// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2000-2005 Silicon Graphics, Inc.
* Copyright (c) 2013 Red Hat, Inc.
* All Rights Reserved.
*/
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_shared.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_bit.h"
#include "xfs_mount.h"
#include "xfs_defer.h"
#include "xfs_da_format.h"
#include "xfs_da_btree.h"
#include "xfs_inode.h"
#include "xfs_trans.h"
#include "xfs_bmap.h"
#include "xfs_attr.h"
#include "xfs_attr_remote.h"
#include "xfs_trace.h"
#include "xfs_error.h"
#include "xfs_health.h"
#define ATTR_RMTVALUE_MAPSIZE 1 /* # of map entries at once */
/*
* Remote Attribute Values
* =======================
*
* Remote extended attribute values are conceptually simple -- they're written
* to data blocks mapped by an inode's attribute fork, and they have an upper
* size limit of 64k. Setting a value does not involve the XFS log.
*
* However, on a v5 filesystem, maximally sized remote attr values require one
* block more than 64k worth of space to hold both the remote attribute value
* header (64 bytes). On a 4k block filesystem this results in a 68k buffer;
* on a 64k block filesystem, this would be a 128k buffer. Note that the log
* format can only handle a dirty buffer of XFS_MAX_BLOCKSIZE length (64k).
* Therefore, we /must/ ensure that remote attribute value buffers never touch
* the logging system and therefore never have a log item.
*/
/* How many bytes can be stored in a remote value buffer? */
inline unsigned int
xfs_attr3_rmt_buf_space(
struct xfs_mount *mp)
{
unsigned int blocksize = mp->m_attr_geo->blksize;
if (xfs_has_crc(mp))
return blocksize - sizeof(struct xfs_attr3_rmt_hdr);
return blocksize;
}
/* Compute number of fsblocks needed to store a remote attr value */
unsigned int
xfs_attr3_rmt_blocks(
struct xfs_mount *mp,
unsigned int attrlen)
{
/*
* Each contiguous block has a header, so it is not just a simple
* attribute length to FSB conversion.
*/
if (xfs_has_crc(mp))
return howmany(attrlen, xfs_attr3_rmt_buf_space(mp));
return XFS_B_TO_FSB(mp, attrlen);
}
/*
* Checking of the remote attribute header is split into two parts. The verifier
* does CRC, location and bounds checking, the unpacking function checks the
* attribute parameters and owner.
*/
static xfs_failaddr_t
xfs_attr3_rmt_hdr_ok(
void *ptr,
xfs_ino_t ino,
uint32_t offset,
uint32_t size,
xfs_daddr_t bno)
{
struct xfs_attr3_rmt_hdr *rmt = ptr;
if (bno != be64_to_cpu(rmt->rm_blkno))
return __this_address;
if (offset != be32_to_cpu(rmt->rm_offset))
return __this_address;
if (size != be32_to_cpu(rmt->rm_bytes))
return __this_address;
if (ino != be64_to_cpu(rmt->rm_owner))
return __this_address;
/* ok */
return NULL;
}
static xfs_failaddr_t
xfs_attr3_rmt_verify(
struct xfs_mount *mp,
struct xfs_buf *bp,
void *ptr,
xfs_daddr_t bno)
{
struct xfs_attr3_rmt_hdr *rmt = ptr;
if (!xfs_verify_magic(bp, rmt->rm_magic))
return __this_address;
if (!uuid_equal(&rmt->rm_uuid, &mp->m_sb.sb_meta_uuid))
return __this_address;
if (be64_to_cpu(rmt->rm_blkno) != bno)
return __this_address;
if (be32_to_cpu(rmt->rm_bytes) > mp->m_attr_geo->blksize - sizeof(*rmt))
return __this_address;
if (be32_to_cpu(rmt->rm_offset) +
be32_to_cpu(rmt->rm_bytes) > XFS_XATTR_SIZE_MAX)
return __this_address;
if (rmt->rm_owner == 0)
return __this_address;
return NULL;
}
static int
__xfs_attr3_rmt_read_verify(
struct xfs_buf *bp,
bool check_crc,
xfs_failaddr_t *failaddr)
{
struct xfs_mount *mp = bp->b_mount;
char *ptr;
unsigned int len;
xfs_daddr_t bno;
unsigned int blksize = mp->m_attr_geo->blksize;
/* no verification of non-crc buffers */
if (!xfs_has_crc(mp))
return 0;
ptr = bp->b_addr;
bno = xfs_buf_daddr(bp);
len = BBTOB(bp->b_length);
ASSERT(len >= blksize);
while (len > 0) {
if (check_crc &&
!xfs_verify_cksum(ptr, blksize, XFS_ATTR3_RMT_CRC_OFF)) {
*failaddr = __this_address;
return -EFSBADCRC;
}
*failaddr = xfs_attr3_rmt_verify(mp, bp, ptr, bno);
if (*failaddr)
return -EFSCORRUPTED;
len -= blksize;
ptr += blksize;
bno += BTOBB(blksize);
}
if (len != 0) {
*failaddr = __this_address;
return -EFSCORRUPTED;
}
return 0;
}
static void
xfs_attr3_rmt_read_verify(
struct xfs_buf *bp)
{
xfs_failaddr_t fa;
int error;
error = __xfs_attr3_rmt_read_verify(bp, true, &fa);
if (error)
xfs_verifier_error(bp, error, fa);
}
static xfs_failaddr_t
xfs_attr3_rmt_verify_struct(
struct xfs_buf *bp)
{
xfs_failaddr_t fa;
int error;
error = __xfs_attr3_rmt_read_verify(bp, false, &fa);
return error ? fa : NULL;
}
static void
xfs_attr3_rmt_write_verify(
struct xfs_buf *bp)
{
struct xfs_mount *mp = bp->b_mount;
xfs_failaddr_t fa;
unsigned int blksize = mp->m_attr_geo->blksize;
char *ptr;
int len;
xfs_daddr_t bno;
/* no verification of non-crc buffers */
if (!xfs_has_crc(mp))
return;
ptr = bp->b_addr;
bno = xfs_buf_daddr(bp);
len = BBTOB(bp->b_length);
ASSERT(len >= blksize);
while (len > 0) {
struct xfs_attr3_rmt_hdr *rmt = (struct xfs_attr3_rmt_hdr *)ptr;
fa = xfs_attr3_rmt_verify(mp, bp, ptr, bno);
if (fa) {
xfs_verifier_error(bp, -EFSCORRUPTED, fa);
return;
}
/*
* Ensure we aren't writing bogus LSNs to disk. See
* xfs_attr3_rmt_hdr_set() for the explanation.
*/
if (rmt->rm_lsn != cpu_to_be64(NULLCOMMITLSN)) {
xfs_verifier_error(bp, -EFSCORRUPTED, __this_address);
return;
}
xfs_update_cksum(ptr, blksize, XFS_ATTR3_RMT_CRC_OFF);
len -= blksize;
ptr += blksize;
bno += BTOBB(blksize);
}
if (len != 0)
xfs_verifier_error(bp, -EFSCORRUPTED, __this_address);
}
const struct xfs_buf_ops xfs_attr3_rmt_buf_ops = {
.name = "xfs_attr3_rmt",
.magic = { 0, cpu_to_be32(XFS_ATTR3_RMT_MAGIC) },
.verify_read = xfs_attr3_rmt_read_verify,
.verify_write = xfs_attr3_rmt_write_verify,
.verify_struct = xfs_attr3_rmt_verify_struct,
};
STATIC int
xfs_attr3_rmt_hdr_set(
struct xfs_mount *mp,
void *ptr,
xfs_ino_t ino,
uint32_t offset,
uint32_t size,
xfs_daddr_t bno)
{
struct xfs_attr3_rmt_hdr *rmt = ptr;
if (!xfs_has_crc(mp))
return 0;
rmt->rm_magic = cpu_to_be32(XFS_ATTR3_RMT_MAGIC);
rmt->rm_offset = cpu_to_be32(offset);
rmt->rm_bytes = cpu_to_be32(size);
uuid_copy(&rmt->rm_uuid, &mp->m_sb.sb_meta_uuid);
rmt->rm_owner = cpu_to_be64(ino);
rmt->rm_blkno = cpu_to_be64(bno);
/*
* Remote attribute blocks are written synchronously, so we don't
* have an LSN that we can stamp in them that makes any sense to log
* recovery. To ensure that log recovery handles overwrites of these
* blocks sanely (i.e. once they've been freed and reallocated as some
* other type of metadata) we need to ensure that the LSN has a value
* that tells log recovery to ignore the LSN and overwrite the buffer
* with whatever is in it's log. To do this, we use the magic
* NULLCOMMITLSN to indicate that the LSN is invalid.
*/
rmt->rm_lsn = cpu_to_be64(NULLCOMMITLSN);
return sizeof(struct xfs_attr3_rmt_hdr);
}
/*
* Helper functions to copy attribute data in and out of the one disk extents
*/
STATIC int
xfs_attr_rmtval_copyout(
struct xfs_mount *mp,
struct xfs_buf *bp,
struct xfs_inode *dp,
xfs_ino_t owner,
unsigned int *offset,
unsigned int *valuelen,
uint8_t **dst)
{
char *src = bp->b_addr;
xfs_daddr_t bno = xfs_buf_daddr(bp);
unsigned int len = BBTOB(bp->b_length);
unsigned int blksize = mp->m_attr_geo->blksize;
ASSERT(len >= blksize);
while (len > 0 && *valuelen > 0) {
unsigned int hdr_size = 0;
unsigned int byte_cnt = xfs_attr3_rmt_buf_space(mp);
byte_cnt = min(*valuelen, byte_cnt);
if (xfs_has_crc(mp)) {
if (xfs_attr3_rmt_hdr_ok(src, owner, *offset,
byte_cnt, bno)) {
xfs_alert(mp,
"remote attribute header mismatch bno/off/len/owner (0x%llx/0x%x/Ox%x/0x%llx)",
bno, *offset, byte_cnt, owner);
xfs_dirattr_mark_sick(dp, XFS_ATTR_FORK);
return -EFSCORRUPTED;
}
hdr_size = sizeof(struct xfs_attr3_rmt_hdr);
}
memcpy(*dst, src + hdr_size, byte_cnt);
/* roll buffer forwards */
len -= blksize;
src += blksize;
bno += BTOBB(blksize);
/* roll attribute data forwards */
*valuelen -= byte_cnt;
*dst += byte_cnt;
*offset += byte_cnt;
}
return 0;
}
STATIC void
xfs_attr_rmtval_copyin(
struct xfs_mount *mp,
struct xfs_buf *bp,
xfs_ino_t ino,
unsigned int *offset,
unsigned int *valuelen,
uint8_t **src)
{
char *dst = bp->b_addr;
xfs_daddr_t bno = xfs_buf_daddr(bp);
unsigned int len = BBTOB(bp->b_length);
unsigned int blksize = mp->m_attr_geo->blksize;
ASSERT(len >= blksize);
while (len > 0 && *valuelen > 0) {
unsigned int hdr_size;
unsigned int byte_cnt = xfs_attr3_rmt_buf_space(mp);
byte_cnt = min(*valuelen, byte_cnt);
hdr_size = xfs_attr3_rmt_hdr_set(mp, dst, ino, *offset,
byte_cnt, bno);
memcpy(dst + hdr_size, *src, byte_cnt);
/*
* If this is the last block, zero the remainder of it.
* Check that we are actually the last block, too.
*/
if (byte_cnt + hdr_size < blksize) {
ASSERT(*valuelen - byte_cnt == 0);
ASSERT(len == blksize);
memset(dst + hdr_size + byte_cnt, 0,
blksize - hdr_size - byte_cnt);
}
/* roll buffer forwards */
len -= blksize;
dst += blksize;
bno += BTOBB(blksize);
/* roll attribute data forwards */
*valuelen -= byte_cnt;
*src += byte_cnt;
*offset += byte_cnt;
}
}
/*
* Read the value associated with an attribute from the out-of-line buffer
* that we stored it in.
*
* Returns 0 on successful retrieval, otherwise an error.
*/
int
xfs_attr_rmtval_get(
struct xfs_da_args *args)
{
struct xfs_bmbt_irec map[ATTR_RMTVALUE_MAPSIZE];
struct xfs_mount *mp = args->dp->i_mount;
struct xfs_buf *bp;
xfs_dablk_t lblkno = args->rmtblkno;
uint8_t *dst = args->value;
unsigned int valuelen;
int nmap;
int error;
unsigned int blkcnt = args->rmtblkcnt;
int i;
unsigned int offset = 0;
trace_xfs_attr_rmtval_get(args);
ASSERT(args->valuelen != 0);
ASSERT(args->rmtvaluelen == args->valuelen);
valuelen = args->rmtvaluelen;
while (valuelen > 0) {
nmap = ATTR_RMTVALUE_MAPSIZE;
error = xfs_bmapi_read(args->dp, (xfs_fileoff_t)lblkno,
blkcnt, map, &nmap,
XFS_BMAPI_ATTRFORK);
if (error)
return error;
ASSERT(nmap >= 1);
for (i = 0; (i < nmap) && (valuelen > 0); i++) {
xfs_daddr_t dblkno;
int dblkcnt;
ASSERT((map[i].br_startblock != DELAYSTARTBLOCK) &&
(map[i].br_startblock != HOLESTARTBLOCK));
dblkno = XFS_FSB_TO_DADDR(mp, map[i].br_startblock);
dblkcnt = XFS_FSB_TO_BB(mp, map[i].br_blockcount);
error = xfs_buf_read(mp->m_ddev_targp, dblkno, dblkcnt,
0, &bp, &xfs_attr3_rmt_buf_ops);
if (xfs_metadata_is_sick(error))
xfs_dirattr_mark_sick(args->dp, XFS_ATTR_FORK);
if (error)
return error;
error = xfs_attr_rmtval_copyout(mp, bp, args->dp,
args->owner, &offset, &valuelen, &dst);
xfs_buf_relse(bp);
if (error)
return error;
/* roll attribute extent map forwards */
lblkno += map[i].br_blockcount;
blkcnt -= map[i].br_blockcount;
}
}
ASSERT(valuelen == 0);
return 0;
}
/*
* Find a "hole" in the attribute address space large enough for us to drop the
* new attributes value into
*/
int
xfs_attr_rmt_find_hole(
struct xfs_da_args *args)
{
struct xfs_inode *dp = args->dp;
struct xfs_mount *mp = dp->i_mount;
int error;
unsigned int blkcnt;
xfs_fileoff_t lfileoff = 0;
/*
* Because CRC enable attributes have headers, we can't just do a
* straight byte to FSB conversion and have to take the header space
* into account.
*/
blkcnt = xfs_attr3_rmt_blocks(mp, args->rmtvaluelen);
error = xfs_bmap_first_unused(args->trans, args->dp, blkcnt, &lfileoff,
XFS_ATTR_FORK);
if (error)
return error;
args->rmtblkno = (xfs_dablk_t)lfileoff;
args->rmtblkcnt = blkcnt;
return 0;
}
int
xfs_attr_rmtval_set_value(
struct xfs_da_args *args)
{
struct xfs_inode *dp = args->dp;
struct xfs_mount *mp = dp->i_mount;
struct xfs_bmbt_irec map;
xfs_dablk_t lblkno;
uint8_t *src = args->value;
unsigned int blkcnt;
unsigned int valuelen;
int nmap;
int error;
unsigned int offset = 0;
/*
* Roll through the "value", copying the attribute value to the
* already-allocated blocks. Blocks are written synchronously
* so that we can know they are all on disk before we turn off
* the INCOMPLETE flag.
*/
lblkno = args->rmtblkno;
blkcnt = args->rmtblkcnt;
valuelen = args->rmtvaluelen;
while (valuelen > 0) {
struct xfs_buf *bp;
xfs_daddr_t dblkno;
int dblkcnt;
ASSERT(blkcnt > 0);
nmap = 1;
error = xfs_bmapi_read(dp, (xfs_fileoff_t)lblkno,
blkcnt, &map, &nmap,
XFS_BMAPI_ATTRFORK);
if (error)
return error;
ASSERT(nmap == 1);
ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
(map.br_startblock != HOLESTARTBLOCK));
dblkno = XFS_FSB_TO_DADDR(mp, map.br_startblock),
dblkcnt = XFS_FSB_TO_BB(mp, map.br_blockcount);
error = xfs_buf_get(mp->m_ddev_targp, dblkno, dblkcnt, &bp);
if (error)
return error;
bp->b_ops = &xfs_attr3_rmt_buf_ops;
xfs_attr_rmtval_copyin(mp, bp, args->owner, &offset, &valuelen,
&src);
error = xfs_bwrite(bp); /* GROT: NOTE: synchronous write */
xfs_buf_relse(bp);
if (error)
return error;
/* roll attribute extent map forwards */
lblkno += map.br_blockcount;
blkcnt -= map.br_blockcount;
}
ASSERT(valuelen == 0);
return 0;
}
/* Mark stale any incore buffers for the remote value. */
int
xfs_attr_rmtval_stale(
struct xfs_inode *ip,
struct xfs_bmbt_irec *map,
xfs_buf_flags_t incore_flags)
{
struct xfs_mount *mp = ip->i_mount;
struct xfs_buf *bp;
int error;
xfs_assert_ilocked(ip, XFS_ILOCK_EXCL);
if (XFS_IS_CORRUPT(mp, map->br_startblock == DELAYSTARTBLOCK) ||
XFS_IS_CORRUPT(mp, map->br_startblock == HOLESTARTBLOCK)) {
xfs_bmap_mark_sick(ip, XFS_ATTR_FORK);
return -EFSCORRUPTED;
}
error = xfs_buf_incore(mp->m_ddev_targp,
XFS_FSB_TO_DADDR(mp, map->br_startblock),
XFS_FSB_TO_BB(mp, map->br_blockcount),
incore_flags, &bp);
if (error) {
if (error == -ENOENT)
return 0;
return error;
}
xfs_buf_stale(bp);
xfs_buf_relse(bp);
return 0;
}
/*
* Find a hole for the attr and store it in the delayed attr context. This
* initializes the context to roll through allocating an attr extent for a
* delayed attr operation
*/
int
xfs_attr_rmtval_find_space(
struct xfs_attr_intent *attr)
{
struct xfs_da_args *args = attr->xattri_da_args;
struct xfs_bmbt_irec *map = &attr->xattri_map;
int error;
attr->xattri_lblkno = 0;
attr->xattri_blkcnt = 0;
args->rmtblkcnt = 0;
args->rmtblkno = 0;
memset(map, 0, sizeof(struct xfs_bmbt_irec));
error = xfs_attr_rmt_find_hole(args);
if (error)
return error;
attr->xattri_blkcnt = args->rmtblkcnt;
attr->xattri_lblkno = args->rmtblkno;
return 0;
}
/*
* Write one block of the value associated with an attribute into the
* out-of-line buffer that we have defined for it. This is similar to a subset
* of xfs_attr_rmtval_set, but records the current block to the delayed attr
* context, and leaves transaction handling to the caller.
*/
int
xfs_attr_rmtval_set_blk(
struct xfs_attr_intent *attr)
{
struct xfs_da_args *args = attr->xattri_da_args;
struct xfs_inode *dp = args->dp;
struct xfs_bmbt_irec *map = &attr->xattri_map;
int nmap;
int error;
nmap = 1;
error = xfs_bmapi_write(args->trans, dp,
(xfs_fileoff_t)attr->xattri_lblkno,
attr->xattri_blkcnt, XFS_BMAPI_ATTRFORK, args->total,
map, &nmap);
if (error)
return error;
ASSERT((map->br_startblock != DELAYSTARTBLOCK) &&
(map->br_startblock != HOLESTARTBLOCK));
/* roll attribute extent map forwards */
attr->xattri_lblkno += map->br_blockcount;
attr->xattri_blkcnt -= map->br_blockcount;
return 0;
}
/*
* Remove the value associated with an attribute by deleting the
* out-of-line buffer that it is stored on.
*/
int
xfs_attr_rmtval_invalidate(
struct xfs_da_args *args)
{
xfs_dablk_t lblkno;
unsigned int blkcnt;
int error;
/*
* Roll through the "value", invalidating the attribute value's blocks.
*/
lblkno = args->rmtblkno;
blkcnt = args->rmtblkcnt;
while (blkcnt > 0) {
struct xfs_bmbt_irec map;
int nmap;
/*
* Try to remember where we decided to put the value.
*/
nmap = 1;
error = xfs_bmapi_read(args->dp, (xfs_fileoff_t)lblkno,
blkcnt, &map, &nmap, XFS_BMAPI_ATTRFORK);
if (error)
return error;
if (XFS_IS_CORRUPT(args->dp->i_mount, nmap != 1)) {
xfs_bmap_mark_sick(args->dp, XFS_ATTR_FORK);
return -EFSCORRUPTED;
}
error = xfs_attr_rmtval_stale(args->dp, &map, XBF_TRYLOCK);
if (error)
return error;
lblkno += map.br_blockcount;
blkcnt -= map.br_blockcount;
}
return 0;
}
/*
* Remove the value associated with an attribute by deleting the out-of-line
* buffer that it is stored on. Returns -EAGAIN for the caller to refresh the
* transaction and re-call the function. Callers should keep calling this
* routine until it returns something other than -EAGAIN.
*/
int
xfs_attr_rmtval_remove(
struct xfs_attr_intent *attr)
{
struct xfs_da_args *args = attr->xattri_da_args;
int error, done;
/*
* Unmap value blocks for this attr.
*/
error = xfs_bunmapi(args->trans, args->dp, args->rmtblkno,
args->rmtblkcnt, XFS_BMAPI_ATTRFORK, 1, &done);
if (error)
return error;
/*
* We don't need an explicit state here to pick up where we left off. We
* can figure it out using the !done return code. The actual value of
* attr->xattri_dela_state may be some value reminiscent of the calling
* function, but it's value is irrelevant with in the context of this
* function. Once we are done here, the next state is set as needed by
* the parent
*/
if (!done) {
trace_xfs_attr_rmtval_remove_return(attr->xattri_dela_state,
args->dp);
return -EAGAIN;
}
args->rmtblkno = 0;
args->rmtblkcnt = 0;
return 0;
}
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