BMC/Intel-BMC/linux.git/net/ceph/messenger.c, branch dev-4.6

mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros

2016-04-04T17:41:08+00:00

PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago with promise that one day it will be possible to implement page cache with bigger chunks than PAGE_SIZE. This promise never materialized. And unlikely will. We have many places where PAGE_CACHE_SIZE assumed to be equal to PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_* or PAGE_* constant should be used in a particular case, especially on the border between fs and mm. Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much breakage to be doable. Let's stop pretending that pages in page cache are special. They are not. The changes are pretty straight-forward: - << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> ; - >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> ; - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN}; - page_cache_get() -> get_page(); - page_cache_release() -> put_page(); This patch contains automated changes generated with coccinelle using script below. For some reason, coccinelle doesn't patch header files. I've called spatch for them manually. The only adjustment after coccinelle is revert of changes to PAGE_CAHCE_ALIGN definition: we are going to drop it later. There are few places in the code where coccinelle didn't reach. I'll fix them manually in a separate patch. Comments and documentation also will be addressed with the separate patch. virtual patch @@ expression E; @@ - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ expression E; @@ - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ @@ - PAGE_CACHE_SHIFT + PAGE_SHIFT @@ @@ - PAGE_CACHE_SIZE + PAGE_SIZE @@ @@ - PAGE_CACHE_MASK + PAGE_MASK @@ expression E; @@ - PAGE_CACHE_ALIGN(E) + PAGE_ALIGN(E) @@ expression E; @@ - page_cache_get(E) + get_page(E) @@ expression E; @@ - page_cache_release(E) + put_page(E) Signed-off-by: Kirill A. Shutemov Acked-by: Michal Hocko Signed-off-by: Linus Torvalds

libceph: use KMEM_CACHE macro

2016-03-25T17:51:57+00:00

Use KMEM_CACHE() instead of kmem_cache_create() to simplify the code. Signed-off-by: Geliang Tang Signed-off-by: Ilya Dryomov

libceph: use sizeof_footer() more

2016-03-25T17:51:53+00:00

Don't open-code sizeof_footer() in read_partial_message() and ceph_msg_revoke(). Also, after switching to sizeof_footer(), it's now possible to use con_out_kvec_add() in prepare_write_message_footer(). Signed-off-by: Ilya Dryomov Reviewed-by: Alex Elder

libceph: use the right footer size when skipping a message

2016-02-24T19:28:40+00:00

ceph_msg_footer is 21 bytes long, while ceph_msg_footer_old is only 13. Don't skip too much when CEPH_FEATURE_MSG_AUTH isn't negotiated. Cc: stable@vger.kernel.org # 3.19+ Signed-off-by: Ilya Dryomov Reviewed-by: Alex Elder

libceph: don't bail early from try_read() when skipping a message

2016-02-24T19:28:31+00:00

The contract between try_read() and try_write() is that when called each processes as much data as possible. When instructed by osd_client to skip a message, try_read() is violating this contract by returning after receiving and discarding a single message instead of checking for more. try_write() then gets a chance to write out more requests, generating more replies/skips for try_read() to handle, forcing the messenger into a starvation loop. Cc: stable@vger.kernel.org # 3.10+ Reported-by: Varada Kari Signed-off-by: Ilya Dryomov Tested-by: Varada Kari Reviewed-by: Alex Elder

libceph: clear messenger auth_retry flag if we fault

2016-01-21T18:36:08+00:00

Commit 20e55c4cc758 ("libceph: clear messenger auth_retry flag when we authenticate") got us only half way there. We clear the flag if the second attempt succeeds, but it also needs to be cleared if that attempt fails, to allow for the exponential backoff to kick in. Otherwise, if ->should_authenticate() thinks our keys are valid, we will busy loop, incrementing auth_retry to no avail: process_connect ffff880079a63830 got BADAUTHORIZER attempt 1 process_connect ffff880079a63830 got BADAUTHORIZER attempt 2 process_connect ffff880079a63830 got BADAUTHORIZER attempt 3 process_connect ffff880079a63830 got BADAUTHORIZER attempt 4 process_connect ffff880079a63830 got BADAUTHORIZER attempt 5 ... Signed-off-by: Ilya Dryomov Reviewed-by: Sage Weil

libceph: fix ceph_msg_revoke()

2016-01-21T18:36:08+00:00

There are a number of problems with revoking a "was sending" message: (1) We never make any attempt to revoke data - only kvecs contibute to con->out_skip. However, once the header (envelope) is written to the socket, our peer learns data_len and sets itself to expect at least data_len bytes to follow front or front+middle. If ceph_msg_revoke() is called while the messenger is sending message's data portion, anything we send after that call is counted by the OSD towards the now revoked message's data portion. The effects vary, the most common one is the eventual hang - higher layers get stuck waiting for the reply to the message that was sent out after ceph_msg_revoke() returned and treated by the OSD as a bunch of data bytes. This is what Matt ran into. (2) Flat out zeroing con->out_kvec_bytes worth of bytes to handle kvecs is wrong. If ceph_msg_revoke() is called before the tag is sent out or while the messenger is sending the header, we will get a connection reset, either due to a bad tag (0 is not a valid tag) or a bad header CRC, which kind of defeats the purpose of revoke. Currently the kernel client refuses to work with header CRCs disabled, but that will likely change in the future, making this even worse. (3) con->out_skip is not reset on connection reset, leading to one or more spurious connection resets if we happen to get a real one between con->out_skip is set in ceph_msg_revoke() and before it's cleared in write_partial_skip(). Fixing (1) and (3) is trivial. The idea behind fixing (2) is to never zero the tag or the header, i.e. send out tag+header regardless of when ceph_msg_revoke() is called. That way the header is always correct, no unnecessary resets are induced and revoke stands ready for disabled CRCs. Since ceph_msg_revoke() rips out con->out_msg, introduce a new "message out temp" and copy the header into it before sending. Cc: stable@vger.kernel.org # 4.0+ Reported-by: Matt Conner Signed-off-by: Ilya Dryomov Tested-by: Matt Conner Reviewed-by: Sage Weil

libceph: use list_for_each_entry_safe

2016-01-21T18:36:08+00:00

Use list_for_each_entry_safe() instead of list_for_each_safe() to simplify the code. Signed-off-by: Geliang Tang [idryomov@gmail.com: nuke call to list_splice_init() as well] Signed-off-by: Ilya Dryomov

libceph: use list_next_entry instead of list_entry_next

2016-01-21T18:36:07+00:00

list_next_entry has been defined in list.h, so I replace list_entry_next with it. Signed-off-by: Geliang Tang Signed-off-by: Ilya Dryomov

libceph: clear msg->con in ceph_msg_release() only

2015-11-02T22:37:46+00:00

The following bit in ceph_msg_revoke_incoming() is unsafe: struct ceph_connection *con = msg->con; if (!con) return; mutex_lock(&con->mutex); con use> There is nothing preventing con from getting destroyed right after msg->con test. One easy way to reproduce this is to disable message signing only on the server side and try to map an image. The system will go into a libceph: read_partial_message ffff880073f0ab68 signature check failed libceph: osd0 192.168.255.155:6801 bad crc/signature libceph: read_partial_message ffff880073f0ab68 signature check failed libceph: osd0 192.168.255.155:6801 bad crc/signature loop which has to be interrupted with Ctrl-C. Hit Ctrl-C and you are likely to end up with a random GP fault if the reset handler executes "within" ceph_msg_revoke_incoming(): ... rbd_obj_request_end ceph_osdc_cancel_request __unregister_request ceph_osdc_put_request ceph_msg_revoke_incoming ... osd_reset __kick_osd_requests __reset_osd remove_osd ceph_con_close reset_connection in_msg->con> put_osd

con use> <-- !!! If ceph_msg_revoke_incoming() executes "before" the reset handler, osd/con will be leaked because ceph_msg_revoke_incoming() clears con->in_msg but doesn't put con ref, while reset_connection() only puts con ref if con->in_msg != NULL. The current msg->con scheme was introduced by commits 38941f8031bf ("libceph: have messages point to their connection") and 92ce034b5a74 ("libceph: have messages take a connection reference"), which defined when messages get associated with a connection and when that association goes away. Part of the problem is that this association is supposed to go away in much too many places; closing this race entirely requires either a rework of the existing or an addition of a new layer of synchronization. In lieu of that, we can make it *much* less likely to hit by disassociating messages only on their destruction and resend through a different connection. This makes the code simpler and is probably a good thing to do regardless - this patch adds a msg_con_set() helper which is is called from only three places: ceph_con_send() and ceph_con_in_msg_alloc() to set msg->con and ceph_msg_release() to clear it. Signed-off-by: Ilya Dryomov