquan He <bhe@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: David Hildenbrand <david@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Liu Shixin <liushixin2@huawei.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-03-30iov_iter: overlay struct iovec and ubuf/lenJens Axboe1-9/+35
Add an internal struct iovec that we can return as a pointer, with the fields of the iovec overlapping with the ITER_UBUF ubuf and length fields. Then we can have iter_iov() check for the appropriate type, and return &iter->__ubuf_iovec for ITER_UBUF and iter->__iov for ITER_IOVEC and things will magically work out for a single segment request regardless of either type. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-03-30iov_iter: set nr_segs = 1 for ITER_UBUFJens Axboe1-1/+2
To avoid needing to check if a given user backed iov_iter is of type ITER_IOVEC or ITER_UBUF, set the number of segments for the ITER_UBUF case to 1 as we're carrying a single segment. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-03-30iov_iter: remove iov_iter_iovec()Jens Axboe1-9/+0
No more users are left of this function. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-03-30iov_iter: add iter_iov_addr() and iter_iov_len() helpersJens Axboe1-0/+2
These just return the address and length of the current iovec segment in the iterator. Convert existing iov_iter_iovec() users to use them instead of getting a copy of the current vec. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-03-30iov_iter: add iter_iovec() helperJens Axboe1-3/+6
This returns a pointer to the current iovec entry in the iterator. Only useful with ITER_IOVEC right now, but it prepares us to treat ITER_UBUF and ITER_IOVEC identically for the first segment. Rename struct iov_iter->iov to iov_iter->__iov to find any potentially troublesome spots, and also to prevent anyone from adding new code that accesses iter->iov directly. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-02-22Merge tag '6.3-rc-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6Linus Torvalds1-2/+33
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 ...
2023-02-20iov_iter: Add a function to extract a page list from an iteratorDavid Howells1-1/+26
Add a function, iov_iter_extract_pages(), to extract a list of pages from an iterator. The pages may be returned with a pin added or nothing, depending on the type of iterator. Add a second function, iov_iter_extract_will_pin(), to determine how the cleanup should be done. There are two cases: (1) ITER_IOVEC or ITER_UBUF iterator. Extracted pages will have pins (FOLL_PIN) obtained on them so that a concurrent fork() will forcibly copy the page so that DMA is done to/from the parent's buffer and is unavailable to/unaffected by the child process. iov_iter_extract_will_pin() will return true for this case. The caller should use something like unpin_user_page() to dispose of the page. (2) Any other sort of iterator. No refs or pins are obtained on the page, the assumption is made that the caller will manage page retention. iov_iter_extract_will_pin() will return false. The pages don't need additional disposal. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jens Axboe <axboe@kernel.dk> cc: Al Viro <viro@zeniv.linux.org.uk> cc: John Hubbard <jhubbard@nvidia.com> cc: David Hildenbrand <david@redhat.com> cc: Matthew Wilcox <willy@infradead.org> cc: linux-fsdevel@vger.kernel.org cc: linux-mm@kvack.org Signed-off-by: Steve French <stfrench@microsoft.com>
2023-02-20iov_iter: Define flags to qualify page extraction.David Howells1-2/+8
Define flags to qualify page extraction to pass into iov_iter_*_pages*() rather than passing in FOLL_* flags. For now only a flag to allow peer-to-peer DMA is supported. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Jens Axboe <axboe@kernel.dk> cc: Al Viro <viro@zeniv.linux.org.uk> cc: Logan Gunthorpe <logang@deltatee.com> cc: linux-fsdevel@vger.kernel.org cc: linux-block@vger.kernel.org Signed-off-by: Steve French <stfrench@microsoft.com>
2023-01-08iov: add import_ubuf()Jens Axboe1-0/+1
Like import_single_range(), but for ITER_UBUF. Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
2022-12-13Merge tag 'for-6.2/block-2022-12-08' of git://git.kernel.dk/linuxLinus Torvalds1-0/+6
Pull block updates from Jens Axboe: - NVMe pull requests via Christoph: - Support some passthrough commands without CAP_SYS_ADMIN (Kanchan Joshi) - Refactor PCIe probing and reset (Christoph Hellwig) - Various fabrics authentication fixes and improvements (Sagi Grimberg) - Avoid fallback to sequential scan due to transient issues (Uday Shankar) - Implement support for the DEAC bit in Write Zeroes (Christoph Hellwig) - Allow overriding the IEEE OUI and firmware revision in configfs for nvmet (Aleksandr Miloserdov) - Force reconnect when number of queue changes in nvmet (Daniel Wagner) - Minor fixes and improvements (Uros Bizjak, Joel Granados, Sagi Grimberg, Christoph Hellwig, Christophe JAILLET) - Fix and cleanup nvme-fc req allocation (Chaitanya Kulkarni) - Use the common tagset helpers in nvme-pci driver (Christoph Hellwig) - Cleanup the nvme-pci removal path (Christoph Hellwig) - Use kstrtobool() instead of strtobool (Christophe JAILLET) - Allow unprivileged passthrough of Identify Controller (Joel Granados) - Support io stats on the mpath device (Sagi Grimberg) - Minor nvmet cleanup (Sagi Grimberg) - MD pull requests via Song: - Code cleanups (Christoph) - Various fixes - Floppy pull request from Denis: - Fix a memory leak in the init error path (Yuan) - Series fixing some batch wakeup issues with sbitmap (Gabriel) - Removal of the pktcdvd driver that was deprecated more than 5 years ago, and subsequent removal of the devnode callback in struct block_device_operations as no users are now left (Greg) - Fix for partition read on an exclusively opened bdev (Jan) - Series of elevator API cleanups (Jinlong, Christoph) - Series of fixes and cleanups for blk-iocost (Kemeng) - Series of fixes and cleanups for blk-throttle (Kemeng) - Series adding concurrent support for sync queues in BFQ (Yu) - Series bringing drbd a bit closer to the out-of-tree maintained version (Christian, Joel, Lars, Philipp) - Misc drbd fixes (Wang) - blk-wbt fixes and tweaks for enable/disable (Yu) - Fixes for mq-deadline for zoned devices (Damien) - Add support for read-only and offline zones for null_blk (Shin'ichiro) - Series fixing the delayed holder tracking, as used by DM (Yu, Christoph) - Series enabling bio alloc caching for IRQ based IO (Pavel) - Series enabling userspace peer-to-peer DMA (Logan) - BFQ waker fixes (Khazhismel) - Series fixing elevator refcount issues (Christoph, Jinlong) - Series cleaning up references around queue destruction (Christoph) - Series doing quiesce by tagset, enabling cleanups in drivers (Christoph, Chao) - Series untangling the queue kobject and queue references (Christoph) - Misc fixes and cleanups (Bart, David, Dawei, Jinlong, Kemeng, Ye, Yang, Waiman, Shin'ichiro, Randy, Pankaj, Christoph) * tag 'for-6.2/block-2022-12-08' of git://git.kernel.dk/linux: (247 commits) blktrace: Fix output non-blktrace event when blk_classic option enabled block: sed-opal: Don't include <linux/kernel.h> sed-opal: allow using IOC_OPAL_SAVE for locking too blk-cgroup: Fix typo in comment block: remove bio_set_op_attrs nvmet: don't open-code NVME_NS_ATTR_RO enumeration nvme-pci: use the tagset alloc/free helpers nvme: add the Apple shared tag workaround to nvme_alloc_io_tag_set nvme: only set reserved_tags in nvme_alloc_io_tag_set for fabrics controllers nvme: consolidate setting the tagset flags nvme: pass nr_maps explicitly to nvme_alloc_io_tag_set block: bio_copy_data_iter nvme-pci: split out a nvme_pci_ctrl_is_dead helper nvme-pci: return early on ctrl state mismatch in nvme_reset_work nvme-pci: rename nvme_disable_io_queues nvme-pci: cleanup nvme_suspend_queue nvme-pci: remove nvme_pci_disable nvme-pci: remove nvme_disable_admin_queue nvme: merge nvme_shutdown_ctrl into nvme_disable_ctrl nvme: use nvme_wait_ready in nvme_shutdown_ctrl ...
2022-11-25use less confusing names for iov_iter direction initializersAl Viro1-0/+3
READ/WRITE proved to be actively confusing - the meanings are "data destination, as used with read(2)" and "data source, as used with write(2)", but people keep interpreting those as "we read data from it" and "we write data to it", i.e. exactly the wrong way. Call them ITER_DEST and ITER_SOURCE - at least that is harder to misinterpret... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-11-09iov_iter: introduce iov_iter_get_pages_[alloc_]flags()Logan Gunthorpe1-0/+6
Add iov_iter_get_pages_flags() and iov_iter_get_pages_alloc_flags() which take a flags argument that is passed to get_user_pages_fast(). This is so that FOLL_PCI_P2PDMA can be passed when appropriate. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20221021174116.7200-4-logang@deltatee.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-16iov_iter: use "maxpages" parameterDan Carpenter1-1/+1
This was intended to be "maxpages" instead of INT_MAX. There is only one caller and it passes INT_MAX so this does not affect runtime. Fixes: b93235e68921 ("tls: cap the output scatter list to something reasonable") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-08-08get rid of non-advancing variantsAl Viro1-22/+2
mechanical change; will be further massaged in subsequent commits Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-08-08iov_iter: advancing variants of iov_iter_get_pages{,_alloc}()Al Viro1-0/+20
Most of the users immediately follow successful iov_iter_get_pages() with advancing by the amount it had returned. Provide inline wrappers doing that, convert trivial open-coded uses of those. BTW, iov_iter_get_pages() never returns more than it had been asked to; such checks in cifs ought to be removed someday... Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-08-08ITER_PIPE: cache the type of last bufferAl Viro1-1/+4
We often need to find whether the last buffer is anon or not, and currently it's rather clumsy: check if ->iov_offset is non-zero (i.e. that pipe is not empty) if so, get the corresponding pipe_buffer and check its ->ops if it's &default_pipe_buf_ops, we have an anon buffer. Let's replace the use of ->iov_offset (which is nowhere near similar to its role for other flavours) with signed field (->last_offset), with the following rules: empty, no buffers occupied: 0 anon, with bytes up to N-1 filled: N zero-copy, with bytes up to N-1 filled: -N That way abs(i->last_offset) is equal to what used to be in i->iov_offset and empty vs. anon vs. zero-copy can be distinguished by the sign of i->last_offset. Checks for "should we extend the last buffer or should we start a new one?" become easier to follow that way. Note that most of the operations can only be done in a sane state - i.e. when the pipe has nothing past the current position of iterator. About the only thing that could be done outside of that state is iov_iter_advance(), which transitions to the sane state by truncating the pipe. There are only two cases where we leave the sane state: 1) iov_iter_get_pages()/iov_iter_get_pages_alloc(). Will be dealt with later, when we make get_pages advancing - the callers are actually happier that way. 2) iov_iter copied, then something is put into the copy. Since they share the underlying pipe, the original gets behind. When we decide that we are done with the copy (original is not usable until then) we advance the original. direct_io used to be done that way; nowadays it operates on the original and we do iov_iter_revert() to discard the excessive data. At the moment there's nothing in the kernel that could do that to ITER_PIPE iterators, so this reason for insane state is theoretical right now. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-08-08new iov_iter flavour - ITER_UBUFAl Viro1-0/+26
Equivalent of single-segment iovec. Initialized by iov_iter_ubuf(), checked for by iter_is_ubuf(), otherwise behaves like ITER_IOVEC ones. We are going to expose the things like ->write_iter() et.al. to those in subsequent commits. New predicate (user_backed_iter()) that is true for ITER_IOVEC and ITER_UBUF; places like direct-IO handling should use that for checking that pages we modify after getting them from iov_iter_get_pages() would need to be dirtied. DO NOT assume that replacing iter_is_iovec() with user_backed_iter() will solve all problems - there's code that uses iter_is_iovec() to decide how to poke around in iov_iter guts and for that the predicate replacement obviously won't suffice. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-08-03Merge tag 'pull-work.iov_iter-base' of ↵Linus Torvalds1-9/+6
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs iov_iter updates from Al Viro: "Part 1 - isolated cleanups and optimizations. One of the goals is to reduce the overhead of using ->read_iter() and ->write_iter() instead of ->read()/->write(). new_sync_{read,write}() has a surprising amount of overhead, in particular inside iocb_flags(). That's the explanation for the beginning of the series is in this pile; it's not directly iov_iter-related, but it's a part of the same work..." * tag 'pull-work.iov_iter-base' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: first_iovec_segment(): just return address iov_iter: massage calling conventions for first_{iovec,bvec}_segment() iov_iter: first_{iovec,bvec}_segment() - simplify a bit iov_iter: lift dealing with maxpages out of first_{iovec,bvec}_segment() iov_iter_get_pages{,_alloc}(): cap the maxsize with MAX_RW_COUNT iov_iter_bvec_advance(): don't bother with bvec_iter copy_page_{to,from}_iter(): switch iovec variants to generic keep iocb_flags() result cached in struct file iocb: delay evaluation of IS_SYNC(...) until we want to check IOCB_DSYNC struct file: use anonymous union member for rcuhead and llist btrfs: use IOMAP_DIO_NOSYNC teach iomap_dio_rw() to suppress dsync No need of likely/unlikely on calls of check_copy_size()
2022-06-27iov: introduce iov_iter_alignedKeith Busch1-0/+2
The existing iov_iter_alignment() function returns the logical OR of address and length. For cases where address and length need to be considered separately, introduce a helper function that a caller can specificy length and address masks that indicate if the iov is unaligned. Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20220610195830.3574005-9-kbusch@fb.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-06-07No need of likely/unlikely on calls of check_copy_size()Al Viro1-9/+6
it's inline and unlikely() inside of it (including the implicit one in WARN_ON_ONCE()) suffice to convince the compiler that getting false from check_copy_size() is unlikely. Spotted-by: Jens Axboe <axboe@kernel.dk> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2022-02-04tls: cap the output scatter list to something reasonableJakub Kicinski1-0/+17
TLS recvmsg() passes user pages as destination for decrypt. The decrypt operation is repeated record by record, each record being 16kB, max. TLS allocates an sg_table and uses iov_iter_get_pages() to populate it with enough pages to fit the decrypted record. Even though we decrypt a single message at a time we size the sg_table based on the entire length of the iovec. This leads to unnecessarily large allocations, risking triggering OOM conditions. Use iov_iter_truncate() / iov_iter_reexpand() to construct a "capped" version of iov_iter_npages(). Alternatively we could parametrize iov_iter_npages() to take the size as arg instead of using i->count, or do something else.. Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-01-12Merge tag 'libnvdimm-for-5.17' of ↵Linus Torvalds1-19/+1
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull dax and libnvdimm updates from Dan Williams: "The bulk of this is a rework of the dax_operations API after discovering the obstacles it posed to the work-in-progress DAX+reflink support for XFS and other copy-on-write filesystem mechanics. Primarily the need to plumb a block_device through the API to handle partition offsets was a sticking point and Christoph untangled that dependency in addition to other cleanups to make landing the DAX+reflink support easier. The DAX_PMEM_COMPAT option has been around for 4 years and not only are distributions shipping userspace that understand the current configuration API, but some are not even bothering to turn this option on anymore, so it seems a good time to remove it per the deprecation schedule. Recall that this was added after the device-dax subsystem moved from /sys/class/dax to /sys/bus/dax for its sysfs organization. All recent functionality depends on /sys/bus/dax. Some other miscellaneous cleanups and reflink prep patches are included as well. Summary: - Simplify the dax_operations API: - Eliminate bdev_dax_pgoff() in favor of the filesystem maintaining and applying a partition offset to all its DAX iomap operations. - Remove wrappers and device-mapper stacked callbacks for ->copy_from_iter() and ->copy_to_iter() in favor of moving block_device relative offset responsibility to the dax_direct_access() caller. - Remove the need for an @bdev in filesystem-DAX infrastructure - Remove unused uio helpers copy_from_iter_flushcache() and copy_mc_to_iter() as only the non-check_copy_size() versions are used for DAX. - Prepare XFS for the pending (next merge window) DAX+reflink support - Remove deprecated DEV_DAX_PMEM_COMPAT support - Cleanup a straggling misuse of the GUID api" * tag 'libnvdimm-for-5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (38 commits) iomap: Fix error handling in iomap_zero_iter() ACPI: NFIT: Import GUID before use dax: remove the copy_from_iter and copy_to_iter methods dax: remove the DAXDEV_F_SYNC flag dax: simplify dax_synchronous and set_dax_synchronous uio: remove copy_from_iter_flushcache() and copy_mc_to_iter() iomap: turn the byte variable in iomap_zero_iter into a ssize_t memremap: remove support for external pgmap refcounts fsdax: don't require CONFIG_BLOCK iomap: build the block based code conditionally dax: fix up some of the block device related ifdefs fsdax: shift partition offset handling into the file systems dax: return the partition offset from fs_dax_get_by_bdev iomap: add a IOMAP_DAX flag xfs: pass the mapping flags to xfs_bmbt_to_iomap xfs: use xfs_direct_write_iomap_ops for DAX zeroing xfs: move dax device handling into xfs_{alloc,free}_buftarg ext4: cleanup the dax handling in ext4_fill_super ext2: cleanup the dax handling in ext2_fill_super fsdax: decouple zeroing from the iomap buffered I/O code ...
2022-01-04iov_iter: Add copy_folio_to_iter()Matthew Wilcox (Oracle)1-0/+7
This wrapper around copy_page_to_iter() works because copy_page_to_iter() handles compound pages correctly. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: William Kucharski <william.kucharski@oracle.com>
2021-12-18uio: remove copy_from_iter_flushcache() and copy_mc_to_iter()Christoph Hellwig1-19/+1
These two wrappers are never used. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20211215084508.435401-2-hch@lst.de Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2021-10-24iov_iter: Introduce nofault flag to disable page faultsAndreas Gruenbacher1-0/+1
Introduce a new nofault flag to indicate to iov_iter_get_pages not to fault in user pages. This is implemented by passing the FOLL_NOFAULT flag to get_user_pages, which causes get_user_pages to fail when it would otherwise fault in a page. We'll use the ->nofault flag to prevent iomap_dio_rw from faulting in pages when page faults are not allowed. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2021-10-20iov_iter: Introduce fault_in_iov_iter_writeableAndreas Gruenbacher1-0/+1
Introduce a new fault_in_iov_iter_writeable helper for safely faulting in an iterator for writing. Uses get_user_pages() to fault in the pages without actually writing to them, which would be destructive. We'll use fault_in_iov_iter_writeable in gfs2 once we've determined that the iterator passed to .read_iter isn't in memory. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2021-10-18iov_iter: Turn iov_iter_fault_in_readable into fault_in_iov_iter_readableAndreas Gruenbacher1-1/+1
Turn iov_iter_fault_in_readable into a function that returns the number of bytes not faulted in, similar to copy_to_user, instead of returning a non-zero value when any of the requested pages couldn't be faulted in. This supports the existing users that require all pages to be faulted in as well as new users that are happy if any pages can be faulted in. Rename iov_iter_fault_in_readable to fault_in_iov_iter_readable to make sure this change doesn't silently break things. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2021-09-15Revert "iov_iter: track truncated size"Jens Axboe1-5/+1
This reverts commit 2112ff5ce0c1128fe7b4d19cfe7f2b8ce5b595fa. We no longer need to track the truncation count, the one user that did need it has been converted to using iov_iter_restore() instead. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-09-14iov_iter: add helper to save iov_iter stateJens Axboe1-0/+15
In an ideal world, when someone is passed an iov_iter and returns X bytes, then X bytes would have been consumed/advanced from the iov_iter. But we have use cases that always consume the entire iterator, a few examples of that are iomap and bdev O_DIRECT. This means we cannot rely on the state of the iov_iter once we've called ->read_iter() or ->write_iter(). This would be easier if we didn't always have to deal with truncate of the iov_iter, as rewinding would be trivial without that. We recently added a commit to track the truncate state, but that grew the iov_iter by 8 bytes and wasn't the best solution. Implement a helper to save enough of the iov_iter state to sanely restore it after we've called the read/write iterator helpers. This currently only works for IOVEC/BVEC/KVEC as that's all we need, support for other iterator types are left as an exercise for the reader. Link: https://lore.kernel.org/linux-fsdevel/CAHk-=wiacKV4Gh-MYjteU0LwNBSGpWrK-Ov25HdqB1ewinrFPg@mail.gmail.com/ Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-09-03iov_iter: track truncated sizePavel Begunkov1-1/+5
Remember how many bytes were truncated and reverted back. Because not reexpanded iterators don't always work well with reverting, we may need to know that to reexpand ourselves when needed. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2021-06-10iov_iter: replace iov_iter_copy_from_user_atomic() with iterator-advancing ↵Al Viro1-2/+2
variant Replacement is called copy_page_from_iter_atomic(); unlike the old primitive the callers do *not* need to do iov_iter_advance() after it. In case when they end up consuming less than they'd been given they need to do iov_iter_revert() on everything they had not consumed. That, however, needs to be done only on slow paths. All in-tree callers converted. And that kills the last user of iterate_all_kinds() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2021-06-10sanitize iov_iter_fault_in_readable()Al Viro1-1/+1
1) constify iov_iter argument; we are not advancing it in this primitive. 2) cap the amount requested by the amount of data in iov_iter. All existing callers should've been safe, but the check is really cheap and doing it here makes for easier analysis, as well as more consistent semantics among the primitives. 3) don't bother with iterate_iovec(). Explicit loop is not any harder to follow, and we get rid of standalone iterate_iovec() users - it's only used by iterate_and_advance() and (soon to be gone) iterate_all_kinds(). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2021-06-10iov_iter: separate direction from flavourAl Viro1-14/+10
Instead of having them mixed in iter->type, use separate ->iter_type and ->data_source (u8 and bool resp.) And don't bother with (pseudo-) bitmap for the former - microoptimizations from being able to check if the flavour is one of two values are not worth the confusion for optimizer. It can't prove that we never get e.g. ITER_IOVEC | ITER_PIPE, so we end up with extra headache. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2021-06-10iov_iter: switch ..._full() variants of primitives to use of iov_iter_revert()Al Viro1-11/+21
Use corresponding plain variants, revert on short copy. That's the way it should've been done from the very beginning, except that we didn't have iov_iter_revert() back then... [fixed another braino caught by Qian Cai <quic_qiancai@quicinc.com>] Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2021-06-03iov_iter: Remove iov_iter_for_each_range()David Howells1-4/+0
Remove iov_iter_for_each_range() as it's no longer used with the removal of lustre. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2021-04-26iov_iter: Four fixes for ITER_XARRAYDavid Howells1-1/+0
Fix four things[1] in the patch that adds ITER_XARRAY[2]: (1) Remove the address_space struct predeclaration. This is a holdover from when it was ITER_MAPPING. (2) Fix _copy_mc_to_iter() so that the xarray segment updates count and iov_offset in the iterator before returning. (3) Fix iov_iter_alignment() to not loop in the xarray case. Because the middle pages are all whole pages, only the end pages need be considered - and this can be reduced to just looking at the start position in the xarray and the iteration size. (4) Fix iov_iter_advance() to limit the size of the advance to no more than the remaining iteration size. Reported-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Al Viro <viro@zeniv.linux.org.uk> Tested-by: Jeff Layton <jlayton@redhat.com> Tested-by: Dave Wysochanski <dwysocha@redhat.com> Link: https://lore.kernel.org/r/YIVrJT8GwLI0Wlgx@zeniv-ca.linux.org.uk [1] Link: https://lore.kernel.org/r/161918448151.3145707.11541538916600921083.stgit@warthog.procyon.org.uk [2]
2021-04-23iov_iter: Add ITER_XARRAYDavid Howells1-0/+11
Add an iterator, ITER_XARRAY, that walks through a set of pages attached to an xarray, starting at a given page and offset and walking for the specified amount of bytes. The iterator supports transparent huge pages. The iterate_xarray() macro calls the helper function with rcu_access() helped. I think that this is only a problem for iov_iter_for_each_range() - and that returns an error for ITER_XARRAY (also, this function does not appear to be called). The caller must guarantee that the pages are all present and they must be locked using PG_locked, PG_writeback or PG_fscache to prevent them from going away or being migrated whilst they're being accessed. This is useful for copying data from socket buffers to inodes in network filesystems and for transferring data between those inodes and the cache using direct I/O. Whilst it is true that ITER_BVEC could be used instead, that would require a bio_vec array to be allocated to refer to all the pages - which should be redundant if inode->i_pages also points to all these pages. Note that older versions of this patch implemented an ITER_MAPPING instead, which was almost the same. Changes: v7: - Rename iter_xarray_copy_pages() to iter_xarray_populate_pages()[1]. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-and-tested-by: Jeff Layton <jlayton@kernel.org> Tested-by: Dave Wysochanski <dwysocha@redhat.com> Tested-By: Marc Dionne <marc.dionne@auristor.com> cc: Alexander Viro <viro@zeniv.linux.org.uk> cc: Matthew Wilcox (Oracle) <willy@infradead.org> cc: Christoph Hellwig <hch@lst.de> cc: linux-mm@kvack.org cc: linux-cachefs@redhat.com cc: linux-afs@lists.infradead.org cc: linux-nfs@vger.kernel.org cc: linux-cifs@vger.kernel.org cc: ceph-devel@vger.kernel.org cc: v9fs-developer@lists.sourceforge.net cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/3577430.1579705075@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/158861205740.340223.16592990225607814022.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/159465785214.1376674.6062549291411362531.stgit@warthog.procyon.org.uk/ Link: https://lore.kernel.org/r/160588477334.3465195.3608963255682568730.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/161118129703.1232039.17141248432017826976.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/161161026313.2537118.14676007075365418649.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/161340386671.1303470.10752208972482479840.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/161539527815.286939.14607323792547049341.stgit@warthog.procyon.org.uk/ # v4 Link: https://lore.kernel.org/r/161653786033.2770958.14154191921867463240.stgit@warthog.procyon.org.uk/ # v5 Link: https://lore.kernel.org/r/161789064740.6155.11932541175173658065.stgit@warthog.procyon.org.uk/ # v6 Link: https://lore.kernel.org/r/27c369a8f42bb8a617672b2dc0126a5c6df5a050.camel@kernel.org [1]