fs/orangefs/dcache.c

Source file repositories/reference/linux-study-clean/fs/orangefs/dcache.c

File Facts

System
Linux kernel
Corpus path
fs/orangefs/dcache.c
Extension
.c
Size
3689 bytes
Lines
140
Domain
Core OS
Bucket
VFS And Filesystem Core
Inferred role
Core OS: implementation source
Status
source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

if (err) {
			gossip_debug(GOSSIP_DCACHE_DEBUG,
			    "%s:%s:%d lookup failure.\n",
			    __FILE__, __func__, __LINE__);
			goto out_drop;
		}
		if (!match_handle(new_op->downcall.resp.lookup.refn.khandle,
		    inode)) {
			gossip_debug(GOSSIP_DCACHE_DEBUG,
			    "%s:%s:%d no match.\n",
			    __FILE__, __func__, __LINE__);
			goto out_drop;
		}

	/* Negative dentry: reject if success or error other than ENOENT. */
	} else {
		gossip_debug(GOSSIP_DCACHE_DEBUG, "%s: negative dentry.\n",
		    __func__);
		if (!err || err != -ENOENT) {
			if (new_op->downcall.status != 0)
				gossip_debug(GOSSIP_DCACHE_DEBUG,
				    "%s:%s:%d lookup failure.\n",
				    __FILE__, __func__, __LINE__);
			goto out_drop;
		}
	}

	orangefs_set_timeout(dentry);
	ret = 1;
out_release_op:
	op_release(new_op);
	return ret;
out_drop:
	gossip_debug(GOSSIP_DCACHE_DEBUG, "%s:%s:%d revalidate failed\n",
	    __FILE__, __func__, __LINE__);
	goto out_release_op;
}

/*
 * Verify that dentry is valid.
 *
 * Should return 1 if dentry can still be trusted, else 0.
 */
static int orangefs_d_revalidate(struct inode *dir, const struct qstr *name,
				 struct dentry *dentry, unsigned int flags)
{
	int ret;
	unsigned long time = (unsigned long) dentry->d_fsdata;

	if (time_before(jiffies, time))
		return 1;

	if (flags & LOOKUP_RCU)
		return -ECHILD;

	gossip_debug(GOSSIP_DCACHE_DEBUG, "%s: called on dentry %p.\n",
		     __func__, dentry);

	/* skip root handle lookups. */
	if (dentry->d_inode && is_root_handle(dentry->d_inode))
		return 1;

	/*
	 * If this passes, the positive dentry still exists or the negative
	 * dentry still does not exist.
	 */
	if (!orangefs_revalidate_lookup(dir, name, dentry))
		return 0;

	/* We do not need to continue with negative dentries. */
	if (!dentry->d_inode) {
		gossip_debug(GOSSIP_DCACHE_DEBUG,
		    "%s: negative dentry or positive dentry and inode valid.\n",
		    __func__);
		return 1;
	}

	/* Now we must perform a getattr to validate the inode contents. */

	ret = orangefs_inode_check_changed(dentry->d_inode);
	if (ret < 0) {
		gossip_debug(GOSSIP_DCACHE_DEBUG, "%s:%s:%d getattr failure.\n",
		    __FILE__, __func__, __LINE__);
		return 0;
	}
	return !ret;
}

const struct dentry_operations orangefs_dentry_operations = {
	.d_revalidate = orangefs_d_revalidate,

Annotation

Implementation Notes