kernel/linux.git/fs/netfs/io.c, branch v6.4

use less confusing names for iov_iter direction initializers

2022-11-25T18:01:55+00:00

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

netfs: Fix missing xas_retry() calls in xarray iteration

2022-11-15T16:49:06+00:00

netfslib has a number of places in which it performs iteration of an xarray whilst being under the RCU read lock. It *should* call xas_retry() as the first thing inside of the loop and do "continue" if it returns true in case the xarray walker passed out a special value indicating that the walk needs to be redone from the root[*]. Fix this by adding the missing retry checks. [*] I wonder if this should be done inside xas_find(), xas_next_node() and suchlike, but I'm told that's not an simple change to effect. This can cause an oops like that below. Note the faulting address - this is an internal value (|0x2) returned from xarray. BUG: kernel NULL pointer dereference, address: 0000000000000402 ... RIP: 0010:netfs_rreq_unlock+0xef/0x380 [netfs] ... Call Trace: netfs_rreq_assess+0xa6/0x240 [netfs] netfs_readpage+0x173/0x3b0 [netfs] ? init_wait_var_entry+0x50/0x50 filemap_read_page+0x33/0xf0 filemap_get_pages+0x2f2/0x3f0 filemap_read+0xaa/0x320 ? do_filp_open+0xb2/0x150 ? rmqueue+0x3be/0xe10 ceph_read_iter+0x1fe/0x680 [ceph] ? new_sync_read+0x115/0x1a0 new_sync_read+0x115/0x1a0 vfs_read+0xf3/0x180 ksys_read+0x5f/0xe0 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae Changes: ======== ver #2) - Changed an unsigned int to a size_t to reduce the likelihood of an overflow as per Willy's suggestion. - Added an additional patch to fix the maths. Fixes: 3d3c95046742 ("netfs: Provide readahead and readpage netfs helpers") Reported-by: George Law Signed-off-by: David Howells Reviewed-by: Jeff Layton Reviewed-by: Jingbo Xu cc: Matthew Wilcox cc: linux-cachefs@redhat.com cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/166749229733.107206.17482609105741691452.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/166757987929.950645.12595273010425381286.stgit@warthog.procyon.org.uk/ # v2

netfs: Split some core bits out into their own file

2022-03-18T09:29:05+00:00

Split some core bits out into their own file. More bits will be added to this file later. Signed-off-by: David Howells Reviewed-by: Jeff Layton cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/164623006934.3564931.17932680017894039748.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/164678218407.1200972.1731208226140990280.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/164692920944.2099075.11990502173226013856.stgit@warthog.procyon.org.uk/ # v3

netfs: Split fs/netfs/read_helper.c

2022-03-18T09:29:05+00:00

Split fs/netfs/read_helper.c into two pieces, one to deal with buffered writes and one to deal with the I/O mechanism. Changes ======= ver #2) - Add kdoc reference to new file. Signed-off-by: David Howells Reviewed-by: Jeff Layton cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/164623005586.3564931.6149556072728481767.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/164678217075.1200972.5101072043126828757.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/164692919953.2099075.7156989585513833046.stgit@warthog.procyon.org.uk/ # v3

netfs: Rename read_helper.c to io.c

2022-03-18T09:29:05+00:00

Rename the read_helper.c file to io.c before splitting out the buffered read functions and some other bits. Changes ======= ver #2) - Rename read_helper.c before splitting. Signed-off-by: David Howells Reviewed-by: Jeff Layton cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/164678216109.1200972.16567696909952495832.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/164692918076.2099075.8120961172717347610.stgit@warthog.procyon.org.uk/ # v3