ceph: set dn offset when spliced

We want to assign an offset when the dentry goes from null to linked, which
is always done by splice_dentry().  Notably, we should NOT assign an
offset when a dentry is first created and is still null.

BUG if we try to splice a non-null dentry (we shouldn't).

Signed-off-by: Sage Weil <sage@newdream.net>
This commit is contained in:
Sage Weil 2010-05-03 22:08:02 -07:00
parent 1b7facc41b
commit 1cd3935bed
2 changed files with 56 additions and 52 deletions

View File

@ -128,7 +128,8 @@ more:
dentry = list_entry(p, struct dentry, d_u.d_child);
di = ceph_dentry(dentry);
while (1) {
dout(" p %p/%p d_subdirs %p/%p\n", p->prev, p->next,
dout(" p %p/%p %s d_subdirs %p/%p\n", p->prev, p->next,
d_unhashed(dentry) ? "!hashed" : "hashed",
parent->d_subdirs.prev, parent->d_subdirs.next);
if (p == &parent->d_subdirs) {
fi->at_end = 1;
@ -571,7 +572,6 @@ static struct dentry *ceph_lookup(struct inode *dir, struct dentry *dentry,
!is_root_ceph_dentry(dir, dentry) &&
(ci->i_ceph_flags & CEPH_I_COMPLETE) &&
(__ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1))) {
di->offset = ci->i_max_offset++;
spin_unlock(&dir->i_lock);
dout(" dir %p complete, -ENOENT\n", dir);
d_add(dentry, NULL);
@ -984,8 +984,9 @@ static int ceph_d_revalidate(struct dentry *dentry, struct nameidata *nd)
{
struct inode *dir = dentry->d_parent->d_inode;
dout("d_revalidate %p '%.*s' inode %p\n", dentry,
dentry->d_name.len, dentry->d_name.name, dentry->d_inode);
dout("d_revalidate %p '%.*s' inode %p offset %lld\n", dentry,
dentry->d_name.len, dentry->d_name.name, dentry->d_inode,
ceph_dentry(dentry)->offset);
/* always trust cached snapped dentries, snapdir dentry */
if (ceph_snap(dir) != CEPH_NOSNAP) {
@ -1177,8 +1178,8 @@ void ceph_dentry_lru_touch(struct dentry *dn)
struct ceph_dentry_info *di = ceph_dentry(dn);
struct ceph_mds_client *mdsc;
dout("dentry_lru_touch %p %p '%.*s'\n", di, dn,
dn->d_name.len, dn->d_name.name);
dout("dentry_lru_touch %p %p '%.*s' (offset %lld)\n", di, dn,
dn->d_name.len, dn->d_name.name, di->offset);
if (di) {
mdsc = &ceph_sb_to_client(dn->d_sb)->mdsc;
spin_lock(&mdsc->dentry_lru_lock);

View File

@ -803,50 +803,6 @@ out_unlock:
return;
}
/*
* splice a dentry to an inode.
* caller must hold directory i_mutex for this to be safe.
*
* we will only rehash the resulting dentry if @prehash is
* true; @prehash will be set to false (for the benefit of
* the caller) if we fail.
*/
static struct dentry *splice_dentry(struct dentry *dn, struct inode *in,
bool *prehash)
{
struct dentry *realdn;
/* dn must be unhashed */
if (!d_unhashed(dn))
d_drop(dn);
realdn = d_materialise_unique(dn, in);
if (IS_ERR(realdn)) {
pr_err("splice_dentry error %p inode %p ino %llx.%llx\n",
dn, in, ceph_vinop(in));
if (prehash)
*prehash = false; /* don't rehash on error */
dn = realdn; /* note realdn contains the error */
goto out;
} else if (realdn) {
dout("dn %p (%d) spliced with %p (%d) "
"inode %p ino %llx.%llx\n",
dn, atomic_read(&dn->d_count),
realdn, atomic_read(&realdn->d_count),
realdn->d_inode, ceph_vinop(realdn->d_inode));
dput(dn);
dn = realdn;
} else {
BUG_ON(!ceph_dentry(dn));
dout("dn %p attached to %p ino %llx.%llx\n",
dn, dn->d_inode, ceph_vinop(dn->d_inode));
}
if ((!prehash || *prehash) && d_unhashed(dn))
d_rehash(dn);
out:
return dn;
}
/*
* Set dentry's directory position based on the current dir's max, and
* order it in d_subdirs, so that dcache_readdir behaves.
@ -878,6 +834,52 @@ static void ceph_set_dentry_offset(struct dentry *dn)
spin_unlock(&dcache_lock);
}
/*
* splice a dentry to an inode.
* caller must hold directory i_mutex for this to be safe.
*
* we will only rehash the resulting dentry if @prehash is
* true; @prehash will be set to false (for the benefit of
* the caller) if we fail.
*/
static struct dentry *splice_dentry(struct dentry *dn, struct inode *in,
bool *prehash)
{
struct dentry *realdn;
BUG_ON(dn->d_inode);
/* dn must be unhashed */
if (!d_unhashed(dn))
d_drop(dn);
realdn = d_materialise_unique(dn, in);
if (IS_ERR(realdn)) {
pr_err("splice_dentry error %p inode %p ino %llx.%llx\n",
dn, in, ceph_vinop(in));
if (prehash)
*prehash = false; /* don't rehash on error */
dn = realdn; /* note realdn contains the error */
goto out;
} else if (realdn) {
dout("dn %p (%d) spliced with %p (%d) "
"inode %p ino %llx.%llx\n",
dn, atomic_read(&dn->d_count),
realdn, atomic_read(&realdn->d_count),
realdn->d_inode, ceph_vinop(realdn->d_inode));
dput(dn);
dn = realdn;
} else {
BUG_ON(!ceph_dentry(dn));
dout("dn %p attached to %p ino %llx.%llx\n",
dn, dn->d_inode, ceph_vinop(dn->d_inode));
}
if ((!prehash || *prehash) && d_unhashed(dn))
d_rehash(dn);
ceph_set_dentry_offset(dn);
out:
return dn;
}
/*
* Incorporate results into the local cache. This is either just
* one inode, or a directory, dentry, and possibly linked-to inode (e.g.,
@ -1030,6 +1032,9 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req,
ceph_invalidate_dentry_lease(dn);
/* take overwritten dentry's readdir offset */
dout("dn %p gets %p offset %lld (old offset %lld)\n",
req->r_old_dentry, dn, ceph_dentry(dn)->offset,
ceph_dentry(req->r_old_dentry)->offset);
ceph_dentry(req->r_old_dentry)->offset =
ceph_dentry(dn)->offset;
@ -1074,7 +1079,6 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req,
goto done;
}
req->r_dentry = dn; /* may have spliced */
ceph_set_dentry_offset(dn);
igrab(in);
} else if (ceph_ino(in) == vino.ino &&
ceph_snap(in) == vino.snap) {
@ -1117,7 +1121,6 @@ int ceph_fill_trace(struct super_block *sb, struct ceph_mds_request *req,
err = PTR_ERR(dn);
goto done;
}
ceph_set_dentry_offset(dn);
req->r_dentry = dn; /* may have spliced */
igrab(in);
rinfo->head->is_dentry = 1; /* fool notrace handlers */