Commit 8b9433eb authored by Ernesto A. Fernández's avatar Ernesto A. Fernández Committed by Jens Axboe

direct-io: allow direct writes to empty inodes

On a DIO_SKIP_HOLES filesystem, the ->get_block() method is currently
not allowed to create blocks for an empty inode.  This confusion comes
from trying to bit shift a negative number, so check the size of the
inode first.

The problem is most visible for hfsplus, because the fallback to
buffered I/O doesn't happen and the write fails with EIO.  This is in
part the fault of the module, because it gives a wrong return value on
->get_block(); that will be fixed in a separate patch.
Reviewed-by: default avatarJeff Moyer <>
Reviewed-by: default avatarJan Kara <>
Signed-off-by: default avatarErnesto A. Fernández <>
Signed-off-by: default avatarJens Axboe <>
parent 38197ca1
......@@ -679,6 +679,7 @@ static int get_more_blocks(struct dio *dio, struct dio_submit *sdio,
unsigned long fs_count; /* Number of filesystem-sized blocks */
int create;
unsigned int i_blkbits = sdio->blkbits + sdio->blkfactor;
loff_t i_size;
* If there was a memory error and we've overwritten all the
......@@ -708,8 +709,8 @@ static int get_more_blocks(struct dio *dio, struct dio_submit *sdio,
create = dio->op == REQ_OP_WRITE;
if (dio->flags & DIO_SKIP_HOLES) {
if (fs_startblk <= ((i_size_read(dio->inode) - 1) >>
i_size = i_size_read(dio->inode);
if (i_size && fs_startblk <= (i_size - 1) >> i_blkbits)
create = 0;
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