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[PATCH] fuse: fix bug in negative lookup

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If negative entries (nodeid == 0) were sent in reply to LOOKUP requests,
two bugs could be triggered:

- looking up a negative entry would return -EIO,

- revaildate on an entry which turned negative would send a FORGET
  request with zero nodeid, which would cause an abort() in the
  library.

The above would only happen if the 'negative_timeout=N' option was used,
otherwise lookups reply -ENOENT, which worked correctly.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Miklos Szeredi 2006-02-28 16:59:03 -08:00 committed by Linus Torvalds
parent 511030bcd2
commit 50322fe7d4
1 changed files with 8 additions and 2 deletions
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10
fs/fuse/dir.c
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@ -111,6 +111,8 @@ static int fuse_dentry_revalidate(struct dentry *entry, struct nameidata *nd)
/* Doesn't hurt to "reset" the validity timeout */ /* Doesn't hurt to "reset" the validity timeout */
fuse_invalidate_entry_cache(entry); fuse_invalidate_entry_cache(entry);
/* For negative dentries, always do a fresh lookup */
if (!inode) if (!inode)
return 0; return 0;
@ -122,6 +124,9 @@ static int fuse_dentry_revalidate(struct dentry *entry, struct nameidata *nd)
fuse_lookup_init(req, entry->d_parent->d_inode, entry, &outarg); fuse_lookup_init(req, entry->d_parent->d_inode, entry, &outarg);
request_send(fc, req); request_send(fc, req);
err = req->out.h.error; err = req->out.h.error;
/* Zero nodeid is same as -ENOENT */
if (!err && !outarg.nodeid)
err = -ENOENT;
if (!err) { if (!err) {
struct fuse_inode *fi = get_fuse_inode(inode); struct fuse_inode *fi = get_fuse_inode(inode);
if (outarg.nodeid != get_node_id(inode)) { if (outarg.nodeid != get_node_id(inode)) {
@ -190,8 +195,9 @@ static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry,
fuse_lookup_init(req, dir, entry, &outarg); fuse_lookup_init(req, dir, entry, &outarg);
request_send(fc, req); request_send(fc, req);
err = req->out.h.error; err = req->out.h.error;
if (!err && ((outarg.nodeid && invalid_nodeid(outarg.nodeid)) || /* Zero nodeid is same as -ENOENT, but with valid timeout */
!valid_mode(outarg.attr.mode))) if (!err && outarg.nodeid &&
(invalid_nodeid(outarg.nodeid) || !valid_mode(outarg.attr.mode)))
err = -EIO; err = -EIO;
if (!err && outarg.nodeid) { if (!err && outarg.nodeid) {
inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation, inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation,