Orangefs: kernel client part 5

Signed-off-by: Mike Marshall <hubcap@omnibond.com>

1 files changed, 532 insertions, 0 deletions

diff --git a/fs/orangefs/xattr.c b/fs/orangefs/xattr.c
new file mode 100644
index 0000000..2766090
--- /dev/null
+++ b/fs/orangefs/xattr.c
@@ -0,0 +1,532 @@
+/*
+ * (C) 2001 Clemson University and The University of Chicago
+ *
+ * See COPYING in top-level directory.
+ */
+
+/*
+ *  Linux VFS extended attribute operations.
+ */
+
+#include "protocol.h"
+#include "pvfs2-kernel.h"
+#include "pvfs2-bufmap.h"
+#include <linux/posix_acl_xattr.h>
+#include <linux/xattr.h>
+
+
+#define SYSTEM_PVFS2_KEY "system.pvfs2."
+#define SYSTEM_PVFS2_KEY_LEN 13
+
+/*
+ * this function returns
+ *   0 if the key corresponding to name is not meant to be printed as part
+ *     of a listxattr.
+ *   1 if the key corresponding to name is meant to be returned as part of
+ *     a listxattr.
+ * The ones that start SYSTEM_PVFS2_KEY are the ones to avoid printing.
+ */
+static int is_reserved_key(const char *key, size_t size)
+{
+
+	if (size < SYSTEM_PVFS2_KEY_LEN)
+		return 1;
+
+	return strncmp(key, SYSTEM_PVFS2_KEY, SYSTEM_PVFS2_KEY_LEN) ?  1 : 0;
+}
+
+static inline int convert_to_internal_xattr_flags(int setxattr_flags)
+{
+	int internal_flag = 0;
+
+	if (setxattr_flags & XATTR_REPLACE) {
+		/* Attribute must exist! */
+		internal_flag = PVFS_XATTR_REPLACE;
+	} else if (setxattr_flags & XATTR_CREATE) {
+		/* Attribute must not exist */
+		internal_flag = PVFS_XATTR_CREATE;
+	}
+	return internal_flag;
+}
+
+
+/*
+ * Tries to get a specified key's attributes of a given
+ * file into a user-specified buffer. Note that the getxattr
+ * interface allows for the users to probe the size of an
+ * extended attribute by passing in a value of 0 to size.
+ * Thus our return value is always the size of the attribute
+ * unless the key does not exist for the file and/or if
+ * there were errors in fetching the attribute value.
+ */
+ssize_t pvfs2_inode_getxattr(struct inode *inode, const char *prefix,
+		const char *name, void *buffer, size_t size)
+{
+	struct pvfs2_inode_s *pvfs2_inode = PVFS2_I(inode);
+	struct pvfs2_kernel_op_s *new_op = NULL;
+	ssize_t ret = -ENOMEM;
+	ssize_t length = 0;
+	int fsuid;
+	int fsgid;
+
+	gossip_debug(GOSSIP_XATTR_DEBUG,
+		     "%s: prefix %s name %s, buffer_size %zd\n",
+		     __func__, prefix, name, size);
+
+	if (name == NULL || (size > 0 && buffer == NULL)) {
+		gossip_err("pvfs2_inode_getxattr: bogus NULL pointers\n");
+		return -EINVAL;
+	}
+	if (size < 0 ||
+	    (strlen(name) + strlen(prefix)) >= PVFS_MAX_XATTR_NAMELEN) {
+		gossip_err("Invalid size (%d) or key length (%d)\n",
+			   (int)size,
+			   (int)(strlen(name) + strlen(prefix)));
+		return -EINVAL;
+	}
+
+	fsuid = from_kuid(current_user_ns(), current_fsuid());
+	fsgid = from_kgid(current_user_ns(), current_fsgid());
+
+	gossip_debug(GOSSIP_XATTR_DEBUG,
+		     "getxattr on inode %pU, name %s "
+		     "(uid %o, gid %o)\n",
+		     get_khandle_from_ino(inode),
+		     name,
+		     fsuid,
+		     fsgid);
+
+	down_read(&pvfs2_inode->xattr_sem);
+
+	new_op = op_alloc(PVFS2_VFS_OP_GETXATTR);
+	if (!new_op)
+		goto out_unlock;
+
+	new_op->upcall.req.getxattr.refn = pvfs2_inode->refn;
+	ret = snprintf((char *)new_op->upcall.req.getxattr.key,
+		       PVFS_MAX_XATTR_NAMELEN, "%s%s", prefix, name);
+
+	/*
+	 * NOTE: Although keys are meant to be NULL terminated textual
+	 * strings, I am going to explicitly pass the length just in case
+	 * we change this later on...
+	 */
+	new_op->upcall.req.getxattr.key_sz = ret + 1;
+
+	ret = service_operation(new_op, "pvfs2_inode_getxattr",
+				get_interruptible_flag(inode));
+	if (ret != 0) {
+		if (ret == -ENOENT) {
+			ret = -ENODATA;
+			gossip_debug(GOSSIP_XATTR_DEBUG,
+				     "pvfs2_inode_getxattr: inode %pU key %s"
+				     " does not exist!\n",
+				     get_khandle_from_ino(inode),
+				     (char *)new_op->upcall.req.getxattr.key);
+		}
+		goto out_release_op;
+	}
+
+	/*
+	 * Length returned includes null terminator.
+	 */
+	length = new_op->downcall.resp.getxattr.val_sz;
+
+	/*
+	 * Just return the length of the queried attribute.
+	 */
+	if (size == 0) {
+		ret = length;
+		goto out_release_op;
+	}
+
+	/*
+	 * Check to see if key length is > provided buffer size.
+	 */
+	if (length > size) {
+		ret = -ERANGE;
+		goto out_release_op;
+	}
+
+	memset(buffer, 0, size);
+	memcpy(buffer, new_op->downcall.resp.getxattr.val, length);
+	gossip_debug(GOSSIP_XATTR_DEBUG,
+	     "pvfs2_inode_getxattr: inode %pU "
+	     "key %s key_sz %d, val_len %d\n",
+	     get_khandle_from_ino(inode),
+	     (char *)new_op->
+		upcall.req.getxattr.key,
+		     (int)new_op->
+		upcall.req.getxattr.key_sz,
+	     (int)ret);
+
+	ret = length;
+
+out_release_op:
+	op_release(new_op);
+out_unlock:
+	up_read(&pvfs2_inode->xattr_sem);
+	return ret;
+}
+
+static int pvfs2_inode_removexattr(struct inode *inode,
+			    const char *prefix,
+			    const char *name,
+			    int flags)
+{
+	struct pvfs2_inode_s *pvfs2_inode = PVFS2_I(inode);
+	struct pvfs2_kernel_op_s *new_op = NULL;
+	int ret = -ENOMEM;
+
+	down_write(&pvfs2_inode->xattr_sem);
+	new_op = op_alloc(PVFS2_VFS_OP_REMOVEXATTR);
+	if (!new_op)
+		goto out_unlock;
+
+	new_op->upcall.req.removexattr.refn = pvfs2_inode->refn;
+	/*
+	 * NOTE: Although keys are meant to be NULL terminated
+	 * textual strings, I am going to explicitly pass the
+	 * length just in case we change this later on...
+	 */
+	ret = snprintf((char *)new_op->upcall.req.removexattr.key,
+		       PVFS_MAX_XATTR_NAMELEN,
+		       "%s%s",
+		       (prefix ? prefix : ""),
+		       name);
+	new_op->upcall.req.removexattr.key_sz = ret + 1;
+
+	gossip_debug(GOSSIP_XATTR_DEBUG,
+		     "pvfs2_inode_removexattr: key %s, key_sz %d\n",
+		     (char *)new_op->upcall.req.removexattr.key,
+		     (int)new_op->upcall.req.removexattr.key_sz);
+
+	ret = service_operation(new_op,
+				"pvfs2_inode_removexattr",
+				get_interruptible_flag(inode));
+	if (ret == -ENOENT) {
+		/*
+		 * Request to replace a non-existent attribute is an error.
+		 */
+		if (flags & XATTR_REPLACE)
+			ret = -ENODATA;
+		else
+			ret = 0;
+	}
+
+	gossip_debug(GOSSIP_XATTR_DEBUG,
+		     "pvfs2_inode_removexattr: returning %d\n", ret);
+
+	op_release(new_op);
+out_unlock:
+	up_write(&pvfs2_inode->xattr_sem);
+	return ret;
+}
+
+/*
+ * Tries to set an attribute for a given key on a file.
+ *
+ * Returns a -ve number on error and 0 on success.  Key is text, but value
+ * can be binary!
+ */
+int pvfs2_inode_setxattr(struct inode *inode, const char *prefix,
+		const char *name, const void *value, size_t size, int flags)
+{
+	struct pvfs2_inode_s *pvfs2_inode = PVFS2_I(inode);
+	struct pvfs2_kernel_op_s *new_op;
+	int internal_flag = 0;
+	int ret = -ENOMEM;
+
+	gossip_debug(GOSSIP_XATTR_DEBUG,
+		     "%s: prefix %s, name %s, buffer_size %zd\n",
+		     __func__, prefix, name, size);
+
+	if (size < 0 ||
+	    size >= PVFS_MAX_XATTR_VALUELEN ||
+	    flags < 0) {
+		gossip_err("pvfs2_inode_setxattr: bogus values of size(%d), flags(%d)\n",
+			   (int)size,
+			   flags);
+		return -EINVAL;
+	}
+
+	if (name == NULL ||
+	    (size > 0 && value == NULL)) {
+		gossip_err("pvfs2_inode_setxattr: bogus NULL pointers!\n");
+		return -EINVAL;
+	}
+
+	internal_flag = convert_to_internal_xattr_flags(flags);
+
+	if (prefix) {
+		if (strlen(name) + strlen(prefix) >= PVFS_MAX_XATTR_NAMELEN) {
+			gossip_err
+			    ("pvfs2_inode_setxattr: bogus key size (%d)\n",
+			     (int)(strlen(name) + strlen(prefix)));
+			return -EINVAL;
+		}
+	} else {
+		if (strlen(name) >= PVFS_MAX_XATTR_NAMELEN) {
+			gossip_err
+			    ("pvfs2_inode_setxattr: bogus key size (%d)\n",
+			     (int)(strlen(name)));
+			return -EINVAL;
+		}
+	}
+
+	/* This is equivalent to a removexattr */
+	if (size == 0 && value == NULL) {
+		gossip_debug(GOSSIP_XATTR_DEBUG,
+			     "removing xattr (%s%s)\n",
+			     prefix,
+			     name);
+		return pvfs2_inode_removexattr(inode, prefix, name, flags);
+	}
+
+	gossip_debug(GOSSIP_XATTR_DEBUG,
+		     "setxattr on inode %pU, name %s\n",
+		     get_khandle_from_ino(inode),
+		     name);
+
+	down_write(&pvfs2_inode->xattr_sem);
+	new_op = op_alloc(PVFS2_VFS_OP_SETXATTR);
+	if (!new_op)
+		goto out_unlock;
+
+
+	new_op->upcall.req.setxattr.refn = pvfs2_inode->refn;
+	new_op->upcall.req.setxattr.flags = internal_flag;
+	/*
+	 * NOTE: Although keys are meant to be NULL terminated textual
+	 * strings, I am going to explicitly pass the length just in
+	 * case we change this later on...
+	 */
+	ret = snprintf((char *)new_op->upcall.req.setxattr.keyval.key,
+		       PVFS_MAX_XATTR_NAMELEN,
+		       "%s%s",
+		       prefix, name);
+	new_op->upcall.req.setxattr.keyval.key_sz = ret + 1;
+	memcpy(new_op->upcall.req.setxattr.keyval.val, value, size);
+	new_op->upcall.req.setxattr.keyval.val_sz = size;
+
+	gossip_debug(GOSSIP_XATTR_DEBUG,
+		     "pvfs2_inode_setxattr: key %s, key_sz %d "
+		     " value size %zd\n",
+		     (char *)new_op->upcall.req.setxattr.keyval.key,
+		     (int)new_op->upcall.req.setxattr.keyval.key_sz,
+		     size);
+
+	ret = service_operation(new_op,
+				"pvfs2_inode_setxattr",
+				get_interruptible_flag(inode));
+
+	gossip_debug(GOSSIP_XATTR_DEBUG,
+		     "pvfs2_inode_setxattr: returning %d\n",
+		     ret);
+
+	/* when request is serviced properly, free req op struct */
+	op_release(new_op);
+out_unlock:
+	up_write(&pvfs2_inode->xattr_sem);
+	return ret;
+}
+
+/*
+ * Tries to get a specified object's keys into a user-specified buffer of a
+ * given size.  Note that like the previous instances of xattr routines, this
+ * also allows you to pass in a NULL pointer and 0 size to probe the size for
+ * subsequent memory allocations. Thus our return value is always the size of
+ * all the keys unless there were errors in fetching the keys!
+ */
+ssize_t pvfs2_listxattr(struct dentry *dentry, char *buffer, size_t size)
+{
+	struct inode *inode = dentry->d_inode;
+	struct pvfs2_inode_s *pvfs2_inode = PVFS2_I(inode);
+	struct pvfs2_kernel_op_s *new_op;
+	__u64 token = PVFS_ITERATE_START;
+	ssize_t ret = -ENOMEM;
+	ssize_t total = 0;
+	ssize_t length = 0;
+	int count_keys = 0;
+	int key_size;
+	int i = 0;
+
+	if (size > 0 && buffer == NULL) {
+		gossip_err("%s: bogus NULL pointers\n", __func__);
+		return -EINVAL;
+	}
+	if (size < 0) {
+		gossip_err("Invalid size (%d)\n", (int)size);
+		return -EINVAL;
+	}
+
+	down_read(&pvfs2_inode->xattr_sem);
+	new_op = op_alloc(PVFS2_VFS_OP_LISTXATTR);
+	if (!new_op)
+		goto out_unlock;
+
+	if (buffer && size > 0)
+		memset(buffer, 0, size);
+
+try_again:
+	key_size = 0;
+	new_op->upcall.req.listxattr.refn = pvfs2_inode->refn;
+	new_op->upcall.req.listxattr.token = token;
+	new_op->upcall.req.listxattr.requested_count =
+	    (size == 0) ? 0 : PVFS_MAX_XATTR_LISTLEN;
+	ret = service_operation(new_op, __func__,
+				get_interruptible_flag(inode));
+	if (ret != 0)
+		goto done;
+
+	if (size == 0) {
+		/*
+		 * This is a bit of a big upper limit, but I did not want to
+		 * spend too much time getting this correct, since users end
+		 * up allocating memory rather than us...
+		 */
+		total = new_op->downcall.resp.listxattr.returned_count *
+			PVFS_MAX_XATTR_NAMELEN;
+		goto done;
+	}
+
+	length = new_op->downcall.resp.listxattr.keylen;
+	if (length == 0)
+		goto done;
+
+	/*
+	 * Check to see how much can be fit in the buffer. Fit only whole keys.
+	 */
+	for (i = 0; i < new_op->downcall.resp.listxattr.returned_count; i++) {
+		if (total + new_op->downcall.resp.listxattr.lengths[i] > size)
+			goto done;
+
+		/*
+		 * Since many dumb programs try to setxattr() on our reserved
+		 * xattrs this is a feeble attempt at defeating those by not
+		 * listing them in the output of listxattr.. sigh
+		 */
+		if (is_reserved_key(new_op->downcall.resp.listxattr.key +
+				    key_size,
+				    new_op->downcall.resp.
+					listxattr.lengths[i])) {
+			gossip_debug(GOSSIP_XATTR_DEBUG, "Copying key %d -> %s\n",
+					i, new_op->downcall.resp.listxattr.key +
+						key_size);
+			memcpy(buffer + total,
+				new_op->downcall.resp.listxattr.key + key_size,
+				new_op->downcall.resp.listxattr.lengths[i]);
+			total += new_op->downcall.resp.listxattr.lengths[i];
+			count_keys++;
+		} else {
+			gossip_debug(GOSSIP_XATTR_DEBUG, "[RESERVED] key %d -> %s\n",
+					i, new_op->downcall.resp.listxattr.key +
+						key_size);
+		}
+		key_size += new_op->downcall.resp.listxattr.lengths[i];
+	}
+
+	/*
+	 * Since the buffer was large enough, we might have to continue
+	 * fetching more keys!
+	 */
+	token = new_op->downcall.resp.listxattr.token;
+	if (token != PVFS_ITERATE_END)
+		goto try_again;
+
+done:
+	gossip_debug(GOSSIP_XATTR_DEBUG, "%s: returning %d"
+		     " [size of buffer %ld] (filled in %d keys)\n",
+		     __func__,
+		     ret ? (int)ret : (int)total,
+		     (long)size,
+		     count_keys);
+	op_release(new_op);
+	if (ret == 0)
+		ret = total;
+out_unlock:
+	up_read(&pvfs2_inode->xattr_sem);
+	return ret;
+}
+
+int pvfs2_xattr_set_default(struct dentry *dentry,
+			    const char *name,
+			    const void *buffer,
+			    size_t size,
+			    int flags,
+			    int handler_flags)
+{
+	return pvfs2_inode_setxattr(dentry->d_inode,
+				    PVFS2_XATTR_NAME_DEFAULT_PREFIX,
+				    name,
+				    buffer,
+				    size,
+				    flags);
+}
+
+int pvfs2_xattr_get_default(struct dentry *dentry,
+			    const char *name,
+			    void *buffer,
+			    size_t size,
+			    int handler_flags)
+{
+	return pvfs2_inode_getxattr(dentry->d_inode,
+				    PVFS2_XATTR_NAME_DEFAULT_PREFIX,
+				    name,
+				    buffer,
+				    size);
+
+}
+
+static int pvfs2_xattr_set_trusted(struct dentry *dentry,
+			    const char *name,
+			    const void *buffer,
+			    size_t size,
+			    int flags,
+			    int handler_flags)
+{
+	return pvfs2_inode_setxattr(dentry->d_inode,
+				    PVFS2_XATTR_NAME_TRUSTED_PREFIX,
+				    name,
+				    buffer,
+				    size,
+				    flags);
+}
+
+static int pvfs2_xattr_get_trusted(struct dentry *dentry,
+			    const char *name,
+			    void *buffer,
+			    size_t size,
+			    int handler_flags)
+{
+	return pvfs2_inode_getxattr(dentry->d_inode,
+				    PVFS2_XATTR_NAME_TRUSTED_PREFIX,
+				    name,
+				    buffer,
+				    size);
+}
+
+static struct xattr_handler pvfs2_xattr_trusted_handler = {
+	.prefix = PVFS2_XATTR_NAME_TRUSTED_PREFIX,
+	.get = pvfs2_xattr_get_trusted,
+	.set = pvfs2_xattr_set_trusted,
+};
+
+static struct xattr_handler pvfs2_xattr_default_handler = {
+	/*
+	 * NOTE: this is set to be the empty string.
+	 * so that all un-prefixed xattrs keys get caught
+	 * here!
+	 */
+	.prefix = PVFS2_XATTR_NAME_DEFAULT_PREFIX,
+	.get = pvfs2_xattr_get_default,
+	.set = pvfs2_xattr_set_default,
+};
+
+const struct xattr_handler *pvfs2_xattr_handlers[] = {
+	&posix_acl_access_xattr_handler,
+	&posix_acl_default_xattr_handler,
+	&pvfs2_xattr_trusted_handler,
+	&pvfs2_xattr_default_handler,
+	NULL
+};