freebsd-dev/sys/nfsclient
John Baldwin a120a7a3cd Rework the handling of stop signals in the NFS client. The changes in
195702, 195703, and 195821 prevented a thread from suspending while holding
locks inside of NFS by forcing the thread to fail sleeps with EINTR or
ERESTART but defer the thread suspension to the user boundary.  However,
this had the effect that stopping a process during an NFS request could
abort the request and trigger EINTR errors that were visible to userland
processes (previously the thread would have suspended and completed the
request once it was resumed).

This change instead effectively masks stop signals while in the NFS client.
It uses the existing TDF_SBDRY flag to effect this since SIGSTOP cannot
be masked directly.  Also, instead of setting PBDRY on individual sleeps,
the NFS client now sets the TDF_SBDRY flag around each NFS request and
stop signals are masked for all sleeps during that region (the previous
change missed sleeps in lockmgr locks).  The end result is that stop
signals sent to threads performing an NFS request are completely
ignored until after the NFS request has finished processing and the
thread prepares to return to userland.  This restores the behavior of
stop signals being transparent to userland processes while still
preventing threads from suspending while holding NFS locks.

Reviewed by:	kib
MFC after:	1 month
2013-02-06 17:06:51 +00:00
..
nfs_bio.c Do not leave invalid pages in the object after the short read for a 2012-08-14 11:45:47 +00:00
nfs_kdtrace.c Fix the module dependency in nfs_kdtrace.c for the old NFS 2011-05-06 19:55:15 +00:00
nfs_krpc.c Rework the handling of stop signals in the NFS client. The changes in 2013-02-06 17:06:51 +00:00
nfs_nfsiod.c Change the sysctl naming for the old and new NFS clients 2011-05-15 20:52:43 +00:00
nfs_node.c r16312 is not any longer real since many years (likely since when VFS 2012-11-19 22:43:45 +00:00
nfs_subs.c Use the VA_UTIMES_NULL flag to detect when NULL was passed to utimes() 2013-01-16 21:52:31 +00:00
nfs_vfsops.c Complete MPSAFE VFS interface and remove MNTK_MPSAFE flag. 2012-11-09 18:02:25 +00:00
nfs_vnops.c Use vfs_timestamp() to set file timestamps rather than invoking 2013-01-18 18:43:38 +00:00
nfs.h Fix a comment that got missed by r221973 which changed 2011-05-16 13:12:09 +00:00
nfsargs.h Move the NFSv4.1 client patches over from projects/nfsv4.1-client 2012-12-08 22:52:39 +00:00
nfsm_subs.h Close a race in NFS lookup processing that could result in stale name cache 2012-01-20 20:02:01 +00:00
nfsmount.h Add a timeout on positive name cache entries in the NFS client. That is, 2012-01-25 20:05:58 +00:00
nfsnode.h PR# 165923 reported intermittent write failures for dirty 2012-05-12 12:02:51 +00:00
nfsstats.h
nlminfo.h