From: David Woodhouse Date: Sun, 16 Apr 2006 23:19:48 +0000 (+0100) Subject: [JFFS2] Fix race in post-mount node checking X-Git-Tag: v2.6.18-rc1~1105^2~155 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d96fb997c6174f98a2a0a98200f99ac13b053bd6;p=linux-2.6 [JFFS2] Fix race in post-mount node checking For a while now, we've postponed CRC-checking of data nodes to be done by the GC thread, instead of being done while the user is waiting for mount to finish. The GC thread would iterate through all the inodes on the system and check each of their data nodes. It would skip over inodes which had already been used or were already being read in by read_inode(), because their data nodes would have been examined anyway. However, we could sometimes reach the end of the for-each-inode loop and still have some unchecked space left, if an inode we'd skipped was _still_ in the process of being read. This fixes that race by actually waiting for read_inode() to finish rather than just moving on. Thanks to Ladislav Michl for coming up with a reproducible test case and helping to track it down. Signed-off-by: David Woodhouse --- diff --git a/fs/jffs2/gc.c b/fs/jffs2/gc.c index f9ffece453..967fb2cf8e 100644 --- a/fs/jffs2/gc.c +++ b/fs/jffs2/gc.c @@ -181,6 +181,10 @@ int jffs2_garbage_collect_pass(struct jffs2_sb_info *c) and trigger the BUG() above while we haven't yet finished checking all its nodes */ D1(printk(KERN_DEBUG "Waiting for ino #%u to finish reading\n", ic->ino)); + /* We need to come back again for the _same_ inode. We've + made no progress in this case, but that should be OK */ + c->checked_ino--; + up(&c->alloc_sem); sleep_on_spinunlock(&c->inocache_wq, &c->inocache_lock); return 0;