kernel/linux.git/fs/nfs/read.c, branch linux-6.0.y

nfs: Leave pages in the pagecache if readpage failed

2022-06-29T12:51:07+00:00

The pagecache handles readpage failing by itself; it doesn't want filesystems to remove pages from under it. Signed-off-by: Matthew Wilcox (Oracle)

nfs: Convert nfs to read_folio

2022-05-09T20:21:46+00:00

This is a "weak" conversion which converts straight back to using pages. A full conversion should be performed at some point, hopefully by someone familiar with the filesystem. Signed-off-by: Matthew Wilcox (Oracle)

NFS: discard NFS_RPC_SWAPFLAGS and RPC_TASK_ROOTCREDS

2022-03-13T16:59:35+00:00

NFS_RPC_SWAPFLAGS is only used for READ requests. It sets RPC_TASK_SWAPPER which gives some memory-allocation priority to requests. This is not needed for swap READ - though it is for writes where it is set via a different mechanism. RPC_TASK_ROOTCREDS causes the 'machine' credential to be used. This is not needed as the root credential is saved when the swap file is opened, and this is used for all IO. So NFS_RPC_SWAPFLAGS isn't needed, and as it is the only user of RPC_TASK_ROOTCREDS, that isn't needed either. Remove both. Signed-off-by: NeilBrown Signed-off-by: Trond Myklebust

NFS: Rename fscache read and write pages functions

2022-03-13T16:59:35+00:00

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 Signed-off-by: Trond Myklebust

Convert NFS from readpages to readahead

2022-02-25T20:07:07+00:00

NFS is one of the last two users of the deprecated ->readpages aop. This conversion looks straightforward, but I have only compile-tested it. Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Trond Myklebust

nfs: Implement cache I/O by accessing the cache directly

2022-01-10T11:53:25+00:00

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 Tested-by: Dave Wysochanski Acked-by: Jeff Layton cc: Trond Myklebust cc: Anna Schumaker 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: Add offset to nfs_aop_readahead tracepoint

2021-11-02T20:44:02+00:00

Add the byte offset of the readahead request to the tracepoint output so we know where the read starts. Before this patch: cat-8104 [002] ..... 813.168775: nfs_aop_readahead: fileid=00:31:141 fhandle=0xe55807f6 version=1756509392533525500 nr_pages=256 cat-8104 [002] ..... 813.174973: nfs_aop_readahead_done: fileid=00:31:141 fhandle=0xe55807f6 version=1756509392533525500 nr_pages=256 ret=0 cat-8104 [002] ..... 813.175963: nfs_aop_readahead: fileid=00:31:141 fhandle=0xe55807f6 version=1756509392533525500 nr_pages=256 cat-8104 [002] ..... 813.183742: nfs_aop_readahead_done: fileid=00:31:141 fhandle=0xe55807f6 version=1756509392533525500 nr_pages=1 ret=0 After this patch: cat-6392 [001] ..... 73.107782: nfs_aop_readahead: fileid=00:31:141 fhandle=0xed22403f version=1756511950029502774 offset=5242880 nr_pages=256 cat-6392 [001] ..... 73.112466: nfs_aop_readahead_done: fileid=00:31:141 fhandle=0xed22403f version=1756511950029502774 nr_pages=256 ret=0 cat-6392 [001] ..... 73.115692: nfs_aop_readahead: fileid=00:31:141 fhandle=0xed22403f version=1756511950029502774 offset=6291456 nr_pages=256 cat-6392 [001] ..... 73.123283: nfs_aop_readahead_done: fileid=00:31:141 fhandle=0xed22403f version=1756511950029502774 nr_pages=256 ret=0 Signed-off-by: Dave Wysochanski Signed-off-by: Trond Myklebust

NFS: Replace dprintk callsites in nfs_readpage(s)

2021-10-20T22:09:54+00:00

These new events report slightly different information for readpage and readpages/readahead. For readpage: fsx-1387 [006] 380.761896: nfs_aop_readpage: fileid=00:28:2 fhandle=0x36fbbe51 version=1752899355910932437 offset=131072 fsx-1387 [006] 380.761900: nfs_aop_readpage_done: fileid=00:28:2 fhandle=0x36fbbe51 version=1752899355910932437 offset=131072 ret=0 The index of a synchronous single-page read is reported. For readpages: fsx-1387 [006] 380.760847: nfs_aop_readahead: fileid=00:28:2 fhandle=0x36fbbe51 version=1752899355909932456 nr_pages=3 fsx-1387 [006] 380.760853: nfs_aop_readahead_done: fileid=00:28:2 fhandle=0x36fbbe51 version=1752899355909932456 nr_pages=3 ret=0 The count of pages requested is reported. nfs_readpages does not wait for the READ requests to complete. Signed-off-by: Chuck Lever Signed-off-by: Trond Myklebust

NFS: Always provide aligned buffers to the RPC read layers

2021-08-30T17:21:38+00:00

Instead of messing around with XDR padding in the RDMA layer, we should just give the RPC layer an aligned buffer. Try to avoid creating extra RPC calls by aligning to the smaller value of ALIGN(len, rsize) and PAGE_SIZE. Signed-off-by: Trond Myklebust Signed-off-by: Anna Schumaker

NFS: Fix fscache read from NFS after cache error

2021-07-08T18:03:26+00:00

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 Signed-off-by: Trond Myklebust