From 7d200960d4f3d1b50c3b9e9688408d9f81c66ff4 Mon Sep 17 00:00:00 2001 From: David Woodhouse Date: Wed, 13 Apr 2005 14:22:38 +0100 Subject: [PATCH] [JFFS2] Fix inode allocation race Signed-off-by: David Woodhouse Signed-off-by: Thomas Gleixner --- fs/jffs2/README.Locking | 6 +++++- fs/jffs2/nodelist.c | 6 +++++- fs/jffs2/write.c | 7 +++---- 3 files changed, 13 insertions(+), 6 deletions(-) diff --git a/fs/jffs2/README.Locking b/fs/jffs2/README.Locking index 49771cf8513a..b7943439b6ec 100644 --- a/fs/jffs2/README.Locking +++ b/fs/jffs2/README.Locking @@ -1,4 +1,4 @@ - $Id: README.Locking,v 1.9 2004/11/20 10:35:40 dwmw2 Exp $ + $Id: README.Locking,v 1.12 2005/04/13 13:22:35 dwmw2 Exp $ JFFS2 LOCKING DOCUMENTATION --------------------------- @@ -108,6 +108,10 @@ in-core jffs2_inode_cache objects (each inode in JFFS2 has the correspondent jffs2_inode_cache object). So, the inocache_lock has to be locked while walking the c->inocache_list hash buckets. +This spinlock also covers allocation of new inode numbers, which is +currently just '++->highest_ino++', but might one day get more complicated +if we need to deal with wrapping after 4 milliard inode numbers are used. + Note, the f->sem guarantees that the correspondent jffs2_inode_cache will not be removed. So, it is allowed to access it without locking the inocache_lock spinlock. diff --git a/fs/jffs2/nodelist.c b/fs/jffs2/nodelist.c index b835a8652623..c9157e1ea40a 100644 --- a/fs/jffs2/nodelist.c +++ b/fs/jffs2/nodelist.c @@ -7,7 +7,7 @@ * * For licensing information, see the file 'LICENCE' in this directory. * - * $Id: nodelist.c,v 1.93 2005/02/27 23:01:32 dwmw2 Exp $ + * $Id: nodelist.c,v 1.94 2005/04/13 13:22:35 dwmw2 Exp $ * */ @@ -491,6 +491,10 @@ void jffs2_add_ino_cache (struct jffs2_sb_info *c, struct jffs2_inode_cache *new struct jffs2_inode_cache **prev; D2(printk(KERN_DEBUG "jffs2_add_ino_cache: Add %p (ino #%u)\n", new, new->ino)); spin_lock(&c->inocache_lock); + if (!new->ino) + new->ino = ++c->highest_ino; + + D2(printk(KERN_DEBUG "jffs2_add_ino_cache: Add %p (ino #%u)\n", new, new->ino)); prev = &c->inocache_list[new->ino % INOCACHE_HASHSIZE]; diff --git a/fs/jffs2/write.c b/fs/jffs2/write.c index f3910dc1c2c8..69100615d9ae 100644 --- a/fs/jffs2/write.c +++ b/fs/jffs2/write.c @@ -7,7 +7,7 @@ * * For licensing information, see the file 'LICENCE' in this directory. * - * $Id: write.c,v 1.91 2005/03/01 10:34:03 dedekind Exp $ + * $Id: write.c,v 1.92 2005/04/13 13:22:35 dwmw2 Exp $ * */ @@ -35,13 +35,12 @@ int jffs2_do_new_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f, uint f->inocache = ic; f->inocache->nlink = 1; f->inocache->nodes = (struct jffs2_raw_node_ref *)f->inocache; - f->inocache->ino = ++c->highest_ino; f->inocache->state = INO_STATE_PRESENT; - ri->ino = cpu_to_je32(f->inocache->ino); - D1(printk(KERN_DEBUG "jffs2_do_new_inode(): Assigned ino# %d\n", f->inocache->ino)); jffs2_add_ino_cache(c, f->inocache); + D1(printk(KERN_DEBUG "jffs2_do_new_inode(): Assigned ino# %d\n", f->inocache->ino)); + ri->ino = cpu_to_je32(f->inocache->ino); ri->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK); ri->nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE);