Joseph Qi
2019-Jul-05 01:14 UTC
[Ocfs2-devel] [PATCH v2 31/35] ocfs2: Use kmemdup rather than duplicating its implementation
On 19/7/4 00:31, Fuqian Huang wrote:> kmemdup is introduced to duplicate a region of memory in a neat way. > Rather than kmalloc/kzalloc + memcpy, which the programmer needs to > write the size twice (sometimes lead to mistakes), kmemdup improves > readability, leads to smaller code and also reduce the chances of mistakes. > Suggestion to use kmemdup rather than using kmalloc/kzalloc + memcpy. > > Signed-off-by: Fuqian Huang <huangfq.daxian at gmail.com>Looks good. Reviewed-by: Joseph Qi <joseph.qi at linux.alibaba.com>> --- > Changes in v2: > - Fix a typo in commit message (memset -> memcpy) > > fs/ocfs2/alloc.c | 8 +++----- > fs/ocfs2/localalloc.c | 6 ++---- > 2 files changed, 5 insertions(+), 9 deletions(-) > > diff --git a/fs/ocfs2/alloc.c b/fs/ocfs2/alloc.c > index d1348fc4ca6d..d4911d70c326 100644 > --- a/fs/ocfs2/alloc.c > +++ b/fs/ocfs2/alloc.c > @@ -6191,17 +6191,15 @@ int ocfs2_begin_truncate_log_recovery(struct ocfs2_super *osb, > if (le16_to_cpu(tl->tl_used)) { > trace_ocfs2_truncate_log_recovery_num(le16_to_cpu(tl->tl_used)); > > - *tl_copy = kmalloc(tl_bh->b_size, GFP_KERNEL); > + /* Assuming the write-out below goes well, this copy > + * will be passed back to recovery for processing. */ > + *tl_copy = kmemdup(tl_bh->b_data, tl_bh->b_size, GFP_KERNEL); > if (!(*tl_copy)) { > status = -ENOMEM; > mlog_errno(status); > goto bail; > } > > - /* Assuming the write-out below goes well, this copy > - * will be passed back to recovery for processing. */ > - memcpy(*tl_copy, tl_bh->b_data, tl_bh->b_size); > - > /* All we need to do to clear the truncate log is set > * tl_used. */ > tl->tl_used = 0; > diff --git a/fs/ocfs2/localalloc.c b/fs/ocfs2/localalloc.c > index f03674afbd30..158e5af767fd 100644 > --- a/fs/ocfs2/localalloc.c > +++ b/fs/ocfs2/localalloc.c > @@ -424,12 +424,11 @@ void ocfs2_shutdown_local_alloc(struct ocfs2_super *osb) > bh = osb->local_alloc_bh; > alloc = (struct ocfs2_dinode *) bh->b_data; > > - alloc_copy = kmalloc(bh->b_size, GFP_NOFS); > + alloc_copy = kmemdup(alloc, bh->b_size, GFP_NOFS); > if (!alloc_copy) { > status = -ENOMEM; > goto out_commit; > } > - memcpy(alloc_copy, alloc, bh->b_size); > > status = ocfs2_journal_access_di(handle, INODE_CACHE(local_alloc_inode), > bh, OCFS2_JOURNAL_ACCESS_WRITE); > @@ -1272,13 +1271,12 @@ static int ocfs2_local_alloc_slide_window(struct ocfs2_super *osb, > * local alloc shutdown won't try to double free main bitmap > * bits. Make a copy so the sync function knows which bits to > * free. */ > - alloc_copy = kmalloc(osb->local_alloc_bh->b_size, GFP_NOFS); > + alloc_copy = kmemdup(alloc, osb->local_alloc_bh->b_size, GFP_NOFS); > if (!alloc_copy) { > status = -ENOMEM; > mlog_errno(status); > goto bail; > } > - memcpy(alloc_copy, alloc, osb->local_alloc_bh->b_size); > > status = ocfs2_journal_access_di(handle, > INODE_CACHE(local_alloc_inode), >