EXIT;
}
+/* Compare if two dentries are the same. Don't match if the existing dentry
+ * is marked invalid. Returns 1 if different, 0 if the same.
+ *
+ * This avoids a race where ll_lookup_it() instantiates a dentry, but we get
+ * an AST before calling d_revalidate_it(). The dentry still exists (marked
+ * INVALID) so d_lookup() matches it, but we have no lock on it (so
+ * lock_match() fails) and we spin around real_lookup().
+ *
+ * This race doesn't apply to lookups in d_alloc_parallel(), and for
+ * those we want to ensure that only one dentry with a given name is
+ * in ll_lookup_nd() at a time. So allow invalid dentries to match
+ * while d_in_lookup(). We will be called again when the lookup
+ * completes, and can give a different answer then.
+ */
+#if defined(HAVE_D_COMPARE_5ARGS)
+static int ll_dcompare(const struct dentry *parent, const struct dentry *dentry,
+ unsigned int len, const char *str,
+ const struct qstr *name)
+#elif defined(HAVE_D_COMPARE_4ARGS)
+static int ll_dcompare(const struct dentry *dentry, unsigned int len,
+ const char *str, const struct qstr *name)
+#endif
+{
+ ENTRY;
+
+ if (len != name->len)
+ RETURN(1);
+
+ if (memcmp(str, name->name, len))
+ RETURN(1);
+
+ CDEBUG(D_DENTRY, "found name %.*s(%p) flags %#x refc %d\n",
+ name->len, name->name, dentry, dentry->d_flags,
+ ll_d_count(dentry));
+
+ /* mountpoint is always valid */
+ if (d_mountpoint((struct dentry *)dentry))
+ RETURN(0);
+
+ /* ensure exclusion against parallel lookup of the same name */
+ if (d_in_lookup((struct dentry *)dentry))
+ return 0;
+
+ if (d_lustre_invalid(dentry))
+ RETURN(1);
+
+ RETURN(0);
+}
+
/**
* Called when last reference to a dentry is dropped and dcache wants to know
* whether or not it should cache it:
ENTRY;
LASSERT(de);
- CDEBUG(D_DENTRY, "%s dentry %.*s (%p, parent %p, inode %p) %s%s\n",
- d_lustre_invalid((struct dentry *)de) ? "deleting" : "keeping",
- de->d_name.len, de->d_name.name, de, de->d_parent, de->d_inode,
+ CDEBUG(D_DENTRY, "%s dentry %pd (%p, parent %p, inode %p) %s%s\n",
+ d_lustre_invalid(de) ? "deleting" : "keeping",
+ de, de, de->d_parent, de->d_inode,
d_unhashed((struct dentry *)de) ? "" : "hashed,",
list_empty(&de->d_subdirs) ? "" : "subdirs");
/* kernel >= 2.6.38 last refcount is decreased after this function. */
LASSERT(ll_d_count(de) == 1);
- if (d_lustre_invalid((struct dentry *)de))
+ if (d_lustre_invalid(de))
RETURN(1);
RETURN(0);
}
ENTRY;
LASSERT(de != NULL);
- CDEBUG(D_DENTRY, "ldd on dentry %.*s (%p) parent %p inode %p refc %d\n",
- de->d_name.len, de->d_name.name, de, de->d_parent, de->d_inode,
- ll_d_count(de));
+ CDEBUG(D_DENTRY, "ldd on dentry %pd (%p) parent %p inode %p refc %d\n",
+ de, de, de->d_parent, de->d_inode,
+ ll_d_count(de));
if (de->d_fsdata == NULL) {
struct ll_dentry_data *lld;
EXIT;
}
-void ll_invalidate_aliases(struct inode *inode)
+/* mark aliases invalid and prune unused aliases */
+void ll_prune_aliases(struct inode *inode)
{
struct dentry *dentry;
ENTRY;
PFID(ll_inode2fid(inode)), inode);
spin_lock(&inode->i_lock);
- hlist_for_each_entry(dentry, &inode->i_dentry, d_alias) {
- CDEBUG(D_DENTRY, "dentry in drop %.*s (%p) parent %p "
- "inode %p flags %d\n", dentry->d_name.len,
- dentry->d_name.name, dentry, dentry->d_parent,
- dentry->d_inode, dentry->d_flags);
-
- d_lustre_invalidate(dentry, 0);
- }
+ hlist_for_each_entry(dentry, &inode->i_dentry, d_alias)
+ d_lustre_invalidate(dentry);
spin_unlock(&inode->i_lock);
+ d_prune_aliases(inode);
+
EXIT;
}
void ll_lookup_finish_locks(struct lookup_intent *it, struct dentry *dentry)
{
- LASSERT(it != NULL);
- LASSERT(dentry != NULL);
+ LASSERT(it != NULL);
+ LASSERT(dentry != NULL);
if (it->it_lock_mode && dentry->d_inode != NULL) {
- struct inode *inode = dentry->d_inode;
- struct ll_sb_info *sbi = ll_i2sbi(dentry->d_inode);
+ struct inode *inode = dentry->d_inode;
+ struct ll_sb_info *sbi = ll_i2sbi(inode);
CDEBUG(D_DLMTRACE, "setting l_data to inode "DFID"(%p)\n",
PFID(ll_inode2fid(inode)), inode);
- ll_set_lock_data(sbi->ll_md_exp, inode, it, NULL);
- }
-
- /* drop lookup or getattr locks immediately */
- if (it->it_op == IT_LOOKUP || it->it_op == IT_GETATTR) {
- /* on 2.6 there are situation when several lookups and
- * revalidations may be requested during single operation.
- * therefore, we don't release intent here -bzzz */
- ll_intent_drop_lock(it);
- }
+ ll_set_lock_data(sbi->ll_md_exp, inode, it, NULL);
+ }
+
+ /* drop lookup or getattr locks immediately */
+ if (it->it_op == IT_LOOKUP || it->it_op == IT_GETATTR)
+ ll_intent_drop_lock(it);
}
static int ll_revalidate_dentry(struct dentry *dentry,
CDEBUG(D_VFSTRACE, "VFS Op:name=%s, flags=%u\n",
dentry->d_name.name, lookup_flags);
- /* mountpoint is always valid */
- if (d_mountpoint((struct dentry *)dentry))
- return 1;
-
- /* No lock -> invalid dentry */
- if (d_lustre_invalid(dentry))
- return 0;
-
/* If this is intermediate component path lookup and we were able to get
* to this dentry, then its lock has not been revoked and the
* path component is valid. */
return 1;
/* Symlink - always valid as long as the dentry was found */
-#ifdef HAVE_IOP_GET_LINK
- if (dentry->d_inode && dentry->d_inode->i_op->get_link)
-#else
- if (dentry->d_inode && dentry->d_inode->i_op->follow_link)
-#endif
- return 1;
+ /* only special case is to prevent ELOOP error from VFS during open
+ * of a foreign symlink file/dir with O_NOFOLLOW, like it happens for
+ * real symlinks. This will allow to open foreign symlink file/dir
+ * for get[dir]stripe/unlock ioctl()s.
+ */
+ if (d_is_symlink(dentry)) {
+ if (!S_ISLNK(dentry->d_inode->i_mode) &&
+ !(lookup_flags & LOOKUP_FOLLOW))
+ return 0;
+ else
+ return 1;
+ }
/*
* VFS warns us that this is the second go around and previous
return -ECHILD;
if (dentry_may_statahead(dir, dentry))
- ll_statahead(dir, &dentry, dentry->d_inode == NULL);
+ ll_revalidate_statahead(dir, &dentry, dentry->d_inode == NULL);
return 1;
}
.d_revalidate = ll_revalidate_dentry,
.d_release = ll_release,
.d_delete = ll_ddelete,
+ .d_compare = ll_dcompare,
};
git://git.whamcloud.com / fs / lustre-release.git / blobdiff