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iomap: use filemap_range_needs_writeback() for O_DIRECT reads

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For reads, use the better variant of checking for the need to call
filemap_write_and_wait_range() when doing O_DIRECT.  This avoids falling
back to the slow path for IOCB_NOWAIT, if there are no pages to wait for
(or write out).

Link: https://lkml.kernel.org/r/20210224164455.1096727-4-axboe@kernel.dk
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Jens Axboe 2021-04-29 22:55:24 -07:00 committed by Linus Torvalds
parent 7a60d6d7b3
commit 985b71db17
1 changed files with 16 additions and 8 deletions
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24
fs/iomap/direct-io.c
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@ -487,12 +487,28 @@ __iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
if (pos >= dio->i_size)
goto out_free_dio;
if (iocb->ki_flags & IOCB_NOWAIT) {
if (filemap_range_needs_writeback(mapping, pos, end)) {
ret = -EAGAIN;
goto out_free_dio;
}
iomap_flags |= IOMAP_NOWAIT;
}
if (iter_is_iovec(iter))
dio->flags |= IOMAP_DIO_DIRTY;
} else {
iomap_flags |= IOMAP_WRITE;
dio->flags |= IOMAP_DIO_WRITE;
if (iocb->ki_flags & IOCB_NOWAIT) {
if (filemap_range_has_page(mapping, pos, end)) {
ret = -EAGAIN;
goto out_free_dio;
}
iomap_flags |= IOMAP_NOWAIT;
}
/* for data sync or sync, we need sync completion processing */
if (iocb->ki_flags & IOCB_DSYNC)
dio->flags |= IOMAP_DIO_NEED_SYNC;
@ -507,14 +523,6 @@ __iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
dio->flags |= IOMAP_DIO_WRITE_FUA;
}
if (iocb->ki_flags & IOCB_NOWAIT) {
if (filemap_range_has_page(mapping, pos, end)) {
ret = -EAGAIN;
goto out_free_dio;
}
iomap_flags |= IOMAP_NOWAIT;
}
if (dio_flags & IOMAP_DIO_OVERWRITE_ONLY) {
ret = -EAGAIN;
if (pos >= dio->i_size || pos + count > dio->i_size)