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xfs: hide log iovec alignment constraints

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Callers currently have to round out the size of buffers to match the
aligment constraints of log iovecs and xlog_write(). They should not
need to know this detail, so introduce a new function to calculate
the iovec length (for use in ->iop_size implementations). Also
modify xlog_finish_iovec() to round up the length to the correct
alignment so the callers don't need to do this, either.

Convert the only user - inode forks - of this alignment rounding to
use the new interface.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Dave Chinner <david@fromorbit.com>
This commit is contained in:
Dave Chinner 2022-05-04 11:45:50 +10:00 committed by Dave Chinner
parent c230a4a85b
commit b2c28035ce
4 changed files with 51 additions and 38 deletions
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20
fs/xfs/libxfs/xfs_inode_fork.c
View File

@ -36,7 +36,7 @@ xfs_init_local_fork(
int64_t size)
{
struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, whichfork);
int mem_size = size, real_size = 0;
int mem_size = size;
bool zero_terminate;
/*
@ -50,13 +50,7 @@ xfs_init_local_fork(
mem_size++;
if (size) {
/*
* As we round up the allocation here, we need to ensure the
* bytes we don't copy data into are zeroed because the log
* vectors still copy them into the journal.
*/
real_size = roundup(mem_size, 4);
ifp->if_u1.if_data = kmem_zalloc(real_size, KM_NOFS);
ifp->if_u1.if_data = kmem_alloc(mem_size, KM_NOFS);
memcpy(ifp->if_u1.if_data, data, size);
if (zero_terminate)
ifp->if_u1.if_data[size] = '\0';
@ -502,14 +496,8 @@ xfs_idata_realloc(
return;
}
/*
* For inline data, the underlying buffer must be a multiple of 4 bytes
* in size so that it can be logged and stay on word boundaries.
* We enforce that here, and use __GFP_ZERO to ensure that size
* extensions always zero the unused roundup area.
*/
ifp->if_u1.if_data = krealloc(ifp->if_u1.if_data, roundup(new_size, 4),
GFP_NOFS | __GFP_NOFAIL | __GFP_ZERO);
ifp->if_u1.if_data = krealloc(ifp->if_u1.if_data, new_size,
GFP_NOFS | __GFP_NOFAIL);
ifp->if_bytes = new_size;
}

25
fs/xfs/xfs_inode_item.c
View File

@ -71,7 +71,7 @@ xfs_inode_item_data_fork_size(
case XFS_DINODE_FMT_LOCAL:
if ((iip->ili_fields & XFS_ILOG_DDATA) &&
ip->i_df.if_bytes > 0) {
*nbytes += roundup(ip->i_df.if_bytes, 4);
*nbytes += xlog_calc_iovec_len(ip->i_df.if_bytes);
*nvecs += 1;
}
break;
@ -112,7 +112,7 @@ xfs_inode_item_attr_fork_size(
case XFS_DINODE_FMT_LOCAL:
if ((iip->ili_fields & XFS_ILOG_ADATA) &&
ip->i_afp->if_bytes > 0) {
*nbytes += roundup(ip->i_afp->if_bytes, 4);
*nbytes += xlog_calc_iovec_len(ip->i_afp->if_bytes);
*nvecs += 1;
}
break;
@ -204,17 +204,12 @@ xfs_inode_item_format_data_fork(
~(XFS_ILOG_DEXT | XFS_ILOG_DBROOT | XFS_ILOG_DEV);
if ((iip->ili_fields & XFS_ILOG_DDATA) &&
ip->i_df.if_bytes > 0) {
/*
* Round i_bytes up to a word boundary.
* The underlying memory is guaranteed
* to be there by xfs_idata_realloc().
*/
data_bytes = roundup(ip->i_df.if_bytes, 4);
ASSERT(ip->i_df.if_u1.if_data != NULL);
ASSERT(ip->i_disk_size > 0);
xlog_copy_iovec(lv, vecp, XLOG_REG_TYPE_ILOCAL,
ip->i_df.if_u1.if_data, data_bytes);
ilf->ilf_dsize = (unsigned)data_bytes;
ip->i_df.if_u1.if_data,
ip->i_df.if_bytes);
ilf->ilf_dsize = (unsigned)ip->i_df.if_bytes;
ilf->ilf_size++;
} else {
iip->ili_fields &= ~XFS_ILOG_DDATA;
@ -288,17 +283,11 @@ xfs_inode_item_format_attr_fork(
if ((iip->ili_fields & XFS_ILOG_ADATA) &&
ip->i_afp->if_bytes > 0) {
/*
* Round i_bytes up to a word boundary.
* The underlying memory is guaranteed
* to be there by xfs_idata_realloc().
*/
data_bytes = roundup(ip->i_afp->if_bytes, 4);
ASSERT(ip->i_afp->if_u1.if_data != NULL);
xlog_copy_iovec(lv, vecp, XLOG_REG_TYPE_IATTR_LOCAL,
ip->i_afp->if_u1.if_data,
data_bytes);
ilf->ilf_asize = (unsigned)data_bytes;
ip->i_afp->if_bytes);
ilf->ilf_asize = (unsigned)ip->i_afp->if_bytes;
ilf->ilf_size++;
} else {
iip->ili_fields &= ~XFS_ILOG_ADATA;

4
fs/xfs/xfs_inode_item_recover.c
View File

@ -462,7 +462,7 @@ xlog_recover_inode_commit_pass2(
ASSERT(in_f->ilf_size <= 4);
ASSERT((in_f->ilf_size == 3) || (fields & XFS_ILOG_AFORK));
ASSERT(!(fields & XFS_ILOG_DFORK) ||
(len == in_f->ilf_dsize));
(len == xlog_calc_iovec_len(in_f->ilf_dsize)));
switch (fields & XFS_ILOG_DFORK) {
case XFS_ILOG_DDATA:
@ -497,7 +497,7 @@ xlog_recover_inode_commit_pass2(
}
len = item->ri_buf[attr_index].i_len;
src = item->ri_buf[attr_index].i_addr;
ASSERT(len == in_f->ilf_asize);
ASSERT(len == xlog_calc_iovec_len(in_f->ilf_asize));
switch (in_f->ilf_fields & XFS_ILOG_AFORK) {
case XFS_ILOG_ADATA:

40
fs/xfs/xfs_log.h
View File

@ -21,23 +21,59 @@ struct xfs_log_vec {
#define XFS_LOG_VEC_ORDERED (-1)
/*
* Calculate the log iovec length for a given user buffer length. Intended to be
* used by ->iop_size implementations when sizing buffers of arbitrary
* alignments.
*/
static inline int
xlog_calc_iovec_len(int len)
{
return roundup(len, sizeof(uint32_t));
}
void *xlog_prepare_iovec(struct xfs_log_vec *lv, struct xfs_log_iovec **vecp,
uint type);
static inline void
xlog_finish_iovec(struct xfs_log_vec *lv, struct xfs_log_iovec *vec, int len)
xlog_finish_iovec(struct xfs_log_vec *lv, struct xfs_log_iovec *vec,
int data_len)
{
struct xlog_op_header *oph = vec->i_addr;
int len;
/* opheader tracks payload length, logvec tracks region length */
/*
* Always round up the length to the correct alignment so callers don't
* need to know anything about this log vec layout requirement. This
* means we have to zero the area the data to be written does not cover.
* This is complicated by fact the payload region is offset into the
* logvec region by the opheader that tracks the payload.
*/
len = xlog_calc_iovec_len(data_len);
if (len - data_len != 0) {
char *buf = vec->i_addr + sizeof(struct xlog_op_header);
memset(buf + data_len, 0, len - data_len);
}
/*
* The opheader tracks aligned payload length, whilst the logvec tracks
* the overall region length.
*/
oph->oh_len = cpu_to_be32(len);
len += sizeof(struct xlog_op_header);
lv->lv_buf_len += len;
lv->lv_bytes += len;
vec->i_len = len;
/* Catch buffer overruns */
ASSERT((void *)lv->lv_buf + lv->lv_bytes <= (void *)lv + lv->lv_size);
}
/*
* Copy the amount of data requested by the caller into a new log iovec.
*/
static inline void *
xlog_copy_iovec(struct xfs_log_vec *lv, struct xfs_log_iovec **vecp,
uint type, void *data, int len)