| Message ID | 20181205122835.19290-4-rgoldwyn@suse.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | btrfs: Support for DAX devices | expand |
On 5.12.18 г. 14:28 ч., Goldwyn Rodrigues wrote: > From: Goldwyn Rodrigues <rgoldwyn@suse.com> > > Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> > --- > fs/btrfs/dax.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/fs/btrfs/dax.c b/fs/btrfs/dax.c > index d614bf73bf8e..5a297674adec 100644 > --- a/fs/btrfs/dax.c > +++ b/fs/btrfs/dax.c > @@ -54,7 +54,12 @@ ssize_t btrfs_file_dax_read(struct kiocb *iocb, struct iov_iter *to) nit: I think it's better if you rename the iterator variable to "iter". > > BUG_ON(em->flags & EXTENT_FLAG_FS_MAPPING); > > - ret = em_dax_rw(inode, em, pos, len, to); > + if (em->block_start == EXTENT_MAP_HOLE) { > + u64 zero_len = min(em->len - (em->start - pos), len); Shouldn't this be em->len - (pos - em->start) since this gives the remaining length of the extent? Isn't pos guaranteed to be >= em->start ? > + ret = iov_iter_zero(zero_len, to); > + } else { > + ret = em_dax_rw(inode, em, pos, len, to); > + } > if (ret < 0) > goto out; > pos += ret; >
diff --git a/fs/btrfs/dax.c b/fs/btrfs/dax.c index d614bf73bf8e..5a297674adec 100644 --- a/fs/btrfs/dax.c +++ b/fs/btrfs/dax.c @@ -54,7 +54,12 @@ ssize_t btrfs_file_dax_read(struct kiocb *iocb, struct iov_iter *to) BUG_ON(em->flags & EXTENT_FLAG_FS_MAPPING); - ret = em_dax_rw(inode, em, pos, len, to); + if (em->block_start == EXTENT_MAP_HOLE) { + u64 zero_len = min(em->len - (em->start - pos), len); + ret = iov_iter_zero(zero_len, to); + } else { + ret = em_dax_rw(inode, em, pos, len, to); + } if (ret < 0) goto out; pos += ret;