ceph: inode operations

Inode cache and inode operations.  We also include routines to
incorporate metadata structures returned by the MDS into the client
cache, and some helpers to deal with file capabilities and metadata
leases.  The bulk of that work is done by fill_inode() and
fill_trace().

Signed-off-by: Sage Weil <sage@newdream.net>

1 files changed, 833 insertions, 0 deletions

diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c
new file mode 100644
index 00000000000..8eaac04d1b8
--- /dev/null
+++ b/fs/ceph/xattr.c
@@ -0,0 +1,833 @@
+#include "ceph_debug.h"
+#include "super.h"
+#include "decode.h"
+
+#include <linux/xattr.h>
+
+static bool ceph_is_valid_xattr(const char *name)
+{
+	return !strncmp(name, XATTR_SECURITY_PREFIX,
+			XATTR_SECURITY_PREFIX_LEN) ||
+	       !strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN) ||
+	       !strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN);
+}
+
+/*
+ * These define virtual xattrs exposing the recursive directory
+ * statistics and layout metadata.
+ */
+struct ceph_vxattr_cb {
+	bool readonly;
+	char *name;
+	size_t (*getxattr_cb)(struct ceph_inode_info *ci, char *val,
+			      size_t size);
+};
+
+/* directories */
+
+static size_t ceph_vxattrcb_entries(struct ceph_inode_info *ci, char *val,
+					size_t size)
+{
+	return snprintf(val, size, "%lld", ci->i_files + ci->i_subdirs);
+}
+
+static size_t ceph_vxattrcb_files(struct ceph_inode_info *ci, char *val,
+				      size_t size)
+{
+	return snprintf(val, size, "%lld", ci->i_files);
+}
+
+static size_t ceph_vxattrcb_subdirs(struct ceph_inode_info *ci, char *val,
+					size_t size)
+{
+	return snprintf(val, size, "%lld", ci->i_subdirs);
+}
+
+static size_t ceph_vxattrcb_rentries(struct ceph_inode_info *ci, char *val,
+					 size_t size)
+{
+	return snprintf(val, size, "%lld", ci->i_rfiles + ci->i_rsubdirs);
+}
+
+static size_t ceph_vxattrcb_rfiles(struct ceph_inode_info *ci, char *val,
+				       size_t size)
+{
+	return snprintf(val, size, "%lld", ci->i_rfiles);
+}
+
+static size_t ceph_vxattrcb_rsubdirs(struct ceph_inode_info *ci, char *val,
+					 size_t size)
+{
+	return snprintf(val, size, "%lld", ci->i_rsubdirs);
+}
+
+static size_t ceph_vxattrcb_rbytes(struct ceph_inode_info *ci, char *val,
+				       size_t size)
+{
+	return snprintf(val, size, "%lld", ci->i_rbytes);
+}
+
+static size_t ceph_vxattrcb_rctime(struct ceph_inode_info *ci, char *val,
+				       size_t size)
+{
+	return snprintf(val, size, "%ld.%ld", (long)ci->i_rctime.tv_sec,
+			(long)ci->i_rctime.tv_nsec);
+}
+
+static struct ceph_vxattr_cb ceph_dir_vxattrs[] = {
+	{ true, "user.ceph.dir.entries", ceph_vxattrcb_entries},
+	{ true, "user.ceph.dir.files", ceph_vxattrcb_files},
+	{ true, "user.ceph.dir.subdirs", ceph_vxattrcb_subdirs},
+	{ true, "user.ceph.dir.rentries", ceph_vxattrcb_rentries},
+	{ true, "user.ceph.dir.rfiles", ceph_vxattrcb_rfiles},
+	{ true, "user.ceph.dir.rsubdirs", ceph_vxattrcb_rsubdirs},
+	{ true, "user.ceph.dir.rbytes", ceph_vxattrcb_rbytes},
+	{ true, "user.ceph.dir.rctime", ceph_vxattrcb_rctime},
+	{ true, NULL, NULL }
+};
+
+/* files */
+
+static size_t ceph_vxattrcb_layout(struct ceph_inode_info *ci, char *val,
+				   size_t size)
+{
+	return snprintf(val, size,
+		"chunk_bytes=%lld\nstripe_count=%lld\nobject_size=%lld\n",
+		(unsigned long long)ceph_file_layout_su(ci->i_layout),
+		(unsigned long long)ceph_file_layout_stripe_count(ci->i_layout),
+		(unsigned long long)ceph_file_layout_object_size(ci->i_layout));
+}
+
+static struct ceph_vxattr_cb ceph_file_vxattrs[] = {
+	{ true, "user.ceph.layout", ceph_vxattrcb_layout},
+	{ NULL, NULL }
+};
+
+static struct ceph_vxattr_cb *ceph_inode_vxattrs(struct inode *inode)
+{
+	if (S_ISDIR(inode->i_mode))
+		return ceph_dir_vxattrs;
+	else if (S_ISREG(inode->i_mode))
+		return ceph_file_vxattrs;
+	return NULL;
+}
+
+static struct ceph_vxattr_cb *ceph_match_vxattr(struct ceph_vxattr_cb *vxattr,
+						const char *name)
+{
+	do {
+		if (strcmp(vxattr->name, name) == 0)
+			return vxattr;
+		vxattr++;
+	} while (vxattr->name);
+	return NULL;
+}
+
+static int __set_xattr(struct ceph_inode_info *ci,
+			   const char *name, int name_len,
+			   const char *val, int val_len,
+			   int dirty,
+			   int should_free_name, int should_free_val,
+			   struct ceph_inode_xattr **newxattr)
+{
+	struct rb_node **p;
+	struct rb_node *parent = NULL;
+	struct ceph_inode_xattr *xattr = NULL;
+	int c;
+	int new = 0;
+
+	p = &ci->i_xattrs.index.rb_node;
+	while (*p) {
+		parent = *p;
+		xattr = rb_entry(parent, struct ceph_inode_xattr, node);
+		c = strncmp(name, xattr->name, min(name_len, xattr->name_len));
+		if (c < 0)
+			p = &(*p)->rb_left;
+		else if (c > 0)
+			p = &(*p)->rb_right;
+		else {
+			if (name_len == xattr->name_len)
+				break;
+			else if (name_len < xattr->name_len)
+				p = &(*p)->rb_left;
+			else
+				p = &(*p)->rb_right;
+		}
+		xattr = NULL;
+	}
+
+	if (!xattr) {
+		new = 1;
+		xattr = *newxattr;
+		xattr->name = name;
+		xattr->name_len = name_len;
+		xattr->should_free_name = should_free_name;
+
+		ci->i_xattrs.count++;
+		dout("__set_xattr count=%d\n", ci->i_xattrs.count);
+	} else {
+		kfree(*newxattr);
+		*newxattr = NULL;
+		if (xattr->should_free_val)
+			kfree((void *)xattr->val);
+
+		if (should_free_name) {
+			kfree((void *)name);
+			name = xattr->name;
+		}
+		ci->i_xattrs.names_size -= xattr->name_len;
+		ci->i_xattrs.vals_size -= xattr->val_len;
+	}
+	if (!xattr) {
+		pr_err("__set_xattr ENOMEM on %p %llx.%llx xattr %s=%s\n",
+		       &ci->vfs_inode, ceph_vinop(&ci->vfs_inode), name,
+		       xattr->val);
+		return -ENOMEM;
+	}
+	ci->i_xattrs.names_size += name_len;
+	ci->i_xattrs.vals_size += val_len;
+	if (val)
+		xattr->val = val;
+	else
+		xattr->val = "";
+
+	xattr->val_len = val_len;
+	xattr->dirty = dirty;
+	xattr->should_free_val = (val && should_free_val);
+
+	if (new) {
+		rb_link_node(&xattr->node, parent, p);
+		rb_insert_color(&xattr->node, &ci->i_xattrs.index);
+		dout("__set_xattr_val p=%p\n", p);
+	}
+
+	dout("__set_xattr_val added %llx.%llx xattr %p %s=%.*s\n",
+	     ceph_vinop(&ci->vfs_inode), xattr, name, val_len, val);
+
+	return 0;
+}
+
+static struct ceph_inode_xattr *__get_xattr(struct ceph_inode_info *ci,
+			   const char *name)
+{
+	struct rb_node **p;
+	struct rb_node *parent = NULL;
+	struct ceph_inode_xattr *xattr = NULL;
+	int c;
+
+	p = &ci->i_xattrs.index.rb_node;
+	while (*p) {
+		parent = *p;
+		xattr = rb_entry(parent, struct ceph_inode_xattr, node);
+		c = strncmp(name, xattr->name, xattr->name_len);
+		if (c < 0)
+			p = &(*p)->rb_left;
+		else if (c > 0)
+			p = &(*p)->rb_right;
+		else {
+			dout("__get_xattr %s: found %.*s\n", name,
+			     xattr->val_len, xattr->val);
+			return xattr;
+		}
+	}
+
+	dout("__get_xattr %s: not found\n", name);
+
+	return NULL;
+}
+
+static void __free_xattr(struct ceph_inode_xattr *xattr)
+{
+	BUG_ON(!xattr);
+
+	if (xattr->should_free_name)
+		kfree((void *)xattr->name);
+	if (xattr->should_free_val)
+		kfree((void *)xattr->val);
+
+	kfree(xattr);
+}
+
+static int __remove_xattr(struct ceph_inode_info *ci,
+			  struct ceph_inode_xattr *xattr)
+{
+	if (!xattr)
+		return -EOPNOTSUPP;
+
+	rb_erase(&xattr->node, &ci->i_xattrs.index);
+
+	if (xattr->should_free_name)
+		kfree((void *)xattr->name);
+	if (xattr->should_free_val)
+		kfree((void *)xattr->val);
+
+	ci->i_xattrs.names_size -= xattr->name_len;
+	ci->i_xattrs.vals_size -= xattr->val_len;
+	ci->i_xattrs.count--;
+	kfree(xattr);
+
+	return 0;
+}
+
+static int __remove_xattr_by_name(struct ceph_inode_info *ci,
+			   const char *name)
+{
+	struct rb_node **p;
+	struct ceph_inode_xattr *xattr;
+	int err;
+
+	p = &ci->i_xattrs.index.rb_node;
+	xattr = __get_xattr(ci, name);
+	err = __remove_xattr(ci, xattr);
+	return err;
+}
+
+static char *__copy_xattr_names(struct ceph_inode_info *ci,
+				char *dest)
+{
+	struct rb_node *p;
+	struct ceph_inode_xattr *xattr = NULL;
+
+	p = rb_first(&ci->i_xattrs.index);
+	dout("__copy_xattr_names count=%d\n", ci->i_xattrs.count);
+
+	while (p) {
+		xattr = rb_entry(p, struct ceph_inode_xattr, node);
+		memcpy(dest, xattr->name, xattr->name_len);
+		dest[xattr->name_len] = '\0';
+
+		dout("dest=%s %p (%s) (%d/%d)\n", dest, xattr, xattr->name,
+		     xattr->name_len, ci->i_xattrs.names_size);
+
+		dest += xattr->name_len + 1;
+		p = rb_next(p);
+	}
+
+	return dest;
+}
+
+void __ceph_destroy_xattrs(struct ceph_inode_info *ci)
+{
+	struct rb_node *p, *tmp;
+	struct ceph_inode_xattr *xattr = NULL;
+
+	p = rb_first(&ci->i_xattrs.index);
+
+	dout("__ceph_destroy_xattrs p=%p\n", p);
+
+	while (p) {
+		xattr = rb_entry(p, struct ceph_inode_xattr, node);
+		tmp = p;
+		p = rb_next(tmp);
+		dout("__ceph_destroy_xattrs next p=%p (%.*s)\n", p,
+		     xattr->name_len, xattr->name);
+		rb_erase(tmp, &ci->i_xattrs.index);
+
+		__free_xattr(xattr);
+	}
+
+	ci->i_xattrs.names_size = 0;
+	ci->i_xattrs.vals_size = 0;
+	ci->i_xattrs.index_version = 0;
+	ci->i_xattrs.count = 0;
+	ci->i_xattrs.index = RB_ROOT;
+}
+
+static int __build_xattrs(struct inode *inode)
+{
+	u32 namelen;
+	u32 numattr = 0;
+	void *p, *end;
+	u32 len;
+	const char *name, *val;
+	struct ceph_inode_info *ci = ceph_inode(inode);
+	int xattr_version;
+	struct ceph_inode_xattr **xattrs = NULL;
+	int err;
+	int i;
+
+	dout("__build_xattrs() len=%d\n",
+	     ci->i_xattrs.blob ? (int)ci->i_xattrs.blob->vec.iov_len : 0);
+
+	if (ci->i_xattrs.index_version >= ci->i_xattrs.version)
+		return 0; /* already built */
+
+	__ceph_destroy_xattrs(ci);
+
+start:
+	/* updated internal xattr rb tree */
+	if (ci->i_xattrs.blob && ci->i_xattrs.blob->vec.iov_len > 4) {
+		p = ci->i_xattrs.blob->vec.iov_base;
+		end = p + ci->i_xattrs.blob->vec.iov_len;
+		ceph_decode_32_safe(&p, end, numattr, bad);
+		xattr_version = ci->i_xattrs.version;
+		spin_unlock(&inode->i_lock);
+
+		xattrs = kcalloc(numattr, sizeof(struct ceph_xattr *),
+				 GFP_NOFS);
+		err = -ENOMEM;
+		if (!xattrs)
+			goto bad_lock;
+		memset(xattrs, 0, numattr*sizeof(struct ceph_xattr *));
+		for (i = 0; i < numattr; i++) {
+			xattrs[i] = kmalloc(sizeof(struct ceph_inode_xattr),
+					    GFP_NOFS);
+			if (!xattrs[i])
+				goto bad_lock;
+		}
+
+		spin_lock(&inode->i_lock);
+		if (ci->i_xattrs.version != xattr_version) {
+			/* lost a race, retry */
+			for (i = 0; i < numattr; i++)
+				kfree(xattrs[i]);
+			kfree(xattrs);
+			goto start;
+		}
+		err = -EIO;
+		while (numattr--) {
+			ceph_decode_32_safe(&p, end, len, bad);
+			namelen = len;
+			name = p;
+			p += len;
+			ceph_decode_32_safe(&p, end, len, bad);
+			val = p;
+			p += len;
+
+			err = __set_xattr(ci, name, namelen, val, len,
+					  0, 0, 0, &xattrs[numattr]);
+
+			if (err < 0)
+				goto bad;
+		}
+		kfree(xattrs);
+	}
+	ci->i_xattrs.index_version = ci->i_xattrs.version;
+	ci->i_xattrs.dirty = false;
+
+	return err;
+bad_lock:
+	spin_lock(&inode->i_lock);
+bad:
+	if (xattrs) {
+		for (i = 0; i < numattr; i++)
+			kfree(xattrs[i]);
+		kfree(xattrs);
+	}
+	ci->i_xattrs.names_size = 0;
+	return err;
+}
+
+static int __get_required_blob_size(struct ceph_inode_info *ci, int name_size,
+				    int val_size)
+{
+	/*
+	 * 4 bytes for the length, and additional 4 bytes per each xattr name,
+	 * 4 bytes per each value
+	 */
+	int size = 4 + ci->i_xattrs.count*(4 + 4) +
+			     ci->i_xattrs.names_size +
+			     ci->i_xattrs.vals_size;
+	dout("__get_required_blob_size c=%d names.size=%d vals.size=%d\n",
+	     ci->i_xattrs.count, ci->i_xattrs.names_size,
+	     ci->i_xattrs.vals_size);
+
+	if (name_size)
+		size += 4 + 4 + name_size + val_size;
+
+	return size;
+}
+
+/*
+ * If there are dirty xattrs, reencode xattrs into the prealloc_blob
+ * and swap into place.
+ */
+void __ceph_build_xattrs_blob(struct ceph_inode_info *ci)
+{
+	struct rb_node *p;
+	struct ceph_inode_xattr *xattr = NULL;
+	void *dest;
+
+	dout("__build_xattrs_blob %p\n", &ci->vfs_inode);
+	if (ci->i_xattrs.dirty) {
+		int need = __get_required_blob_size(ci, 0, 0);
+
+		BUG_ON(need > ci->i_xattrs.prealloc_blob->alloc_len);
+
+		p = rb_first(&ci->i_xattrs.index);
+		dest = ci->i_xattrs.prealloc_blob->vec.iov_base;
+
+		ceph_encode_32(&dest, ci->i_xattrs.count);
+		while (p) {
+			xattr = rb_entry(p, struct ceph_inode_xattr, node);
+
+			ceph_encode_32(&dest, xattr->name_len);
+			memcpy(dest, xattr->name, xattr->name_len);
+			dest += xattr->name_len;
+			ceph_encode_32(&dest, xattr->val_len);
+			memcpy(dest, xattr->val, xattr->val_len);
+			dest += xattr->val_len;
+
+			p = rb_next(p);
+		}
+
+		/* adjust buffer len; it may be larger than we need */
+		ci->i_xattrs.prealloc_blob->vec.iov_len =
+			dest - ci->i_xattrs.prealloc_blob->vec.iov_base;
+
+		ceph_buffer_put(ci->i_xattrs.blob);
+		ci->i_xattrs.blob = ci->i_xattrs.prealloc_blob;
+		ci->i_xattrs.prealloc_blob = NULL;
+		ci->i_xattrs.dirty = false;
+	}
+}
+
+ssize_t ceph_getxattr(struct dentry *dentry, const char *name, void *value,
+		      size_t size)
+{
+	struct inode *inode = dentry->d_inode;
+	struct ceph_inode_info *ci = ceph_inode(inode);
+	struct ceph_vxattr_cb *vxattrs = ceph_inode_vxattrs(inode);
+	int err;
+	struct ceph_inode_xattr *xattr;
+	struct ceph_vxattr_cb *vxattr = NULL;
+
+	if (!ceph_is_valid_xattr(name))
+		return -ENODATA;
+
+	/* let's see if a virtual xattr was requested */
+	if (vxattrs)
+		vxattr = ceph_match_vxattr(vxattrs, name);
+
+	spin_lock(&inode->i_lock);
+	dout("getxattr %p ver=%lld index_ver=%lld\n", inode,
+	     ci->i_xattrs.version, ci->i_xattrs.index_version);
+
+	if (__ceph_caps_issued_mask(ci, CEPH_CAP_XATTR_SHARED, 1) &&
+	    (ci->i_xattrs.index_version >= ci->i_xattrs.version)) {
+		goto get_xattr;
+	} else {
+		spin_unlock(&inode->i_lock);
+		/* get xattrs from mds (if we don't already have them) */
+		err = ceph_do_getattr(inode, CEPH_STAT_CAP_XATTR);
+		if (err)
+			return err;
+	}
+
+	spin_lock(&inode->i_lock);
+
+	if (vxattr && vxattr->readonly) {
+		err = vxattr->getxattr_cb(ci, value, size);
+		goto out;
+	}
+
+	err = __build_xattrs(inode);
+	if (err < 0)
+		goto out;
+
+get_xattr:
+	err = -ENODATA;  /* == ENOATTR */
+	xattr = __get_xattr(ci, name);
+	if (!xattr) {
+		if (vxattr)
+			err = vxattr->getxattr_cb(ci, value, size);
+		goto out;
+	}
+
+	err = -ERANGE;
+	if (size && size < xattr->val_len)
+		goto out;
+
+	err = xattr->val_len;
+	if (size == 0)
+		goto out;
+
+	memcpy(value, xattr->val, xattr->val_len);
+
+out:
+	spin_unlock(&inode->i_lock);
+	return err;
+}
+
+ssize_t ceph_listxattr(struct dentry *dentry, char *names, size_t size)
+{
+	struct inode *inode = dentry->d_inode;
+	struct ceph_inode_info *ci = ceph_inode(inode);
+	struct ceph_vxattr_cb *vxattrs = ceph_inode_vxattrs(inode);
+	u32 vir_namelen = 0;
+	u32 namelen;
+	int err;
+	u32 len;
+	int i;
+
+	spin_lock(&inode->i_lock);
+	dout("listxattr %p ver=%lld index_ver=%lld\n", inode,
+	     ci->i_xattrs.version, ci->i_xattrs.index_version);
+
+	if (__ceph_caps_issued_mask(ci, CEPH_CAP_XATTR_SHARED, 1) &&
+	    (ci->i_xattrs.index_version > ci->i_xattrs.version)) {
+		goto list_xattr;
+	} else {
+		spin_unlock(&inode->i_lock);
+		err = ceph_do_getattr(inode, CEPH_STAT_CAP_XATTR);
+		if (err)
+			return err;
+	}
+
+	spin_lock(&inode->i_lock);
+
+	err = __build_xattrs(inode);
+	if (err < 0)
+		goto out;
+
+list_xattr:
+	vir_namelen = 0;
+	/* include virtual dir xattrs */
+	if (vxattrs)
+		for (i = 0; vxattrs[i].name; i++)
+			vir_namelen += strlen(vxattrs[i].name) + 1;
+	/* adding 1 byte per each variable due to the null termination */
+	namelen = vir_namelen + ci->i_xattrs.names_size + ci->i_xattrs.count;
+	err = -ERANGE;
+	if (size && namelen > size)
+		goto out;
+
+	err = namelen;
+	if (size == 0)
+		goto out;
+
+	names = __copy_xattr_names(ci, names);
+
+	/* virtual xattr names, too */
+	if (vxattrs)
+		for (i = 0; vxattrs[i].name; i++) {
+			len = sprintf(names, "%s", vxattrs[i].name);
+			names += len + 1;
+		}
+
+out:
+	spin_unlock(&inode->i_lock);
+	return err;
+}
+
+static int ceph_sync_setxattr(struct dentry *dentry, const char *name,
+			      const char *value, size_t size, int flags)
+{
+	struct ceph_client *client = ceph_client(dentry->d_sb);
+	struct inode *inode = dentry->d_inode;
+	struct ceph_inode_info *ci = ceph_inode(inode);
+	struct inode *parent_inode = dentry->d_parent->d_inode;
+	struct ceph_mds_request *req;
+	struct ceph_mds_client *mdsc = &client->mdsc;
+	int err;
+	int i, nr_pages;
+	struct page **pages = NULL;
+	void *kaddr;
+
+	/* copy value into some pages */
+	nr_pages = calc_pages_for(0, size);
+	if (nr_pages) {
+		pages = kmalloc(sizeof(pages[0])*nr_pages, GFP_NOFS);
+		if (!pages)
+			return -ENOMEM;
+		err = -ENOMEM;
+		for (i = 0; i < nr_pages; i++) {
+			pages[i] = alloc_page(GFP_NOFS);
+			if (!pages[i]) {
+				nr_pages = i;
+				goto out;
+			}
+			kaddr = kmap(pages[i]);
+			memcpy(kaddr, value + i*PAGE_CACHE_SIZE,
+			       min(PAGE_CACHE_SIZE, size-i*PAGE_CACHE_SIZE));
+		}
+	}
+
+	dout("setxattr value=%.*s\n", (int)size, value);
+
+	/* do request */
+	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_SETXATTR,
+				       USE_AUTH_MDS);
+	if (IS_ERR(req))
+		return PTR_ERR(req);
+	req->r_inode = igrab(inode);
+	req->r_inode_drop = CEPH_CAP_XATTR_SHARED;
+	req->r_num_caps = 1;
+	req->r_args.setxattr.flags = cpu_to_le32(flags);
+	req->r_path2 = kstrdup(name, GFP_NOFS);
+
+	req->r_pages = pages;
+	req->r_num_pages = nr_pages;
+	req->r_data_len = size;
+
+	dout("xattr.ver (before): %lld\n", ci->i_xattrs.version);
+	err = ceph_mdsc_do_request(mdsc, parent_inode, req);
+	ceph_mdsc_put_request(req);
+	dout("xattr.ver (after): %lld\n", ci->i_xattrs.version);
+
+out:
+	if (pages) {
+		for (i = 0; i < nr_pages; i++)
+			__free_page(pages[i]);
+		kfree(pages);
+	}
+	return err;
+}
+
+int ceph_setxattr(struct dentry *dentry, const char *name,
+		  const void *value, size_t size, int flags)
+{
+	struct inode *inode = dentry->d_inode;
+	struct ceph_inode_info *ci = ceph_inode(inode);
+	struct ceph_vxattr_cb *vxattrs = ceph_inode_vxattrs(inode);
+	int err;
+	int name_len = strlen(name);
+	int val_len = size;
+	char *newname = NULL;
+	char *newval = NULL;
+	struct ceph_inode_xattr *xattr = NULL;
+	int issued;
+	int required_blob_size;
+
+	if (ceph_snap(inode) != CEPH_NOSNAP)
+		return -EROFS;
+
+	if (!ceph_is_valid_xattr(name))
+		return -EOPNOTSUPP;
+
+	if (vxattrs) {
+		struct ceph_vxattr_cb *vxattr =
+			ceph_match_vxattr(vxattrs, name);
+		if (vxattr && vxattr->readonly)
+			return -EOPNOTSUPP;
+	}
+
+	/* preallocate memory for xattr name, value, index node */
+	err = -ENOMEM;
+	newname = kmalloc(name_len + 1, GFP_NOFS);
+	if (!newname)
+		goto out;
+	memcpy(newname, name, name_len + 1);
+
+	if (val_len) {
+		newval = kmalloc(val_len + 1, GFP_NOFS);
+		if (!newval)
+			goto out;
+		memcpy(newval, value, val_len);
+		newval[val_len] = '\0';
+	}
+
+	xattr = kmalloc(sizeof(struct ceph_inode_xattr), GFP_NOFS);
+	if (!xattr)
+		goto out;
+
+	spin_lock(&inode->i_lock);
+retry:
+	issued = __ceph_caps_issued(ci, NULL);
+	if (!(issued & CEPH_CAP_XATTR_EXCL))
+		goto do_sync;
+	__build_xattrs(inode);
+
+	required_blob_size = __get_required_blob_size(ci, name_len, val_len);
+
+	if (!ci->i_xattrs.prealloc_blob ||
+	    required_blob_size > ci->i_xattrs.prealloc_blob->alloc_len) {
+		struct ceph_buffer *blob = NULL;
+
+		spin_unlock(&inode->i_lock);
+		dout(" preaallocating new blob size=%d\n", required_blob_size);
+		blob = ceph_buffer_new_alloc(required_blob_size, GFP_NOFS);
+		if (!blob)
+			goto out;
+		spin_lock(&inode->i_lock);
+		ceph_buffer_put(ci->i_xattrs.prealloc_blob);
+		ci->i_xattrs.prealloc_blob = blob;
+		goto retry;
+	}
+
+	dout("setxattr %p issued %s\n", inode, ceph_cap_string(issued));
+	err = __set_xattr(ci, newname, name_len, newval,
+			  val_len, 1, 1, 1, &xattr);
+	__ceph_mark_dirty_caps(ci, CEPH_CAP_XATTR_EXCL);
+	ci->i_xattrs.dirty = true;
+	inode->i_ctime = CURRENT_TIME;
+	spin_unlock(&inode->i_lock);
+
+	return err;
+
+do_sync:
+	spin_unlock(&inode->i_lock);
+	err = ceph_sync_setxattr(dentry, name, value, size, flags);
+out:
+	kfree(newname);
+	kfree(newval);
+	kfree(xattr);
+	return err;
+}
+
+static int ceph_send_removexattr(struct dentry *dentry, const char *name)
+{
+	struct ceph_client *client = ceph_client(dentry->d_sb);
+	struct ceph_mds_client *mdsc = &client->mdsc;
+	struct inode *inode = dentry->d_inode;
+	struct inode *parent_inode = dentry->d_parent->d_inode;
+	struct ceph_mds_request *req;
+	int err;
+
+	req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_RMXATTR,
+				       USE_AUTH_MDS);
+	if (IS_ERR(req))
+		return PTR_ERR(req);
+	req->r_inode = igrab(inode);
+	req->r_inode_drop = CEPH_CAP_XATTR_SHARED;
+	req->r_num_caps = 1;
+	req->r_path2 = kstrdup(name, GFP_NOFS);
+
+	err = ceph_mdsc_do_request(mdsc, parent_inode, req);
+	ceph_mdsc_put_request(req);
+	return err;
+}
+
+int ceph_removexattr(struct dentry *dentry, const char *name)
+{
+	struct inode *inode = dentry->d_inode;
+	struct ceph_inode_info *ci = ceph_inode(inode);
+	struct ceph_vxattr_cb *vxattrs = ceph_inode_vxattrs(inode);
+	int issued;
+	int err;
+
+	if (ceph_snap(inode) != CEPH_NOSNAP)
+		return -EROFS;
+
+	if (!ceph_is_valid_xattr(name))
+		return -EOPNOTSUPP;
+
+	if (vxattrs) {
+		struct ceph_vxattr_cb *vxattr =
+			ceph_match_vxattr(vxattrs, name);
+		if (vxattr && vxattr->readonly)
+			return -EOPNOTSUPP;
+	}
+
+	spin_lock(&inode->i_lock);
+	__build_xattrs(inode);
+	issued = __ceph_caps_issued(ci, NULL);
+	dout("removexattr %p issued %s\n", inode, ceph_cap_string(issued));
+
+	if (!(issued & CEPH_CAP_XATTR_EXCL))
+		goto do_sync;
+
+	err = __remove_xattr_by_name(ceph_inode(inode), name);
+	__ceph_mark_dirty_caps(ci, CEPH_CAP_XATTR_EXCL);
+	ci->i_xattrs.dirty = true;
+	inode->i_ctime = CURRENT_TIME;
+
+	spin_unlock(&inode->i_lock);
+
+	return err;
+do_sync:
+	spin_unlock(&inode->i_lock);
+	err = ceph_send_removexattr(dentry, name);
+	return err;
+}
+