cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

xattr.c (36783B)


      1// SPDX-License-Identifier: GPL-2.0
      2#include <linux/ceph/ceph_debug.h>
      3#include <linux/ceph/pagelist.h>
      4
      5#include "super.h"
      6#include "mds_client.h"
      7
      8#include <linux/ceph/decode.h>
      9
     10#include <linux/xattr.h>
     11#include <linux/security.h>
     12#include <linux/posix_acl_xattr.h>
     13#include <linux/slab.h>
     14
     15#define XATTR_CEPH_PREFIX "ceph."
     16#define XATTR_CEPH_PREFIX_LEN (sizeof (XATTR_CEPH_PREFIX) - 1)
     17
     18static int __remove_xattr(struct ceph_inode_info *ci,
     19			  struct ceph_inode_xattr *xattr);
     20
     21static bool ceph_is_valid_xattr(const char *name)
     22{
     23	return !strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) ||
     24	       !strncmp(name, XATTR_CEPH_PREFIX, XATTR_CEPH_PREFIX_LEN) ||
     25	       !strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN) ||
     26	       !strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN);
     27}
     28
     29/*
     30 * These define virtual xattrs exposing the recursive directory
     31 * statistics and layout metadata.
     32 */
     33struct ceph_vxattr {
     34	char *name;
     35	size_t name_size;	/* strlen(name) + 1 (for '\0') */
     36	ssize_t (*getxattr_cb)(struct ceph_inode_info *ci, char *val,
     37			       size_t size);
     38	bool (*exists_cb)(struct ceph_inode_info *ci);
     39	unsigned int flags;
     40};
     41
     42#define VXATTR_FLAG_READONLY		(1<<0)
     43#define VXATTR_FLAG_HIDDEN		(1<<1)
     44#define VXATTR_FLAG_RSTAT		(1<<2)
     45#define VXATTR_FLAG_DIRSTAT		(1<<3)
     46
     47/* layouts */
     48
     49static bool ceph_vxattrcb_layout_exists(struct ceph_inode_info *ci)
     50{
     51	struct ceph_file_layout *fl = &ci->i_layout;
     52	return (fl->stripe_unit > 0 || fl->stripe_count > 0 ||
     53		fl->object_size > 0 || fl->pool_id >= 0 ||
     54		rcu_dereference_raw(fl->pool_ns) != NULL);
     55}
     56
     57static ssize_t ceph_vxattrcb_layout(struct ceph_inode_info *ci, char *val,
     58				    size_t size)
     59{
     60	struct ceph_fs_client *fsc = ceph_sb_to_client(ci->netfs.inode.i_sb);
     61	struct ceph_osd_client *osdc = &fsc->client->osdc;
     62	struct ceph_string *pool_ns;
     63	s64 pool = ci->i_layout.pool_id;
     64	const char *pool_name;
     65	const char *ns_field = " pool_namespace=";
     66	char buf[128];
     67	size_t len, total_len = 0;
     68	ssize_t ret;
     69
     70	pool_ns = ceph_try_get_string(ci->i_layout.pool_ns);
     71
     72	dout("ceph_vxattrcb_layout %p\n", &ci->netfs.inode);
     73	down_read(&osdc->lock);
     74	pool_name = ceph_pg_pool_name_by_id(osdc->osdmap, pool);
     75	if (pool_name) {
     76		len = snprintf(buf, sizeof(buf),
     77		"stripe_unit=%u stripe_count=%u object_size=%u pool=",
     78		ci->i_layout.stripe_unit, ci->i_layout.stripe_count,
     79	        ci->i_layout.object_size);
     80		total_len = len + strlen(pool_name);
     81	} else {
     82		len = snprintf(buf, sizeof(buf),
     83		"stripe_unit=%u stripe_count=%u object_size=%u pool=%lld",
     84		ci->i_layout.stripe_unit, ci->i_layout.stripe_count,
     85		ci->i_layout.object_size, pool);
     86		total_len = len;
     87	}
     88
     89	if (pool_ns)
     90		total_len += strlen(ns_field) + pool_ns->len;
     91
     92	ret = total_len;
     93	if (size >= total_len) {
     94		memcpy(val, buf, len);
     95		ret = len;
     96		if (pool_name) {
     97			len = strlen(pool_name);
     98			memcpy(val + ret, pool_name, len);
     99			ret += len;
    100		}
    101		if (pool_ns) {
    102			len = strlen(ns_field);
    103			memcpy(val + ret, ns_field, len);
    104			ret += len;
    105			memcpy(val + ret, pool_ns->str, pool_ns->len);
    106			ret += pool_ns->len;
    107		}
    108	}
    109	up_read(&osdc->lock);
    110	ceph_put_string(pool_ns);
    111	return ret;
    112}
    113
    114/*
    115 * The convention with strings in xattrs is that they should not be NULL
    116 * terminated, since we're returning the length with them. snprintf always
    117 * NULL terminates however, so call it on a temporary buffer and then memcpy
    118 * the result into place.
    119 */
    120static __printf(3, 4)
    121int ceph_fmt_xattr(char *val, size_t size, const char *fmt, ...)
    122{
    123	int ret;
    124	va_list args;
    125	char buf[96]; /* NB: reevaluate size if new vxattrs are added */
    126
    127	va_start(args, fmt);
    128	ret = vsnprintf(buf, size ? sizeof(buf) : 0, fmt, args);
    129	va_end(args);
    130
    131	/* Sanity check */
    132	if (size && ret + 1 > sizeof(buf)) {
    133		WARN_ONCE(true, "Returned length too big (%d)", ret);
    134		return -E2BIG;
    135	}
    136
    137	if (ret <= size)
    138		memcpy(val, buf, ret);
    139	return ret;
    140}
    141
    142static ssize_t ceph_vxattrcb_layout_stripe_unit(struct ceph_inode_info *ci,
    143						char *val, size_t size)
    144{
    145	return ceph_fmt_xattr(val, size, "%u", ci->i_layout.stripe_unit);
    146}
    147
    148static ssize_t ceph_vxattrcb_layout_stripe_count(struct ceph_inode_info *ci,
    149						 char *val, size_t size)
    150{
    151	return ceph_fmt_xattr(val, size, "%u", ci->i_layout.stripe_count);
    152}
    153
    154static ssize_t ceph_vxattrcb_layout_object_size(struct ceph_inode_info *ci,
    155						char *val, size_t size)
    156{
    157	return ceph_fmt_xattr(val, size, "%u", ci->i_layout.object_size);
    158}
    159
    160static ssize_t ceph_vxattrcb_layout_pool(struct ceph_inode_info *ci,
    161					 char *val, size_t size)
    162{
    163	ssize_t ret;
    164	struct ceph_fs_client *fsc = ceph_sb_to_client(ci->netfs.inode.i_sb);
    165	struct ceph_osd_client *osdc = &fsc->client->osdc;
    166	s64 pool = ci->i_layout.pool_id;
    167	const char *pool_name;
    168
    169	down_read(&osdc->lock);
    170	pool_name = ceph_pg_pool_name_by_id(osdc->osdmap, pool);
    171	if (pool_name) {
    172		ret = strlen(pool_name);
    173		if (ret <= size)
    174			memcpy(val, pool_name, ret);
    175	} else {
    176		ret = ceph_fmt_xattr(val, size, "%lld", pool);
    177	}
    178	up_read(&osdc->lock);
    179	return ret;
    180}
    181
    182static ssize_t ceph_vxattrcb_layout_pool_namespace(struct ceph_inode_info *ci,
    183						   char *val, size_t size)
    184{
    185	ssize_t ret = 0;
    186	struct ceph_string *ns = ceph_try_get_string(ci->i_layout.pool_ns);
    187
    188	if (ns) {
    189		ret = ns->len;
    190		if (ret <= size)
    191			memcpy(val, ns->str, ret);
    192		ceph_put_string(ns);
    193	}
    194	return ret;
    195}
    196
    197/* directories */
    198
    199static ssize_t ceph_vxattrcb_dir_entries(struct ceph_inode_info *ci, char *val,
    200					 size_t size)
    201{
    202	return ceph_fmt_xattr(val, size, "%lld", ci->i_files + ci->i_subdirs);
    203}
    204
    205static ssize_t ceph_vxattrcb_dir_files(struct ceph_inode_info *ci, char *val,
    206				       size_t size)
    207{
    208	return ceph_fmt_xattr(val, size, "%lld", ci->i_files);
    209}
    210
    211static ssize_t ceph_vxattrcb_dir_subdirs(struct ceph_inode_info *ci, char *val,
    212					 size_t size)
    213{
    214	return ceph_fmt_xattr(val, size, "%lld", ci->i_subdirs);
    215}
    216
    217static ssize_t ceph_vxattrcb_dir_rentries(struct ceph_inode_info *ci, char *val,
    218					  size_t size)
    219{
    220	return ceph_fmt_xattr(val, size, "%lld",
    221				ci->i_rfiles + ci->i_rsubdirs);
    222}
    223
    224static ssize_t ceph_vxattrcb_dir_rfiles(struct ceph_inode_info *ci, char *val,
    225					size_t size)
    226{
    227	return ceph_fmt_xattr(val, size, "%lld", ci->i_rfiles);
    228}
    229
    230static ssize_t ceph_vxattrcb_dir_rsubdirs(struct ceph_inode_info *ci, char *val,
    231					  size_t size)
    232{
    233	return ceph_fmt_xattr(val, size, "%lld", ci->i_rsubdirs);
    234}
    235
    236static ssize_t ceph_vxattrcb_dir_rsnaps(struct ceph_inode_info *ci, char *val,
    237					  size_t size)
    238{
    239	return ceph_fmt_xattr(val, size, "%lld", ci->i_rsnaps);
    240}
    241
    242static ssize_t ceph_vxattrcb_dir_rbytes(struct ceph_inode_info *ci, char *val,
    243					size_t size)
    244{
    245	return ceph_fmt_xattr(val, size, "%lld", ci->i_rbytes);
    246}
    247
    248static ssize_t ceph_vxattrcb_dir_rctime(struct ceph_inode_info *ci, char *val,
    249					size_t size)
    250{
    251	return ceph_fmt_xattr(val, size, "%lld.%09ld", ci->i_rctime.tv_sec,
    252				ci->i_rctime.tv_nsec);
    253}
    254
    255/* dir pin */
    256static bool ceph_vxattrcb_dir_pin_exists(struct ceph_inode_info *ci)
    257{
    258	return ci->i_dir_pin != -ENODATA;
    259}
    260
    261static ssize_t ceph_vxattrcb_dir_pin(struct ceph_inode_info *ci, char *val,
    262				     size_t size)
    263{
    264	return ceph_fmt_xattr(val, size, "%d", (int)ci->i_dir_pin);
    265}
    266
    267/* quotas */
    268static bool ceph_vxattrcb_quota_exists(struct ceph_inode_info *ci)
    269{
    270	bool ret = false;
    271	spin_lock(&ci->i_ceph_lock);
    272	if ((ci->i_max_files || ci->i_max_bytes) &&
    273	    ci->i_vino.snap == CEPH_NOSNAP &&
    274	    ci->i_snap_realm &&
    275	    ci->i_snap_realm->ino == ci->i_vino.ino)
    276		ret = true;
    277	spin_unlock(&ci->i_ceph_lock);
    278	return ret;
    279}
    280
    281static ssize_t ceph_vxattrcb_quota(struct ceph_inode_info *ci, char *val,
    282				   size_t size)
    283{
    284	return ceph_fmt_xattr(val, size, "max_bytes=%llu max_files=%llu",
    285				ci->i_max_bytes, ci->i_max_files);
    286}
    287
    288static ssize_t ceph_vxattrcb_quota_max_bytes(struct ceph_inode_info *ci,
    289					     char *val, size_t size)
    290{
    291	return ceph_fmt_xattr(val, size, "%llu", ci->i_max_bytes);
    292}
    293
    294static ssize_t ceph_vxattrcb_quota_max_files(struct ceph_inode_info *ci,
    295					     char *val, size_t size)
    296{
    297	return ceph_fmt_xattr(val, size, "%llu", ci->i_max_files);
    298}
    299
    300/* snapshots */
    301static bool ceph_vxattrcb_snap_btime_exists(struct ceph_inode_info *ci)
    302{
    303	return (ci->i_snap_btime.tv_sec != 0 || ci->i_snap_btime.tv_nsec != 0);
    304}
    305
    306static ssize_t ceph_vxattrcb_snap_btime(struct ceph_inode_info *ci, char *val,
    307					size_t size)
    308{
    309	return ceph_fmt_xattr(val, size, "%lld.%09ld", ci->i_snap_btime.tv_sec,
    310				ci->i_snap_btime.tv_nsec);
    311}
    312
    313static ssize_t ceph_vxattrcb_cluster_fsid(struct ceph_inode_info *ci,
    314					  char *val, size_t size)
    315{
    316	struct ceph_fs_client *fsc = ceph_sb_to_client(ci->netfs.inode.i_sb);
    317
    318	return ceph_fmt_xattr(val, size, "%pU", &fsc->client->fsid);
    319}
    320
    321static ssize_t ceph_vxattrcb_client_id(struct ceph_inode_info *ci,
    322				       char *val, size_t size)
    323{
    324	struct ceph_fs_client *fsc = ceph_sb_to_client(ci->netfs.inode.i_sb);
    325
    326	return ceph_fmt_xattr(val, size, "client%lld",
    327			      ceph_client_gid(fsc->client));
    328}
    329
    330static ssize_t ceph_vxattrcb_caps(struct ceph_inode_info *ci, char *val,
    331					size_t size)
    332{
    333	int issued;
    334
    335	spin_lock(&ci->i_ceph_lock);
    336	issued = __ceph_caps_issued(ci, NULL);
    337	spin_unlock(&ci->i_ceph_lock);
    338
    339	return ceph_fmt_xattr(val, size, "%s/0x%x",
    340			      ceph_cap_string(issued), issued);
    341}
    342
    343static ssize_t ceph_vxattrcb_auth_mds(struct ceph_inode_info *ci,
    344				       char *val, size_t size)
    345{
    346	int ret;
    347
    348	spin_lock(&ci->i_ceph_lock);
    349	ret = ceph_fmt_xattr(val, size, "%d",
    350			     ci->i_auth_cap ? ci->i_auth_cap->session->s_mds : -1);
    351	spin_unlock(&ci->i_ceph_lock);
    352	return ret;
    353}
    354
    355#define CEPH_XATTR_NAME(_type, _name)	XATTR_CEPH_PREFIX #_type "." #_name
    356#define CEPH_XATTR_NAME2(_type, _name, _name2)	\
    357	XATTR_CEPH_PREFIX #_type "." #_name "." #_name2
    358
    359#define XATTR_NAME_CEPH(_type, _name, _flags)				\
    360	{								\
    361		.name = CEPH_XATTR_NAME(_type, _name),			\
    362		.name_size = sizeof (CEPH_XATTR_NAME(_type, _name)), \
    363		.getxattr_cb = ceph_vxattrcb_ ## _type ## _ ## _name, \
    364		.exists_cb = NULL,					\
    365		.flags = (VXATTR_FLAG_READONLY | _flags),		\
    366	}
    367#define XATTR_RSTAT_FIELD(_type, _name)			\
    368	XATTR_NAME_CEPH(_type, _name, VXATTR_FLAG_RSTAT)
    369#define XATTR_RSTAT_FIELD_UPDATABLE(_type, _name)			\
    370	{								\
    371		.name = CEPH_XATTR_NAME(_type, _name),			\
    372		.name_size = sizeof (CEPH_XATTR_NAME(_type, _name)),	\
    373		.getxattr_cb = ceph_vxattrcb_ ## _type ## _ ## _name,	\
    374		.exists_cb = NULL,					\
    375		.flags = VXATTR_FLAG_RSTAT,				\
    376	}
    377#define XATTR_LAYOUT_FIELD(_type, _name, _field)			\
    378	{								\
    379		.name = CEPH_XATTR_NAME2(_type, _name, _field),	\
    380		.name_size = sizeof (CEPH_XATTR_NAME2(_type, _name, _field)), \
    381		.getxattr_cb = ceph_vxattrcb_ ## _name ## _ ## _field, \
    382		.exists_cb = ceph_vxattrcb_layout_exists,	\
    383		.flags = VXATTR_FLAG_HIDDEN,			\
    384	}
    385#define XATTR_QUOTA_FIELD(_type, _name)					\
    386	{								\
    387		.name = CEPH_XATTR_NAME(_type, _name),			\
    388		.name_size = sizeof(CEPH_XATTR_NAME(_type, _name)),	\
    389		.getxattr_cb = ceph_vxattrcb_ ## _type ## _ ## _name,	\
    390		.exists_cb = ceph_vxattrcb_quota_exists,		\
    391		.flags = VXATTR_FLAG_HIDDEN,				\
    392	}
    393
    394static struct ceph_vxattr ceph_dir_vxattrs[] = {
    395	{
    396		.name = "ceph.dir.layout",
    397		.name_size = sizeof("ceph.dir.layout"),
    398		.getxattr_cb = ceph_vxattrcb_layout,
    399		.exists_cb = ceph_vxattrcb_layout_exists,
    400		.flags = VXATTR_FLAG_HIDDEN,
    401	},
    402	XATTR_LAYOUT_FIELD(dir, layout, stripe_unit),
    403	XATTR_LAYOUT_FIELD(dir, layout, stripe_count),
    404	XATTR_LAYOUT_FIELD(dir, layout, object_size),
    405	XATTR_LAYOUT_FIELD(dir, layout, pool),
    406	XATTR_LAYOUT_FIELD(dir, layout, pool_namespace),
    407	XATTR_NAME_CEPH(dir, entries, VXATTR_FLAG_DIRSTAT),
    408	XATTR_NAME_CEPH(dir, files, VXATTR_FLAG_DIRSTAT),
    409	XATTR_NAME_CEPH(dir, subdirs, VXATTR_FLAG_DIRSTAT),
    410	XATTR_RSTAT_FIELD(dir, rentries),
    411	XATTR_RSTAT_FIELD(dir, rfiles),
    412	XATTR_RSTAT_FIELD(dir, rsubdirs),
    413	XATTR_RSTAT_FIELD(dir, rsnaps),
    414	XATTR_RSTAT_FIELD(dir, rbytes),
    415	XATTR_RSTAT_FIELD_UPDATABLE(dir, rctime),
    416	{
    417		.name = "ceph.dir.pin",
    418		.name_size = sizeof("ceph.dir.pin"),
    419		.getxattr_cb = ceph_vxattrcb_dir_pin,
    420		.exists_cb = ceph_vxattrcb_dir_pin_exists,
    421		.flags = VXATTR_FLAG_HIDDEN,
    422	},
    423	{
    424		.name = "ceph.quota",
    425		.name_size = sizeof("ceph.quota"),
    426		.getxattr_cb = ceph_vxattrcb_quota,
    427		.exists_cb = ceph_vxattrcb_quota_exists,
    428		.flags = VXATTR_FLAG_HIDDEN,
    429	},
    430	XATTR_QUOTA_FIELD(quota, max_bytes),
    431	XATTR_QUOTA_FIELD(quota, max_files),
    432	{
    433		.name = "ceph.snap.btime",
    434		.name_size = sizeof("ceph.snap.btime"),
    435		.getxattr_cb = ceph_vxattrcb_snap_btime,
    436		.exists_cb = ceph_vxattrcb_snap_btime_exists,
    437		.flags = VXATTR_FLAG_READONLY,
    438	},
    439	{
    440		.name = "ceph.caps",
    441		.name_size = sizeof("ceph.caps"),
    442		.getxattr_cb = ceph_vxattrcb_caps,
    443		.exists_cb = NULL,
    444		.flags = VXATTR_FLAG_HIDDEN,
    445	},
    446	{ .name = NULL, 0 }	/* Required table terminator */
    447};
    448
    449/* files */
    450
    451static struct ceph_vxattr ceph_file_vxattrs[] = {
    452	{
    453		.name = "ceph.file.layout",
    454		.name_size = sizeof("ceph.file.layout"),
    455		.getxattr_cb = ceph_vxattrcb_layout,
    456		.exists_cb = ceph_vxattrcb_layout_exists,
    457		.flags = VXATTR_FLAG_HIDDEN,
    458	},
    459	XATTR_LAYOUT_FIELD(file, layout, stripe_unit),
    460	XATTR_LAYOUT_FIELD(file, layout, stripe_count),
    461	XATTR_LAYOUT_FIELD(file, layout, object_size),
    462	XATTR_LAYOUT_FIELD(file, layout, pool),
    463	XATTR_LAYOUT_FIELD(file, layout, pool_namespace),
    464	{
    465		.name = "ceph.snap.btime",
    466		.name_size = sizeof("ceph.snap.btime"),
    467		.getxattr_cb = ceph_vxattrcb_snap_btime,
    468		.exists_cb = ceph_vxattrcb_snap_btime_exists,
    469		.flags = VXATTR_FLAG_READONLY,
    470	},
    471	{
    472		.name = "ceph.caps",
    473		.name_size = sizeof("ceph.caps"),
    474		.getxattr_cb = ceph_vxattrcb_caps,
    475		.exists_cb = NULL,
    476		.flags = VXATTR_FLAG_HIDDEN,
    477	},
    478	{ .name = NULL, 0 }	/* Required table terminator */
    479};
    480
    481static struct ceph_vxattr ceph_common_vxattrs[] = {
    482	{
    483		.name = "ceph.cluster_fsid",
    484		.name_size = sizeof("ceph.cluster_fsid"),
    485		.getxattr_cb = ceph_vxattrcb_cluster_fsid,
    486		.exists_cb = NULL,
    487		.flags = VXATTR_FLAG_READONLY,
    488	},
    489	{
    490		.name = "ceph.client_id",
    491		.name_size = sizeof("ceph.client_id"),
    492		.getxattr_cb = ceph_vxattrcb_client_id,
    493		.exists_cb = NULL,
    494		.flags = VXATTR_FLAG_READONLY,
    495	},
    496	{
    497		.name = "ceph.auth_mds",
    498		.name_size = sizeof("ceph.auth_mds"),
    499		.getxattr_cb = ceph_vxattrcb_auth_mds,
    500		.exists_cb = NULL,
    501		.flags = VXATTR_FLAG_READONLY,
    502	},
    503	{ .name = NULL, 0 }	/* Required table terminator */
    504};
    505
    506static struct ceph_vxattr *ceph_inode_vxattrs(struct inode *inode)
    507{
    508	if (S_ISDIR(inode->i_mode))
    509		return ceph_dir_vxattrs;
    510	else if (S_ISREG(inode->i_mode))
    511		return ceph_file_vxattrs;
    512	return NULL;
    513}
    514
    515static struct ceph_vxattr *ceph_match_vxattr(struct inode *inode,
    516						const char *name)
    517{
    518	struct ceph_vxattr *vxattr = ceph_inode_vxattrs(inode);
    519
    520	if (vxattr) {
    521		while (vxattr->name) {
    522			if (!strcmp(vxattr->name, name))
    523				return vxattr;
    524			vxattr++;
    525		}
    526	}
    527
    528	vxattr = ceph_common_vxattrs;
    529	while (vxattr->name) {
    530		if (!strcmp(vxattr->name, name))
    531			return vxattr;
    532		vxattr++;
    533	}
    534
    535	return NULL;
    536}
    537
    538static int __set_xattr(struct ceph_inode_info *ci,
    539			   const char *name, int name_len,
    540			   const char *val, int val_len,
    541			   int flags, int update_xattr,
    542			   struct ceph_inode_xattr **newxattr)
    543{
    544	struct rb_node **p;
    545	struct rb_node *parent = NULL;
    546	struct ceph_inode_xattr *xattr = NULL;
    547	int c;
    548	int new = 0;
    549
    550	p = &ci->i_xattrs.index.rb_node;
    551	while (*p) {
    552		parent = *p;
    553		xattr = rb_entry(parent, struct ceph_inode_xattr, node);
    554		c = strncmp(name, xattr->name, min(name_len, xattr->name_len));
    555		if (c < 0)
    556			p = &(*p)->rb_left;
    557		else if (c > 0)
    558			p = &(*p)->rb_right;
    559		else {
    560			if (name_len == xattr->name_len)
    561				break;
    562			else if (name_len < xattr->name_len)
    563				p = &(*p)->rb_left;
    564			else
    565				p = &(*p)->rb_right;
    566		}
    567		xattr = NULL;
    568	}
    569
    570	if (update_xattr) {
    571		int err = 0;
    572
    573		if (xattr && (flags & XATTR_CREATE))
    574			err = -EEXIST;
    575		else if (!xattr && (flags & XATTR_REPLACE))
    576			err = -ENODATA;
    577		if (err) {
    578			kfree(name);
    579			kfree(val);
    580			kfree(*newxattr);
    581			return err;
    582		}
    583		if (update_xattr < 0) {
    584			if (xattr)
    585				__remove_xattr(ci, xattr);
    586			kfree(name);
    587			kfree(*newxattr);
    588			return 0;
    589		}
    590	}
    591
    592	if (!xattr) {
    593		new = 1;
    594		xattr = *newxattr;
    595		xattr->name = name;
    596		xattr->name_len = name_len;
    597		xattr->should_free_name = update_xattr;
    598
    599		ci->i_xattrs.count++;
    600		dout("__set_xattr count=%d\n", ci->i_xattrs.count);
    601	} else {
    602		kfree(*newxattr);
    603		*newxattr = NULL;
    604		if (xattr->should_free_val)
    605			kfree(xattr->val);
    606
    607		if (update_xattr) {
    608			kfree(name);
    609			name = xattr->name;
    610		}
    611		ci->i_xattrs.names_size -= xattr->name_len;
    612		ci->i_xattrs.vals_size -= xattr->val_len;
    613	}
    614	ci->i_xattrs.names_size += name_len;
    615	ci->i_xattrs.vals_size += val_len;
    616	if (val)
    617		xattr->val = val;
    618	else
    619		xattr->val = "";
    620
    621	xattr->val_len = val_len;
    622	xattr->dirty = update_xattr;
    623	xattr->should_free_val = (val && update_xattr);
    624
    625	if (new) {
    626		rb_link_node(&xattr->node, parent, p);
    627		rb_insert_color(&xattr->node, &ci->i_xattrs.index);
    628		dout("__set_xattr_val p=%p\n", p);
    629	}
    630
    631	dout("__set_xattr_val added %llx.%llx xattr %p %.*s=%.*s\n",
    632	     ceph_vinop(&ci->netfs.inode), xattr, name_len, name, val_len, val);
    633
    634	return 0;
    635}
    636
    637static struct ceph_inode_xattr *__get_xattr(struct ceph_inode_info *ci,
    638			   const char *name)
    639{
    640	struct rb_node **p;
    641	struct rb_node *parent = NULL;
    642	struct ceph_inode_xattr *xattr = NULL;
    643	int name_len = strlen(name);
    644	int c;
    645
    646	p = &ci->i_xattrs.index.rb_node;
    647	while (*p) {
    648		parent = *p;
    649		xattr = rb_entry(parent, struct ceph_inode_xattr, node);
    650		c = strncmp(name, xattr->name, xattr->name_len);
    651		if (c == 0 && name_len > xattr->name_len)
    652			c = 1;
    653		if (c < 0)
    654			p = &(*p)->rb_left;
    655		else if (c > 0)
    656			p = &(*p)->rb_right;
    657		else {
    658			dout("__get_xattr %s: found %.*s\n", name,
    659			     xattr->val_len, xattr->val);
    660			return xattr;
    661		}
    662	}
    663
    664	dout("__get_xattr %s: not found\n", name);
    665
    666	return NULL;
    667}
    668
    669static void __free_xattr(struct ceph_inode_xattr *xattr)
    670{
    671	BUG_ON(!xattr);
    672
    673	if (xattr->should_free_name)
    674		kfree(xattr->name);
    675	if (xattr->should_free_val)
    676		kfree(xattr->val);
    677
    678	kfree(xattr);
    679}
    680
    681static int __remove_xattr(struct ceph_inode_info *ci,
    682			  struct ceph_inode_xattr *xattr)
    683{
    684	if (!xattr)
    685		return -ENODATA;
    686
    687	rb_erase(&xattr->node, &ci->i_xattrs.index);
    688
    689	if (xattr->should_free_name)
    690		kfree(xattr->name);
    691	if (xattr->should_free_val)
    692		kfree(xattr->val);
    693
    694	ci->i_xattrs.names_size -= xattr->name_len;
    695	ci->i_xattrs.vals_size -= xattr->val_len;
    696	ci->i_xattrs.count--;
    697	kfree(xattr);
    698
    699	return 0;
    700}
    701
    702static char *__copy_xattr_names(struct ceph_inode_info *ci,
    703				char *dest)
    704{
    705	struct rb_node *p;
    706	struct ceph_inode_xattr *xattr = NULL;
    707
    708	p = rb_first(&ci->i_xattrs.index);
    709	dout("__copy_xattr_names count=%d\n", ci->i_xattrs.count);
    710
    711	while (p) {
    712		xattr = rb_entry(p, struct ceph_inode_xattr, node);
    713		memcpy(dest, xattr->name, xattr->name_len);
    714		dest[xattr->name_len] = '\0';
    715
    716		dout("dest=%s %p (%s) (%d/%d)\n", dest, xattr, xattr->name,
    717		     xattr->name_len, ci->i_xattrs.names_size);
    718
    719		dest += xattr->name_len + 1;
    720		p = rb_next(p);
    721	}
    722
    723	return dest;
    724}
    725
    726void __ceph_destroy_xattrs(struct ceph_inode_info *ci)
    727{
    728	struct rb_node *p, *tmp;
    729	struct ceph_inode_xattr *xattr = NULL;
    730
    731	p = rb_first(&ci->i_xattrs.index);
    732
    733	dout("__ceph_destroy_xattrs p=%p\n", p);
    734
    735	while (p) {
    736		xattr = rb_entry(p, struct ceph_inode_xattr, node);
    737		tmp = p;
    738		p = rb_next(tmp);
    739		dout("__ceph_destroy_xattrs next p=%p (%.*s)\n", p,
    740		     xattr->name_len, xattr->name);
    741		rb_erase(tmp, &ci->i_xattrs.index);
    742
    743		__free_xattr(xattr);
    744	}
    745
    746	ci->i_xattrs.names_size = 0;
    747	ci->i_xattrs.vals_size = 0;
    748	ci->i_xattrs.index_version = 0;
    749	ci->i_xattrs.count = 0;
    750	ci->i_xattrs.index = RB_ROOT;
    751}
    752
    753static int __build_xattrs(struct inode *inode)
    754	__releases(ci->i_ceph_lock)
    755	__acquires(ci->i_ceph_lock)
    756{
    757	u32 namelen;
    758	u32 numattr = 0;
    759	void *p, *end;
    760	u32 len;
    761	const char *name, *val;
    762	struct ceph_inode_info *ci = ceph_inode(inode);
    763	u64 xattr_version;
    764	struct ceph_inode_xattr **xattrs = NULL;
    765	int err = 0;
    766	int i;
    767
    768	dout("__build_xattrs() len=%d\n",
    769	     ci->i_xattrs.blob ? (int)ci->i_xattrs.blob->vec.iov_len : 0);
    770
    771	if (ci->i_xattrs.index_version >= ci->i_xattrs.version)
    772		return 0; /* already built */
    773
    774	__ceph_destroy_xattrs(ci);
    775
    776start:
    777	/* updated internal xattr rb tree */
    778	if (ci->i_xattrs.blob && ci->i_xattrs.blob->vec.iov_len > 4) {
    779		p = ci->i_xattrs.blob->vec.iov_base;
    780		end = p + ci->i_xattrs.blob->vec.iov_len;
    781		ceph_decode_32_safe(&p, end, numattr, bad);
    782		xattr_version = ci->i_xattrs.version;
    783		spin_unlock(&ci->i_ceph_lock);
    784
    785		xattrs = kcalloc(numattr, sizeof(struct ceph_inode_xattr *),
    786				 GFP_NOFS);
    787		err = -ENOMEM;
    788		if (!xattrs)
    789			goto bad_lock;
    790
    791		for (i = 0; i < numattr; i++) {
    792			xattrs[i] = kmalloc(sizeof(struct ceph_inode_xattr),
    793					    GFP_NOFS);
    794			if (!xattrs[i])
    795				goto bad_lock;
    796		}
    797
    798		spin_lock(&ci->i_ceph_lock);
    799		if (ci->i_xattrs.version != xattr_version) {
    800			/* lost a race, retry */
    801			for (i = 0; i < numattr; i++)
    802				kfree(xattrs[i]);
    803			kfree(xattrs);
    804			xattrs = NULL;
    805			goto start;
    806		}
    807		err = -EIO;
    808		while (numattr--) {
    809			ceph_decode_32_safe(&p, end, len, bad);
    810			namelen = len;
    811			name = p;
    812			p += len;
    813			ceph_decode_32_safe(&p, end, len, bad);
    814			val = p;
    815			p += len;
    816
    817			err = __set_xattr(ci, name, namelen, val, len,
    818					  0, 0, &xattrs[numattr]);
    819
    820			if (err < 0)
    821				goto bad;
    822		}
    823		kfree(xattrs);
    824	}
    825	ci->i_xattrs.index_version = ci->i_xattrs.version;
    826	ci->i_xattrs.dirty = false;
    827
    828	return err;
    829bad_lock:
    830	spin_lock(&ci->i_ceph_lock);
    831bad:
    832	if (xattrs) {
    833		for (i = 0; i < numattr; i++)
    834			kfree(xattrs[i]);
    835		kfree(xattrs);
    836	}
    837	ci->i_xattrs.names_size = 0;
    838	return err;
    839}
    840
    841static int __get_required_blob_size(struct ceph_inode_info *ci, int name_size,
    842				    int val_size)
    843{
    844	/*
    845	 * 4 bytes for the length, and additional 4 bytes per each xattr name,
    846	 * 4 bytes per each value
    847	 */
    848	int size = 4 + ci->i_xattrs.count*(4 + 4) +
    849			     ci->i_xattrs.names_size +
    850			     ci->i_xattrs.vals_size;
    851	dout("__get_required_blob_size c=%d names.size=%d vals.size=%d\n",
    852	     ci->i_xattrs.count, ci->i_xattrs.names_size,
    853	     ci->i_xattrs.vals_size);
    854
    855	if (name_size)
    856		size += 4 + 4 + name_size + val_size;
    857
    858	return size;
    859}
    860
    861/*
    862 * If there are dirty xattrs, reencode xattrs into the prealloc_blob
    863 * and swap into place.  It returns the old i_xattrs.blob (or NULL) so
    864 * that it can be freed by the caller as the i_ceph_lock is likely to be
    865 * held.
    866 */
    867struct ceph_buffer *__ceph_build_xattrs_blob(struct ceph_inode_info *ci)
    868{
    869	struct rb_node *p;
    870	struct ceph_inode_xattr *xattr = NULL;
    871	struct ceph_buffer *old_blob = NULL;
    872	void *dest;
    873
    874	dout("__build_xattrs_blob %p\n", &ci->netfs.inode);
    875	if (ci->i_xattrs.dirty) {
    876		int need = __get_required_blob_size(ci, 0, 0);
    877
    878		BUG_ON(need > ci->i_xattrs.prealloc_blob->alloc_len);
    879
    880		p = rb_first(&ci->i_xattrs.index);
    881		dest = ci->i_xattrs.prealloc_blob->vec.iov_base;
    882
    883		ceph_encode_32(&dest, ci->i_xattrs.count);
    884		while (p) {
    885			xattr = rb_entry(p, struct ceph_inode_xattr, node);
    886
    887			ceph_encode_32(&dest, xattr->name_len);
    888			memcpy(dest, xattr->name, xattr->name_len);
    889			dest += xattr->name_len;
    890			ceph_encode_32(&dest, xattr->val_len);
    891			memcpy(dest, xattr->val, xattr->val_len);
    892			dest += xattr->val_len;
    893
    894			p = rb_next(p);
    895		}
    896
    897		/* adjust buffer len; it may be larger than we need */
    898		ci->i_xattrs.prealloc_blob->vec.iov_len =
    899			dest - ci->i_xattrs.prealloc_blob->vec.iov_base;
    900
    901		if (ci->i_xattrs.blob)
    902			old_blob = ci->i_xattrs.blob;
    903		ci->i_xattrs.blob = ci->i_xattrs.prealloc_blob;
    904		ci->i_xattrs.prealloc_blob = NULL;
    905		ci->i_xattrs.dirty = false;
    906		ci->i_xattrs.version++;
    907	}
    908
    909	return old_blob;
    910}
    911
    912static inline int __get_request_mask(struct inode *in) {
    913	struct ceph_mds_request *req = current->journal_info;
    914	int mask = 0;
    915	if (req && req->r_target_inode == in) {
    916		if (req->r_op == CEPH_MDS_OP_LOOKUP ||
    917		    req->r_op == CEPH_MDS_OP_LOOKUPINO ||
    918		    req->r_op == CEPH_MDS_OP_LOOKUPPARENT ||
    919		    req->r_op == CEPH_MDS_OP_GETATTR) {
    920			mask = le32_to_cpu(req->r_args.getattr.mask);
    921		} else if (req->r_op == CEPH_MDS_OP_OPEN ||
    922			   req->r_op == CEPH_MDS_OP_CREATE) {
    923			mask = le32_to_cpu(req->r_args.open.mask);
    924		}
    925	}
    926	return mask;
    927}
    928
    929ssize_t __ceph_getxattr(struct inode *inode, const char *name, void *value,
    930		      size_t size)
    931{
    932	struct ceph_inode_info *ci = ceph_inode(inode);
    933	struct ceph_inode_xattr *xattr;
    934	struct ceph_vxattr *vxattr;
    935	int req_mask;
    936	ssize_t err;
    937
    938	if (strncmp(name, XATTR_CEPH_PREFIX, XATTR_CEPH_PREFIX_LEN))
    939		goto handle_non_vxattrs;
    940
    941	/* let's see if a virtual xattr was requested */
    942	vxattr = ceph_match_vxattr(inode, name);
    943	if (vxattr) {
    944		int mask = 0;
    945		if (vxattr->flags & VXATTR_FLAG_RSTAT)
    946			mask |= CEPH_STAT_RSTAT;
    947		if (vxattr->flags & VXATTR_FLAG_DIRSTAT)
    948			mask |= CEPH_CAP_FILE_SHARED;
    949		err = ceph_do_getattr(inode, mask, true);
    950		if (err)
    951			return err;
    952		err = -ENODATA;
    953		if (!(vxattr->exists_cb && !vxattr->exists_cb(ci))) {
    954			err = vxattr->getxattr_cb(ci, value, size);
    955			if (size && size < err)
    956				err = -ERANGE;
    957		}
    958		return err;
    959	} else {
    960		err = ceph_do_getvxattr(inode, name, value, size);
    961		/* this would happen with a new client and old server combo */
    962		if (err == -EOPNOTSUPP)
    963			err = -ENODATA;
    964		return err;
    965	}
    966handle_non_vxattrs:
    967	req_mask = __get_request_mask(inode);
    968
    969	spin_lock(&ci->i_ceph_lock);
    970	dout("getxattr %p name '%s' ver=%lld index_ver=%lld\n", inode, name,
    971	     ci->i_xattrs.version, ci->i_xattrs.index_version);
    972
    973	if (ci->i_xattrs.version == 0 ||
    974	    !((req_mask & CEPH_CAP_XATTR_SHARED) ||
    975	      __ceph_caps_issued_mask_metric(ci, CEPH_CAP_XATTR_SHARED, 1))) {
    976		spin_unlock(&ci->i_ceph_lock);
    977
    978		/* security module gets xattr while filling trace */
    979		if (current->journal_info) {
    980			pr_warn_ratelimited("sync getxattr %p "
    981					    "during filling trace\n", inode);
    982			return -EBUSY;
    983		}
    984
    985		/* get xattrs from mds (if we don't already have them) */
    986		err = ceph_do_getattr(inode, CEPH_STAT_CAP_XATTR, true);
    987		if (err)
    988			return err;
    989		spin_lock(&ci->i_ceph_lock);
    990	}
    991
    992	err = __build_xattrs(inode);
    993	if (err < 0)
    994		goto out;
    995
    996	err = -ENODATA;  /* == ENOATTR */
    997	xattr = __get_xattr(ci, name);
    998	if (!xattr)
    999		goto out;
   1000
   1001	err = -ERANGE;
   1002	if (size && size < xattr->val_len)
   1003		goto out;
   1004
   1005	err = xattr->val_len;
   1006	if (size == 0)
   1007		goto out;
   1008
   1009	memcpy(value, xattr->val, xattr->val_len);
   1010
   1011	if (current->journal_info &&
   1012	    !strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) &&
   1013	    security_ismaclabel(name + XATTR_SECURITY_PREFIX_LEN))
   1014		ci->i_ceph_flags |= CEPH_I_SEC_INITED;
   1015out:
   1016	spin_unlock(&ci->i_ceph_lock);
   1017	return err;
   1018}
   1019
   1020ssize_t ceph_listxattr(struct dentry *dentry, char *names, size_t size)
   1021{
   1022	struct inode *inode = d_inode(dentry);
   1023	struct ceph_inode_info *ci = ceph_inode(inode);
   1024	bool len_only = (size == 0);
   1025	u32 namelen;
   1026	int err;
   1027
   1028	spin_lock(&ci->i_ceph_lock);
   1029	dout("listxattr %p ver=%lld index_ver=%lld\n", inode,
   1030	     ci->i_xattrs.version, ci->i_xattrs.index_version);
   1031
   1032	if (ci->i_xattrs.version == 0 ||
   1033	    !__ceph_caps_issued_mask_metric(ci, CEPH_CAP_XATTR_SHARED, 1)) {
   1034		spin_unlock(&ci->i_ceph_lock);
   1035		err = ceph_do_getattr(inode, CEPH_STAT_CAP_XATTR, true);
   1036		if (err)
   1037			return err;
   1038		spin_lock(&ci->i_ceph_lock);
   1039	}
   1040
   1041	err = __build_xattrs(inode);
   1042	if (err < 0)
   1043		goto out;
   1044
   1045	/* add 1 byte for each xattr due to the null termination */
   1046	namelen = ci->i_xattrs.names_size + ci->i_xattrs.count;
   1047	if (!len_only) {
   1048		if (namelen > size) {
   1049			err = -ERANGE;
   1050			goto out;
   1051		}
   1052		names = __copy_xattr_names(ci, names);
   1053		size -= namelen;
   1054	}
   1055	err = namelen;
   1056out:
   1057	spin_unlock(&ci->i_ceph_lock);
   1058	return err;
   1059}
   1060
   1061static int ceph_sync_setxattr(struct inode *inode, const char *name,
   1062			      const char *value, size_t size, int flags)
   1063{
   1064	struct ceph_fs_client *fsc = ceph_sb_to_client(inode->i_sb);
   1065	struct ceph_inode_info *ci = ceph_inode(inode);
   1066	struct ceph_mds_request *req;
   1067	struct ceph_mds_client *mdsc = fsc->mdsc;
   1068	struct ceph_osd_client *osdc = &fsc->client->osdc;
   1069	struct ceph_pagelist *pagelist = NULL;
   1070	int op = CEPH_MDS_OP_SETXATTR;
   1071	int err;
   1072
   1073	if (size > 0) {
   1074		/* copy value into pagelist */
   1075		pagelist = ceph_pagelist_alloc(GFP_NOFS);
   1076		if (!pagelist)
   1077			return -ENOMEM;
   1078
   1079		err = ceph_pagelist_append(pagelist, value, size);
   1080		if (err)
   1081			goto out;
   1082	} else if (!value) {
   1083		if (flags & CEPH_XATTR_REPLACE)
   1084			op = CEPH_MDS_OP_RMXATTR;
   1085		else
   1086			flags |= CEPH_XATTR_REMOVE;
   1087	}
   1088
   1089	dout("setxattr value=%.*s\n", (int)size, value);
   1090
   1091	/* do request */
   1092	req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
   1093	if (IS_ERR(req)) {
   1094		err = PTR_ERR(req);
   1095		goto out;
   1096	}
   1097
   1098	req->r_path2 = kstrdup(name, GFP_NOFS);
   1099	if (!req->r_path2) {
   1100		ceph_mdsc_put_request(req);
   1101		err = -ENOMEM;
   1102		goto out;
   1103	}
   1104
   1105	if (op == CEPH_MDS_OP_SETXATTR) {
   1106		req->r_args.setxattr.flags = cpu_to_le32(flags);
   1107		req->r_args.setxattr.osdmap_epoch =
   1108			cpu_to_le32(osdc->osdmap->epoch);
   1109		req->r_pagelist = pagelist;
   1110		pagelist = NULL;
   1111	}
   1112
   1113	req->r_inode = inode;
   1114	ihold(inode);
   1115	req->r_num_caps = 1;
   1116	req->r_inode_drop = CEPH_CAP_XATTR_SHARED;
   1117
   1118	dout("xattr.ver (before): %lld\n", ci->i_xattrs.version);
   1119	err = ceph_mdsc_do_request(mdsc, NULL, req);
   1120	ceph_mdsc_put_request(req);
   1121	dout("xattr.ver (after): %lld\n", ci->i_xattrs.version);
   1122
   1123out:
   1124	if (pagelist)
   1125		ceph_pagelist_release(pagelist);
   1126	return err;
   1127}
   1128
   1129int __ceph_setxattr(struct inode *inode, const char *name,
   1130			const void *value, size_t size, int flags)
   1131{
   1132	struct ceph_vxattr *vxattr;
   1133	struct ceph_inode_info *ci = ceph_inode(inode);
   1134	struct ceph_mds_client *mdsc = ceph_sb_to_client(inode->i_sb)->mdsc;
   1135	struct ceph_cap_flush *prealloc_cf = NULL;
   1136	struct ceph_buffer *old_blob = NULL;
   1137	int issued;
   1138	int err;
   1139	int dirty = 0;
   1140	int name_len = strlen(name);
   1141	int val_len = size;
   1142	char *newname = NULL;
   1143	char *newval = NULL;
   1144	struct ceph_inode_xattr *xattr = NULL;
   1145	int required_blob_size;
   1146	bool check_realm = false;
   1147	bool lock_snap_rwsem = false;
   1148
   1149	if (ceph_snap(inode) != CEPH_NOSNAP)
   1150		return -EROFS;
   1151
   1152	vxattr = ceph_match_vxattr(inode, name);
   1153	if (vxattr) {
   1154		if (vxattr->flags & VXATTR_FLAG_READONLY)
   1155			return -EOPNOTSUPP;
   1156		if (value && !strncmp(vxattr->name, "ceph.quota", 10))
   1157			check_realm = true;
   1158	}
   1159
   1160	/* pass any unhandled ceph.* xattrs through to the MDS */
   1161	if (!strncmp(name, XATTR_CEPH_PREFIX, XATTR_CEPH_PREFIX_LEN))
   1162		goto do_sync_unlocked;
   1163
   1164	/* preallocate memory for xattr name, value, index node */
   1165	err = -ENOMEM;
   1166	newname = kmemdup(name, name_len + 1, GFP_NOFS);
   1167	if (!newname)
   1168		goto out;
   1169
   1170	if (val_len) {
   1171		newval = kmemdup(value, val_len, GFP_NOFS);
   1172		if (!newval)
   1173			goto out;
   1174	}
   1175
   1176	xattr = kmalloc(sizeof(struct ceph_inode_xattr), GFP_NOFS);
   1177	if (!xattr)
   1178		goto out;
   1179
   1180	prealloc_cf = ceph_alloc_cap_flush();
   1181	if (!prealloc_cf)
   1182		goto out;
   1183
   1184	spin_lock(&ci->i_ceph_lock);
   1185retry:
   1186	issued = __ceph_caps_issued(ci, NULL);
   1187	if (ci->i_xattrs.version == 0 || !(issued & CEPH_CAP_XATTR_EXCL))
   1188		goto do_sync;
   1189
   1190	if (!lock_snap_rwsem && !ci->i_head_snapc) {
   1191		lock_snap_rwsem = true;
   1192		if (!down_read_trylock(&mdsc->snap_rwsem)) {
   1193			spin_unlock(&ci->i_ceph_lock);
   1194			down_read(&mdsc->snap_rwsem);
   1195			spin_lock(&ci->i_ceph_lock);
   1196			goto retry;
   1197		}
   1198	}
   1199
   1200	dout("setxattr %p name '%s' issued %s\n", inode, name,
   1201	     ceph_cap_string(issued));
   1202	__build_xattrs(inode);
   1203
   1204	required_blob_size = __get_required_blob_size(ci, name_len, val_len);
   1205
   1206	if (!ci->i_xattrs.prealloc_blob ||
   1207	    required_blob_size > ci->i_xattrs.prealloc_blob->alloc_len) {
   1208		struct ceph_buffer *blob;
   1209
   1210		spin_unlock(&ci->i_ceph_lock);
   1211		ceph_buffer_put(old_blob); /* Shouldn't be required */
   1212		dout(" pre-allocating new blob size=%d\n", required_blob_size);
   1213		blob = ceph_buffer_new(required_blob_size, GFP_NOFS);
   1214		if (!blob)
   1215			goto do_sync_unlocked;
   1216		spin_lock(&ci->i_ceph_lock);
   1217		/* prealloc_blob can't be released while holding i_ceph_lock */
   1218		if (ci->i_xattrs.prealloc_blob)
   1219			old_blob = ci->i_xattrs.prealloc_blob;
   1220		ci->i_xattrs.prealloc_blob = blob;
   1221		goto retry;
   1222	}
   1223
   1224	err = __set_xattr(ci, newname, name_len, newval, val_len,
   1225			  flags, value ? 1 : -1, &xattr);
   1226
   1227	if (!err) {
   1228		dirty = __ceph_mark_dirty_caps(ci, CEPH_CAP_XATTR_EXCL,
   1229					       &prealloc_cf);
   1230		ci->i_xattrs.dirty = true;
   1231		inode->i_ctime = current_time(inode);
   1232	}
   1233
   1234	spin_unlock(&ci->i_ceph_lock);
   1235	ceph_buffer_put(old_blob);
   1236	if (lock_snap_rwsem)
   1237		up_read(&mdsc->snap_rwsem);
   1238	if (dirty)
   1239		__mark_inode_dirty(inode, dirty);
   1240	ceph_free_cap_flush(prealloc_cf);
   1241	return err;
   1242
   1243do_sync:
   1244	spin_unlock(&ci->i_ceph_lock);
   1245do_sync_unlocked:
   1246	if (lock_snap_rwsem)
   1247		up_read(&mdsc->snap_rwsem);
   1248
   1249	/* security module set xattr while filling trace */
   1250	if (current->journal_info) {
   1251		pr_warn_ratelimited("sync setxattr %p "
   1252				    "during filling trace\n", inode);
   1253		err = -EBUSY;
   1254	} else {
   1255		err = ceph_sync_setxattr(inode, name, value, size, flags);
   1256		if (err >= 0 && check_realm) {
   1257			/* check if snaprealm was created for quota inode */
   1258			spin_lock(&ci->i_ceph_lock);
   1259			if ((ci->i_max_files || ci->i_max_bytes) &&
   1260			    !(ci->i_snap_realm &&
   1261			      ci->i_snap_realm->ino == ci->i_vino.ino))
   1262				err = -EOPNOTSUPP;
   1263			spin_unlock(&ci->i_ceph_lock);
   1264		}
   1265	}
   1266out:
   1267	ceph_free_cap_flush(prealloc_cf);
   1268	kfree(newname);
   1269	kfree(newval);
   1270	kfree(xattr);
   1271	return err;
   1272}
   1273
   1274static int ceph_get_xattr_handler(const struct xattr_handler *handler,
   1275				  struct dentry *dentry, struct inode *inode,
   1276				  const char *name, void *value, size_t size)
   1277{
   1278	if (!ceph_is_valid_xattr(name))
   1279		return -EOPNOTSUPP;
   1280	return __ceph_getxattr(inode, name, value, size);
   1281}
   1282
   1283static int ceph_set_xattr_handler(const struct xattr_handler *handler,
   1284				  struct user_namespace *mnt_userns,
   1285				  struct dentry *unused, struct inode *inode,
   1286				  const char *name, const void *value,
   1287				  size_t size, int flags)
   1288{
   1289	if (!ceph_is_valid_xattr(name))
   1290		return -EOPNOTSUPP;
   1291	return __ceph_setxattr(inode, name, value, size, flags);
   1292}
   1293
   1294static const struct xattr_handler ceph_other_xattr_handler = {
   1295	.prefix = "",  /* match any name => handlers called with full name */
   1296	.get = ceph_get_xattr_handler,
   1297	.set = ceph_set_xattr_handler,
   1298};
   1299
   1300#ifdef CONFIG_SECURITY
   1301bool ceph_security_xattr_wanted(struct inode *in)
   1302{
   1303	return in->i_security != NULL;
   1304}
   1305
   1306bool ceph_security_xattr_deadlock(struct inode *in)
   1307{
   1308	struct ceph_inode_info *ci;
   1309	bool ret;
   1310	if (!in->i_security)
   1311		return false;
   1312	ci = ceph_inode(in);
   1313	spin_lock(&ci->i_ceph_lock);
   1314	ret = !(ci->i_ceph_flags & CEPH_I_SEC_INITED) &&
   1315	      !(ci->i_xattrs.version > 0 &&
   1316		__ceph_caps_issued_mask(ci, CEPH_CAP_XATTR_SHARED, 0));
   1317	spin_unlock(&ci->i_ceph_lock);
   1318	return ret;
   1319}
   1320
   1321#ifdef CONFIG_CEPH_FS_SECURITY_LABEL
   1322int ceph_security_init_secctx(struct dentry *dentry, umode_t mode,
   1323			   struct ceph_acl_sec_ctx *as_ctx)
   1324{
   1325	struct ceph_pagelist *pagelist = as_ctx->pagelist;
   1326	const char *name;
   1327	size_t name_len;
   1328	int err;
   1329
   1330	err = security_dentry_init_security(dentry, mode, &dentry->d_name,
   1331					    &name, &as_ctx->sec_ctx,
   1332					    &as_ctx->sec_ctxlen);
   1333	if (err < 0) {
   1334		WARN_ON_ONCE(err != -EOPNOTSUPP);
   1335		err = 0; /* do nothing */
   1336		goto out;
   1337	}
   1338
   1339	err = -ENOMEM;
   1340	if (!pagelist) {
   1341		pagelist = ceph_pagelist_alloc(GFP_KERNEL);
   1342		if (!pagelist)
   1343			goto out;
   1344		err = ceph_pagelist_reserve(pagelist, PAGE_SIZE);
   1345		if (err)
   1346			goto out;
   1347		ceph_pagelist_encode_32(pagelist, 1);
   1348	}
   1349
   1350	/*
   1351	 * FIXME: Make security_dentry_init_security() generic. Currently
   1352	 * It only supports single security module and only selinux has
   1353	 * dentry_init_security hook.
   1354	 */
   1355	name_len = strlen(name);
   1356	err = ceph_pagelist_reserve(pagelist,
   1357				    4 * 2 + name_len + as_ctx->sec_ctxlen);
   1358	if (err)
   1359		goto out;
   1360
   1361	if (as_ctx->pagelist) {
   1362		/* update count of KV pairs */
   1363		BUG_ON(pagelist->length <= sizeof(__le32));
   1364		if (list_is_singular(&pagelist->head)) {
   1365			le32_add_cpu((__le32*)pagelist->mapped_tail, 1);
   1366		} else {
   1367			struct page *page = list_first_entry(&pagelist->head,
   1368							     struct page, lru);
   1369			void *addr = kmap_atomic(page);
   1370			le32_add_cpu((__le32*)addr, 1);
   1371			kunmap_atomic(addr);
   1372		}
   1373	} else {
   1374		as_ctx->pagelist = pagelist;
   1375	}
   1376
   1377	ceph_pagelist_encode_32(pagelist, name_len);
   1378	ceph_pagelist_append(pagelist, name, name_len);
   1379
   1380	ceph_pagelist_encode_32(pagelist, as_ctx->sec_ctxlen);
   1381	ceph_pagelist_append(pagelist, as_ctx->sec_ctx, as_ctx->sec_ctxlen);
   1382
   1383	err = 0;
   1384out:
   1385	if (pagelist && !as_ctx->pagelist)
   1386		ceph_pagelist_release(pagelist);
   1387	return err;
   1388}
   1389#endif /* CONFIG_CEPH_FS_SECURITY_LABEL */
   1390#endif /* CONFIG_SECURITY */
   1391
   1392void ceph_release_acl_sec_ctx(struct ceph_acl_sec_ctx *as_ctx)
   1393{
   1394#ifdef CONFIG_CEPH_FS_POSIX_ACL
   1395	posix_acl_release(as_ctx->acl);
   1396	posix_acl_release(as_ctx->default_acl);
   1397#endif
   1398#ifdef CONFIG_CEPH_FS_SECURITY_LABEL
   1399	security_release_secctx(as_ctx->sec_ctx, as_ctx->sec_ctxlen);
   1400#endif
   1401	if (as_ctx->pagelist)
   1402		ceph_pagelist_release(as_ctx->pagelist);
   1403}
   1404
   1405/*
   1406 * List of handlers for synthetic system.* attributes. Other
   1407 * attributes are handled directly.
   1408 */
   1409const struct xattr_handler *ceph_xattr_handlers[] = {
   1410#ifdef CONFIG_CEPH_FS_POSIX_ACL
   1411	&posix_acl_access_xattr_handler,
   1412	&posix_acl_default_xattr_handler,
   1413#endif
   1414	&ceph_other_xattr_handler,
   1415	NULL,
   1416};