Date: Wed, 4 Feb 1998 07:16:59 +0000 (GMT) From: Terry Lambert <tlambert@primenet.com> To: julian@whistle.com (Julian Elischer) Cc: mckusick@mckusick.com, current@FreeBSD.ORG Subject: Re: sb being written to r/o disks. Message-ID: <199802040716.AAA04564@usr08.primenet.com> In-Reply-To: <34D7B6B0.31DFF4F5@whistle.com> from "Julian Elischer" at Feb 3, 98 04:30:41 pm
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> something is doing syncronous writes to a r/o FS.. > who? that's easy.. > > # mount -u -ordonly / > Breakpoint at _mount: pushl %ebp > db> b bwrite > db> c > Breakpoint at _bwrite: pushl %ebp > db> tr > _bwrite(f245ccf4,0) at _bwrite > _ffs_sbupdate(f045f200,1) at _ffs_sbupdate+0xb0 > _ffs_mount(f045fc00,efbfd268,efbfd1cc,f3666eb8,f364e740) at > _ffs_mount+0x1e5 > _mount(f364e740,f3666f94,0,efbfd268,1201) at _mount+0x416 > _syscall(27,27,1201,efbfd268,efbfd238) at _syscall+0x187 > _Xsyscall() at _Xsyscall+0x35 > --- syscall 0x15, eip = 0x6a95, esp = 0xefbfd188, ebp = 0xefbfd238 --- > db> > > apparently _ffs_sbupdate() doesn't know to check if the fs is readonly.. This is kind of well known; this is because R/O FS's get their "last mounted on" information updated. This is probably a bad thing. Probably the "last mounted on" information for a R/O FS should be set by newfs. It really means "please mount me here". Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers.
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