// SPDX-License-Identifier: GPL-2.0
#include <linux/ceph/ceph_debug.h>
#include <linux/ceph/pagelist.h>

#include "super.h"
#include "mds_client.h"

#include <linux/ceph/decode.h>

#include <linux/xattr.h>
#include <linux/security.h>
#include <linux/posix_acl_xattr.h>
#include <linux/slab.h>

#define XATTR_CEPH_PREFIX "ceph."
#define XATTR_CEPH_PREFIX_LEN (sizeof (XATTR_CEPH_PREFIX) - 1)

static int __remove_xattr(struct ceph_inode_info *ci,
                          struct ceph_inode_xattr *xattr);

static bool ceph_is_valid_xattr(const char *name)
{
        return !strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) ||
               !strncmp(name, XATTR_CEPH_PREFIX, XATTR_CEPH_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 {
        char *name;
        size_t name_size;       /* strlen(name) + 1 (for '\0') */
        ssize_t (*getxattr_cb)(struct ceph_inode_info *ci, char *val,
                               size_t size);
        bool (*exists_cb)(struct ceph_inode_info *ci);
        unsigned int flags;
};

#define VXATTR_FLAG_READONLY            (1<<0)
#define VXATTR_FLAG_HIDDEN              (1<<1)
#define VXATTR_FLAG_RSTAT               (1<<2)
#define VXATTR_FLAG_DIRSTAT             (1<<3)

/* layouts */

static bool ceph_vxattrcb_layout_exists(struct ceph_inode_info *ci)
{
        struct ceph_file_layout *fl = &ci->i_layout;
        return (fl->stripe_unit > 0 || fl->stripe_count > 0 ||
                fl->object_size > 0 || fl->pool_id >= 0 ||
                rcu_dereference_raw(fl->pool_ns) != NULL);
}

static ssize_t ceph_vxattrcb_layout(struct ceph_inode_info *ci, char *val,
                                    size_t size)
{
        struct ceph_fs_client *fsc = ceph_sb_to_fs_client(ci->netfs.inode.i_sb);
        struct ceph_client *cl = fsc->client;
        struct ceph_osd_client *osdc = &fsc->client->osdc;
        struct ceph_string *pool_ns;
        s64 pool = ci->i_layout.pool_id;
        const char *pool_name;
        const char *ns_field = " pool_namespace=";
        char buf[128];
        size_t len, total_len = 0;
        ssize_t ret;

        pool_ns = ceph_try_get_string(ci->i_layout.pool_ns);

        doutc(cl, "%p\n", &ci->netfs.inode);
        down_read(&osdc->lock);
        pool_name = ceph_pg_pool_name_by_id(osdc->osdmap, pool);
        if (pool_name) {
                len = snprintf(buf, sizeof(buf),
                "stripe_unit=%u stripe_count=%u object_size=%u pool=",
                ci->i_layout.stripe_unit, ci->i_layout.stripe_count,
                ci->i_layout.object_size);
                total_len = len + strlen(pool_name);
        } else {
                len = snprintf(buf, sizeof(buf),
                "stripe_unit=%u stripe_count=%u object_size=%u pool=%lld",
                ci->i_layout.stripe_unit, ci->i_layout.stripe_count,
                ci->i_layout.object_size, pool);
                total_len = len;
        }

        if (pool_ns)
                total_len += strlen(ns_field) + pool_ns->len;

        ret = total_len;
        if (size >= total_len) {
                memcpy(val, buf, len);
                ret = len;
                if (pool_name) {
                        len = strlen(pool_name);
                        memcpy(val + ret, pool_name, len);
                        ret += len;
                }
                if (pool_ns) {
                        len = strlen(ns_field);
                        memcpy(val + ret, ns_field, len);
                        ret += len;
                        memcpy(val + ret, pool_ns->str, pool_ns->len);
                        ret += pool_ns->len;
                }
        }
        up_read(&osdc->lock);
        ceph_put_string(pool_ns);
        return ret;
}

/*
 * The convention with strings in xattrs is that they should not be NULL
 * terminated, since we're returning the length with them. snprintf always
 * NULL terminates however, so call it on a temporary buffer and then memcpy
 * the result into place.
 */
static __printf(3, 4)
int ceph_fmt_xattr(char *val, size_t size, const char *fmt, ...)
{
        int ret;
        va_list args;
        char buf[96]; /* NB: reevaluate size if new vxattrs are added */

        va_start(args, fmt);
        ret = vsnprintf(buf, size ? sizeof(buf) : 0, fmt, args);
        va_end(args);

        /* Sanity check */
        if (size && ret + 1 > sizeof(buf)) {
                WARN_ONCE(true, "Returned length too big (%d)", ret);
                return -E2BIG;
        }

        if (ret <= size)
                memcpy(val, buf, ret);
        return ret;
}

static ssize_t ceph_vxattrcb_layout_stripe_unit(struct ceph_inode_info *ci,
                                                char *val, size_t size)
{
        return ceph_fmt_xattr(val, size, "%u", ci->i_layout.stripe_unit);
}

static ssize_t ceph_vxattrcb_layout_stripe_count(struct ceph_inode_info *ci,
                                                 char *val, size_t size)
{
        return ceph_fmt_xattr(val, size, "%u", ci->i_layout.stripe_count);
}

static ssize_t ceph_vxattrcb_layout_object_size(struct ceph_inode_info *ci,
                                                char *val, size_t size)
{
        return ceph_fmt_xattr(val, size, "%u", ci->i_layout.object_size);
}

static ssize_t ceph_vxattrcb_layout_pool(struct ceph_inode_info *ci,
                                         char *val, size_t size)
{
        ssize_t ret;
        struct ceph_fs_client *fsc = ceph_sb_to_fs_client(ci->netfs.inode.i_sb);
        struct ceph_osd_client *osdc = &fsc->client->osdc;
        s64 pool = ci->i_layout.pool_id;
        const char *pool_name;

        down_read(&osdc->lock);
        pool_name = ceph_pg_pool_name_by_id(osdc->osdmap, pool);
        if (pool_name) {
                ret = strlen(pool_name);
                if (ret <= size)
                        memcpy(val, pool_name, ret);
        } else {
                ret = ceph_fmt_xattr(val, size, "%lld", pool);
        }
        up_read(&osdc->lock);
        return ret;
}

static ssize_t ceph_vxattrcb_layout_pool_namespace(struct ceph_inode_info *ci,
                                                   char *val, size_t size)
{
        ssize_t ret = 0;
        struct ceph_string *ns = ceph_try_get_string(ci->i_layout.pool_ns);

        if (ns) {
                ret = ns->len;
                if (ret <= size)
                        memcpy(val, ns->str, ret);
                ceph_put_string(ns);
        }
        return ret;
}

/* directories */

static ssize_t ceph_vxattrcb_dir_entries(struct ceph_inode_info *ci, char *val,
                                         size_t size)
{
        return ceph_fmt_xattr(val, size, "%lld", ci->i_files + ci->i_subdirs);
}

static ssize_t ceph_vxattrcb_dir_files(struct ceph_inode_info *ci, char *val,
                                       size_t size)
{
        return ceph_fmt_xattr(val, size, "%lld", ci->i_files);
}

static ssize_t ceph_vxattrcb_dir_subdirs(struct ceph_inode_info *ci, char *val,
                                         size_t size)
{
        return ceph_fmt_xattr(val, size, "%lld", ci->i_subdirs);
}

static ssize_t ceph_vxattrcb_dir_rentries(struct ceph_inode_info *ci, char *val,
                                          size_t size)
{
        return ceph_fmt_xattr(val, size, "%lld",
                                ci->i_rfiles + ci->i_rsubdirs);
}

static ssize_t ceph_vxattrcb_dir_rfiles(struct ceph_inode_info *ci, char *val,
                                        size_t size)
{
        return ceph_fmt_xattr(val, size, "%lld", ci->i_rfiles);
}

static ssize_t ceph_vxattrcb_dir_rsubdirs(struct ceph_inode_info *ci, char *val,
                                          size_t size)
{
        return ceph_fmt_xattr(val, size, "%lld", ci->i_rsubdirs);
}

static ssize_t ceph_vxattrcb_dir_rsnaps(struct ceph_inode_info *ci, char *val,
                                          size_t size)
{
        return ceph_fmt_xattr(val, size, "%lld", ci->i_rsnaps);
}

static ssize_t ceph_vxattrcb_dir_rbytes(struct ceph_inode_info *ci, char *val,
                                        size_t size)
{
        return ceph_fmt_xattr(val, size, "%lld", ci->i_rbytes);
}

static ssize_t ceph_vxattrcb_dir_rctime(struct ceph_inode_info *ci, char *val,
                                        size_t size)
{
        return ceph_fmt_xattr(val, size, "%ptSp", &ci->i_rctime);
}

/* dir pin */
static bool ceph_vxattrcb_dir_pin_exists(struct ceph_inode_info *ci)
{
        return ci->i_dir_pin != -ENODATA;
}

static ssize_t ceph_vxattrcb_dir_pin(struct ceph_inode_info *ci, char *val,
                                     size_t size)
{
        return ceph_fmt_xattr(val, size, "%d", (int)ci->i_dir_pin);
}

/* quotas */
static bool ceph_vxattrcb_quota_exists(struct ceph_inode_info *ci)
{
        bool ret = false;
        spin_lock(&ci->i_ceph_lock);
        if ((ci->i_max_files || ci->i_max_bytes) &&
            ci->i_vino.snap == CEPH_NOSNAP &&
            ci->i_snap_realm &&
            ci->i_snap_realm->ino == ci->i_vino.ino)
                ret = true;
        spin_unlock(&ci->i_ceph_lock);
        return ret;
}

static ssize_t ceph_vxattrcb_quota(struct ceph_inode_info *ci, char *val,
                                   size_t size)
{
        return ceph_fmt_xattr(val, size, "max_bytes=%llu max_files=%llu",
                                ci->i_max_bytes, ci->i_max_files);
}

static ssize_t ceph_vxattrcb_quota_max_bytes(struct ceph_inode_info *ci,
                                             char *val, size_t size)
{
        return ceph_fmt_xattr(val, size, "%llu", ci->i_max_bytes);
}

static ssize_t ceph_vxattrcb_quota_max_files(struct ceph_inode_info *ci,
                                             char *val, size_t size)
{
        return ceph_fmt_xattr(val, size, "%llu", ci->i_max_files);
}

/* snapshots */
static bool ceph_vxattrcb_snap_btime_exists(struct ceph_inode_info *ci)
{
        return (ci->i_snap_btime.tv_sec != 0 || ci->i_snap_btime.tv_nsec != 0);
}

static ssize_t ceph_vxattrcb_snap_btime(struct ceph_inode_info *ci, char *val,
                                        size_t size)
{
        return ceph_fmt_xattr(val, size, "%ptSp", &ci->i_snap_btime);
}

static ssize_t ceph_vxattrcb_cluster_fsid(struct ceph_inode_info *ci,
                                          char *val, size_t size)
{
        struct ceph_fs_client *fsc = ceph_sb_to_fs_client(ci->netfs.inode.i_sb);

        return ceph_fmt_xattr(val, size, "%pU", &fsc->client->fsid);
}

static ssize_t ceph_vxattrcb_client_id(struct ceph_inode_info *ci,
                                       char *val, size_t size)
{
        struct ceph_fs_client *fsc = ceph_sb_to_fs_client(ci->netfs.inode.i_sb);

        return ceph_fmt_xattr(val, size, "client%lld",
                              ceph_client_gid(fsc->client));
}

static ssize_t ceph_vxattrcb_caps(struct ceph_inode_info *ci, char *val,
                                        size_t size)
{
        int issued;

        spin_lock(&ci->i_ceph_lock);
        issued = __ceph_caps_issued(ci, NULL);
        spin_unlock(&ci->i_ceph_lock);

        return ceph_fmt_xattr(val, size, "%s/0x%x",
                              ceph_cap_string(issued), issued);
}

static ssize_t ceph_vxattrcb_auth_mds(struct ceph_inode_info *ci,
                                       char *val, size_t size)
{
        int ret;

        spin_lock(&ci->i_ceph_lock);
        ret = ceph_fmt_xattr(val, size, "%d",
                             ci->i_auth_cap ? ci->i_auth_cap->session->s_mds : -1);
        spin_unlock(&ci->i_ceph_lock);
        return ret;
}

#if IS_ENABLED(CONFIG_FS_ENCRYPTION)
static bool ceph_vxattrcb_fscrypt_auth_exists(struct ceph_inode_info *ci)
{
        return ci->fscrypt_auth_len;
}

static ssize_t ceph_vxattrcb_fscrypt_auth(struct ceph_inode_info *ci,
                                          char *val, size_t size)
{
        if (size) {
                if (size < ci->fscrypt_auth_len)
                        return -ERANGE;
                memcpy(val, ci->fscrypt_auth, ci->fscrypt_auth_len);
        }
        return ci->fscrypt_auth_len;
}
#endif /* CONFIG_FS_ENCRYPTION */

#define CEPH_XATTR_NAME(_type, _name)   XATTR_CEPH_PREFIX #_type "." #_name
#define CEPH_XATTR_NAME2(_type, _name, _name2)  \
        XATTR_CEPH_PREFIX #_type "." #_name "." #_name2

#define XATTR_NAME_CEPH(_type, _name, _flags)                           \
        {                                                               \
                .name = CEPH_XATTR_NAME(_type, _name),                  \
                .name_size = sizeof (CEPH_XATTR_NAME(_type, _name)), \
                .getxattr_cb = ceph_vxattrcb_ ## _type ## _ ## _name, \
                .exists_cb = NULL,                                      \
                .flags = (VXATTR_FLAG_READONLY | _flags),               \
        }
#define XATTR_RSTAT_FIELD(_type, _name)                 \
        XATTR_NAME_CEPH(_type, _name, VXATTR_FLAG_RSTAT)
#define XATTR_RSTAT_FIELD_UPDATABLE(_type, _name)                       \
        {                                                               \
                .name = CEPH_XATTR_NAME(_type, _name),                  \
                .name_size = sizeof (CEPH_XATTR_NAME(_type, _name)),    \
                .getxattr_cb = ceph_vxattrcb_ ## _type ## _ ## _name,   \
                .exists_cb = NULL,                                      \
                .flags = VXATTR_FLAG_RSTAT,                             \
        }
#define XATTR_LAYOUT_FIELD(_type, _name, _field)                        \
        {                                                               \
                .name = CEPH_XATTR_NAME2(_type, _name, _field), \
                .name_size = sizeof (CEPH_XATTR_NAME2(_type, _name, _field)), \
                .getxattr_cb = ceph_vxattrcb_ ## _name ## _ ## _field, \
                .exists_cb = ceph_vxattrcb_layout_exists,       \
                .flags = VXATTR_FLAG_HIDDEN,                    \
        }
#define XATTR_QUOTA_FIELD(_type, _name)                                 \
        {                                                               \
                .name = CEPH_XATTR_NAME(_type, _name),                  \
                .name_size = sizeof(CEPH_XATTR_NAME(_type, _name)),     \
                .getxattr_cb = ceph_vxattrcb_ ## _type ## _ ## _name,   \
                .exists_cb = ceph_vxattrcb_quota_exists,                \
                .flags = VXATTR_FLAG_HIDDEN,                            \
        }

static struct ceph_vxattr ceph_dir_vxattrs[] = {
        {
                .name = "ceph.dir.layout",
                .name_size = sizeof("ceph.dir.layout"),
                .getxattr_cb = ceph_vxattrcb_layout,
                .exists_cb = ceph_vxattrcb_layout_exists,
                .flags = VXATTR_FLAG_HIDDEN,
        },
        XATTR_LAYOUT_FIELD(dir, layout, stripe_unit),
        XATTR_LAYOUT_FIELD(dir, layout, stripe_count),
        XATTR_LAYOUT_FIELD(dir, layout, object_size),
        XATTR_LAYOUT_FIELD(dir, layout, pool),
        XATTR_LAYOUT_FIELD(dir, layout, pool_namespace),
        XATTR_NAME_CEPH(dir, entries, VXATTR_FLAG_DIRSTAT),
        XATTR_NAME_CEPH(dir, files, VXATTR_FLAG_DIRSTAT),
        XATTR_NAME_CEPH(dir, subdirs, VXATTR_FLAG_DIRSTAT),
        XATTR_RSTAT_FIELD(dir, rentries),
        XATTR_RSTAT_FIELD(dir, rfiles),
        XATTR_RSTAT_FIELD(dir, rsubdirs),
        XATTR_RSTAT_FIELD(dir, rsnaps),
        XATTR_RSTAT_FIELD(dir, rbytes),
        XATTR_RSTAT_FIELD_UPDATABLE(dir, rctime),
        {
                .name = "ceph.dir.pin",
                .name_size = sizeof("ceph.dir.pin"),
                .getxattr_cb = ceph_vxattrcb_dir_pin,
                .exists_cb = ceph_vxattrcb_dir_pin_exists,
                .flags = VXATTR_FLAG_HIDDEN,
        },
        {
                .name = "ceph.quota",
                .name_size = sizeof("ceph.quota"),
                .getxattr_cb = ceph_vxattrcb_quota,
                .exists_cb = ceph_vxattrcb_quota_exists,
                .flags = VXATTR_FLAG_HIDDEN,
        },
        XATTR_QUOTA_FIELD(quota, max_bytes),
        XATTR_QUOTA_FIELD(quota, max_files),
        {
                .name = "ceph.snap.btime",
                .name_size = sizeof("ceph.snap.btime"),
                .getxattr_cb = ceph_vxattrcb_snap_btime,
                .exists_cb = ceph_vxattrcb_snap_btime_exists,
                .flags = VXATTR_FLAG_READONLY,
        },
        {
                .name = "ceph.caps",
                .name_size = sizeof("ceph.caps"),
                .getxattr_cb = ceph_vxattrcb_caps,
                .exists_cb = NULL,
                .flags = VXATTR_FLAG_HIDDEN,
        },
        { .name = NULL, 0 }     /* Required table terminator */
};

/* files */

static struct ceph_vxattr ceph_file_vxattrs[] = {
        {
                .name = "ceph.file.layout",
                .name_size = sizeof("ceph.file.layout"),
                .getxattr_cb = ceph_vxattrcb_layout,
                .exists_cb = ceph_vxattrcb_layout_exists,
                .flags = VXATTR_FLAG_HIDDEN,
        },
        XATTR_LAYOUT_FIELD(file, layout, stripe_unit),
        XATTR_LAYOUT_FIELD(file, layout, stripe_count),
        XATTR_LAYOUT_FIELD(file, layout, object_size),
        XATTR_LAYOUT_FIELD(file, layout, pool),
        XATTR_LAYOUT_FIELD(file, layout, pool_namespace),
        {
                .name = "ceph.snap.btime",
                .name_size = sizeof("ceph.snap.btime"),
                .getxattr_cb = ceph_vxattrcb_snap_btime,
                .exists_cb = ceph_vxattrcb_snap_btime_exists,
                .flags = VXATTR_FLAG_READONLY,
        },
        {
                .name = "ceph.caps",
                .name_size = sizeof("ceph.caps"),
                .getxattr_cb = ceph_vxattrcb_caps,
                .exists_cb = NULL,
                .flags = VXATTR_FLAG_HIDDEN,
        },
        { .name = NULL, 0 }     /* Required table terminator */
};

static struct ceph_vxattr ceph_common_vxattrs[] = {
        {
                .name = "ceph.cluster_fsid",
                .name_size = sizeof("ceph.cluster_fsid"),
                .getxattr_cb = ceph_vxattrcb_cluster_fsid,
                .exists_cb = NULL,
                .flags = VXATTR_FLAG_READONLY,
        },
        {
                .name = "ceph.client_id",
                .name_size = sizeof("ceph.client_id"),
                .getxattr_cb = ceph_vxattrcb_client_id,
                .exists_cb = NULL,
                .flags = VXATTR_FLAG_READONLY,
        },
        {
                .name = "ceph.auth_mds",
                .name_size = sizeof("ceph.auth_mds"),
                .getxattr_cb = ceph_vxattrcb_auth_mds,
                .exists_cb = NULL,
                .flags = VXATTR_FLAG_READONLY,
        },
#if IS_ENABLED(CONFIG_FS_ENCRYPTION)
        {
                .name = "ceph.fscrypt.auth",
                .name_size = sizeof("ceph.fscrypt.auth"),
                .getxattr_cb = ceph_vxattrcb_fscrypt_auth,
                .exists_cb = ceph_vxattrcb_fscrypt_auth_exists,
                .flags = VXATTR_FLAG_READONLY,
        },
#endif /* CONFIG_FS_ENCRYPTION */
        { .name = NULL, 0 }     /* Required table terminator */
};

static struct ceph_vxattr *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 *ceph_match_vxattr(struct inode *inode,
                                                const char *name)
{
        struct ceph_vxattr *vxattr = ceph_inode_vxattrs(inode);

        if (vxattr) {
                while (vxattr->name) {
                        if (!strcmp(vxattr->name, name))
                                return vxattr;
                        vxattr++;
                }
        }

        vxattr = ceph_common_vxattrs;
        while (vxattr->name) {
                if (!strcmp(vxattr->name, name))
                        return vxattr;
                vxattr++;
        }

        return NULL;
}

#define MAX_XATTR_VAL_PRINT_LEN 256

static int __set_xattr(struct ceph_inode_info *ci,
                           const char *name, int name_len,
                           const char *val, int val_len,
                           int flags, int update_xattr,
                           struct ceph_inode_xattr **newxattr)
{
        struct inode *inode = &ci->netfs.inode;
        struct ceph_client *cl = ceph_inode_to_client(inode);
        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 (update_xattr) {
                int err = 0;

                if (xattr && (flags & XATTR_CREATE))
                        err = -EEXIST;
                else if (!xattr && (flags & XATTR_REPLACE))
                        err = -ENODATA;
                if (err) {
                        kfree(name);
                        kfree(val);
                        kfree(*newxattr);
                        return err;
                }
                if (update_xattr < 0) {
                        if (xattr)
                                __remove_xattr(ci, xattr);
                        kfree(name);
                        kfree(*newxattr);
                        return 0;
                }
        }

        if (!xattr) {
                new = 1;
                xattr = *newxattr;
                xattr->name = name;
                xattr->name_len = name_len;
                xattr->should_free_name = update_xattr;

                ci->i_xattrs.count++;
                doutc(cl, "count=%d\n", ci->i_xattrs.count);
        } else {
                kfree(*newxattr);
                *newxattr = NULL;
                if (xattr->should_free_val)
                        kfree(xattr->val);

                if (update_xattr) {
                        kfree(name);
                        name = xattr->name;
                }
                ci->i_xattrs.names_size -= xattr->name_len;
                ci->i_xattrs.vals_size -= xattr->val_len;
        }
        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 = update_xattr;
        xattr->should_free_val = (val && update_xattr);

        if (new) {
                rb_link_node(&xattr->node, parent, p);
                rb_insert_color(&xattr->node, &ci->i_xattrs.index);
                doutc(cl, "p=%p\n", p);
        }

        doutc(cl, "added %p %llx.%llx xattr %p %.*s=%.*s%s\n", inode,
              ceph_vinop(inode), xattr, name_len, name, min(val_len,
              MAX_XATTR_VAL_PRINT_LEN), val,
              val_len > MAX_XATTR_VAL_PRINT_LEN ? "..." : "");

        return 0;
}

static struct ceph_inode_xattr *__get_xattr(struct ceph_inode_info *ci,
                           const char *name)
{
        struct ceph_client *cl = ceph_inode_to_client(&ci->netfs.inode);
        struct rb_node **p;
        struct rb_node *parent = NULL;
        struct ceph_inode_xattr *xattr = NULL;
        int name_len = strlen(name);
        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 && name_len > xattr->name_len)
                        c = 1;
                if (c < 0)
                        p = &(*p)->rb_left;
                else if (c > 0)
                        p = &(*p)->rb_right;
                else {
                        int len = min(xattr->val_len, MAX_XATTR_VAL_PRINT_LEN);

                        doutc(cl, "%s found %.*s%s\n", name, len, xattr->val,
                              xattr->val_len > len ? "..." : "");
                        return xattr;
                }
        }

        doutc(cl, "%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(xattr->name);
        if (xattr->should_free_val)
                kfree(xattr->val);

        kfree(xattr);
}

static int __remove_xattr(struct ceph_inode_info *ci,
                          struct ceph_inode_xattr *xattr)
{
        if (!xattr)
                return -ENODATA;

        rb_erase(&xattr->node, &ci->i_xattrs.index);

        if (xattr->should_free_name)
                kfree(xattr->name);
        if (xattr->should_free_val)
                kfree(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 char *__copy_xattr_names(struct ceph_inode_info *ci,
                                char *dest)
{
        struct ceph_client *cl = ceph_inode_to_client(&ci->netfs.inode);
        struct rb_node *p;
        struct ceph_inode_xattr *xattr = NULL;

        p = rb_first(&ci->i_xattrs.index);
        doutc(cl, "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';

                doutc(cl, "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 ceph_client *cl = ceph_inode_to_client(&ci->netfs.inode);
        struct rb_node *p, *tmp;
        struct ceph_inode_xattr *xattr = NULL;

        p = rb_first(&ci->i_xattrs.index);

        doutc(cl, "p=%p\n", p);

        while (p) {
                xattr = rb_entry(p, struct ceph_inode_xattr, node);
                tmp = p;
                p = rb_next(tmp);
                doutc(cl, "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)
        __releases(ci->i_ceph_lock)
        __acquires(ci->i_ceph_lock)
{
        struct ceph_client *cl = ceph_inode_to_client(inode);
        u32 namelen;
        u32 numattr = 0;
        void *p, *end;
        u32 len;
        const char *name, *val;
        struct ceph_inode_info *ci = ceph_inode(inode);
        u64 xattr_version;
        struct ceph_inode_xattr **xattrs = NULL;
        int err = 0;
        int i;

        doutc(cl, "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(&ci->i_ceph_lock);

                xattrs = kzalloc_objs(struct ceph_inode_xattr *, numattr,
                                      GFP_NOFS);
                err = -ENOMEM;
                if (!xattrs)
                        goto bad_lock;

                for (i = 0; i < numattr; i++) {
                        xattrs[i] = kmalloc_obj(struct ceph_inode_xattr,
                                                GFP_NOFS);
                        if (!xattrs[i])
                                goto bad_lock;
                }

                spin_lock(&ci->i_ceph_lock);
                if (ci->i_xattrs.version != xattr_version) {
                        /* lost a race, retry */
                        for (i = 0; i < numattr; i++)
                                kfree(xattrs[i]);
                        kfree(xattrs);
                        xattrs = NULL;
                        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, &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(&ci->i_ceph_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)
{
        struct ceph_client *cl = ceph_inode_to_client(&ci->netfs.inode);

        /*
         * 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;
        doutc(cl, "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, re-encode xattrs into the prealloc_blob
 * and swap into place.  It returns the old i_xattrs.blob (or NULL) so
 * that it can be freed by the caller as the i_ceph_lock is likely to be
 * held.
 */
struct ceph_buffer *__ceph_build_xattrs_blob(struct ceph_inode_info *ci)
{
        struct inode *inode = &ci->netfs.inode;
        struct ceph_client *cl = ceph_inode_to_client(inode);
        struct rb_node *p;
        struct ceph_inode_xattr *xattr = NULL;
        struct ceph_buffer *old_blob = NULL;
        void *dest;

        doutc(cl, "%p %llx.%llx\n", inode, ceph_vinop(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;

                if (ci->i_xattrs.blob)
                        old_blob = ci->i_xattrs.blob;
                ci->i_xattrs.blob = ci->i_xattrs.prealloc_blob;
                ci->i_xattrs.prealloc_blob = NULL;
                ci->i_xattrs.dirty = false;
                ci->i_xattrs.version++;
        }

        return old_blob;
}

static inline int __get_request_mask(struct inode *in) {
        struct ceph_mds_request *req = current->journal_info;
        int mask = 0;
        if (req && req->r_target_inode == in) {
                if (req->r_op == CEPH_MDS_OP_LOOKUP ||
                    req->r_op == CEPH_MDS_OP_LOOKUPINO ||
                    req->r_op == CEPH_MDS_OP_LOOKUPPARENT ||
                    req->r_op == CEPH_MDS_OP_GETATTR) {
                        mask = le32_to_cpu(req->r_args.getattr.mask);
                } else if (req->r_op == CEPH_MDS_OP_OPEN ||
                           req->r_op == CEPH_MDS_OP_CREATE) {
                        mask = le32_to_cpu(req->r_args.open.mask);
                }
        }
        return mask;
}

ssize_t __ceph_getxattr(struct inode *inode, const char *name, void *value,
                      size_t size)
{
        struct ceph_client *cl = ceph_inode_to_client(inode);
        struct ceph_inode_info *ci = ceph_inode(inode);
        struct ceph_inode_xattr *xattr;
        struct ceph_vxattr *vxattr;
        int req_mask;
        ssize_t err;

        if (strncmp(name, XATTR_CEPH_PREFIX, XATTR_CEPH_PREFIX_LEN))
                goto handle_non_vxattrs;

        /* let's see if a virtual xattr was requested */
        vxattr = ceph_match_vxattr(inode, name);
        if (vxattr) {
                int mask = 0;
                if (vxattr->flags & VXATTR_FLAG_RSTAT)
                        mask |= CEPH_STAT_RSTAT;
                if (vxattr->flags & VXATTR_FLAG_DIRSTAT)
                        mask |= CEPH_CAP_FILE_SHARED;
                err = ceph_do_getattr(inode, mask, true);
                if (err)
                        return err;
                err = -ENODATA;
                if (!(vxattr->exists_cb && !vxattr->exists_cb(ci))) {
                        err = vxattr->getxattr_cb(ci, value, size);
                        if (size && size < err)
                                err = -ERANGE;
                }
                return err;
        } else {
                err = ceph_do_getvxattr(inode, name, value, size);
                /* this would happen with a new client and old server combo */
                if (err == -EOPNOTSUPP)
                        err = -ENODATA;
                return err;
        }
handle_non_vxattrs:
        req_mask = __get_request_mask(inode);

        spin_lock(&ci->i_ceph_lock);
        doutc(cl, "%p %llx.%llx name '%s' ver=%lld index_ver=%lld\n", inode,
              ceph_vinop(inode), name, ci->i_xattrs.version,
              ci->i_xattrs.index_version);

        if (ci->i_xattrs.version == 0 ||
            !((req_mask & CEPH_CAP_XATTR_SHARED) ||
              __ceph_caps_issued_mask_metric(ci, CEPH_CAP_XATTR_SHARED, 1))) {
                spin_unlock(&ci->i_ceph_lock);

                /* security module gets xattr while filling trace */
                if (current->journal_info) {
                        pr_warn_ratelimited_client(cl,
                                "sync %p %llx.%llx during filling trace\n",
                                inode, ceph_vinop(inode));
                        return -EBUSY;
                }

                /* get xattrs from mds (if we don't already have them) */
                err = ceph_do_getattr(inode, CEPH_STAT_CAP_XATTR, true);
                if (err)
                        return err;
                spin_lock(&ci->i_ceph_lock);
        }

        err = __build_xattrs(inode);
        if (err < 0)
                goto out;

        err = -ENODATA;  /* == ENOATTR */
        xattr = __get_xattr(ci, name);
        if (!xattr)
                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);

        if (current->journal_info &&
            !strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) &&
            security_ismaclabel(name + XATTR_SECURITY_PREFIX_LEN))
                ci->i_ceph_flags |= CEPH_I_SEC_INITED;
out:
        spin_unlock(&ci->i_ceph_lock);
        return err;
}

ssize_t ceph_listxattr(struct dentry *dentry, char *names, size_t size)
{
        struct inode *inode = d_inode(dentry);
        struct ceph_client *cl = ceph_inode_to_client(inode);
        struct ceph_inode_info *ci = ceph_inode(inode);
        bool len_only = (size == 0);
        u32 namelen;
        int err;

        spin_lock(&ci->i_ceph_lock);
        doutc(cl, "%p %llx.%llx ver=%lld index_ver=%lld\n", inode,
              ceph_vinop(inode), ci->i_xattrs.version,
              ci->i_xattrs.index_version);

        if (ci->i_xattrs.version == 0 ||
            !__ceph_caps_issued_mask_metric(ci, CEPH_CAP_XATTR_SHARED, 1)) {
                spin_unlock(&ci->i_ceph_lock);
                err = ceph_do_getattr(inode, CEPH_STAT_CAP_XATTR, true);
                if (err)
                        return err;
                spin_lock(&ci->i_ceph_lock);
        }

        err = __build_xattrs(inode);
        if (err < 0)
                goto out;

        /* add 1 byte for each xattr due to the null termination */
        namelen = ci->i_xattrs.names_size + ci->i_xattrs.count;
        if (!len_only) {
                if (namelen > size) {
                        err = -ERANGE;
                        goto out;
                }
                names = __copy_xattr_names(ci, names);
                size -= namelen;
        }
        err = namelen;
out:
        spin_unlock(&ci->i_ceph_lock);
        return err;
}

static int ceph_sync_setxattr(struct inode *inode, const char *name,
                              const char *value, size_t size, int flags)
{
        struct ceph_fs_client *fsc = ceph_sb_to_fs_client(inode->i_sb);
        struct ceph_client *cl = ceph_inode_to_client(inode);
        struct ceph_inode_info *ci = ceph_inode(inode);
        struct ceph_mds_request *req;
        struct ceph_mds_client *mdsc = fsc->mdsc;
        struct ceph_osd_client *osdc = &fsc->client->osdc;
        struct ceph_pagelist *pagelist = NULL;
        int op = CEPH_MDS_OP_SETXATTR;
        int err;

        if (size > 0) {
                /* copy value into pagelist */
                pagelist = ceph_pagelist_alloc(GFP_NOFS);
                if (!pagelist)
                        return -ENOMEM;

                err = ceph_pagelist_append(pagelist, value, size);
                if (err)
                        goto out;
        } else if (!value) {
                if (flags & CEPH_XATTR_REPLACE)
                        op = CEPH_MDS_OP_RMXATTR;
                else
                        flags |= CEPH_XATTR_REMOVE;
        }

        doutc(cl, "name %s value size %zu\n", name, size);

        /* do request */
        req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
        if (IS_ERR(req)) {
                err = PTR_ERR(req);
                goto out;
        }

        req->r_path2 = kstrdup(name, GFP_NOFS);
        if (!req->r_path2) {
                ceph_mdsc_put_request(req);
                err = -ENOMEM;
                goto out;
        }

        if (op == CEPH_MDS_OP_SETXATTR) {
                req->r_args.setxattr.flags = cpu_to_le32(flags);
                req->r_args.setxattr.osdmap_epoch =
                        cpu_to_le32(osdc->osdmap->epoch);
                req->r_pagelist = pagelist;
                pagelist = NULL;
        }

        req->r_inode = inode;
        ihold(inode);
        req->r_num_caps = 1;
        req->r_inode_drop = CEPH_CAP_XATTR_SHARED;

        doutc(cl, "xattr.ver (before): %lld\n", ci->i_xattrs.version);
        err = ceph_mdsc_do_request(mdsc, NULL, req);
        ceph_mdsc_put_request(req);
        doutc(cl, "xattr.ver (after): %lld\n", ci->i_xattrs.version);

out:
        if (pagelist)
                ceph_pagelist_release(pagelist);
        return err;
}

int __ceph_setxattr(struct inode *inode, const char *name,
                        const void *value, size_t size, int flags)
{
        struct ceph_client *cl = ceph_inode_to_client(inode);
        struct ceph_vxattr *vxattr;
        struct ceph_inode_info *ci = ceph_inode(inode);
        struct ceph_mds_client *mdsc = ceph_sb_to_fs_client(inode->i_sb)->mdsc;
        struct ceph_cap_flush *prealloc_cf = NULL;
        struct ceph_buffer *old_blob = NULL;
        int issued;
        int err;
        int dirty = 0;
        int name_len = strlen(name);
        int val_len = size;
        char *newname = NULL;
        char *newval = NULL;
        struct ceph_inode_xattr *xattr = NULL;
        int required_blob_size;
        bool check_realm = false;
        bool lock_snap_rwsem = false;

        if (ceph_snap(inode) != CEPH_NOSNAP)
                return -EROFS;

        vxattr = ceph_match_vxattr(inode, name);
        if (vxattr) {
                if (vxattr->flags & VXATTR_FLAG_READONLY)
                        return -EOPNOTSUPP;
                if (value && !strncmp(vxattr->name, "ceph.quota", 10))
                        check_realm = true;
        }

        /* pass any unhandled ceph.* xattrs through to the MDS */
        if (!strncmp(name, XATTR_CEPH_PREFIX, XATTR_CEPH_PREFIX_LEN))
                goto do_sync_unlocked;

        /* preallocate memory for xattr name, value, index node */
        err = -ENOMEM;
        newname = kmemdup(name, name_len + 1, GFP_NOFS);
        if (!newname)
                goto out;

        if (val_len) {
                newval = kmemdup(value, val_len, GFP_NOFS);
                if (!newval)
                        goto out;
        }

        xattr = kmalloc_obj(struct ceph_inode_xattr, GFP_NOFS);
        if (!xattr)
                goto out;

        prealloc_cf = ceph_alloc_cap_flush();
        if (!prealloc_cf)
                goto out;

        spin_lock(&ci->i_ceph_lock);
retry:
        issued = __ceph_caps_issued(ci, NULL);
        required_blob_size = __get_required_blob_size(ci, name_len, val_len);
        if ((ci->i_xattrs.version == 0) || !(issued & CEPH_CAP_XATTR_EXCL) ||
            (required_blob_size > mdsc->mdsmap->m_max_xattr_size)) {
                doutc(cl, "sync version: %llu size: %d max: %llu\n",
                      ci->i_xattrs.version, required_blob_size,
                      mdsc->mdsmap->m_max_xattr_size);
                goto do_sync;
        }

        if (!lock_snap_rwsem && !ci->i_head_snapc) {
                lock_snap_rwsem = true;
                if (!down_read_trylock(&mdsc->snap_rwsem)) {
                        spin_unlock(&ci->i_ceph_lock);
                        down_read(&mdsc->snap_rwsem);
                        spin_lock(&ci->i_ceph_lock);
                        goto retry;
                }
        }

        doutc(cl, "%p %llx.%llx name '%s' issued %s\n", inode,
              ceph_vinop(inode), name, ceph_cap_string(issued));
        __build_xattrs(inode);

        if (!ci->i_xattrs.prealloc_blob ||
            required_blob_size > ci->i_xattrs.prealloc_blob->alloc_len) {
                struct ceph_buffer *blob;

                spin_unlock(&ci->i_ceph_lock);
                ceph_buffer_put(old_blob); /* Shouldn't be required */
                doutc(cl, " pre-allocating new blob size=%d\n",
                      required_blob_size);
                blob = ceph_buffer_new(required_blob_size, GFP_NOFS);
                if (!blob)
                        goto do_sync_unlocked;
                spin_lock(&ci->i_ceph_lock);
                /* prealloc_blob can't be released while holding i_ceph_lock */
                if (ci->i_xattrs.prealloc_blob)
                        old_blob = ci->i_xattrs.prealloc_blob;
                ci->i_xattrs.prealloc_blob = blob;
                goto retry;
        }

        err = __set_xattr(ci, newname, name_len, newval, val_len,
                          flags, value ? 1 : -1, &xattr);

        if (!err) {
                dirty = __ceph_mark_dirty_caps(ci, CEPH_CAP_XATTR_EXCL,
                                               &prealloc_cf);
                ci->i_xattrs.dirty = true;
                inode_set_ctime_current(inode);
        }

        spin_unlock(&ci->i_ceph_lock);
        ceph_buffer_put(old_blob);
        if (lock_snap_rwsem)
                up_read(&mdsc->snap_rwsem);
        if (dirty)
                __mark_inode_dirty(inode, dirty);
        ceph_free_cap_flush(prealloc_cf);
        return err;

do_sync:
        spin_unlock(&ci->i_ceph_lock);
do_sync_unlocked:
        if (lock_snap_rwsem)
                up_read(&mdsc->snap_rwsem);

        /* security module set xattr while filling trace */
        if (current->journal_info) {
                pr_warn_ratelimited_client(cl,
                                "sync %p %llx.%llx during filling trace\n",
                                inode, ceph_vinop(inode));
                err = -EBUSY;
        } else {
                err = ceph_sync_setxattr(inode, name, value, size, flags);
                if (err >= 0 && check_realm) {
                        /* check if snaprealm was created for quota inode */
                        spin_lock(&ci->i_ceph_lock);
                        if ((ci->i_max_files || ci->i_max_bytes) &&
                            !(ci->i_snap_realm &&
                              ci->i_snap_realm->ino == ci->i_vino.ino))
                                err = -EOPNOTSUPP;
                        spin_unlock(&ci->i_ceph_lock);
                }
        }
out:
        ceph_free_cap_flush(prealloc_cf);
        kfree(newname);
        kfree(newval);
        kfree(xattr);
        return err;
}

static int ceph_get_xattr_handler(const struct xattr_handler *handler,
                                  struct dentry *dentry, struct inode *inode,
                                  const char *name, void *value, size_t size)
{
        if (!ceph_is_valid_xattr(name))
                return -EOPNOTSUPP;
        return __ceph_getxattr(inode, name, value, size);
}

static int ceph_set_xattr_handler(const struct xattr_handler *handler,
                                  struct mnt_idmap *idmap,
                                  struct dentry *unused, struct inode *inode,
                                  const char *name, const void *value,
                                  size_t size, int flags)
{
        if (!ceph_is_valid_xattr(name))
                return -EOPNOTSUPP;
        return __ceph_setxattr(inode, name, value, size, flags);
}

static const struct xattr_handler ceph_other_xattr_handler = {
        .prefix = "",  /* match any name => handlers called with full name */
        .get = ceph_get_xattr_handler,
        .set = ceph_set_xattr_handler,
};

#ifdef CONFIG_SECURITY
bool ceph_security_xattr_wanted(struct inode *in)
{
        return in->i_security != NULL;
}

bool ceph_security_xattr_deadlock(struct inode *in)
{
        struct ceph_inode_info *ci;
        bool ret;
        if (!in->i_security)
                return false;
        ci = ceph_inode(in);
        spin_lock(&ci->i_ceph_lock);
        ret = !(ci->i_ceph_flags & CEPH_I_SEC_INITED) &&
              !(ci->i_xattrs.version > 0 &&
                __ceph_caps_issued_mask(ci, CEPH_CAP_XATTR_SHARED, 0));
        spin_unlock(&ci->i_ceph_lock);
        return ret;
}

#ifdef CONFIG_CEPH_FS_SECURITY_LABEL
int ceph_security_init_secctx(struct dentry *dentry, umode_t mode,
                           struct ceph_acl_sec_ctx *as_ctx)
{
        struct ceph_pagelist *pagelist = as_ctx->pagelist;
        const char *name;
        size_t name_len;
        int err;

        err = security_dentry_init_security(dentry, mode, &dentry->d_name,
                                            &name, &as_ctx->lsmctx);
        if (err < 0) {
                WARN_ON_ONCE(err != -EOPNOTSUPP);
                err = 0; /* do nothing */
                goto out;
        }

        err = -ENOMEM;
        if (!pagelist) {
                pagelist = ceph_pagelist_alloc(GFP_KERNEL);
                if (!pagelist)
                        goto out;
                err = ceph_pagelist_reserve(pagelist, PAGE_SIZE);
                if (err)
                        goto out;
                ceph_pagelist_encode_32(pagelist, 1);
        }

        /*
         * FIXME: Make security_dentry_init_security() generic. Currently
         * It only supports single security module and only selinux has
         * dentry_init_security hook.
         */
        name_len = strlen(name);
        err = ceph_pagelist_reserve(pagelist,
                                    4 * 2 + name_len + as_ctx->lsmctx.len);
        if (err)
                goto out;

        if (as_ctx->pagelist) {
                /* update count of KV pairs */
                BUG_ON(pagelist->length <= sizeof(__le32));
                if (list_is_singular(&pagelist->head)) {
                        le32_add_cpu((__le32*)pagelist->mapped_tail, 1);
                } else {
                        struct page *page = list_first_entry(&pagelist->head,
                                                             struct page, lru);
                        void *addr = kmap_atomic(page);
                        le32_add_cpu((__le32*)addr, 1);
                        kunmap_atomic(addr);
                }
        } else {
                as_ctx->pagelist = pagelist;
        }

        ceph_pagelist_encode_32(pagelist, name_len);
        ceph_pagelist_append(pagelist, name, name_len);

        ceph_pagelist_encode_32(pagelist, as_ctx->lsmctx.len);
        ceph_pagelist_append(pagelist, as_ctx->lsmctx.context,
                             as_ctx->lsmctx.len);

        err = 0;
out:
        if (pagelist && !as_ctx->pagelist)
                ceph_pagelist_release(pagelist);
        return err;
}
#endif /* CONFIG_CEPH_FS_SECURITY_LABEL */
#endif /* CONFIG_SECURITY */

void ceph_release_acl_sec_ctx(struct ceph_acl_sec_ctx *as_ctx)
{
#ifdef CONFIG_CEPH_FS_POSIX_ACL
        posix_acl_release(as_ctx->acl);
        posix_acl_release(as_ctx->default_acl);
#endif
#ifdef CONFIG_CEPH_FS_SECURITY_LABEL
        security_release_secctx(&as_ctx->lsmctx);
#endif
#ifdef CONFIG_FS_ENCRYPTION
        kfree(as_ctx->fscrypt_auth);
#endif
        if (as_ctx->pagelist)
                ceph_pagelist_release(as_ctx->pagelist);
}

/*
 * List of handlers for synthetic system.* attributes. Other
 * attributes are handled directly.
 */
const struct xattr_handler * const ceph_xattr_handlers[] = {
        &ceph_other_xattr_handler,
        NULL,
};