diff options
author | Dave Chinner <dchinner@redhat.com> | 2022-05-04 04:45:50 +0300 |
---|---|---|
committer | Dave Chinner <david@fromorbit.com> | 2022-05-04 04:45:50 +0300 |
commit | b2c28035cea290edbcec697504e5b7a4b1e023e7 (patch) | |
tree | 2fe371632c8f256fe309422aea7110f96ed35233 | |
parent | c230a4a85bcdbfc1a7415deec6caf04e8fca1301 (diff) | |
download | linux-b2c28035cea290edbcec697504e5b7a4b1e023e7.tar.xz |
xfs: hide log iovec alignment constraints
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>
-rw-r--r-- | fs/xfs/libxfs/xfs_inode_fork.c | 20 | ||||
-rw-r--r-- | fs/xfs/xfs_inode_item.c | 25 | ||||
-rw-r--r-- | fs/xfs/xfs_inode_item_recover.c | 4 | ||||
-rw-r--r-- | fs/xfs/xfs_log.h | 42 |
4 files changed, 52 insertions, 39 deletions
diff --git a/fs/xfs/libxfs/xfs_inode_fork.c b/fs/xfs/libxfs/xfs_inode_fork.c index a15ff38c3d41..1a4cdf550f6d 100644 --- a/fs/xfs/libxfs/xfs_inode_fork.c +++ b/fs/xfs/libxfs/xfs_inode_fork.c @@ -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; } diff --git a/fs/xfs/xfs_inode_item.c b/fs/xfs/xfs_inode_item.c index 00733a18ccdc..721def0639fd 100644 --- a/fs/xfs/xfs_inode_item.c +++ b/fs/xfs/xfs_inode_item.c @@ -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; diff --git a/fs/xfs/xfs_inode_item_recover.c b/fs/xfs/xfs_inode_item_recover.c index 6d44f5fd6d7e..d28ffaebd067 100644 --- a/fs/xfs/xfs_inode_item_recover.c +++ b/fs/xfs/xfs_inode_item_recover.c @@ -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: diff --git a/fs/xfs/xfs_log.h b/fs/xfs/xfs_log.h index 8dafe8f771c7..3a4f6a4e4eb7 100644 --- a/fs/xfs/xfs_log.h +++ b/fs/xfs/xfs_log.h @@ -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; - - /* opheader tracks payload length, logvec tracks region length */ + int len; + + /* + * 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) |