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* 9p: Fix DIO read through netfsDominique Martinet2024-08-131-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a program is watching a file on a 9p mount, it won't see any change in size if the file being exported by the server is changed directly in the source filesystem, presumably because 9p doesn't have change notifications, and because netfs skips the reads if the file is empty. Fix this by attempting to read the full size specified when a DIO read is requested (such as when 9p is operating in unbuffered mode) and dealing with a short read if the EOF was less than the expected read. To make this work, filesystems using netfslib must not set NETFS_SREQ_CLEAR_TAIL if performing a DIO read where that read hit the EOF. I don't want to mandatorily clear this flag in netfslib for DIO because, say, ceph might make a read from an object that is not completely filled, but does not reside at the end of file - and so we need to clear the excess. This can be tested by watching an empty file over 9p within a VM (such as in the ktest framework): while true; do read content; if [ -n "$content" ]; then echo $content; break; fi; done < /host/tmp/foo then writing something into the empty file. The watcher should immediately display the file content and break out of the loop. Without this fix, it remains in the loop indefinitely. Fixes: 80105ed2fd27 ("9p: Use netfslib read/write_iter") Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218916 Signed-off-by: David Howells <dhowells@redhat.com> Link: https://lore.kernel.org/r/1229195.1723211769@warthog.procyon.org.uk cc: Eric Van Hensbergen <ericvh@kernel.org> cc: Latchesar Ionkov <lucho@ionkov.net> cc: Christian Schoenebeck <linux_oss@crudebyte.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: Ilya Dryomov <idryomov@gmail.com> cc: Steve French <sfrench@samba.org> cc: Paulo Alcantara <pc@manguebit.com> cc: Trond Myklebust <trond.myklebust@hammerspace.com> cc: v9fs@lists.linux.dev cc: linux-afs@lists.infradead.org cc: ceph-devel@vger.kernel.org cc: linux-cifs@vger.kernel.org cc: linux-nfs@vger.kernel.org cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Dominique Martinet <asmadeus@codewreck.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
* netfs: Fix handling of USE_PGPRIV2 and WRITE_TO_CACHE flagsDavid Howells2024-08-121-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The NETFS_RREQ_USE_PGPRIV2 and NETFS_RREQ_WRITE_TO_CACHE flags aren't used correctly. The problem is that we try to set them up in the request initialisation, but we the cache may be in the process of setting up still, and so the state may not be correct. Further, we secondarily sample the cache state and make contradictory decisions later. The issue arises because we set up the cache resources, which allows the cache's ->prepare_read() to switch on NETFS_SREQ_COPY_TO_CACHE - which triggers cache writing even if we didn't set the flags when allocating. Fix this in the following way: (1) Drop NETFS_ICTX_USE_PGPRIV2 and instead set NETFS_RREQ_USE_PGPRIV2 in ->init_request() rather than trying to juggle that in netfs_alloc_request(). (2) Repurpose NETFS_RREQ_USE_PGPRIV2 to merely indicate that if caching is to be done, then PG_private_2 is to be used rather than only setting it if we decide to cache and then having netfs_rreq_unlock_folios() set the non-PG_private_2 writeback-to-cache if it wasn't set. (3) Split netfs_rreq_unlock_folios() into two functions, one of which contains the deprecated code for using PG_private_2 to avoid accidentally doing the writeback path - and always use it if USE_PGPRIV2 is set. (4) As NETFS_ICTX_USE_PGPRIV2 is removed, make netfs_write_begin() always wait for PG_private_2. This function is deprecated and only used by ceph anyway, and so label it so. (5) Drop the NETFS_RREQ_WRITE_TO_CACHE flag and use fscache_operation_valid() on the cache_resources instead. This has the advantage of picking up the result of netfs_begin_cache_read() and fscache_begin_write_operation() - which are called after the object is initialised and will wait for the cache to come to a usable state. Just reverting ae678317b95e[1] isn't a sufficient fix, so this need to be applied on top of that. Without this as well, things like: rcu: INFO: rcu_sched detected expedited stalls on CPUs/tasks: { and: WARNING: CPU: 13 PID: 3621 at fs/ceph/caps.c:3386 may happen, along with some UAFs due to PG_private_2 not getting used to wait on writeback completion. Fixes: 2ff1e97587f4 ("netfs: Replace PG_fscache by setting folio->private and marking dirty") Reported-by: Max Kellermann <max.kellermann@ionos.com> Signed-off-by: David Howells <dhowells@redhat.com> cc: Ilya Dryomov <idryomov@gmail.com> cc: Xiubo Li <xiubli@redhat.com> cc: Hristo Venev <hristo@venev.name> cc: Jeff Layton <jlayton@kernel.org> cc: Matthew Wilcox <willy@infradead.org> cc: ceph-devel@vger.kernel.org cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org cc: linux-mm@kvack.org Link: https://lore.kernel.org/r/3575457.1722355300@warthog.procyon.org.uk/ [1] Link: https://lore.kernel.org/r/1173209.1723152682@warthog.procyon.org.uk Signed-off-by: Christian Brauner <brauner@kernel.org>
* nfs: remove dead code for the old swap over NFS implementationChristoph Hellwig2024-07-081-1/+1
| | | | | | | | | | Remove the code testing folio_test_swapcache either explicitly or implicitly in pagemap.h headers, as is now handled using the direct I/O path and not the buffered I/O path that these helpers are located in. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
* NFS: Fix nfs_netfs_issue_read() xarray locking for writeback interruptDave Wysochanski2024-03-091-7/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The loop inside nfs_netfs_issue_read() currently does not disable interrupts while iterating through pages in the xarray to submit for NFS read. This is not safe though since after taking xa_lock, another page in the mapping could be processed for writeback inside an interrupt, and deadlock can occur. The fix is simple and clean if we use xa_for_each_range(), which handles the iteration with RCU while reducing code complexity. The problem is easily reproduced with the following test: mount -o vers=3,fsc 127.0.0.1:/export /mnt/nfs dd if=/dev/zero of=/mnt/nfs/file1.bin bs=4096 count=1 echo 3 > /proc/sys/vm/drop_caches dd if=/mnt/nfs/file1.bin of=/dev/null umount /mnt/nfs On the console with a lockdep-enabled kernel a message similar to the following will be seen: ================================ WARNING: inconsistent lock state 6.7.0-lockdbg+ #10 Not tainted -------------------------------- inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage. test5/1708 [HC0[0]:SC0[0]:HE1:SE1] takes: ffff888127baa598 (&xa->xa_lock#4){+.?.}-{3:3}, at: nfs_netfs_issue_read+0x1b2/0x4b0 [nfs] {IN-SOFTIRQ-W} state was registered at: lock_acquire+0x144/0x380 _raw_spin_lock_irqsave+0x4e/0xa0 __folio_end_writeback+0x17e/0x5c0 folio_end_writeback+0x93/0x1b0 iomap_finish_ioend+0xeb/0x6a0 blk_update_request+0x204/0x7f0 blk_mq_end_request+0x30/0x1c0 blk_complete_reqs+0x7e/0xa0 __do_softirq+0x113/0x544 __irq_exit_rcu+0xfe/0x120 irq_exit_rcu+0xe/0x20 sysvec_call_function_single+0x6f/0x90 asm_sysvec_call_function_single+0x1a/0x20 pv_native_safe_halt+0xf/0x20 default_idle+0x9/0x20 default_idle_call+0x67/0xa0 do_idle+0x2b5/0x300 cpu_startup_entry+0x34/0x40 start_secondary+0x19d/0x1c0 secondary_startup_64_no_verify+0x18f/0x19b irq event stamp: 176891 hardirqs last enabled at (176891): [<ffffffffa67a0be4>] _raw_spin_unlock_irqrestore+0x44/0x60 hardirqs last disabled at (176890): [<ffffffffa67a0899>] _raw_spin_lock_irqsave+0x79/0xa0 softirqs last enabled at (176646): [<ffffffffa515d91e>] __irq_exit_rcu+0xfe/0x120 softirqs last disabled at (176633): [<ffffffffa515d91e>] __irq_exit_rcu+0xfe/0x120 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&xa->xa_lock#4); <Interrupt> lock(&xa->xa_lock#4); *** DEADLOCK *** 2 locks held by test5/1708: #0: ffff888127baa498 (&sb->s_type->i_mutex_key#22){++++}-{4:4}, at: nfs_start_io_read+0x28/0x90 [nfs] #1: ffff888127baa650 (mapping.invalidate_lock#3){.+.+}-{4:4}, at: page_cache_ra_unbounded+0xa4/0x280 stack backtrace: CPU: 6 PID: 1708 Comm: test5 Kdump: loaded Not tainted 6.7.0-lockdbg+ Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-1.fc39 04/01/2014 Call Trace: dump_stack_lvl+0x5b/0x90 mark_lock+0xb3f/0xd20 __lock_acquire+0x77b/0x3360 _raw_spin_lock+0x34/0x80 nfs_netfs_issue_read+0x1b2/0x4b0 [nfs] netfs_begin_read+0x77f/0x980 [netfs] nfs_netfs_readahead+0x45/0x60 [nfs] nfs_readahead+0x323/0x5a0 [nfs] read_pages+0xf3/0x5c0 page_cache_ra_unbounded+0x1c8/0x280 filemap_get_pages+0x38c/0xae0 filemap_read+0x206/0x5e0 nfs_file_read+0xb7/0x140 [nfs] vfs_read+0x2a9/0x460 ksys_read+0xb7/0x140 Fixes: 000dbe0bec05 ("NFS: Convert buffered read paths to use netfs when fscache is enabled") Suggested-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Dave Wysochanski <dwysocha@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
* netfs, fscache: Remove ->begin_cache_operationDavid Howells2023-12-241-7/+0
| | | | | | | | | | Remove ->begin_cache_operation() in favour of just calling fscache directly. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: Christian Brauner <christian@brauner.io> cc: linux-fsdevel@vger.kernel.org cc: linux-cachefs@redhat.com
* mm, netfs, fscache: stop read optimisation when folio removed from pagecacheDavid Howells2023-08-181-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fscache has an optimisation by which reads from the cache are skipped until we know that (a) there's data there to be read and (b) that data isn't entirely covered by pages resident in the netfs pagecache. This is done with two flags manipulated by fscache_note_page_release(): if (... test_bit(FSCACHE_COOKIE_HAVE_DATA, &cookie->flags) && test_bit(FSCACHE_COOKIE_NO_DATA_TO_READ, &cookie->flags)) clear_bit(FSCACHE_COOKIE_NO_DATA_TO_READ, &cookie->flags); where the NO_DATA_TO_READ flag causes cachefiles_prepare_read() to indicate that netfslib should download from the server or clear the page instead. The fscache_note_page_release() function is intended to be called from ->releasepage() - but that only gets called if PG_private or PG_private_2 is set - and currently the former is at the discretion of the network filesystem and the latter is only set whilst a page is being written to the cache, so sometimes we miss clearing the optimisation. Fix this by following Willy's suggestion[1] and adding an address_space flag, AS_RELEASE_ALWAYS, that causes filemap_release_folio() to always call ->release_folio() if it's set, even if PG_private or PG_private_2 aren't set. Note that this would require folio_test_private() and page_has_private() to become more complicated. To avoid that, in the places[*] where these are used to conditionalise calls to filemap_release_folio() and try_to_release_page(), the tests are removed the those functions just jumped to unconditionally and the test is performed there. [*] There are some exceptions in vmscan.c where the check guards more than just a call to the releaser. I've added a function, folio_needs_release() to wrap all the checks for that. AS_RELEASE_ALWAYS should be set if a non-NULL cookie is obtained from fscache and cleared in ->evict_inode() before truncate_inode_pages_final() is called. Additionally, the FSCACHE_COOKIE_NO_DATA_TO_READ flag needs to be cleared and the optimisation cancelled if a cachefiles object already contains data when we open it. [dwysocha@redhat.com: call folio_mapping() inside folio_needs_release()] Link: https://github.com/DaveWysochanskiRH/kernel/commit/902c990e311120179fa5de99d68364b2947b79ec Link: https://lkml.kernel.org/r/20230628104852.3391651-3-dhowells@redhat.com Fixes: 1f67e6d0b188 ("fscache: Provide a function to note the release of a page") Fixes: 047487c947e8 ("cachefiles: Implement the I/O routines") Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Dave Wysochanski <dwysocha@redhat.com> Reported-by: Rohith Surabattula <rohiths.msft@gmail.com> Suggested-by: Matthew Wilcox <willy@infradead.org> Tested-by: SeongJae Park <sj@kernel.org> Cc: Daire Byrne <daire.byrne@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Steve French <sfrench@samba.org> Cc: Shyam Prasad N <nspmangalore@gmail.com> Cc: Rohith Surabattula <rohiths.msft@gmail.com> Cc: Dave Wysochanski <dwysocha@redhat.com> Cc: Dominique Martinet <asmadeus@codewreck.org> Cc: Ilya Dryomov <idryomov@gmail.com> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Jingbo Xu <jefflexu@linux.alibaba.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Xiubo Li <xiubli@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* NFS: set varaiable nfs_netfs_debug_id storage-class-specifier to staticTom Rix2023-04-211-1/+1
| | | | | | | | | | | smatch reports fs/nfs/fscache.c:260:10: warning: symbol 'nfs_netfs_debug_id' was not declared. Should it be static? This variable is only used in its defining file, so it should be static Signed-off-by: Tom Rix <trix@redhat.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
* NFS: Convert buffered read paths to use netfs when fscache is enabledDave Wysochanski2023-04-111-87/+135
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Convert the NFS buffered read code paths to corresponding netfs APIs, but only when fscache is configured and enabled. The netfs API defines struct netfs_request_ops which must be filled in by the network filesystem. For NFS, we only need to define 5 of the functions, the main one being the issue_read() function. The issue_read() function is called by the netfs layer when a read cannot be fulfilled locally, and must be sent to the server (either the cache is not active, or it is active but the data is not available). Once the read from the server is complete, netfs requires a call to netfs_subreq_terminated() which conveys either how many bytes were read successfully, or an error. Note that issue_read() is called with a structure, netfs_io_subrequest, which defines the IO requested, and contains a start and a length (both in bytes), and assumes the underlying netfs will return a either an error on the whole region, or the number of bytes successfully read. The NFS IO path is page based and the main APIs are the pgio APIs defined in pagelist.c. For the pgio APIs, there is no way for the caller to know how many RPCs will be sent and how the pages will be broken up into underlying RPCs, each of which will have their own completion and return code. In contrast, netfs is subrequest based, a single subrequest may contain multiple pages, and a single subrequest is initiated with issue_read() and terminated with netfs_subreq_terminated(). Thus, to utilze the netfs APIs, NFS needs some way to accommodate the netfs API requirement on the single response to the whole subrequest, while also minimizing disruptive changes to the NFS pgio layer. The approach taken with this patch is to allocate a small structure for each nfs_netfs_issue_read() call, store the final error and number of bytes successfully transferred in the structure, and update these values as each RPC completes. The refcount on the structure is used as a marker for the last RPC completion, is incremented in nfs_netfs_read_initiate(), and decremented inside nfs_netfs_read_completion(), when a nfs_pgio_header contains a valid pointer to the data. On the final put (which signals the final outstanding RPC is complete) in nfs_netfs_read_completion(), call netfs_subreq_terminated() with either the final error value (if one or more READs complete with an error) or the number of bytes successfully transferred (if all RPCs complete successfully). Note that when all RPCs complete successfully, the number of bytes transferred is capped to the length of the subrequest. Capping the transferred length to the subrequest length prevents "Subreq overread" warnings from netfs. This is due to the "aligned_len" in nfs_pageio_add_page(), and the corner case where NFS requests a full page at the end of the file, even when i_size reflects only a partial page (NFS overread). Signed-off-by: Dave Wysochanski <dwysocha@redhat.com> Tested-by: Daire Byrne <daire@dneg.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
* NFS: Configure support for netfs when NFS fscache is configuredDave Wysochanski2023-04-111-11/+9
| | | | | | | | | | | | | | | | | | | | | As first steps for support of the netfs library when NFS_FSCACHE is configured, add NETFS_SUPPORT to Kconfig and add the required netfs_inode into struct nfs_inode. Using netfs requires we move the VFS inode structure to be stored inside struct netfs_inode, along with the fscache_cookie. Thus, if NFS_FSCACHE is configured, place netfs_inode inside an anonymous union so the vfs_inode memory is the same and we do not need to modify other non-fscache areas of NFS. In addition, inside the NFS fscache code, use the new helpers, netfs_inode() and netfs_i_cookie() helpers, and remove our own helper, nfs_i_fscache(). Later patches will convert NFS fscache to fully use netfs. Signed-off-by: Dave Wysochanski <dwysocha@redhat.com> Tested-by: Daire Byrne <daire@dneg.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
* nfs: use bvec_set_page to initialize bvecsChristoph Hellwig2023-02-031-10/+6
| | | | | | | | | Use the bvec_set_page helper to initialize bvecs. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Trond Myklebust <trond.myklebust@hammerspace.com> Link: https://lore.kernel.org/r/20230203150634.3199647-16-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
* use less confusing names for iov_iter direction initializersAl Viro2022-11-251-2/+2
| | | | | | | | | | | | | 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>
* NFS: Pass i_size to fscache_unuse_cookie() when a file is releasedDave Wysochanski2022-05-171-4/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pass updated i_size in fscache_unuse_cookie() when called from nfs_fscache_release_file(), which ensures the size of an fscache object gets written to the cache storage. Failing to do so results in unnessary reads from the NFS server, even when the data is cached, due to a cachefiles object coherency check failing with a trace similar to the following: cachefiles_coherency: o=0000000e BAD osiz B=afbb3 c=0 This problem can be reproduced as follows: #!/bin/bash v=4.2; NFS_SERVER=127.0.0.1 set -e; trap cleanup EXIT; rc=1 function cleanup { umount /mnt/nfs > /dev/null 2>&1 RC_STR="TEST PASS" [ $rc -eq 1 ] && RC_STR="TEST FAIL" echo "$RC_STR on $(uname -r) with NFSv$v and server $NFS_SERVER" } mount -o vers=$v,fsc $NFS_SERVER:/export /mnt/nfs rm -f /mnt/nfs/file1.bin > /dev/null 2>&1 dd if=/dev/zero of=/mnt/nfs/file1.bin bs=4096 count=1 > /dev/null 2>&1 echo 3 > /proc/sys/vm/drop_caches echo Read file 1st time from NFS server into fscache dd if=/mnt/nfs/file1.bin of=/dev/null > /dev/null 2>&1 umount /mnt/nfs && mount -o vers=$v,fsc $NFS_SERVER:/export /mnt/nfs echo 3 > /proc/sys/vm/drop_caches echo Read file 2nd time from fscache dd if=/mnt/nfs/file1.bin of=/dev/null > /dev/null 2>&1 echo Check mountstats for NFS read grep -q "READ: 0" /proc/self/mountstats # (1st number) == 0 [ $? -eq 0 ] && rc=0 Fixes: a6b5a28eb56c "nfs: Convert to new fscache volume/cookie API" Signed-off-by: Dave Wysochanski <dwysocha@redhat.com> Tested-by: Daire Byrne <daire@dneg.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
* Merge tag 'netfs-prep-20220318' of ↵Linus Torvalds2022-04-011-8/+0
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs Pull netfs updates from David Howells: "Netfs prep for write helpers. Having had a go at implementing write helpers and content encryption support in netfslib, it seems that the netfs_read_{,sub}request structs and the equivalent write request structs were almost the same and so should be merged, thereby requiring only one set of alloc/get/put functions and a common set of tracepoints. Merging the structs also has the advantage that if a bounce buffer is added to the request struct, a read operation can be performed to fill the bounce buffer, the contents of the buffer can be modified and then a write operation can be performed on it to send the data wherever it needs to go using the same request structure all the way through. The I/O handlers would then transparently perform any required crypto. This should make it easier to perform RMW cycles if needed. The potentially common functions and structs, however, by their names all proclaim themselves to be associated with the read side of things. The bulk of these changes alter this in the following ways: - Rename struct netfs_read_{,sub}request to netfs_io_{,sub}request. - Rename some enums, members and flags to make them more appropriate. - Adjust some comments to match. - Drop "read"/"rreq" from the names of common functions. For instance, netfs_get_read_request() becomes netfs_get_request(). - The ->init_rreq() and ->issue_op() methods become ->init_request() and ->issue_read(). I've kept the latter as a read-specific function and in another branch added an ->issue_write() method. The driver source is then reorganised into a number of files: fs/netfs/buffered_read.c Create read reqs to the pagecache fs/netfs/io.c Dispatchers for read and write reqs fs/netfs/main.c Some general miscellaneous bits fs/netfs/objects.c Alloc, get and put functions fs/netfs/stats.c Optional procfs statistics. and future development can be fitted into this scheme, e.g.: fs/netfs/buffered_write.c Modify the pagecache fs/netfs/buffered_flush.c Writeback from the pagecache fs/netfs/direct_read.c DIO read support fs/netfs/direct_write.c DIO write support fs/netfs/unbuffered_write.c Write modifications directly back Beyond the above changes, there are also some changes that affect how things work: - Make fscache_end_operation() generally available. - In the netfs tracing header, generate enums from the symbol -> string mapping tables rather than manually coding them. - Add a struct for filesystems that uses netfslib to put into their inode wrapper structs to hold extra state that netfslib is interested in, such as the fscache cookie. This allows netfslib functions to be set in filesystem operation tables and jumped to directly without having to have a filesystem wrapper. - Add a member to the struct added above to track the remote inode length as that may differ if local modifications are buffered. We may need to supply an appropriate EOF pointer when storing data (in AFS for example). - Pass extra information to netfs_alloc_request() so that the ->init_request() hook can access it and retain information to indicate the origin of the operation. - Make the ->init_request() hook return an error, thereby allowing a filesystem that isn't allowed to cache an inode (ceph or cifs, for example) to skip readahead. - Switch to using refcount_t for subrequests and add tracepoints to log refcount changes for the request and subrequest structs. - Add a function to consolidate dispatching a read request. Similar code is used in three places and another couple are likely to be added in the future" Link: https://lore.kernel.org/all/2639515.1648483225@warthog.procyon.org.uk/ * tag 'netfs-prep-20220318' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: afs: Maintain netfs_i_context::remote_i_size netfs: Keep track of the actual remote file size netfs: Split some core bits out into their own file netfs: Split fs/netfs/read_helper.c netfs: Rename read_helper.c to io.c netfs: Prepare to split read_helper.c netfs: Add a function to consolidate beginning a read netfs: Add a netfs inode context ceph: Make ceph_init_request() check caps on readahead netfs: Change ->init_request() to return an error code netfs: Refactor arguments for netfs_alloc_read_request netfs: Adjust the netfs_failure tracepoint to indicate non-subreq lines netfs: Trace refcounting on the netfs_io_subrequest struct netfs: Trace refcounting on the netfs_io_request struct netfs: Adjust the netfs_rreq tracepoint slightly netfs: Split netfs_io_* object handling out netfs: Finish off rename of netfs_read_request to netfs_io_request netfs: Rename netfs_read_*request to netfs_io_*request netfs: Generate enums from trace symbol mapping lists fscache: export fscache_end_operation()
| * fscache: export fscache_end_operation()Jeffle Xu2022-03-181-8/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Export fscache_end_operation() to avoid code duplication. Besides, considering the paired fscache_begin_read_operation() is already exported, it shall make sense to also export fscache_end_operation(). Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/20220302125134.131039-2-jefflexu@linux.alibaba.com/ # Jeffle's v4 Link: https://lore.kernel.org/r/164622971432.3564931.12184135678781328146.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/164678190346.1200972.7453733431978569479.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/164692888334.2099075.5166283293894267365.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/20220316131723.111553-2-jefflexu@linux.alibaba.com/ # v5
* | NFS: Remove remaining dfprintks related to fscache and remove NFSDBG_FSCACHEDave Wysochanski2022-03-131-10/+0
| | | | | | | | | | | | | | | | | | | | | | | | The fscache cookie APIs including fscache_acquire_cookie() and fscache_relinquish_cookie() now have very good tracing. Thus, there is no real need for dfprintks in the NFS fscache interface. The NFS fscache interface has removed all dfprintks so remove the NFSDBG_FSCACHE defines. Signed-off-by: Dave Wysochanski <dwysocha@redhat.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
* | NFS: Replace dfprintks with tracepoints in fscache read and write page functionsDave Wysochanski2022-03-131-18/+11
| | | | | | | | | | | | | | | | | | Most of fscache and other NFS IO paths are now using tracepoints. Remove the dfprintks in the NFS fscache read/write page functions and replace with tracepoints at the begin and end of the functions. Signed-off-by: Dave Wysochanski <dwysocha@redhat.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
* | NFS: Rename fscache read and write pages functionsDave Wysochanski2022-03-131-3/+3
| | | | | | | | | | | | | | | | Rename NFS fscache functions in a more consistent fashion to better reflect when we read from and write to fscache. Signed-off-by: Dave Wysochanski <dwysocha@redhat.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
* | NFS: Cleanup usage of nfs_inode in fscache interfaceDave Wysochanski2022-03-131-6/+4
|/ | | | | | | | A number of places in the fscache interface used nfs_inode when inode could be used, simplifying the code. Signed-off-by: Dave Wysochanski <dwysocha@redhat.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
* nfs: Implement cache I/O by accessing the cache directlyDavid Howells2022-01-101-23/+103
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move NFS to using fscache DIO API instead of the old upstream I/O API as that has been removed. This is a stopgap solution as the intention is that at sometime in the future, the cache will move to using larger blocks and won't be able to store individual pages in order to deal with the potential for data corruption due to the backing filesystem being able insert/remove bridging blocks of zeros into its extent list[1]. NFS then reads and writes cache pages synchronously and one page at a time. The preferred change would be to use the netfs lib, but the new I/O API can be used directly. It's just that as the cache now needs to track data for itself, caching blocks may exceed page size... This code is somewhat borrowed from my "fallback I/O" patchset[2]. Changes ======= ver #3: - Restore lost =n fallback for nfs_fscache_release_page()[2]. Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Dave Wysochanski <dwysocha@redhat.com> Acked-by: Jeff Layton <jlayton@kernel.org> cc: Trond Myklebust <trond.myklebust@hammerspace.com> cc: Anna Schumaker <anna.schumaker@netapp.com> cc: linux-nfs@vger.kernel.org cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/YO17ZNOcq+9PajfQ@mit.edu [1] Link: https://lore.kernel.org/r/202112100957.2oEDT20W-lkp@intel.com/ [2] Link: https://lore.kernel.org/r/163189108292.2509237.12615909591150927232.stgit@warthog.procyon.org.uk/ [2] Link: https://lore.kernel.org/r/163906981318.143852.17220018647843475985.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/163967184451.1823006.6450645559828329590.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/164021577632.640689.11069627070150063812.stgit@warthog.procyon.org.uk/ # v4
* nfs: Convert to new fscache volume/cookie APIDave Wysochanski2022-01-101-329/+105
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change the nfs filesystem to support fscache's indexing rewrite and reenable caching in nfs. The following changes have been made: (1) The fscache_netfs struct is no more, and there's no need to register the filesystem as a whole. (2) The session cookie is now an fscache_volume cookie, allocated with fscache_acquire_volume(). That takes three parameters: a string representing the "volume" in the index, a string naming the cache to use (or NULL) and a u64 that conveys coherency metadata for the volume. For nfs, I've made it render the volume name string as: "nfs,<ver>,<family>,<address>,<port>,<fsidH>,<fsidL>*<,param>[,<uniq>]" (3) The fscache_cookie_def is no more and needed information is passed directly to fscache_acquire_cookie(). The cache no longer calls back into the filesystem, but rather metadata changes are indicated at other times. fscache_acquire_cookie() is passed the same keying and coherency information as before. (4) fscache_enable/disable_cookie() have been removed. Call fscache_use_cookie() and fscache_unuse_cookie() when a file is opened or closed to prevent a cache file from being culled and to keep resources to hand that are needed to do I/O. If a file is opened for writing, we invalidate it with FSCACHE_INVAL_DIO_WRITE in lieu of doing writeback to the cache, thereby making it cease caching until all currently open files are closed. This should give the same behaviour as the uptream code. Making the cache store local modifications isn't straightforward for NFS, so that's left for future patches. (5) fscache_invalidate() now needs to be given uptodate auxiliary data and a file size. It also takes a flag to indicate if this was due to a DIO write. (6) Call nfs_fscache_invalidate() with FSCACHE_INVAL_DIO_WRITE on a file to which a DIO write is made. (7) Call fscache_note_page_release() from nfs_release_page(). (8) Use a killable wait in nfs_vm_page_mkwrite() when waiting for PG_fscache to be cleared. (9) The functions to read and write data to/from the cache are stubbed out pending a conversion to use netfslib. Changes ======= ver #3: - Added missing =n fallback for nfs_fscache_release_file()[1][2]. ver #2: - Use gfpflags_allow_blocking() rather than using flag directly. - fscache_acquire_volume() now returns errors. - Remove NFS_INO_FSCACHE as it's no longer used. - Need to unuse a cookie on file-release, not inode-clear. Signed-off-by: Dave Wysochanski <dwysocha@redhat.com> Co-developed-by: David Howells <dhowells@redhat.com> Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Dave Wysochanski <dwysocha@redhat.com> Acked-by: Jeff Layton <jlayton@kernel.org> cc: Trond Myklebust <trond.myklebust@hammerspace.com> cc: Anna Schumaker <anna.schumaker@netapp.com> cc: linux-nfs@vger.kernel.org cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/202112100804.nksO8K4u-lkp@intel.com/ [1] Link: https://lore.kernel.org/r/202112100957.2oEDT20W-lkp@intel.com/ [2] Link: https://lore.kernel.org/r/163819668938.215744.14448852181937731615.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/163906979003.143852.2601189243864854724.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/163967182112.1823006.7791504655391213379.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/164021575950.640689.12069642327533368467.stgit@warthog.procyon.org.uk/ # v4
* NFS: Fix fscache read from NFS after cache errorDave Wysochanski2021-07-081-5/+13
| | | | | | | | | | | | | | | | | | | Earlier commits refactored some NFS read code and removed nfs_readpage_async(), but neglected to properly fixup nfs_readpage_from_fscache_complete(). The code path is only hit when something unusual occurs with the cachefiles backing filesystem, such as an IO error or while a cookie is being invalidated. Mark page with PG_checked if fscache IO completes in error, unlock the page, and let the VM decide to re-issue based on PG_uptodate. When the VM reissues the readpage, PG_checked allows us to skip over fscache and read from the server. Link: https://marc.info/?l=linux-nfs&m=162498209518739 Fixes: 1e83b173b266 ("NFS: Add nfs_pageio_complete_read() and remove nfs_readpage_async()") Signed-off-by: Dave Wysochanski <dwysocha@redhat.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
* NFS: Add nfs_pageio_complete_read() and remove nfs_readpage_async()Dave Wysochanski2021-02-011-4/+0
| | | | | | | | | Add nfs_pageio_complete_read() and call this from both nfs_readpage() and nfs_readpages(), since the submission and accounting is the same for both functions. Signed-off-by: Dave Wysochanski <dwysocha@redhat.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
* NFSv4: Fix fscache cookie aux_data to ensure change_attr is includedDave Wysochanski2020-05-081-18/+16
| | | | | | | | | | | | | | | | | | | | Commit 402cb8dda949 ("fscache: Attach the index key and aux data to the cookie") added the aux_data and aux_data_len to parameters to fscache_acquire_cookie(), and updated the callers in the NFS client. In the process it modified the aux_data to include the change_attr, but missed adding change_attr to a couple places where aux_data was used. Specifically, when opening a file and the change_attr is not added, the following attempt to lookup an object will fail inside cachefiles_check_object_xattr() = -116 due to nfs_fscache_inode_check_aux() failing memcmp on auxdata and returning FSCACHE_CHECKAUX_OBSOLETE. Fix this by adding nfs_fscache_update_auxdata() to set the auxdata from all relevant fields in the inode, including the change_attr. Fixes: 402cb8dda949 ("fscache: Attach the index key and aux data to the cookie") Signed-off-by: Dave Wysochanski <dwysocha@redhat.com> Signed-off-by: David Howells <dhowells@redhat.com>
* NFS: Fix fscache super_cookie allocationDave Wysochanski2020-05-081-2/+0
| | | | | | | | | | | | | | | | Commit f2aedb713c28 ("NFS: Add fs_context support.") reworked NFS mount code paths for fs_context support which included super_block initialization. In the process there was an extra return left in the code and so we never call nfs_fscache_get_super_cookie even if 'fsc' is given on as mount option. In addition, there is an extra check inside nfs_fscache_get_super_cookie for the NFS_OPTION_FSCACHE which is unnecessary since the only caller nfs_get_cache_cookie checks this flag. Fixes: f2aedb713c28 ("NFS: Add fs_context support.") Signed-off-by: Dave Wysochanski <dwysocha@redhat.com> Signed-off-by: David Howells <dhowells@redhat.com>
* NFS: Fix fscache super_cookie index_key from changing after umountDave Wysochanski2020-05-081-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 402cb8dda949 ("fscache: Attach the index key and aux data to the cookie") added the index_key and index_key_len parameters to fscache_acquire_cookie(), and updated the callers in the NFS client. One of the callers was inside nfs_fscache_get_super_cookie() and was changed to use the full struct nfs_fscache_key as the index_key. However, a couple members of this structure contain pointers and thus will change each time the same NFS share is remounted. Since index_key is used for fscache_cookie->key_hash and this subsequently is used to compare cookies, the effectiveness of fscache with NFS is reduced to the point at which a umount occurs. Any subsequent remount of the same share will cause a unique NFS super_block index_key and key_hash to be generated for the same data, rendering any prior fscache data unable to be found. A simple reproducer demonstrates the problem. 1. Mount share with 'fsc', create a file, drop page cache systemctl start cachefilesd mount -o vers=3,fsc 127.0.0.1:/export /mnt dd if=/dev/zero of=/mnt/file1.bin bs=4096 count=1 echo 3 > /proc/sys/vm/drop_caches 2. Read file into page cache and fscache, then unmount dd if=/mnt/file1.bin of=/dev/null bs=4096 count=1 umount /mnt 3. Remount and re-read which should come from fscache mount -o vers=3,fsc 127.0.0.1:/export /mnt echo 3 > /proc/sys/vm/drop_caches dd if=/mnt/file1.bin of=/dev/null bs=4096 count=1 4. Check for READ ops in mountstats - there should be none grep READ: /proc/self/mountstats Looking at the history and the removed function, nfs_super_get_key(), we should only use nfs_fscache_key.key plus any uniquifier, for the fscache index_key. Fixes: 402cb8dda949 ("fscache: Attach the index key and aux data to the cookie") Signed-off-by: Dave Wysochanski <dwysocha@redhat.com> Signed-off-by: David Howells <dhowells@redhat.com>
* nfs: add minor version to nfs_server_key for fscacheScott Mayhew2020-02-251-0/+2
| | | | | | | | | | | | | | | | An NFS client that mounts multiple exports from the same NFS server with higher NFSv4 versions disabled (i.e. 4.2) and without forcing a specific NFS version results in fscache index cookie collisions and the following messages: [ 570.004348] FS-Cache: Duplicate cookie detected Each nfs_client structure should have its own fscache index cookie, so add the minorversion to nfs_server_key. Link: https://bugzilla.kernel.org/show_bug.cgi?id=200145 Signed-off-by: Scott Mayhew <smayhew@redhat.com> Signed-off-by: Dave Wysochanski <dwysocha@redhat.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
* nfs: fscache: use timespec64 in inode auxdataArnd Bergmann2020-01-151-6/+12
| | | | | | | | | | | | | | | | | | | | | nfs currently behaves differently on 32-bit and 64-bit kernels regarding the on-disk format of nfs_fscache_inode_auxdata. That format should really be the same on any kernel, and we should avoid the 'timespec' type in order to remove that from the kernel later on. Using plain 'timespec64' would not be good here, since that includes implied padding and would possibly leak kernel stack data to the on-disk format on 32-bit architectures. struct __kernel_timespec would work as a replacement, but open-coding the two struct members in nfs_fscache_inode_auxdata makes it more obvious what's going on here, and keeps the current format for 64-bit architectures. Cc: David Howells <dhowells@redhat.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
* NFS: Additional refactoring for fs_context conversionScott Mayhew2020-01-151-1/+1
| | | | | | | | | | | | | | | | Split out from commit "NFS: Add fs_context support." This patch adds additional refactoring for the conversion of NFS to use fs_context, namely: (*) Merge nfs_mount_info and nfs_clone_mount into nfs_fs_context. nfs_clone_mount has had several fields removed, and nfs_mount_info has been removed altogether. (*) Various functions now take an fs_context as an argument instead of nfs_mount_info, nfs_fs_context, etc. Signed-off-by: Scott Mayhew <smayhew@redhat.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
* NFS: Fix regression whereby fscache errors are appearing on 'nofsc' mountsTrond Myklebust2019-08-051-1/+6
| | | | | | | | | | | | | | | | | | People are reporing seeing fscache errors being reported concerning duplicate cookies even in cases where they are not setting up fscache at all. The rule needs to be that if fscache is not enabled, then it should have no side effects at all. To ensure this is the case, we disable fscache completely on all superblocks for which the 'fsc' mount option was not set. In order to avoid issues with '-oremount', we also disable the ability to turn fscache on via remount. Fixes: f1fe29b4a02d ("NFS: Use i_writecount to control whether...") Link: https://bugzilla.kernel.org/show_bug.cgi?id=200145 Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Steve Dickson <steved@redhat.com> Cc: David Howells <dhowells@redhat.com>
* treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 36Thomas Gleixner2019-05-241-5/+1
| | | | | | | | | | | | | | | | | | | | | | Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public licence as published by the free software foundation either version 2 of the licence or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 114 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190520170857.552531963@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* vfs: change inode times to use struct timespec64Deepa Dinamani2018-06-061-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | struct timespec is not y2038 safe. Transition vfs to use y2038 safe struct timespec64 instead. The change was made with the help of the following cocinelle script. This catches about 80% of the changes. All the header file and logic changes are included in the first 5 rules. The rest are trivial substitutions. I avoid changing any of the function signatures or any other filesystem specific data structures to keep the patch simple for review. The script can be a little shorter by combining different cases. But, this version was sufficient for my usecase. virtual patch @ depends on patch @ identifier now; @@ - struct timespec + struct timespec64 current_time ( ... ) { - struct timespec now = current_kernel_time(); + struct timespec64 now = current_kernel_time64(); ... - return timespec_trunc( + return timespec64_trunc( ... ); } @ depends on patch @ identifier xtime; @@ struct \( iattr \| inode \| kstat \) { ... - struct timespec xtime; + struct timespec64 xtime; ... } @ depends on patch @ identifier t; @@ struct inode_operations { ... int (*update_time) (..., - struct timespec t, + struct timespec64 t, ...); ... } @ depends on patch @ identifier t; identifier fn_update_time =~ "update_time$"; @@ fn_update_time (..., - struct timespec *t, + struct timespec64 *t, ...) { ... } @ depends on patch @ identifier t; @@ lease_get_mtime( ... , - struct timespec *t + struct timespec64 *t ) { ... } @te depends on patch forall@ identifier ts; local idexpression struct inode *inode_node; identifier i_xtime =~ "^i_[acm]time$"; identifier ia_xtime =~ "^ia_[acm]time$"; identifier fn_update_time =~ "update_time$"; identifier fn; expression e, E3; local idexpression struct inode *node1; local idexpression struct inode *node2; local idexpression struct iattr *attr1; local idexpression struct iattr *attr2; local idexpression struct iattr attr; identifier i_xtime1 =~ "^i_[acm]time$"; identifier i_xtime2 =~ "^i_[acm]time$"; identifier ia_xtime1 =~ "^ia_[acm]time$"; identifier ia_xtime2 =~ "^ia_[acm]time$"; @@ ( ( - struct timespec ts; + struct timespec64 ts; | - struct timespec ts = current_time(inode_node); + struct timespec64 ts = current_time(inode_node); ) <+... when != ts ( - timespec_equal(&inode_node->i_xtime, &ts) + timespec64_equal(&inode_node->i_xtime, &ts) | - timespec_equal(&ts, &inode_node->i_xtime) + timespec64_equal(&ts, &inode_node->i_xtime) | - timespec_compare(&inode_node->i_xtime, &ts) + timespec64_compare(&inode_node->i_xtime, &ts) | - timespec_compare(&ts, &inode_node->i_xtime) + timespec64_compare(&ts, &inode_node->i_xtime) | ts = current_time(e) | fn_update_time(..., &ts,...) | inode_node->i_xtime = ts | node1->i_xtime = ts | ts = inode_node->i_xtime | <+... attr1->ia_xtime ...+> = ts | ts = attr1->ia_xtime | ts.tv_sec | ts.tv_nsec | btrfs_set_stack_timespec_sec(..., ts.tv_sec) | btrfs_set_stack_timespec_nsec(..., ts.tv_nsec) | - ts = timespec64_to_timespec( + ts = ... -) | - ts = ktime_to_timespec( + ts = ktime_to_timespec64( ...) | - ts = E3 + ts = timespec_to_timespec64(E3) | - ktime_get_real_ts(&ts) + ktime_get_real_ts64(&ts) | fn(..., - ts + timespec64_to_timespec(ts) ,...) ) ...+> ( <... when != ts - return ts; + return timespec64_to_timespec(ts); ...> ) | - timespec_equal(&node1->i_xtime1, &node2->i_xtime2) + timespec64_equal(&node1->i_xtime2, &node2->i_xtime2) | - timespec_equal(&node1->i_xtime1, &attr2->ia_xtime2) + timespec64_equal(&node1->i_xtime2, &attr2->ia_xtime2) | - timespec_compare(&node1->i_xtime1, &node2->i_xtime2) + timespec64_compare(&node1->i_xtime1, &node2->i_xtime2) | node1->i_xtime1 = - timespec_trunc(attr1->ia_xtime1, + timespec64_trunc(attr1->ia_xtime1, ...) | - attr1->ia_xtime1 = timespec_trunc(attr2->ia_xtime2, + attr1->ia_xtime1 = timespec64_trunc(attr2->ia_xtime2, ...) | - ktime_get_real_ts(&attr1->ia_xtime1) + ktime_get_real_ts64(&attr1->ia_xtime1) | - ktime_get_real_ts(&attr.ia_xtime1) + ktime_get_real_ts64(&attr.ia_xtime1) ) @ depends on patch @ struct inode *node; struct iattr *attr; identifier fn; identifier i_xtime =~ "^i_[acm]time$"; identifier ia_xtime =~ "^ia_[acm]time$"; expression e; @@ ( - fn(node->i_xtime); + fn(timespec64_to_timespec(node->i_xtime)); | fn(..., - node->i_xtime); + timespec64_to_timespec(node->i_xtime)); | - e = fn(attr->ia_xtime); + e = fn(timespec64_to_timespec(attr->ia_xtime)); ) @ depends on patch forall @ struct inode *node; struct iattr *attr; identifier i_xtime =~ "^i_[acm]time$"; identifier ia_xtime =~ "^ia_[acm]time$"; identifier fn; @@ { + struct timespec ts; <+... ( + ts = timespec64_to_timespec(node->i_xtime); fn (..., - &node->i_xtime, + &ts, ...); | + ts = timespec64_to_timespec(attr->ia_xtime); fn (..., - &attr->ia_xtime, + &ts, ...); ) ...+> } @ depends on patch forall @ struct inode *node; struct iattr *attr; struct kstat *stat; identifier ia_xtime =~ "^ia_[acm]time$"; identifier i_xtime =~ "^i_[acm]time$"; identifier xtime =~ "^[acm]time$"; identifier fn, ret; @@ { + struct timespec ts; <+... ( + ts = timespec64_to_timespec(node->i_xtime); ret = fn (..., - &node->i_xtime, + &ts, ...); | + ts = timespec64_to_timespec(node->i_xtime); ret = fn (..., - &node->i_xtime); + &ts); | + ts = timespec64_to_timespec(attr->ia_xtime); ret = fn (..., - &attr->ia_xtime, + &ts, ...); | + ts = timespec64_to_timespec(attr->ia_xtime); ret = fn (..., - &attr->ia_xtime); + &ts); | + ts = timespec64_to_timespec(stat->xtime); ret = fn (..., - &stat->xtime); + &ts); ) ...+> } @ depends on patch @ struct inode *node; struct inode *node2; identifier i_xtime1 =~ "^i_[acm]time$"; identifier i_xtime2 =~ "^i_[acm]time$"; identifier i_xtime3 =~ "^i_[acm]time$"; struct iattr *attrp; struct iattr *attrp2; struct iattr attr ; identifier ia_xtime1 =~ "^ia_[acm]time$"; identifier ia_xtime2 =~ "^ia_[acm]time$"; struct kstat *stat; struct kstat stat1; struct timespec64 ts; identifier xtime =~ "^[acmb]time$"; expression e; @@ ( ( node->i_xtime2 \| attrp->ia_xtime2 \| attr.ia_xtime2 \) = node->i_xtime1 ; | node->i_xtime2 = \( node2->i_xtime1 \| timespec64_trunc(...) \); | node->i_xtime2 = node->i_xtime1 = node->i_xtime3 = \(ts \| current_time(...) \); | node->i_xtime1 = node->i_xtime3 = \(ts \| current_time(...) \); | stat->xtime = node2->i_xtime1; | stat1.xtime = node2->i_xtime1; | ( node->i_xtime2 \| attrp->ia_xtime2 \) = attrp->ia_xtime1 ; | ( attrp->ia_xtime1 \| attr.ia_xtime1 \) = attrp2->ia_xtime2; | - e = node->i_xtime1; + e = timespec64_to_timespec( node->i_xtime1 ); | - e = attrp->ia_xtime1; + e = timespec64_to_timespec( attrp->ia_xtime1 ); | node->i_xtime1 = current_time(...); | node->i_xtime2 = node->i_xtime1 = node->i_xtime3 = - e; + timespec_to_timespec64(e); | node->i_xtime1 = node->i_xtime3 = - e; + timespec_to_timespec64(e); | - node->i_xtime1 = e; + node->i_xtime1 = timespec_to_timespec64(e); ) Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Cc: <anton@tuxera.com> Cc: <balbi@kernel.org> Cc: <bfields@fieldses.org> Cc: <darrick.wong@oracle.com> Cc: <dhowells@redhat.com> Cc: <dsterba@suse.com> Cc: <dwmw2@infradead.org> Cc: <hch@lst.de> Cc: <hirofumi@mail.parknet.co.jp> Cc: <hubcap@omnibond.com> Cc: <jack@suse.com> Cc: <jaegeuk@kernel.org> Cc: <jaharkes@cs.cmu.edu> Cc: <jslaby@suse.com> Cc: <keescook@chromium.org> Cc: <mark@fasheh.com> Cc: <miklos@szeredi.hu> Cc: <nico@linaro.org> Cc: <reiserfs-devel@vger.kernel.org> Cc: <richard@nod.at> Cc: <sage@redhat.com> Cc: <sfrench@samba.org> Cc: <swhiteho@redhat.com> Cc: <tj@kernel.org> Cc: <trond.myklebust@primarydata.com> Cc: <tytso@mit.edu> Cc: <viro@zeniv.linux.org.uk>
* fscache: Pass object size in rather than calling back for itDavid Howells2018-04-061-8/+6
| | | | | | | | | | | | | | Pass the object size in to fscache_acquire_cookie() and fscache_write_page() rather than the netfs providing a callback by which it can be received. This makes it easier to update the size of the object when a new page is written that extends the object. The current object size is also passed by fscache to the check_aux function, obviating the need to store it in the aux data. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Anna Schumaker <anna.schumaker@netapp.com> Tested-by: Steve Dickson <steved@redhat.com>
* fscache: Attach the index key and aux data to the cookieDavid Howells2018-04-041-5/+78
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Attach copies of the index key and auxiliary data to the fscache cookie so that: (1) The callbacks to the netfs for this stuff can be eliminated. This can simplify things in the cache as the information is still available, even after the cache has relinquished the cookie. (2) Simplifies the locking requirements of accessing the information as we don't have to worry about the netfs object going away on us. (3) The cache can do lazy updating of the coherency information on disk. As long as the cache is flushed before reboot/poweroff, there's no need to update the coherency info on disk every time it changes. (4) Cookies can be hashed or put in a tree as the index key is easily available. This allows: (a) Checks for duplicate cookies can be made at the top fscache layer rather than down in the bowels of the cache backend. (b) Caching can be added to a netfs object that has a cookie if the cache is brought online after the netfs object is allocated. A certain amount of space is made in the cookie for inline copies of the data, but if it won't fit there, extra memory will be allocated for it. The downside of this is that live cache operation requires more memory. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Anna Schumaker <anna.schumaker@netapp.com> Tested-by: Steve Dickson <steved@redhat.com>
* nfs: define nfs_inc_fscache_stats and using it as possibleLi RongQing2014-11-251-12/+12
| | | | | | | | Define and use nfs_inc_fscache_stats when plus one, which can save to pass one parameter. Signed-off-by: Li RongQing <roy.qing.li@gmail.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
* NFS: Use i_writecount to control whether to get an fscache cookie in nfs_open()David Howells2013-09-271-142/+56
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use i_writecount to control whether to get an fscache cookie in nfs_open() as NFS does not do write caching yet. I *think* this is the cause of a problem encountered by Mark Moseley whereby __fscache_uncache_page() gets a NULL pointer dereference because cookie->def is NULL: BUG: unable to handle kernel NULL pointer dereference at 0000000000000010 IP: [<ffffffff812a1903>] __fscache_uncache_page+0x23/0x160 PGD 0 Thread overran stack, or stack corrupted Oops: 0000 [#1] SMP Modules linked in: ... CPU: 7 PID: 18993 Comm: php Not tainted 3.11.1 #1 Hardware name: Dell Inc. PowerEdge R420/072XWF, BIOS 1.3.5 08/21/2012 task: ffff8804203460c0 ti: ffff880420346640 RIP: 0010:[<ffffffff812a1903>] __fscache_uncache_page+0x23/0x160 RSP: 0018:ffff8801053af878 EFLAGS: 00210286 RAX: 0000000000000000 RBX: ffff8800be2f8780 RCX: ffff88022ffae5e8 RDX: 0000000000004c66 RSI: ffffea00055ff440 RDI: ffff8800be2f8780 RBP: ffff8801053af898 R08: 0000000000000001 R09: 0000000000000003 R10: 0000000000000000 R11: 0000000000000000 R12: ffffea00055ff440 R13: 0000000000001000 R14: ffff8800c50be538 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88042fc60000(0063) knlGS:00000000e439c700 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 0000000000000010 CR3: 0000000001d8f000 CR4: 00000000000607f0 Stack: ... Call Trace: [<ffffffff81365a72>] __nfs_fscache_invalidate_page+0x42/0x70 [<ffffffff813553d5>] nfs_invalidate_page+0x75/0x90 [<ffffffff811b8f5e>] truncate_inode_page+0x8e/0x90 [<ffffffff811b90ad>] truncate_inode_pages_range.part.12+0x14d/0x620 [<ffffffff81d6387d>] ? __mutex_lock_slowpath+0x1fd/0x2e0 [<ffffffff811b95d3>] truncate_inode_pages_range+0x53/0x70 [<ffffffff811b969d>] truncate_inode_pages+0x2d/0x40 [<ffffffff811b96ff>] truncate_pagecache+0x4f/0x70 [<ffffffff81356840>] nfs_setattr_update_inode+0xa0/0x120 [<ffffffff81368de4>] nfs3_proc_setattr+0xc4/0xe0 [<ffffffff81357f78>] nfs_setattr+0xc8/0x150 [<ffffffff8122d95b>] notify_change+0x1cb/0x390 [<ffffffff8120a55b>] do_truncate+0x7b/0xc0 [<ffffffff8121f96c>] do_last+0xa4c/0xfd0 [<ffffffff8121ffbc>] path_openat+0xcc/0x670 [<ffffffff81220a0e>] do_filp_open+0x4e/0xb0 [<ffffffff8120ba1f>] do_sys_open+0x13f/0x2b0 [<ffffffff8126aaf6>] compat_SyS_open+0x36/0x50 [<ffffffff81d7204c>] sysenter_dispatch+0x7/0x24 The code at the instruction pointer was disassembled: > (gdb) disas __fscache_uncache_page > Dump of assembler code for function __fscache_uncache_page: > ... > 0xffffffff812a18ff <+31>: mov 0x48(%rbx),%rax > 0xffffffff812a1903 <+35>: cmpb $0x0,0x10(%rax) > 0xffffffff812a1907 <+39>: je 0xffffffff812a19cd <__fscache_uncache_page+237> These instructions make up: ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX); That cmpb is the faulting instruction (%rax is 0). So cookie->def is NULL - which presumably means that the cookie has already been at least partway through __fscache_relinquish_cookie(). What I think may be happening is something like a three-way race on the same file: PROCESS 1 PROCESS 2 PROCESS 3 =============== =============== =============== open(O_TRUNC|O_WRONLY) open(O_RDONLY) open(O_WRONLY) -->nfs_open() -->nfs_fscache_set_inode_cookie() nfs_fscache_inode_lock() nfs_fscache_disable_inode_cookie() __fscache_relinquish_cookie() nfs_inode->fscache = NULL <--nfs_fscache_set_inode_cookie() -->nfs_open() -->nfs_fscache_set_inode_cookie() nfs_fscache_inode_lock() nfs_fscache_enable_inode_cookie() __fscache_acquire_cookie() nfs_inode->fscache = cookie <--nfs_fscache_set_inode_cookie() <--nfs_open() -->nfs_setattr() ... ... -->nfs_invalidate_page() -->__nfs_fscache_invalidate_page() cookie = nfsi->fscache -->nfs_open() -->nfs_fscache_set_inode_cookie() nfs_fscache_inode_lock() nfs_fscache_disable_inode_cookie() -->__fscache_relinquish_cookie() -->__fscache_uncache_page(cookie) <crash> <--__fscache_relinquish_cookie() nfs_inode->fscache = NULL <--nfs_fscache_set_inode_cookie() What is needed is something to prevent process #2 from reacquiring the cookie - and I think checking i_writecount should do the trick. It's also possible to have a two-way race on this if the file is opened O_TRUNC|O_RDONLY instead. Reported-by: Mark Moseley <moseleymark@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com>
* FS-Cache: Provide the ability to enable/disable cookiesDavid Howells2013-09-271-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Provide the ability to enable and disable fscache cookies. A disabled cookie will reject or ignore further requests to: Acquire a child cookie Invalidate and update backing objects Check the consistency of a backing object Allocate storage for backing page Read backing pages Write to backing pages but still allows: Checks/waits on the completion of already in-progress objects Uncaching of pages Relinquishment of cookies Two new operations are provided: (1) Disable a cookie: void fscache_disable_cookie(struct fscache_cookie *cookie, bool invalidate); If the cookie is not already disabled, this locks the cookie against other dis/enablement ops, marks the cookie as being disabled, discards or invalidates any backing objects and waits for cessation of activity on any associated object. This is a wrapper around a chunk split out of fscache_relinquish_cookie(), but it reinitialises the cookie such that it can be reenabled. All possible failures are handled internally. The caller should consider calling fscache_uncache_all_inode_pages() afterwards to make sure all page markings are cleared up. (2) Enable a cookie: void fscache_enable_cookie(struct fscache_cookie *cookie, bool (*can_enable)(void *data), void *data) If the cookie is not already enabled, this locks the cookie against other dis/enablement ops, invokes can_enable() and, if the cookie is not an index cookie, will begin the procedure of acquiring backing objects. The optional can_enable() function is passed the data argument and returns a ruling as to whether or not enablement should actually be permitted to begin. All possible failures are handled internally. The cookie will only be marked as enabled if provisional backing objects are allocated. A later patch will introduce these to NFS. Cookie enablement during nfs_open() is then contingent on i_writecount <= 0. can_enable() checks for a race between open(O_RDONLY) and open(O_WRONLY/O_RDWR). This simplifies NFS's cookie handling and allows us to get rid of open(O_RDONLY) accidentally introducing caching to an inode that's open for writing already. One operation has its API modified: (3) Acquire a cookie. struct fscache_cookie *fscache_acquire_cookie( struct fscache_cookie *parent, const struct fscache_cookie_def *def, void *netfs_data, bool enable); This now has an additional argument that indicates whether the requested cookie should be enabled by default. It doesn't need the can_enable() function because the caller must prevent multiple calls for the same netfs object and it doesn't need to take the enablement lock because no one else can get at the cookie before this returns. Signed-off-by: David Howells <dhowells@redhat.com
* NFS4: Open files for fscachingDavid Howells2012-12-201-0/+1
| | | | | | nfs4_file_open() should open files for fscaching. Signed-off-by: David Howells <dhowells@redhat.com>
* NFS: Don't pass mount data to nfs_fscache_get_super_cookie()Bryan Schumaker2012-05-151-13/+2
| | | | | | | | | | I intend on creating a single nfs_fs_mount() function used by all our mount paths. To avoid checking between new mounts and clone mounts, I instead pass both structures to a new function in super.c that finds the cache key and then looks up the super cookie. Signed-off-by: Bryan Schumaker <bjschuma@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* NFS: Fix more NFS debug related build warningsTrond Myklebust2012-03-211-1/+1
| | | | Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* FS-Cache: Add a helper to bulk uncache pages on an inodeDavid Howells2011-07-071-5/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add an FS-Cache helper to bulk uncache pages on an inode. This will only work for the circumstance where the pages in the cache correspond 1:1 with the pages attached to an inode's page cache. This is required for CIFS and NFS: When disabling inode cookie, we were returning the cookie and setting cifsi->fscache to NULL but failed to invalidate any previously mapped pages. This resulted in "Bad page state" errors and manifested in other kind of errors when running fsstress. Fix it by uncaching mapped pages when we disable the inode cookie. This patch should fix the following oops and "Bad page state" errors seen during fsstress testing. ------------[ cut here ]------------ kernel BUG at fs/cachefiles/namei.c:201! invalid opcode: 0000 [#1] SMP Pid: 5, comm: kworker/u:0 Not tainted 2.6.38.7-30.fc15.x86_64 #1 Bochs Bochs RIP: 0010: cachefiles_walk_to_object+0x436/0x745 [cachefiles] RSP: 0018:ffff88002ce6dd00 EFLAGS: 00010282 RAX: ffff88002ef165f0 RBX: ffff88001811f500 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000100 RDI: 0000000000000282 RBP: ffff88002ce6dda0 R08: 0000000000000100 R09: ffffffff81b3a300 R10: 0000ffff00066c0a R11: 0000000000000003 R12: ffff88002ae54840 R13: ffff88002ae54840 R14: ffff880029c29c00 R15: ffff88001811f4b0 FS: 00007f394dd32720(0000) GS:ffff88002ef00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 00007fffcb62ddf8 CR3: 000000001825f000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process kworker/u:0 (pid: 5, threadinfo ffff88002ce6c000, task ffff88002ce55cc0) Stack: 0000000000000246 ffff88002ce55cc0 ffff88002ce6dd58 ffff88001815dc00 ffff8800185246c0 ffff88001811f618 ffff880029c29d18 ffff88001811f380 ffff88002ce6dd50 ffffffff814757e4 ffff88002ce6dda0 ffffffff8106ac56 Call Trace: cachefiles_lookup_object+0x78/0xd4 [cachefiles] fscache_lookup_object+0x131/0x16d [fscache] fscache_object_work_func+0x1bc/0x669 [fscache] process_one_work+0x186/0x298 worker_thread+0xda/0x15d kthread+0x84/0x8c kernel_thread_helper+0x4/0x10 RIP cachefiles_walk_to_object+0x436/0x745 [cachefiles] ---[ end trace 1d481c9af1804caa ]--- I tested the uncaching by the following means: (1) Create a big file on my NFS server (104857600 bytes). (2) Read the file into the cache with md5sum on the NFS client. Look in /proc/fs/fscache/stats: Pages : mrk=25601 unc=0 (3) Open the file for read/write ("bash 5<>/warthog/bigfile"). Look in proc again: Pages : mrk=25601 unc=25601 Reported-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-and-Tested-by: Suresh Jayaraman <sjayaraman@suse.de> cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* NFS: Squelch compiler warningChuck Lever2010-05-141-1/+2
| | | | | | | | | | | | | | | Seen with -Wextra: /home/cel/linux/fs/nfs/fscache.c: In function ‘__nfs_readpages_from_fscache’: /home/cel/linux/fs/nfs/fscache.c:479: warning: comparison between signed and unsigned integer expressions The comparison implicitly converts "int" to "unsigned", making it safe. But there's no need for the implicit type conversions here, and the dfprintk() already uses a "%u" formatter for "npages." Better to reduce confusion. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo2010-03-301-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
* NFS: Fix a bug in nfs_fscache_release_page()Trond Myklebust2010-02-091-5/+4
| | | | | | | | | | | Not having an fscache cookie is perfectly valid if the user didn't mount with the fscache option. This patch fixes http://bugzilla.kernel.org/show_bug.cgi?id=15234 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Acked-by: David Howells <dhowells@redhat.com> Cc: stable@kernel.org
* FS-Cache: Handle pages pending storage that get evicted under OOM conditionsDavid Howells2009-11-191-7/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Handle netfs pages that the vmscan algorithm wants to evict from the pagecache under OOM conditions, but that are waiting for write to the cache. Under these conditions, vmscan calls the releasepage() function of the netfs, asking if a page can be discarded. The problem is typified by the following trace of a stuck process: kslowd005 D 0000000000000000 0 4253 2 0x00000080 ffff88001b14f370 0000000000000046 ffff880020d0d000 0000000000000007 0000000000000006 0000000000000001 ffff88001b14ffd8 ffff880020d0d2a8 000000000000ddf0 00000000000118c0 00000000000118c0 ffff880020d0d2a8 Call Trace: [<ffffffffa00782d8>] __fscache_wait_on_page_write+0x8b/0xa7 [fscache] [<ffffffff8104c0f1>] ? autoremove_wake_function+0x0/0x34 [<ffffffffa0078240>] ? __fscache_check_page_write+0x63/0x70 [fscache] [<ffffffffa00b671d>] nfs_fscache_release_page+0x4e/0xc4 [nfs] [<ffffffffa00927f0>] nfs_release_page+0x3c/0x41 [nfs] [<ffffffff810885d3>] try_to_release_page+0x32/0x3b [<ffffffff81093203>] shrink_page_list+0x316/0x4ac [<ffffffff8109372b>] shrink_inactive_list+0x392/0x67c [<ffffffff813532fa>] ? __mutex_unlock_slowpath+0x100/0x10b [<ffffffff81058df0>] ? trace_hardirqs_on_caller+0x10c/0x130 [<ffffffff8135330e>] ? mutex_unlock+0x9/0xb [<ffffffff81093aa2>] shrink_list+0x8d/0x8f [<ffffffff81093d1c>] shrink_zone+0x278/0x33c [<ffffffff81052d6c>] ? ktime_get_ts+0xad/0xba [<ffffffff81094b13>] try_to_free_pages+0x22e/0x392 [<ffffffff81091e24>] ? isolate_pages_global+0x0/0x212 [<ffffffff8108e743>] __alloc_pages_nodemask+0x3dc/0x5cf [<ffffffff81089529>] grab_cache_page_write_begin+0x65/0xaa [<ffffffff8110f8c0>] ext3_write_begin+0x78/0x1eb [<ffffffff81089ec5>] generic_file_buffered_write+0x109/0x28c [<ffffffff8103cb69>] ? current_fs_time+0x22/0x29 [<ffffffff8108a509>] __generic_file_aio_write+0x350/0x385 [<ffffffff8108a588>] ? generic_file_aio_write+0x4a/0xae [<ffffffff8108a59e>] generic_file_aio_write+0x60/0xae [<ffffffff810b2e82>] do_sync_write+0xe3/0x120 [<ffffffff8104c0f1>] ? autoremove_wake_function+0x0/0x34 [<ffffffff810b18e1>] ? __dentry_open+0x1a5/0x2b8 [<ffffffff810b1a76>] ? dentry_open+0x82/0x89 [<ffffffffa00e693c>] cachefiles_write_page+0x298/0x335 [cachefiles] [<ffffffffa0077147>] fscache_write_op+0x178/0x2c2 [fscache] [<ffffffffa0075656>] fscache_op_execute+0x7a/0xd1 [fscache] [<ffffffff81082093>] slow_work_execute+0x18f/0x2d1 [<ffffffff8108239a>] slow_work_thread+0x1c5/0x308 [<ffffffff8104c0f1>] ? autoremove_wake_function+0x0/0x34 [<ffffffff810821d5>] ? slow_work_thread+0x0/0x308 [<ffffffff8104be91>] kthread+0x7a/0x82 [<ffffffff8100beda>] child_rip+0xa/0x20 [<ffffffff8100b87c>] ? restore_args+0x0/0x30 [<ffffffff8102ef83>] ? tg_shares_up+0x171/0x227 [<ffffffff8104be17>] ? kthread+0x0/0x82 [<ffffffff8100bed0>] ? child_rip+0x0/0x20 In the above backtrace, the following is happening: (1) A page storage operation is being executed by a slow-work thread (fscache_write_op()). (2) FS-Cache farms the operation out to the cache to perform (cachefiles_write_page()). (3) CacheFiles is then calling Ext3 to perform the actual write, using Ext3's standard write (do_sync_write()) under KERNEL_DS directly from the netfs page. (4) However, for Ext3 to perform the write, it must allocate some memory, in particular, it must allocate at least one page cache page into which it can copy the data from the netfs page. (5) Under OOM conditions, the memory allocator can't immediately come up with a page, so it uses vmscan to find something to discard (try_to_free_pages()). (6) vmscan finds a clean netfs page it might be able to discard (possibly the one it's trying to write out). (7) The netfs is called to throw the page away (nfs_release_page()) - but it's called with __GFP_WAIT, so the netfs decides to wait for the store to complete (__fscache_wait_on_page_write()). (8) This blocks a slow-work processing thread - possibly against itself. The system ends up stuck because it can't write out any netfs pages to the cache without allocating more memory. To avoid this, we make FS-Cache cancel some writes that aren't in the middle of actually being performed. This means that some data won't make it into the cache this time. To support this, a new FS-Cache function is added fscache_maybe_release_page() that replaces what the netfs releasepage() functions used to do with respect to the cache. The decisions fscache_maybe_release_page() makes are counted and displayed through /proc/fs/fscache/stats on a line labelled "VmScan". There are four counters provided: "nos=N" - pages that weren't pending storage; "gon=N" - pages that were pending storage when we first looked, but weren't by the time we got the object lock; "bsy=N" - pages that we ignored as they were actively being written when we looked; and "can=N" - pages that we cancelled the storage of. What I'd really like to do is alter the behaviour of the cancellation heuristics, depending on how necessary it is to expel pages. If there are plenty of other pages that aren't waiting to be written to the cache that could be ejected first, then it would be nice to hold up on immediate cancellation of cache writes - but I don't see a way of doing that. Signed-off-by: David Howells <dhowells@redhat.com>
* NFS: Propagate 'fsc' mount option through automountsDavid Howells2009-09-231-4/+21
| | | | | | | | | | | | | | | | | | | | | | | | Propagate the NFS 'fsc' mount option through NFS automounts of various types. This is now required as commit: commit c02d7adf8c5429727a98bad1d039bccad4c61c50 Author: Trond Myklebust <Trond.Myklebust@netapp.com> Date: Mon Jun 22 15:09:14 2009 -0400 NFSv4: Replace nfs4_path_walk() with VFS path lookup in a private namespace uses VFS-driven automounting to reach all submounts barring the root, thus preventing fscaching from being enabled on any submount other than the root. This patch gets around that by propagating the NFS_OPTION_FSCACHE flag across automounts. If a uniquifier is supplied to a mount then this is propagated to all automounts of that mount too. Signed-off-by: David Howells <dhowells@redhat.com> [Trond: Fixed up the definition of nfs_fscache_get_super_cookie for the case of #undef CONFIG_NFS_FSCACHE] Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* NFS: Store pages from an NFS inode into a local cacheDavid Howells2009-04-031-0/+28
| | | | | | | | | | | Store pages from an NFS inode into the cache data storage object associated with that inode. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Steve Dickson <steved@redhat.com> Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Tested-by: Daire Byrne <Daire.Byrne@framestore.com>
* NFS: Read pages from FS-Cache into an NFS inodeDavid Howells2009-04-031-0/+112
| | | | | | | | | | | Read pages from an FS-Cache data storage object representing an inode into an NFS inode. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Steve Dickson <steved@redhat.com> Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Tested-by: Daire Byrne <Daire.Byrne@framestore.com>
* NFS: FS-Cache page managementDavid Howells2009-04-031-0/+53
| | | | | | | | | | | | FS-Cache page management for NFS. This includes hooking the releasing and invalidation of pages marked with PG_fscache (aka PG_private_2) and waiting for completion of the write-to-cache flag (PG_fscache_write aka PG_owner_priv_2). Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Steve Dickson <steved@redhat.com> Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Tested-by: Daire Byrne <Daire.Byrne@framestore.com>
* NFS: Use local disk inode cacheDavid Howells2009-04-031-0/+162
| | | | | | | | | | Bind data storage objects in the local cache to NFS inodes. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Steve Dickson <steved@redhat.com> Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Tested-by: Daire Byrne <Daire.Byrne@framestore.com>
* NFS: Define and create superblock-level objectsDavid Howells2009-04-031-0/+116
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Define and create superblock-level cache index objects (as managed by nfs_server structs). Each superblock object is created in a server level index object and is itself an index into which inode-level objects are inserted. Ideally there would be one superblock-level object per server, and the former would be folded into the latter; however, since the "nosharecache" option exists this isn't possible. The superblock object key is a sequence consisting of: (1) Certain superblock s_flags. (2) Various connection parameters that serve to distinguish superblocks for sget(). (3) The volume FSID. (4) The security flavour. (5) The uniquifier length. (6) The uniquifier text. This is normally an empty string, unless the fsc=xyz mount option was used to explicitly specify a uniquifier. The key blob is of variable length, depending on the length of (6). The superblock object is given no coherency data to carry in the auxiliary data permitted by the cache. It is assumed that the superblock is always coherent. This patch also adds uniquification handling such that two otherwise identical superblocks, at least one of which is marked "nosharecache", won't end up trying to share the on-disk cache. It will be possible to manually provide a uniquifier through a mount option with a later patch to avoid the error otherwise produced. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Steve Dickson <steved@redhat.com> Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Tested-by: Daire Byrne <Daire.Byrne@framestore.com>