From: "Darrick J. Wong" <djwong@kernel.org>
To: djwong@kernel.org, jane.chu@oracle.com
Cc: linux-xfs@vger.kernel.org, hch@infradead.org,
dan.j.williams@intel.com, linux-fsdevel@vger.kernel.org
Subject: [PATCH 2/5] iomap: use accelerated zeroing on a block device to zero a file range
Date: Fri, 17 Sep 2021 18:30:55 -0700 [thread overview]
Message-ID: <163192865577.417973.11122330974455662098.stgit@magnolia> (raw)
In-Reply-To: <163192864476.417973.143014658064006895.stgit@magnolia>
From: Darrick J. Wong <djwong@kernel.org>
Create a function that ensures that the storage backing part of a file
contains zeroes and will not trip over old media errors if the contents
are re-read.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
---
fs/iomap/direct-io.c | 75 +++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/iomap.h | 3 ++
2 files changed, 78 insertions(+)
diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
index 4ecd255e0511..48826a49f976 100644
--- a/fs/iomap/direct-io.c
+++ b/fs/iomap/direct-io.c
@@ -652,3 +652,78 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
return iomap_dio_complete(dio);
}
EXPORT_SYMBOL_GPL(iomap_dio_rw);
+
+static loff_t
+iomap_zeroinit_iter(struct iomap_iter *iter)
+{
+ struct iomap *iomap = &iter->iomap;
+ const struct iomap *srcmap = iomap_iter_srcmap(iter);
+ const u64 start = iomap->addr + iter->pos - iomap->offset;
+ const u64 nr_bytes = iomap_length(iter);
+ sector_t sector = start >> SECTOR_SHIFT;
+ sector_t nr_sectors = nr_bytes >> SECTOR_SHIFT;
+ int ret;
+
+ if (!iomap->bdev)
+ return -ECANCELED;
+
+ /* The physical extent must be sector-aligned for block layer APIs. */
+ if ((start | nr_bytes) & (SECTOR_SIZE - 1))
+ return -EINVAL;
+
+ /* Must be able to zero storage directly without fs intervention. */
+ if (iomap->flags & IOMAP_F_SHARED)
+ return -ECANCELED;
+ if (srcmap != iomap)
+ return -ECANCELED;
+
+ switch (iomap->type) {
+ case IOMAP_MAPPED:
+ ret = blkdev_issue_zeroout(iomap->bdev, sector, nr_sectors,
+ GFP_KERNEL, 0);
+ if (ret)
+ return ret;
+ fallthrough;
+ case IOMAP_UNWRITTEN:
+ return nr_bytes;
+ }
+
+ /* Reject holes, inline data, or delalloc extents. */
+ return -ECANCELED;
+}
+
+/*
+ * Use a storage device's accelerated zero-writing command to ensure the media
+ * are ready to accept read and write commands. FSDAX is not supported.
+ *
+ * The range arguments must be aligned to sector size. The file must be backed
+ * by a block device. The extents returned must not require copy on write (or
+ * any other mapping interventions from the filesystem) and must be contiguous.
+ * @done will be set to true if the reset succeeded.
+ *
+ * Returns 0 if the zero initialization succeeded, -ECANCELED if the storage
+ * mappings do not support zero initialization, -EOPNOTSUPP if the device does
+ * not support it, or the usual negative errno.
+ */
+int
+iomap_zeroout_range(struct inode *inode, loff_t pos, u64 len,
+ const struct iomap_ops *ops)
+{
+ struct iomap_iter iter = {
+ .inode = inode,
+ .pos = pos,
+ .len = len,
+ .flags = IOMAP_REPORT,
+ };
+ int ret;
+
+ if (IS_DAX(inode))
+ return -EINVAL;
+ if (pos + len > i_size_read(inode))
+ return -EINVAL;
+
+ while ((ret = iomap_iter(&iter, ops)) > 0)
+ iter.processed = iomap_zeroinit_iter(&iter);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(iomap_zeroout_range);
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index 24f8489583ca..f4b9c6698388 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -339,6 +339,9 @@ struct iomap_dio *__iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
ssize_t iomap_dio_complete(struct iomap_dio *dio);
int iomap_dio_iopoll(struct kiocb *kiocb, bool spin);
+int iomap_zeroout_range(struct inode *inode, loff_t pos, u64 len,
+ const struct iomap_ops *ops);
+
#ifdef CONFIG_SWAP
struct file;
struct swap_info_struct;
next prev parent reply other threads:[~2021-09-18 1:30 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-18 1:30 [PATCHSET RFC v2 jane 0/5] vfs: enable userspace to reset damaged file storage Darrick J. Wong
2021-09-18 1:30 ` [PATCH 1/5] dax: prepare pmem for use by zero-initializing contents and clearing poisons Darrick J. Wong
2021-09-18 16:54 ` riteshh
2021-09-20 17:22 ` Darrick J. Wong
2021-09-21 4:07 ` riteshh
2021-09-22 18:26 ` Darrick J. Wong
2021-09-22 19:47 ` riteshh
2021-09-22 20:26 ` Dan Williams
2021-09-21 8:34 ` Christoph Hellwig
2021-09-22 18:10 ` Darrick J. Wong
2021-09-18 1:30 ` Darrick J. Wong [this message]
2021-09-18 16:55 ` [PATCH 2/5] iomap: use accelerated zeroing on a block device to zero a file range riteshh
2021-09-21 8:29 ` Christoph Hellwig
2021-09-22 18:53 ` Darrick J. Wong
2021-09-21 22:33 ` Dave Chinner
2021-09-22 18:54 ` Darrick J. Wong
2021-09-18 1:31 ` [PATCH 3/5] vfs: add a zero-initialization mode to fallocate Darrick J. Wong
2021-09-18 16:58 ` riteshh
2021-09-20 17:52 ` Eric Biggers
2021-09-20 18:06 ` Darrick J. Wong
2021-09-21 0:44 ` Dave Chinner
2021-09-21 8:31 ` Christoph Hellwig
2021-09-22 2:16 ` Dan Williams
2021-09-22 2:38 ` Darrick J. Wong
2021-09-22 3:59 ` Dave Chinner
2021-09-22 4:13 ` Darrick J. Wong
2021-09-22 5:49 ` Dave Chinner
2021-09-22 21:27 ` Darrick J. Wong
2021-09-23 0:02 ` Darrick J. Wong
2021-09-23 0:44 ` Darrick J. Wong
2021-09-23 1:42 ` Dave Chinner
2021-09-23 2:43 ` Dan Williams
2021-09-23 5:42 ` Dan Williams
2021-09-23 22:54 ` Dave Chinner
2021-09-24 1:18 ` Dan Williams
2021-09-24 1:21 ` Jane Chu
2021-09-24 1:35 ` Darrick J. Wong
2021-09-27 21:07 ` Dave Chinner
2021-09-27 21:57 ` Jane Chu
2021-09-28 0:08 ` Dan Williams
2021-09-22 5:28 ` riteshh
2021-09-18 1:31 ` [PATCH 4/5] xfs: implement FALLOC_FL_ZEROINIT_RANGE Darrick J. Wong
2021-09-18 1:31 ` [PATCH 5/5] ext4: " Darrick J. Wong
2021-09-18 17:07 ` riteshh
2021-09-20 18:11 ` Darrick J. Wong
2021-09-21 6:10 ` riteshh
2021-09-18 18:05 ` [PATCHSET RFC v2 jane 0/5] vfs: enable userspace to reset damaged file storage Dan Williams
2021-09-23 0:51 ` Darrick J. Wong
2021-09-23 1:17 ` Dan Williams
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