From 0a0898cf413876d4ed6e371f3e04bf38600a9205 Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Sun, 30 Jul 2006 03:04:10 -0700 Subject: [PATCH] [PATCH] fuse: use jiffies_64 It is entirely possible (though rare) that jiffies half-wraps around, while a dentry/inode remains in the cache. This could mean that the dentry/inode is not invalidated for another half wraparound-time. To get around this problem, use 64-bit jiffies. The only problem with this is that dentry->d_time is 32 bits on 32-bit archs. So use d_fsdata as the high 32 bits. This is an ugly hack, but far simpler, than having to allocate private data just for this purpose. Since 64-bit jiffies can be assumed never to wrap around, simple comparison can be used, and a zero time value can represent "invalid". Signed-off-by: Miklos Szeredi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/fuse/dir.c | 44 ++++++++++++++++++++++++++++++++++++-------- fs/fuse/fuse_i.h | 2 +- fs/fuse/inode.c | 2 +- 3 files changed, 38 insertions(+), 10 deletions(-) diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c index 6db66ec386ae..409ce6a7cca4 100644 --- a/fs/fuse/dir.c +++ b/fs/fuse/dir.c @@ -14,6 +14,33 @@ #include #include +#if BITS_PER_LONG >= 64 +static inline void fuse_dentry_settime(struct dentry *entry, u64 time) +{ + entry->d_time = time; +} + +static inline u64 fuse_dentry_time(struct dentry *entry) +{ + return entry->d_time; +} +#else +/* + * On 32 bit archs store the high 32 bits of time in d_fsdata + */ +static void fuse_dentry_settime(struct dentry *entry, u64 time) +{ + entry->d_time = time; + entry->d_fsdata = (void *) (unsigned long) (time >> 32); +} + +static u64 fuse_dentry_time(struct dentry *entry) +{ + return (u64) entry->d_time + + ((u64) (unsigned long) entry->d_fsdata << 32); +} +#endif + /* * FUSE caches dentries and attributes with separate timeout. The * time in jiffies until the dentry/attributes are valid is stored in @@ -23,13 +50,13 @@ /* * Calculate the time in jiffies until a dentry/attributes are valid */ -static unsigned long time_to_jiffies(unsigned long sec, unsigned long nsec) +static u64 time_to_jiffies(unsigned long sec, unsigned long nsec) { if (sec || nsec) { struct timespec ts = {sec, nsec}; - return jiffies + timespec_to_jiffies(&ts); + return get_jiffies_64() + timespec_to_jiffies(&ts); } else - return jiffies - 1; + return 0; } /* @@ -38,7 +65,8 @@ static unsigned long time_to_jiffies(unsigned long sec, unsigned long nsec) */ static void fuse_change_timeout(struct dentry *entry, struct fuse_entry_out *o) { - entry->d_time = time_to_jiffies(o->entry_valid, o->entry_valid_nsec); + fuse_dentry_settime(entry, + time_to_jiffies(o->entry_valid, o->entry_valid_nsec)); if (entry->d_inode) get_fuse_inode(entry->d_inode)->i_time = time_to_jiffies(o->attr_valid, o->attr_valid_nsec); @@ -50,7 +78,7 @@ static void fuse_change_timeout(struct dentry *entry, struct fuse_entry_out *o) */ void fuse_invalidate_attr(struct inode *inode) { - get_fuse_inode(inode)->i_time = jiffies - 1; + get_fuse_inode(inode)->i_time = 0; } /* @@ -63,7 +91,7 @@ void fuse_invalidate_attr(struct inode *inode) */ static void fuse_invalidate_entry_cache(struct dentry *entry) { - entry->d_time = jiffies - 1; + fuse_dentry_settime(entry, 0); } /* @@ -105,7 +133,7 @@ static int fuse_dentry_revalidate(struct dentry *entry, struct nameidata *nd) if (inode && is_bad_inode(inode)) return 0; - else if (time_after(jiffies, entry->d_time)) { + else if (fuse_dentry_time(entry) < get_jiffies_64()) { int err; struct fuse_entry_out outarg; struct fuse_conn *fc; @@ -669,7 +697,7 @@ static int fuse_revalidate(struct dentry *entry) if (!fuse_allow_task(fc, current)) return -EACCES; if (get_node_id(inode) != FUSE_ROOT_ID && - time_before_eq(jiffies, fi->i_time)) + fi->i_time >= get_jiffies_64()) return 0; return fuse_do_getattr(inode); diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index 0dbf96621841..69c7750d55b8 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -59,7 +59,7 @@ struct fuse_inode { struct fuse_req *forget_req; /** Time in jiffies until the file attributes are valid */ - unsigned long i_time; + u64 i_time; }; /** FUSE specific file data */ diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index dcaaabd3b9c4..7d25092262ae 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -51,7 +51,7 @@ static struct inode *fuse_alloc_inode(struct super_block *sb) return NULL; fi = get_fuse_inode(inode); - fi->i_time = jiffies - 1; + fi->i_time = 0; fi->nodeid = 0; fi->nlookup = 0; fi->forget_req = fuse_request_alloc(); -- 2.20.1