Date: Sat, 11 Dec 1999 23:35:19 -0800 (PST) From: Matthew Dillon <dillon@apollo.backplane.com> To: freebsd-stable@freebsd.org, freebsd-hackers@freebsd.org Subject: Recent NFS commits, plus Heads up to 2.2.x users Hello everyone. There have been a number of recent NFS commits to fix bugs. Everything is hunky dory, but I do not have a 2.2.x box to test the MFC to 2.2.x so this is a head's up to 2.2.x users who are using NFS that these (relatively simple) bug fixes have been MFC'd, but not tested. It would be nice if I could get confirmation that 2.2.x hasn't blow up :-) -Matt Matthew Dillon <dillon@backplane.com> dillon 1999/12/11 19:19:33 PST Modified files: sys/kern vfs_subr.c vfs_syscalls.c sys/vm vm_fault.c vm_map.c vm_map.h vm_mmap.c vm_object.c vm_object.h vm_page.c vm_page.h sys/sys mman.h lib/libc/sys madvise.2 mmap.2 Log: Add MAP_NOSYNC feature to mmap(), and MADV_NOSYNC and MADV_AUTOSYNC to madvise(). This feature prevents the update daemon from gratuitously flushing dirty pages associated with a mapped file-backed region of memory. The system pager will still page the memory as necessary and the VM system will still be fully coherent with the filesystem. Modifications made by other means to the same area of memory, for example by write(), are unaffected. The feature works on a page-granularity basis. MAP_NOSYNC allows one to use mmap() to share memory between processes without incuring any significant filesystem overhead, putting it in the same performance category as SysV Shared memory and anonymous memory. Reviewed by: julian, alc, dg Revision Changes Path 1.239 +2 -2 src/sys/kern/vfs_subr.c 1.147 +3 -2 src/sys/kern/vfs_syscalls.c 1.108 +17 -3 src/sys/vm/vm_fault.c 1.184 +16 -3 src/sys/vm/vm_map.c 1.52 +3 -2 src/sys/vm/vm_map.h 1.105 +5 -4 src/sys/vm/vm_mmap.c 1.171 +32 -5 src/sys/vm/vm_object.c 1.62 +4 -3 src/sys/vm/vm_object.h 1.147 +8 -4 src/sys/vm/vm_page.c 1.74 +5 -5 src/sys/vm/vm_page.h 1.27 +4 -1 src/sys/sys/mman.h 1.16 +28 -1 src/lib/libc/sys/madvise.2 1.18 +30 -1 src/lib/libc/sys/mmap.2 dillon 1999/12/11 19:28:15 PST Modified files: sys/kern vfs_syscalls.c Log: Remove accidental pollution unrelated to previous commit. The issue here is real but has not yet been discussed with Eivind. Revision Changes Path 1.148 +2 -3 src/sys/kern/vfs_syscalls.c dillon 1999/12/11 22:09:58 PST Modified files: sys/nfs nfs_bio.c nfs_subs.c nfs_vnops.c sys/sys buf.h Log: Synopsis of problem being fixed: Dan Nelson originally reported that blocks of zeros could wind up in a file written to over NFS by a client. The problem only occurs a few times per several gigabytes of data. This problem turned out to be bug #3 below. bug #1: B_CLUSTEROK must be cleared when an NFS buffer is reverted from stage 2 (ready for commit rpc) to stage 1 (ready for write). Reversions can occur when a dirty NFS buffer is redirtied with new data. Otherwise the VFS/BIO system may end up thinking that a stage 1 NFS buffer is clusterable. Stage 1 NFS buffers are not clusterable. bug #2: B_CLUSTEROK was inappropriately set for a 'short' NFS buffer (short buffers only occur near the EOF of the file). Change to only set when the buffer is a full biosize (usually 8K). This bug has no effect but should be fixed in -current anyway. It need not be backported. bug #3: B_NEEDCOMMIT was inappropriately set in nfs_flush() (which is typically only called by the update daemon). nfs_flush() does a multi-pass loop but due to the lack of vnode locking it is possible for new buffers to be added to the dirtyblkhd list while a flush operation is going on. This may result in nfs_flush() setting B_NEEDCOMMIT on a buffer which has *NOT* yet gone through its stage 1 write, causing only the commit rpc to be made and thus causing the contents of the buffer to be thrown away (never sent to the server). The patch also contains some cleanup, which only applies to the commit into -current. Reviewed by: dg, julian Originally Reported by: Dan Nelson <dnelson@emsphone.com> Revision Changes Path 1.81 +27 -11 src/sys/nfs/nfs_bio.c 1.86 +15 -7 src/sys/nfs/nfs_subs.c 1.148 +3 -27 src/sys/nfs/nfs_vnops.c 1.85 +8 -1 src/sys/sys/buf.h dillon 1999/12/11 22:52:35 PST Modified files: (Branch: RELENG_3) sys/nfs nfs_bio.c nfs_subs.c nfs_vnops.c Log: MFC nfs_bio.c 1.81, nfs_subs.c 1.86, nfs_vnops.c 1.148. Fixed two rare-occuring bugs in NFS. First, B_CLUSTEROK must be cleared when B_NEEDCOMMIT is cleared since uncommitted dirty buffers may not be clustered. Second, B_NEEDCOMMIT cannot be gratuitously set in nfs_flush(). Due to lack of locking a buffer may be added to the dirtyblkhd list during the flush and setting B_NEEDCOMMIT can result in the buffer's data being thrown away rather then written to the server. Reviewed by: dg Approved by: jkh Revision Changes Path 1.65.2.3 +4 -4 src/sys/nfs/nfs_bio.c 1.70.2.4 +2 -2 src/sys/nfs/nfs_subs.c 1.116.2.8 +4 -4 src/sys/nfs/nfs_vnops.c dillon 1999/12/11 23:06:40 PST Modified files: sys/nfs nfs_nqlease.c nfs_serv.c nfs_subs.c Log: Fix a number of server-side issues related to aborting badly formed NFS packets, mainly initializing structure pointers to NULL which are conditionally freed prior to return. PR: kern/15249 Submitted by: Ian Dowse <iedowse@maths.tcd.ie> Revision Changes Path 1.47 +4 -2 src/sys/nfs/nfs_nqlease.c 1.89 +5 -5 src/sys/nfs/nfs_serv.c 1.87 +4 -1 src/sys/nfs/nfs_subs.c dillon 1999/12/11 23:16:21 PST Modified files: (Branch: RELENG_3) sys/nfs nfs_nqlease.c nfs_serv.c nfs_subs.c Log: MFC nfs_nqlease 1.47, nfs_serv.c 1.89, nfs_subs.c 1.87. Prevent panics in server side abort code when dealing with malformed NFS packets. Approved by: jkh Revision Changes Path 1.39.2.3 +4 -2 src/sys/nfs/nfs_nqlease.c 1.72.2.6 +5 -5 src/sys/nfs/nfs_serv.c 1.70.2.5 +4 -1 src/sys/nfs/nfs_subs.c dillon 1999/12/11 23:25:12 PST Modified files: (Branch: RELENG_2_2) sys/nfs nfs_nqlease.c nfs_subs.c Log: MFC nfs_nqlease 1.47, nfs_serv.c 1.89, nfs_subs.c 1.87. Note that no changes to nfs_serv.c were required, the bugs in that routine were introduced after 2.2.x. Revision Changes Path 1.20.2.2 +4 -2 src/sys/nfs/nfs_nqlease.c 1.33.2.4 +3 -1 src/sys/nfs/nfs_subs.c dillon 1999/12/11 23:28:52 PST Modified files: (Branch: RELENG_2_2) sys/nfs nfs_bio.c nfs_subs.c nfs_vnops.c Log: MFC nfs_bio.c 1.81, nfs_subs.c 1.86, nfs_vnops.c 1.148 Revision Changes Path 1.28.2.11 +3 -3 src/sys/nfs/nfs_bio.c 1.33.2.5 +2 -2 src/sys/nfs/nfs_subs.c 1.36.2.12 +4 -4 src/sys/nfs/nfs_vnops.c Message-ID: <199912120735.XAA70827@apollo.backplane.com>
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