linux-stable/fs/gfs2/xattr.c

1506 lines
33 KiB
C
Raw Normal View History

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
* Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
*/
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/xattr.h>
#include <linux/gfs2_ondisk.h>
#include <linux/posix_acl_xattr.h>
#include <linux/uaccess.h>
#include "gfs2.h"
#include "incore.h"
#include "acl.h"
#include "xattr.h"
#include "glock.h"
#include "inode.h"
#include "meta_io.h"
#include "quota.h"
#include "rgrp.h"
#include "super.h"
#include "trans.h"
#include "util.h"
/*
* ea_calc_size - returns the actual number of bytes the request will take up
* (not counting any unstuffed data blocks)
*
* Returns: 1 if the EA should be stuffed
*/
static int ea_calc_size(struct gfs2_sbd *sdp, unsigned int nsize, size_t dsize,
unsigned int *size)
{
unsigned int jbsize = sdp->sd_jbsize;
/* Stuffed */
*size = ALIGN(sizeof(struct gfs2_ea_header) + nsize + dsize, 8);
if (*size <= jbsize)
return 1;
/* Unstuffed */
*size = ALIGN(sizeof(struct gfs2_ea_header) + nsize +
(sizeof(__be64) * DIV_ROUND_UP(dsize, jbsize)), 8);
return 0;
}
static int ea_check_size(struct gfs2_sbd *sdp, unsigned int nsize, size_t dsize)
{
unsigned int size;
if (dsize > GFS2_EA_MAX_DATA_LEN)
return -ERANGE;
ea_calc_size(sdp, nsize, dsize, &size);
/* This can only happen with 512 byte blocks */
if (size > sdp->sd_jbsize)
return -ERANGE;
return 0;
}
static bool gfs2_eatype_valid(struct gfs2_sbd *sdp, u8 type)
{
switch(sdp->sd_sb.sb_fs_format) {
case GFS2_FS_FORMAT_MAX:
return true;
case GFS2_FS_FORMAT_MIN:
return type <= GFS2_EATYPE_SECURITY;
default:
return false;
}
}
typedef int (*ea_call_t) (struct gfs2_inode *ip, struct buffer_head *bh,
struct gfs2_ea_header *ea,
struct gfs2_ea_header *prev, void *private);
static int ea_foreach_i(struct gfs2_inode *ip, struct buffer_head *bh,
ea_call_t ea_call, void *data)
{
struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
struct gfs2_ea_header *ea, *prev = NULL;
int error = 0;
if (gfs2_metatype_check(GFS2_SB(&ip->i_inode), bh, GFS2_METATYPE_EA))
return -EIO;
for (ea = GFS2_EA_BH2FIRST(bh);; prev = ea, ea = GFS2_EA2NEXT(ea)) {
if (!GFS2_EA_REC_LEN(ea))
goto fail;
if (!(bh->b_data <= (char *)ea && (char *)GFS2_EA2NEXT(ea) <=
bh->b_data + bh->b_size))
goto fail;
if (!gfs2_eatype_valid(sdp, ea->ea_type))
goto fail;
error = ea_call(ip, bh, ea, prev, data);
if (error)
return error;
if (GFS2_EA_IS_LAST(ea)) {
if ((char *)GFS2_EA2NEXT(ea) !=
bh->b_data + bh->b_size)
goto fail;
break;
}
}
return error;
fail:
gfs2_consist_inode(ip);
return -EIO;
}
static int ea_foreach(struct gfs2_inode *ip, ea_call_t ea_call, void *data)
{
struct buffer_head *bh, *eabh;
__be64 *eablk, *end;
int error;
error = gfs2_meta_read(ip->i_gl, ip->i_eattr, DIO_WAIT, 0, &bh);
if (error)
return error;
if (!(ip->i_diskflags & GFS2_DIF_EA_INDIRECT)) {
error = ea_foreach_i(ip, bh, ea_call, data);
goto out;
}
if (gfs2_metatype_check(GFS2_SB(&ip->i_inode), bh, GFS2_METATYPE_IN)) {
error = -EIO;
goto out;
}
eablk = (__be64 *)(bh->b_data + sizeof(struct gfs2_meta_header));
end = eablk + GFS2_SB(&ip->i_inode)->sd_inptrs;
for (; eablk < end; eablk++) {
u64 bn;
if (!*eablk)
break;
bn = be64_to_cpu(*eablk);
error = gfs2_meta_read(ip->i_gl, bn, DIO_WAIT, 0, &eabh);
if (error)
break;
error = ea_foreach_i(ip, eabh, ea_call, data);
brelse(eabh);
if (error)
break;
}
out:
brelse(bh);
return error;
}
struct ea_find {
int type;
const char *name;
size_t namel;
struct gfs2_ea_location *ef_el;
};
static int ea_find_i(struct gfs2_inode *ip, struct buffer_head *bh,
struct gfs2_ea_header *ea, struct gfs2_ea_header *prev,
void *private)
{
struct ea_find *ef = private;
if (ea->ea_type == GFS2_EATYPE_UNUSED)
return 0;
if (ea->ea_type == ef->type) {
if (ea->ea_name_len == ef->namel &&
!memcmp(GFS2_EA2NAME(ea), ef->name, ea->ea_name_len)) {
struct gfs2_ea_location *el = ef->ef_el;
get_bh(bh);
el->el_bh = bh;
el->el_ea = ea;
el->el_prev = prev;
return 1;
}
}
return 0;
}
static int gfs2_ea_find(struct gfs2_inode *ip, int type, const char *name,
struct gfs2_ea_location *el)
{
struct ea_find ef;
int error;
ef.type = type;
ef.name = name;
ef.namel = strlen(name);
ef.ef_el = el;
memset(el, 0, sizeof(struct gfs2_ea_location));
error = ea_foreach(ip, ea_find_i, &ef);
if (error > 0)
return 0;
return error;
}
/*
* ea_dealloc_unstuffed
*
* Take advantage of the fact that all unstuffed blocks are
* allocated from the same RG. But watch, this may not always
* be true.
*
* Returns: errno
*/
static int ea_dealloc_unstuffed(struct gfs2_inode *ip, struct buffer_head *bh,
struct gfs2_ea_header *ea,
struct gfs2_ea_header *prev, void *private)
{
int *leave = private;
struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
struct gfs2_rgrpd *rgd;
struct gfs2_holder rg_gh;
__be64 *dataptrs;
u64 bn = 0;
u64 bstart = 0;
unsigned int blen = 0;
unsigned int blks = 0;
unsigned int x;
int error;
error = gfs2_rindex_update(sdp);
if (error)
return error;
if (GFS2_EA_IS_STUFFED(ea))
return 0;
dataptrs = GFS2_EA2DATAPTRS(ea);
for (x = 0; x < ea->ea_num_ptrs; x++, dataptrs++) {
if (*dataptrs) {
blks++;
bn = be64_to_cpu(*dataptrs);
}
}
if (!blks)
return 0;
rgd = gfs2_blk2rgrpd(sdp, bn, 1);
if (!rgd) {
gfs2_consist_inode(ip);
return -EIO;
}
error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_EXCLUSIVE,
LM_FLAG_NODE_SCOPE, &rg_gh);
if (error)
return error;
error = gfs2_trans_begin(sdp, rgd->rd_length + RES_DINODE +
RES_EATTR + RES_STATFS + RES_QUOTA, blks);
if (error)
goto out_gunlock;
gfs2_trans_add_meta(ip->i_gl, bh);
dataptrs = GFS2_EA2DATAPTRS(ea);
for (x = 0; x < ea->ea_num_ptrs; x++, dataptrs++) {
if (!*dataptrs)
break;
bn = be64_to_cpu(*dataptrs);
if (bstart + blen == bn)
blen++;
else {
if (bstart)
gfs2_free_meta(ip, rgd, bstart, blen);
bstart = bn;
blen = 1;
}
*dataptrs = 0;
gfs2_add_inode_blocks(&ip->i_inode, -1);
}
if (bstart)
gfs2_free_meta(ip, rgd, bstart, blen);
if (prev && !leave) {
u32 len;
len = GFS2_EA_REC_LEN(prev) + GFS2_EA_REC_LEN(ea);
prev->ea_rec_len = cpu_to_be32(len);
if (GFS2_EA_IS_LAST(ea))
prev->ea_flags |= GFS2_EAFLAG_LAST;
} else {
ea->ea_type = GFS2_EATYPE_UNUSED;
ea->ea_num_ptrs = 0;
}
ip->i_inode.i_ctime = current_time(&ip->i_inode);
__mark_inode_dirty(&ip->i_inode, I_DIRTY_DATASYNC);
gfs2_trans_end(sdp);
out_gunlock:
gfs2_glock_dq_uninit(&rg_gh);
return error;
}
static int ea_remove_unstuffed(struct gfs2_inode *ip, struct buffer_head *bh,
struct gfs2_ea_header *ea,
struct gfs2_ea_header *prev, int leave)
{
int error;
error = gfs2_rindex_update(GFS2_SB(&ip->i_inode));
if (error)
return error;
error = gfs2_quota_hold(ip, NO_UID_QUOTA_CHANGE, NO_GID_QUOTA_CHANGE);
if (error)
goto out_alloc;
error = ea_dealloc_unstuffed(ip, bh, ea, prev, (leave) ? &error : NULL);
gfs2_quota_unhold(ip);
out_alloc:
return error;
}
struct ea_list {
struct gfs2_ea_request *ei_er;
unsigned int ei_size;
};
static int ea_list_i(struct gfs2_inode *ip, struct buffer_head *bh,
struct gfs2_ea_header *ea, struct gfs2_ea_header *prev,
void *private)
{
struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
struct ea_list *ei = private;
struct gfs2_ea_request *er = ei->ei_er;
unsigned int ea_size;
char *prefix;
unsigned int l;
if (ea->ea_type == GFS2_EATYPE_UNUSED)
return 0;
BUG_ON(ea->ea_type > GFS2_EATYPE_SECURITY &&
sdp->sd_sb.sb_fs_format == GFS2_FS_FORMAT_MIN);
switch (ea->ea_type) {
case GFS2_EATYPE_USR:
prefix = "user.";
l = 5;
break;
case GFS2_EATYPE_SYS:
prefix = "system.";
l = 7;
break;
case GFS2_EATYPE_SECURITY:
prefix = "security.";
l = 9;
break;
case GFS2_EATYPE_TRUSTED:
prefix = "trusted.";
l = 8;
break;
default:
return 0;
}
ea_size = l + ea->ea_name_len + 1;
if (er->er_data_len) {
if (ei->ei_size + ea_size > er->er_data_len)
return -ERANGE;
memcpy(er->er_data + ei->ei_size, prefix, l);
memcpy(er->er_data + ei->ei_size + l, GFS2_EA2NAME(ea),
ea->ea_name_len);
er->er_data[ei->ei_size + ea_size - 1] = 0;
}
ei->ei_size += ea_size;
return 0;
}
/**
* gfs2_listxattr - List gfs2 extended attributes
* @dentry: The dentry whose inode we are interested in
* @buffer: The buffer to write the results
* @size: The size of the buffer
*
* Returns: actual size of data on success, -errno on error
*/
ssize_t gfs2_listxattr(struct dentry *dentry, char *buffer, size_t size)
{
struct gfs2_inode *ip = GFS2_I(d_inode(dentry));
struct gfs2_ea_request er;
struct gfs2_holder i_gh;
int error;
memset(&er, 0, sizeof(struct gfs2_ea_request));
if (size) {
er.er_data = buffer;
er.er_data_len = size;
}
error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
if (error)
return error;
if (ip->i_eattr) {
struct ea_list ei = { .ei_er = &er, .ei_size = 0 };
error = ea_foreach(ip, ea_list_i, &ei);
if (!error)
error = ei.ei_size;
}
gfs2_glock_dq_uninit(&i_gh);
return error;
}
/**
* gfs2_iter_unstuffed - copies the unstuffed xattr data to/from the
* request buffer
* @ip: The GFS2 inode
* @ea: The extended attribute header structure
* @din: The data to be copied in
* @dout: The data to be copied out (one of din,dout will be NULL)
*
* Returns: errno
*/
static int gfs2_iter_unstuffed(struct gfs2_inode *ip, struct gfs2_ea_header *ea,
const char *din, char *dout)
{
struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
struct buffer_head **bh;
unsigned int amount = GFS2_EA_DATA_LEN(ea);
unsigned int nptrs = DIV_ROUND_UP(amount, sdp->sd_jbsize);
__be64 *dataptrs = GFS2_EA2DATAPTRS(ea);
unsigned int x;
int error = 0;
unsigned char *pos;
unsigned cp_size;
bh = kcalloc(nptrs, sizeof(struct buffer_head *), GFP_NOFS);
if (!bh)
return -ENOMEM;
for (x = 0; x < nptrs; x++) {
error = gfs2_meta_read(ip->i_gl, be64_to_cpu(*dataptrs), 0, 0,
bh + x);
if (error) {
while (x--)
brelse(bh[x]);
goto out;
}
dataptrs++;
}
for (x = 0; x < nptrs; x++) {
error = gfs2_meta_wait(sdp, bh[x]);
if (error) {
for (; x < nptrs; x++)
brelse(bh[x]);
goto out;
}
if (gfs2_metatype_check(sdp, bh[x], GFS2_METATYPE_ED)) {
for (; x < nptrs; x++)
brelse(bh[x]);
error = -EIO;
goto out;
}
pos = bh[x]->b_data + sizeof(struct gfs2_meta_header);
cp_size = (sdp->sd_jbsize > amount) ? amount : sdp->sd_jbsize;
if (dout) {
memcpy(dout, pos, cp_size);
dout += sdp->sd_jbsize;
}
if (din) {
gfs2_trans_add_meta(ip->i_gl, bh[x]);
memcpy(pos, din, cp_size);
din += sdp->sd_jbsize;
}
amount -= sdp->sd_jbsize;
brelse(bh[x]);
}
out:
kfree(bh);
return error;
}
static int gfs2_ea_get_copy(struct gfs2_inode *ip, struct gfs2_ea_location *el,
char *data, size_t size)
{
int ret;
size_t len = GFS2_EA_DATA_LEN(el->el_ea);
if (len > size)
return -ERANGE;
if (GFS2_EA_IS_STUFFED(el->el_ea)) {
memcpy(data, GFS2_EA2DATA(el->el_ea), len);
return len;
}
ret = gfs2_iter_unstuffed(ip, el->el_ea, NULL, data);
if (ret < 0)
return ret;
return len;
}
int gfs2_xattr_acl_get(struct gfs2_inode *ip, const char *name, char **ppdata)
{
struct gfs2_ea_location el;
int error;
int len;
char *data;
error = gfs2_ea_find(ip, GFS2_EATYPE_SYS, name, &el);
if (error)
return error;
if (!el.el_ea)
goto out;
if (!GFS2_EA_DATA_LEN(el.el_ea))
goto out;
len = GFS2_EA_DATA_LEN(el.el_ea);
data = kmalloc(len, GFP_NOFS);
error = -ENOMEM;
if (data == NULL)
goto out;
error = gfs2_ea_get_copy(ip, &el, data, len);
if (error < 0)
kfree(data);
else
*ppdata = data;
out:
brelse(el.el_bh);
return error;
}
/**
* __gfs2_xattr_get - Get a GFS2 extended attribute
* @inode: The inode
* @name: The name of the extended attribute
* @buffer: The buffer to write the result into
* @size: The size of the buffer
* @type: The type of extended attribute
*
* Returns: actual size of data on success, -errno on error
*/
static int __gfs2_xattr_get(struct inode *inode, const char *name,
void *buffer, size_t size, int type)
{
struct gfs2_inode *ip = GFS2_I(inode);
struct gfs2_ea_location el;
int error;
if (!ip->i_eattr)
return -ENODATA;
if (strlen(name) > GFS2_EA_MAX_NAME_LEN)
return -EINVAL;
error = gfs2_ea_find(ip, type, name, &el);
if (error)
return error;
if (!el.el_ea)
return -ENODATA;
if (size)
error = gfs2_ea_get_copy(ip, &el, buffer, size);
else
error = GFS2_EA_DATA_LEN(el.el_ea);
brelse(el.el_bh);
return error;
}
static int gfs2_xattr_get(const struct xattr_handler *handler,
struct dentry *unused, struct inode *inode,
const char *name, void *buffer, size_t size)
{
struct gfs2_inode *ip = GFS2_I(inode);
struct gfs2_holder gh;
int ret;
/* During lookup, SELinux calls this function with the glock locked. */
if (!gfs2_glock_is_locked_by_me(ip->i_gl)) {
ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &gh);
if (ret)
return ret;
} else {
gfs2_holder_mark_uninitialized(&gh);
}
ret = __gfs2_xattr_get(inode, name, buffer, size, handler->flags);
if (gfs2_holder_initialized(&gh))
gfs2_glock_dq_uninit(&gh);
return ret;
}
/**
* ea_alloc_blk - allocates a new block for extended attributes.
* @ip: A pointer to the inode that's getting extended attributes
* @bhp: Pointer to pointer to a struct buffer_head
*
* Returns: errno
*/
static int ea_alloc_blk(struct gfs2_inode *ip, struct buffer_head **bhp)
{
struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
struct gfs2_ea_header *ea;
unsigned int n = 1;
u64 block;
int error;
error = gfs2_alloc_blocks(ip, &block, &n, 0, NULL);
if (error)
return error;
gfs2_trans_remove_revoke(sdp, block, 1);
*bhp = gfs2_meta_new(ip->i_gl, block);
gfs2_trans_add_meta(ip->i_gl, *bhp);
gfs2_metatype_set(*bhp, GFS2_METATYPE_EA, GFS2_FORMAT_EA);
gfs2_buffer_clear_tail(*bhp, sizeof(struct gfs2_meta_header));
ea = GFS2_EA_BH2FIRST(*bhp);
ea->ea_rec_len = cpu_to_be32(sdp->sd_jbsize);
ea->ea_type = GFS2_EATYPE_UNUSED;
ea->ea_flags = GFS2_EAFLAG_LAST;
ea->ea_num_ptrs = 0;
gfs2_add_inode_blocks(&ip->i_inode, 1);
return 0;
}
/**
* ea_write - writes the request info to an ea, creating new blocks if
* necessary
* @ip: inode that is being modified
* @ea: the location of the new ea in a block
* @er: the write request
*
* Note: does not update ea_rec_len or the GFS2_EAFLAG_LAST bin of ea_flags
*
* returns : errno
*/
static int ea_write(struct gfs2_inode *ip, struct gfs2_ea_header *ea,
struct gfs2_ea_request *er)
{
struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
int error;
ea->ea_data_len = cpu_to_be32(er->er_data_len);
ea->ea_name_len = er->er_name_len;
ea->ea_type = er->er_type;
ea->__pad = 0;
memcpy(GFS2_EA2NAME(ea), er->er_name, er->er_name_len);
if (GFS2_EAREQ_SIZE_STUFFED(er) <= sdp->sd_jbsize) {
ea->ea_num_ptrs = 0;
memcpy(GFS2_EA2DATA(ea), er->er_data, er->er_data_len);
} else {
__be64 *dataptr = GFS2_EA2DATAPTRS(ea);
const char *data = er->er_data;
unsigned int data_len = er->er_data_len;
unsigned int copy;
unsigned int x;
ea->ea_num_ptrs = DIV_ROUND_UP(er->er_data_len, sdp->sd_jbsize);
for (x = 0; x < ea->ea_num_ptrs; x++) {
struct buffer_head *bh;
u64 block;
int mh_size = sizeof(struct gfs2_meta_header);
unsigned int n = 1;
error = gfs2_alloc_blocks(ip, &block, &n, 0, NULL);
if (error)
return error;
gfs2_trans_remove_revoke(sdp, block, 1);
bh = gfs2_meta_new(ip->i_gl, block);
gfs2_trans_add_meta(ip->i_gl, bh);
gfs2_metatype_set(bh, GFS2_METATYPE_ED, GFS2_FORMAT_ED);
gfs2_add_inode_blocks(&ip->i_inode, 1);
copy = data_len > sdp->sd_jbsize ? sdp->sd_jbsize :
data_len;
memcpy(bh->b_data + mh_size, data, copy);
if (copy < sdp->sd_jbsize)
memset(bh->b_data + mh_size + copy, 0,
sdp->sd_jbsize - copy);
*dataptr++ = cpu_to_be64(bh->b_blocknr);
data += copy;
data_len -= copy;
brelse(bh);
}
gfs2_assert_withdraw(sdp, !data_len);
}
return 0;
}
typedef int (*ea_skeleton_call_t) (struct gfs2_inode *ip,
struct gfs2_ea_request *er, void *private);
static int ea_alloc_skeleton(struct gfs2_inode *ip, struct gfs2_ea_request *er,
unsigned int blks,
ea_skeleton_call_t skeleton_call, void *private)
{
struct gfs2_alloc_parms ap = { .target = blks };
int error;
error = gfs2_rindex_update(GFS2_SB(&ip->i_inode));
if (error)
return error;
error = gfs2_quota_lock_check(ip, &ap);
if (error)
return error;
error = gfs2_inplace_reserve(ip, &ap);
if (error)
goto out_gunlock_q;
error = gfs2_trans_begin(GFS2_SB(&ip->i_inode),
blks + gfs2_rg_blocks(ip, blks) +
RES_DINODE + RES_STATFS + RES_QUOTA, 0);
if (error)
goto out_ipres;
error = skeleton_call(ip, er, private);
if (error)
goto out_end_trans;
ip->i_inode.i_ctime = current_time(&ip->i_inode);
__mark_inode_dirty(&ip->i_inode, I_DIRTY_DATASYNC);
out_end_trans:
gfs2_trans_end(GFS2_SB(&ip->i_inode));
out_ipres:
gfs2_inplace_release(ip);
out_gunlock_q:
gfs2_quota_unlock(ip);
return error;
}
static int ea_init_i(struct gfs2_inode *ip, struct gfs2_ea_request *er,
void *private)
{
struct buffer_head *bh;
int error;
error = ea_alloc_blk(ip, &bh);
if (error)
return error;
ip->i_eattr = bh->b_blocknr;
error = ea_write(ip, GFS2_EA_BH2FIRST(bh), er);
brelse(bh);
return error;
}
/*
* ea_init - initializes a new eattr block
*
* Returns: errno
*/
static int ea_init(struct gfs2_inode *ip, int type, const char *name,
const void *data, size_t size)
{
struct gfs2_ea_request er;
unsigned int jbsize = GFS2_SB(&ip->i_inode)->sd_jbsize;
unsigned int blks = 1;
er.er_type = type;
er.er_name = name;
er.er_name_len = strlen(name);
er.er_data = (void *)data;
er.er_data_len = size;
if (GFS2_EAREQ_SIZE_STUFFED(&er) > jbsize)
blks += DIV_ROUND_UP(er.er_data_len, jbsize);
return ea_alloc_skeleton(ip, &er, blks, ea_init_i, NULL);
}
static struct gfs2_ea_header *ea_split_ea(struct gfs2_ea_header *ea)
{
u32 ea_size = GFS2_EA_SIZE(ea);
struct gfs2_ea_header *new = (struct gfs2_ea_header *)((char *)ea +
ea_size);
u32 new_size = GFS2_EA_REC_LEN(ea) - ea_size;
int last = ea->ea_flags & GFS2_EAFLAG_LAST;
ea->ea_rec_len = cpu_to_be32(ea_size);
ea->ea_flags ^= last;
new->ea_rec_len = cpu_to_be32(new_size);
new->ea_flags = last;
return new;
}
static void ea_set_remove_stuffed(struct gfs2_inode *ip,
struct gfs2_ea_location *el)
{
struct gfs2_ea_header *ea = el->el_ea;
struct gfs2_ea_header *prev = el->el_prev;
u32 len;
gfs2_trans_add_meta(ip->i_gl, el->el_bh);
if (!prev || !GFS2_EA_IS_STUFFED(ea)) {
ea->ea_type = GFS2_EATYPE_UNUSED;
return;
} else if (GFS2_EA2NEXT(prev) != ea) {
prev = GFS2_EA2NEXT(prev);
gfs2_assert_withdraw(GFS2_SB(&ip->i_inode), GFS2_EA2NEXT(prev) == ea);
}
len = GFS2_EA_REC_LEN(prev) + GFS2_EA_REC_LEN(ea);
prev->ea_rec_len = cpu_to_be32(len);
if (GFS2_EA_IS_LAST(ea))
prev->ea_flags |= GFS2_EAFLAG_LAST;
}
struct ea_set {
int ea_split;
struct gfs2_ea_request *es_er;
struct gfs2_ea_location *es_el;
struct buffer_head *es_bh;
struct gfs2_ea_header *es_ea;
};
static int ea_set_simple_noalloc(struct gfs2_inode *ip, struct buffer_head *bh,
struct gfs2_ea_header *ea, struct ea_set *es)
{
struct gfs2_ea_request *er = es->es_er;
int error;
error = gfs2_trans_begin(GFS2_SB(&ip->i_inode), RES_DINODE + 2 * RES_EATTR, 0);
if (error)
return error;
gfs2_trans_add_meta(ip->i_gl, bh);
if (es->ea_split)
ea = ea_split_ea(ea);
ea_write(ip, ea, er);
if (es->es_el)
ea_set_remove_stuffed(ip, es->es_el);
ip->i_inode.i_ctime = current_time(&ip->i_inode);
__mark_inode_dirty(&ip->i_inode, I_DIRTY_DATASYNC);
gfs2_trans_end(GFS2_SB(&ip->i_inode));
return error;
}
static int ea_set_simple_alloc(struct gfs2_inode *ip,
struct gfs2_ea_request *er, void *private)
{
struct ea_set *es = private;
struct gfs2_ea_header *ea = es->es_ea;
int error;
gfs2_trans_add_meta(ip->i_gl, es->es_bh);
if (es->ea_split)
ea = ea_split_ea(ea);
error = ea_write(ip, ea, er);
if (error)
return error;
if (es->es_el)
ea_set_remove_stuffed(ip, es->es_el);
return 0;
}
static int ea_set_simple(struct gfs2_inode *ip, struct buffer_head *bh,
struct gfs2_ea_header *ea, struct gfs2_ea_header *prev,
void *private)
{
struct ea_set *es = private;
unsigned int size;
int stuffed;
int error;
stuffed = ea_calc_size(GFS2_SB(&ip->i_inode), es->es_er->er_name_len,
es->es_er->er_data_len, &size);
if (ea->ea_type == GFS2_EATYPE_UNUSED) {
if (GFS2_EA_REC_LEN(ea) < size)
return 0;
if (!GFS2_EA_IS_STUFFED(ea)) {
error = ea_remove_unstuffed(ip, bh, ea, prev, 1);
if (error)
return error;
}
es->ea_split = 0;
} else if (GFS2_EA_REC_LEN(ea) - GFS2_EA_SIZE(ea) >= size)
es->ea_split = 1;
else
return 0;
if (stuffed) {
error = ea_set_simple_noalloc(ip, bh, ea, es);
if (error)
return error;
} else {
unsigned int blks;
es->es_bh = bh;
es->es_ea = ea;
blks = 2 + DIV_ROUND_UP(es->es_er->er_data_len,
GFS2_SB(&ip->i_inode)->sd_jbsize);
error = ea_alloc_skeleton(ip, es->es_er, blks,
ea_set_simple_alloc, es);
if (error)
return error;
}
return 1;
}
static int ea_set_block(struct gfs2_inode *ip, struct gfs2_ea_request *er,
void *private)
{
struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
struct buffer_head *indbh, *newbh;
__be64 *eablk;
int error;
int mh_size = sizeof(struct gfs2_meta_header);
if (ip->i_diskflags & GFS2_DIF_EA_INDIRECT) {
__be64 *end;
error = gfs2_meta_read(ip->i_gl, ip->i_eattr, DIO_WAIT, 0,
&indbh);
if (error)
return error;
if (gfs2_metatype_check(sdp, indbh, GFS2_METATYPE_IN)) {
error = -EIO;
goto out;
}
eablk = (__be64 *)(indbh->b_data + mh_size);
end = eablk + sdp->sd_inptrs;
for (; eablk < end; eablk++)
if (!*eablk)
break;
if (eablk == end) {
error = -ENOSPC;
goto out;
}
gfs2_trans_add_meta(ip->i_gl, indbh);
} else {
u64 blk;
unsigned int n = 1;
error = gfs2_alloc_blocks(ip, &blk, &n, 0, NULL);
if (error)
return error;
gfs2_trans_remove_revoke(sdp, blk, 1);
indbh = gfs2_meta_new(ip->i_gl, blk);
gfs2_trans_add_meta(ip->i_gl, indbh);
gfs2_metatype_set(indbh, GFS2_METATYPE_IN, GFS2_FORMAT_IN);
gfs2_buffer_clear_tail(indbh, mh_size);
eablk = (__be64 *)(indbh->b_data + mh_size);
*eablk = cpu_to_be64(ip->i_eattr);
ip->i_eattr = blk;
ip->i_diskflags |= GFS2_DIF_EA_INDIRECT;
gfs2_add_inode_blocks(&ip->i_inode, 1);
eablk++;
}
error = ea_alloc_blk(ip, &newbh);
if (error)
goto out;
*eablk = cpu_to_be64((u64)newbh->b_blocknr);
error = ea_write(ip, GFS2_EA_BH2FIRST(newbh), er);
brelse(newbh);
if (error)
goto out;
if (private)
ea_set_remove_stuffed(ip, private);
out:
brelse(indbh);
return error;
}
static int ea_set_i(struct gfs2_inode *ip, int type, const char *name,
const void *value, size_t size, struct gfs2_ea_location *el)
{
struct gfs2_ea_request er;
struct ea_set es;
unsigned int blks = 2;
int error;
er.er_type = type;
er.er_name = name;
er.er_data = (void *)value;
er.er_name_len = strlen(name);
er.er_data_len = size;
memset(&es, 0, sizeof(struct ea_set));
es.es_er = &er;
es.es_el = el;
error = ea_foreach(ip, ea_set_simple, &es);
if (error > 0)
return 0;
if (error)
return error;
if (!(ip->i_diskflags & GFS2_DIF_EA_INDIRECT))
blks++;
if (GFS2_EAREQ_SIZE_STUFFED(&er) > GFS2_SB(&ip->i_inode)->sd_jbsize)
blks += DIV_ROUND_UP(er.er_data_len, GFS2_SB(&ip->i_inode)->sd_jbsize);
return ea_alloc_skeleton(ip, &er, blks, ea_set_block, el);
}
static int ea_set_remove_unstuffed(struct gfs2_inode *ip,
struct gfs2_ea_location *el)
{
if (el->el_prev && GFS2_EA2NEXT(el->el_prev) != el->el_ea) {
el->el_prev = GFS2_EA2NEXT(el->el_prev);
gfs2_assert_withdraw(GFS2_SB(&ip->i_inode),
GFS2_EA2NEXT(el->el_prev) == el->el_ea);
}
return ea_remove_unstuffed(ip, el->el_bh, el->el_ea, el->el_prev, 0);
}
static int ea_remove_stuffed(struct gfs2_inode *ip, struct gfs2_ea_location *el)
{
struct gfs2_ea_header *ea = el->el_ea;
struct gfs2_ea_header *prev = el->el_prev;
int error;
error = gfs2_trans_begin(GFS2_SB(&ip->i_inode), RES_DINODE + RES_EATTR, 0);
if (error)
return error;
gfs2_trans_add_meta(ip->i_gl, el->el_bh);
if (prev) {
u32 len;
len = GFS2_EA_REC_LEN(prev) + GFS2_EA_REC_LEN(ea);
prev->ea_rec_len = cpu_to_be32(len);
if (GFS2_EA_IS_LAST(ea))
prev->ea_flags |= GFS2_EAFLAG_LAST;
} else {
ea->ea_type = GFS2_EATYPE_UNUSED;
}
ip->i_inode.i_ctime = current_time(&ip->i_inode);
__mark_inode_dirty(&ip->i_inode, I_DIRTY_DATASYNC);
gfs2_trans_end(GFS2_SB(&ip->i_inode));
return error;
}
/**
* gfs2_xattr_remove - Remove a GFS2 extended attribute
* @ip: The inode
* @type: The type of the extended attribute
* @name: The name of the extended attribute
*
* This is not called directly by the VFS since we use the (common)
* scheme of making a "set with NULL data" mean a remove request. Note
* that this is different from a set with zero length data.
*
* Returns: 0, or errno on failure
*/
static int gfs2_xattr_remove(struct gfs2_inode *ip, int type, const char *name)
{
struct gfs2_ea_location el;
int error;
if (!ip->i_eattr)
return -ENODATA;
error = gfs2_ea_find(ip, type, name, &el);
if (error)
return error;
if (!el.el_ea)
return -ENODATA;
if (GFS2_EA_IS_STUFFED(el.el_ea))
error = ea_remove_stuffed(ip, &el);
else
error = ea_remove_unstuffed(ip, el.el_bh, el.el_ea, el.el_prev, 0);
brelse(el.el_bh);
return error;
}
/**
* __gfs2_xattr_set - Set (or remove) a GFS2 extended attribute
* @inode: The inode
* @name: The name of the extended attribute
* @value: The value of the extended attribute (NULL for remove)
* @size: The size of the @value argument
* @flags: Create or Replace
* @type: The type of the extended attribute
*
* See gfs2_xattr_remove() for details of the removal of xattrs.
*
* Returns: 0 or errno on failure
*/
int __gfs2_xattr_set(struct inode *inode, const char *name,
const void *value, size_t size, int flags, int type)
{
struct gfs2_inode *ip = GFS2_I(inode);
struct gfs2_sbd *sdp = GFS2_SB(inode);
struct gfs2_ea_location el;
unsigned int namel = strlen(name);
int error;
if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
return -EPERM;
if (namel > GFS2_EA_MAX_NAME_LEN)
return -ERANGE;
if (value == NULL) {
error = gfs2_xattr_remove(ip, type, name);
if (error == -ENODATA && !(flags & XATTR_REPLACE))
error = 0;
return error;
}
if (ea_check_size(sdp, namel, size))
return -ERANGE;
if (!ip->i_eattr) {
if (flags & XATTR_REPLACE)
return -ENODATA;
return ea_init(ip, type, name, value, size);
}
error = gfs2_ea_find(ip, type, name, &el);
if (error)
return error;
if (el.el_ea) {
if (ip->i_diskflags & GFS2_DIF_APPENDONLY) {
brelse(el.el_bh);
return -EPERM;
}
error = -EEXIST;
if (!(flags & XATTR_CREATE)) {
int unstuffed = !GFS2_EA_IS_STUFFED(el.el_ea);
error = ea_set_i(ip, type, name, value, size, &el);
if (!error && unstuffed)
ea_set_remove_unstuffed(ip, &el);
}
brelse(el.el_bh);
return error;
}
error = -ENODATA;
if (!(flags & XATTR_REPLACE))
error = ea_set_i(ip, type, name, value, size, NULL);
return error;
}
static int gfs2_xattr_set(const struct xattr_handler *handler,
acl: handle idmapped mounts The posix acl permission checking helpers determine whether a caller is privileged over an inode according to the acls associated with the inode. Add helpers that make it possible to handle acls on idmapped mounts. The vfs and the filesystems targeted by this first iteration make use of posix_acl_fix_xattr_from_user() and posix_acl_fix_xattr_to_user() to translate basic posix access and default permissions such as the ACL_USER and ACL_GROUP type according to the initial user namespace (or the superblock's user namespace) to and from the caller's current user namespace. Adapt these two helpers to handle idmapped mounts whereby we either map from or into the mount's user namespace depending on in which direction we're translating. Similarly, cap_convert_nscap() is used by the vfs to translate user namespace and non-user namespace aware filesystem capabilities from the superblock's user namespace to the caller's user namespace. Enable it to handle idmapped mounts by accounting for the mount's user namespace. In addition the fileystems targeted in the first iteration of this patch series make use of the posix_acl_chmod() and, posix_acl_update_mode() helpers. Both helpers perform permission checks on the target inode. Let them handle idmapped mounts. These two helpers are called when posix acls are set by the respective filesystems to handle this case we extend the ->set() method to take an additional user namespace argument to pass the mount's user namespace down. Link: https://lore.kernel.org/r/20210121131959.646623-9-christian.brauner@ubuntu.com Cc: Christoph Hellwig <hch@lst.de> Cc: David Howells <dhowells@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-21 13:19:27 +00:00
struct user_namespace *mnt_userns,
struct dentry *unused, struct inode *inode,
const char *name, const void *value,
size_t size, int flags)
{
struct gfs2_inode *ip = GFS2_I(inode);
struct gfs2_holder gh;
int ret;
ret = gfs2_qa_get(ip);
if (ret)
return ret;
/* May be called from gfs_setattr with the glock locked. */
if (!gfs2_glock_is_locked_by_me(ip->i_gl)) {
ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
if (ret)
goto out;
} else {
if (WARN_ON_ONCE(ip->i_gl->gl_state != LM_ST_EXCLUSIVE)) {
ret = -EIO;
goto out;
}
gfs2_holder_mark_uninitialized(&gh);
}
ret = __gfs2_xattr_set(inode, name, value, size, flags, handler->flags);
if (gfs2_holder_initialized(&gh))
gfs2_glock_dq_uninit(&gh);
out:
gfs2_qa_put(ip);
return ret;
}
static int ea_dealloc_indirect(struct gfs2_inode *ip)
{
struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
struct gfs2_rgrp_list rlist;
struct gfs2_rgrpd *rgd;
struct buffer_head *indbh, *dibh;
__be64 *eablk, *end;
unsigned int rg_blocks = 0;
u64 bstart = 0;
unsigned int blen = 0;
unsigned int blks = 0;
unsigned int x;
int error;
error = gfs2_rindex_update(sdp);
if (error)
return error;
memset(&rlist, 0, sizeof(struct gfs2_rgrp_list));
error = gfs2_meta_read(ip->i_gl, ip->i_eattr, DIO_WAIT, 0, &indbh);
if (error)
return error;
if (gfs2_metatype_check(sdp, indbh, GFS2_METATYPE_IN)) {
error = -EIO;
goto out;
}
eablk = (__be64 *)(indbh->b_data + sizeof(struct gfs2_meta_header));
end = eablk + sdp->sd_inptrs;
for (; eablk < end; eablk++) {
u64 bn;
if (!*eablk)
break;
bn = be64_to_cpu(*eablk);
if (bstart + blen == bn)
blen++;
else {
if (bstart)
gfs2_rlist_add(ip, &rlist, bstart);
bstart = bn;
blen = 1;
}
blks++;
}
if (bstart)
gfs2_rlist_add(ip, &rlist, bstart);
else
goto out;
gfs2_rlist_alloc(&rlist);
for (x = 0; x < rlist.rl_rgrps; x++) {
rgd = gfs2_glock2rgrp(rlist.rl_ghs[x].gh_gl);
rg_blocks += rgd->rd_length;
}
error = gfs2_glock_nq_m(rlist.rl_rgrps, rlist.rl_ghs);
if (error)
goto out_rlist_free;
error = gfs2_trans_begin(sdp, rg_blocks + RES_DINODE + RES_INDIRECT +
RES_STATFS + RES_QUOTA, blks);
if (error)
goto out_gunlock;
gfs2_trans_add_meta(ip->i_gl, indbh);
eablk = (__be64 *)(indbh->b_data + sizeof(struct gfs2_meta_header));
bstart = 0;
rgd = NULL;
blen = 0;
for (; eablk < end; eablk++) {
u64 bn;
if (!*eablk)
break;
bn = be64_to_cpu(*eablk);
if (bstart + blen == bn)
blen++;
else {
if (bstart)
gfs2_free_meta(ip, rgd, bstart, blen);
bstart = bn;
rgd = gfs2_blk2rgrpd(sdp, bstart, true);
blen = 1;
}
*eablk = 0;
gfs2_add_inode_blocks(&ip->i_inode, -1);
}
if (bstart)
gfs2_free_meta(ip, rgd, bstart, blen);
ip->i_diskflags &= ~GFS2_DIF_EA_INDIRECT;
error = gfs2_meta_inode_buffer(ip, &dibh);
if (!error) {
gfs2_trans_add_meta(ip->i_gl, dibh);
gfs2_dinode_out(ip, dibh->b_data);
brelse(dibh);
}
gfs2_trans_end(sdp);
out_gunlock:
gfs2_glock_dq_m(rlist.rl_rgrps, rlist.rl_ghs);
out_rlist_free:
gfs2_rlist_free(&rlist);
out:
brelse(indbh);
return error;
}
static int ea_dealloc_block(struct gfs2_inode *ip)
{
struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
struct gfs2_rgrpd *rgd;
struct buffer_head *dibh;
struct gfs2_holder gh;
int error;
error = gfs2_rindex_update(sdp);
if (error)
return error;
rgd = gfs2_blk2rgrpd(sdp, ip->i_eattr, 1);
if (!rgd) {
gfs2_consist_inode(ip);
return -EIO;
}
error = gfs2_glock_nq_init(rgd->rd_gl, LM_ST_EXCLUSIVE,
LM_FLAG_NODE_SCOPE, &gh);
if (error)
return error;
error = gfs2_trans_begin(sdp, RES_RG_BIT + RES_DINODE + RES_STATFS +
RES_QUOTA, 1);
if (error)
goto out_gunlock;
gfs2_free_meta(ip, rgd, ip->i_eattr, 1);
ip->i_eattr = 0;
gfs2_add_inode_blocks(&ip->i_inode, -1);
error = gfs2_meta_inode_buffer(ip, &dibh);
if (!error) {
gfs2_trans_add_meta(ip->i_gl, dibh);
gfs2_dinode_out(ip, dibh->b_data);
brelse(dibh);
}
gfs2_trans_end(sdp);
out_gunlock:
gfs2_glock_dq_uninit(&gh);
return error;
}
/**
* gfs2_ea_dealloc - deallocate the extended attribute fork
* @ip: the inode
*
* Returns: errno
*/
int gfs2_ea_dealloc(struct gfs2_inode *ip)
{
int error;
error = gfs2_rindex_update(GFS2_SB(&ip->i_inode));
if (error)
return error;
error = gfs2_quota_hold(ip, NO_UID_QUOTA_CHANGE, NO_GID_QUOTA_CHANGE);
if (error)
return error;
error = ea_foreach(ip, ea_dealloc_unstuffed, NULL);
if (error)
goto out_quota;
if (ip->i_diskflags & GFS2_DIF_EA_INDIRECT) {
error = ea_dealloc_indirect(ip);
if (error)
goto out_quota;
}
error = ea_dealloc_block(ip);
out_quota:
gfs2_quota_unhold(ip);
return error;
}
static const struct xattr_handler gfs2_xattr_user_handler = {
.prefix = XATTR_USER_PREFIX,
.flags = GFS2_EATYPE_USR,
.get = gfs2_xattr_get,
.set = gfs2_xattr_set,
};
static const struct xattr_handler gfs2_xattr_security_handler = {
.prefix = XATTR_SECURITY_PREFIX,
.flags = GFS2_EATYPE_SECURITY,
.get = gfs2_xattr_get,
.set = gfs2_xattr_set,
};
static bool
gfs2_xattr_trusted_list(struct dentry *dentry)
{
return capable(CAP_SYS_ADMIN);
}
static const struct xattr_handler gfs2_xattr_trusted_handler = {
.prefix = XATTR_TRUSTED_PREFIX,
.flags = GFS2_EATYPE_TRUSTED,
.list = gfs2_xattr_trusted_list,
.get = gfs2_xattr_get,
.set = gfs2_xattr_set,
};
const struct xattr_handler *gfs2_xattr_handlers_max[] = {
/* GFS2_FS_FORMAT_MAX */
&gfs2_xattr_trusted_handler,
/* GFS2_FS_FORMAT_MIN */
&gfs2_xattr_user_handler,
&gfs2_xattr_security_handler,
&posix_acl_access_xattr_handler,
&posix_acl_default_xattr_handler,
NULL,
};
const struct xattr_handler **gfs2_xattr_handlers_min = gfs2_xattr_handlers_max + 1;