On Wed, Aug 08, 2018 at 12:30:54PM +0000, Rick Macklem wrote: > Konstantin Belousov wrote: > >On Tue, Aug 07, 2018 at 12:28:33PM +0000, Rick Macklem wrote: > >> Hi, > >> > >> During testing of the pNFS server I get an ffs_truncate3 panic every once > >> in a while. > >> A few things that might be relevant: > >> - Seems to happen more often when soft update journaling is enabled, but > >> will > >> happen when it is disabled. > >> - Normally happens when a fairly large subtree of the file system is being > >> removed. > - Oh, and this is an old i386 with 256Mbytes (not one of them new fangled > computers, > where memory is in Gbytes;-) > > >> > >> These file systems are a bit odd, since all the regular files in them are > >> empty but > >> have extended attributes that are accessed during the subtree removal. (The > >> extended attributes tell the server where the data files are.) > >> > >> I replaced the panic() with a printf() and every time the printf() > >> happens... > >> bo->bo_dirty.bv_cnt == 0 and bo->bo_clean.bv_cnt == 1. > >> After one of these printf()s, the system continues to run ok. When the file > >> system is fsck'd after this has occurred, it passes fine and I haven't > >> seen and > >> indication of file system corruption after running with this file system > >> for > >> quite a while after the printf()s first occurred. > >The lack of corruption is, most likely, because the files are removed. > >Would the files truncated to zero length and then extended, I am almost > >sure that a corruption occur. > > > >Can you print the only buffer on the clean queue when the panic occur ? > ffst3 vtyp=1 bodirty=0 boclean=1 > buf at 0x428a110 > b_flags = 0x20001020<vmio,reuse,cache>, b_xflags=0x2<clean>, b_vflags=0x0 > b_error = 0, b_bufsize = 4096, b_bcount = 4096, b_resid = 0 > b_bufobj = (0xfd8ba94), b_data = 0x5170000, b_blkno = -1, b_lblkno = -1, > b_dep = 0 > b_kvabase = 0x5170000, b_kvasize = 32768 So the buffer was indeed for extended attrs, and never written to the disk. I am quite interested what was the inode content prior to the truncation, esp. the di_extsize.
Could you try to formulate a way to reproduce the panic so that Peter can recreate it, please ? > > >Also, it is interesting to know the initial length of the file. > Since they are regular files, they are 0 length. (Just inodes with extended > attributes.) > > >> > >> Since the panic() only occurs when "options INVARIANTS" is enabled and I > >> don't > >> see evidence of file system corruption, I'm wondering if this panic() is > >> valid and > >> needed? > > rick _______________________________________________ freebsd-current@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"
