kernel/linux.git/include/linux/ceph, branch v5.8.14

libceph: move away from global osd_req_flags

2020-06-16T14:01:53+00:00

osd_req_flags is overly general and doesn't suit its only user (read_from_replica option) well: - applying osd_req_flags in account_request() affects all OSD requests, including linger (i.e. watch and notify). However, linger requests should always go to the primary even though some of them are reads (e.g. notify has side effects but it is a read because it doesn't result in mutation on the OSDs). - calls to class methods that are reads are allowed to go to the replica, but most such calls issued for "rbd map" and/or exclusive lock transitions are requested to be resent to the primary via EAGAIN, doubling the latency. Get rid of global osd_req_flags and set read_from_replica flag only on specific OSD requests instead. Fixes: 8ad44d5e0d1e ("libceph: read_from_replica option") Signed-off-by: Ilya Dryomov Reviewed-by: Jeff Layton

libceph: support for alloc hint flags

2020-06-01T21:32:35+00:00

Allow indicating future I/O pattern via flags. This is supported since Kraken (and bluestore persists flags together with expected_object_size and expected_write_size). Signed-off-by: Ilya Dryomov Reviewed-by: Jason Dillaman

libceph: read_from_replica option

2020-06-01T11:22:53+00:00

Expose replica reads through read_from_replica=balance and read_from_replica=localize. The default is to read from primary (read_from_replica=no). Signed-off-by: Ilya Dryomov Reviewed-by: Jeff Layton

libceph: support for balanced and localized reads

2020-06-01T11:22:53+00:00

OSD-side issues with reads from replica have been resolved in Octopus. Reading from replica should be safe wrt. unstable or uncommitted state now, so add support for balanced and localized reads. There are two cases when a read from replica can't be served: - OSD may silently drop the request, expecting the client to notice that the acting set has changed and resend via the usual means (handled with t->used_replica) - OSD may return EAGAIN, expecting the client to resend to the primary, ignoring replica read flags (see handle_reply()) Signed-off-by: Ilya Dryomov Reviewed-by: Jeff Layton

libceph: crush_location infrastructure

2020-06-01T11:22:53+00:00

Allow expressing client's location in terms of CRUSH hierarchy as a set of (bucket type name, bucket name) pairs. The userspace syntax "crush_location = key1=value1 key2=value2" is incompatible with mount options and needed adaptation. Key-value pairs are separated by '|' and we use ':' instead of '=' to separate keys from values. So for: crush_location = host=foo rack=bar one would write: crush_location=host:foo|rack:bar As in userspace, "multipath" locations are supported, so indicating locality for parallel hierarchies is possible: crush_location=rack:foo1|rack:foo2|datacenter:bar Signed-off-by: Ilya Dryomov Reviewed-by: Jeff Layton

libceph: add non-asserting rbtree insertion helper

2020-06-01T11:22:53+00:00

Needed for the next commit and useful for ceph_pg_pool_info tree as well. I'm leaving the asserting helper in for now, but we should look at getting rid of it in the future. Signed-off-by: Ilya Dryomov Reviewed-by: Jeff Layton

libceph, rbd: replace zero-length array with flexible-array

2020-06-01T11:22:53+00:00

The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] sizeof(flexible-array-member) triggers a warning because flexible array members have incomplete type[1]. There are some instances of code in which the sizeof operator is being incorrectly/erroneously applied to zero-length arrays and the result is zero. Such instances may be hiding some bugs. So, this work (flexible-array member conversions) will also help to get completely rid of those sorts of issues. This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva Reviewed-by: Ilya Dryomov Signed-off-by: Ilya Dryomov

ceph: add read/write latency metric support

2020-06-01T11:22:51+00:00

Calculate the latency for OSD read requests. Add a new r_end_stamp field to struct ceph_osd_request that will hold the time of that the reply was received. Use that to calculate the RTT for each call, and divide the sum of those by number of calls to get averate RTT. Keep a tally of RTT for OSD writes and number of calls to track average latency of OSD writes. URL: https://tracker.ceph.com/issues/43215 Signed-off-by: Xiubo Li Reviewed-by: Jeff Layton Signed-off-by: Ilya Dryomov

ceph: consider inode's last read/write when calculating wanted caps

2020-03-30T10:42:42+00:00

Add i_last_rd and i_last_wr to ceph_inode_info. These fields are used to track the last time the client acquired read/write caps for the inode. If there is no read/write on an inode for 'caps_wanted_delay_max' seconds, __ceph_caps_file_wanted() does not request caps for read/write even there are open files. Call __ceph_touch_fmode() for dir operations. __ceph_caps_file_wanted() calculates dir's wanted caps according to last dir read/modification. If there is recent dir read, dir inode wants CEPH_CAP_ANY_SHARED caps. If there is recent dir modification, also wants CEPH_CAP_FILE_EXCL. Readdir is a special case. Dir inode wants CEPH_CAP_FILE_EXCL after readdir, as with that, modifications do not need to release CEPH_CAP_FILE_SHARED or invalidate all dentry leases issued by readdir. Signed-off-by: "Yan, Zheng" Reviewed-by: Jeff Layton Signed-off-by: Ilya Dryomov

ceph: attempt to do async create when possible

2020-03-30T10:42:42+00:00

With the Octopus release, the MDS will hand out directory create caps. If we have Fxc caps on the directory, and complete directory information or a known negative dentry, then we can return without waiting on the reply, allowing the open() call to return very quickly to userland. We use the normal ceph_fill_inode() routine to fill in the inode, so we have to gin up some reply inode information with what we'd expect the newly-created inode to have. The client assumes that it has a full set of caps on the new inode, and that the MDS will revoke them when there is conflicting access. This functionality is gated on the wsync/nowsync mount options. Signed-off-by: Jeff Layton Reviewed-by: "Yan, Zheng" Signed-off-by: Ilya Dryomov