From: "Darrick J. Wong" <darrick.wong@oracle.com>
To: david@fromorbit.com, darrick.wong@oracle.com
Cc: sandeen@redhat.com, linux-nfs@vger.kernel.org,
linux-cifs@vger.kernel.org, Amir Goldstein <amir73il@gmail.com>,
linux-unionfs@vger.kernel.org, linux-xfs@vger.kernel.org,
linux-mm@kvack.org, linux-btrfs@vger.kernel.org,
linux-fsdevel@vger.kernel.org, ocfs2-devel@oss.oracle.com
Subject: [PATCH 17/25] vfs: enable remap callers that can handle short operations
Date: Wed, 10 Oct 2018 21:14:26 -0700 [thread overview]
Message-ID: <153923126628.5546.3484461137192547927.stgit@magnolia> (raw)
In-Reply-To: <153923113649.5546.9840926895953408273.stgit@magnolia>
From: Darrick J. Wong <darrick.wong@oracle.com>
Plumb in a remap flag that enables the filesystem remap handler to
shorten remapping requests for callers that can handle it. Now
copy_file_range can report partial success (in case we run up against
alignment problems, resource limits, etc.).
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
---
fs/read_write.c | 15 +++++++++------
include/linux/fs.h | 7 +++++--
mm/filemap.c | 16 ++++++++++++----
3 files changed, 26 insertions(+), 12 deletions(-)
diff --git a/fs/read_write.c b/fs/read_write.c
index 6ec908f9a69b..3713893b7e38 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -1593,7 +1593,8 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in,
cloned = file_in->f_op->remap_file_range(file_in, pos_in,
file_out, pos_out,
- min_t(loff_t, MAX_RW_COUNT, len), 0);
+ min_t(loff_t, MAX_RW_COUNT, len),
+ RFR_CAN_SHORTEN);
if (cloned > 0) {
ret = cloned;
goto done;
@@ -1804,16 +1805,18 @@ int generic_remap_file_range_prep(struct file *file_in, loff_t pos_in,
* If the user is attempting to remap a partial EOF block and
* it's inside the destination EOF then reject it.
*
- * We don't support shortening requests, so we can only reject
- * them.
+ * If possible, shorten the request instead of rejecting it.
*/
if (is_dedupe)
ret = -EBADE;
else if (pos_out + *len < i_size_read(inode_out))
ret = -EINVAL;
- if (ret)
- return ret;
+ if (ret) {
+ if (!(remap_flags & RFR_CAN_SHORTEN))
+ return ret;
+ *len &= ~blkmask;
+ }
}
return 1;
@@ -2112,7 +2115,7 @@ int vfs_dedupe_file_range(struct file *file, struct file_dedupe_range *same)
deduped = vfs_dedupe_file_range_one(file, off, dst_file,
info->dest_offset, len,
- 0);
+ RFR_CAN_SHORTEN);
if (deduped == -EBADE)
info->status = FILE_DEDUPE_RANGE_DIFFERS;
else if (deduped < 0)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index b9c314f9d5a4..57cb56bbc30a 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1726,14 +1726,17 @@ struct block_device_operations;
*
* RFR_SAME_DATA: only remap if contents identical (i.e. deduplicate)
* RFR_TO_SRC_EOF: remap to the end of the source file
+ * RFR_CAN_SHORTEN: caller can handle a shortened request
*/
#define RFR_SAME_DATA (1 << 0)
#define RFR_TO_SRC_EOF (1 << 1)
+#define RFR_CAN_SHORTEN (1 << 2)
-#define RFR_VALID_FLAGS (RFR_SAME_DATA | RFR_TO_SRC_EOF)
+#define RFR_VALID_FLAGS (RFR_SAME_DATA | RFR_TO_SRC_EOF | \
+ RFR_CAN_SHORTEN)
/* Implemented by the VFS, so these are advisory. */
-#define RFR_VFS_FLAGS (RFR_TO_SRC_EOF)
+#define RFR_VFS_FLAGS (RFR_TO_SRC_EOF | RFR_CAN_SHORTEN)
/*
* Filesystem remapping implementations should call this helper on their
diff --git a/mm/filemap.c b/mm/filemap.c
index 369cfd164e90..bccbd3621238 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -3051,8 +3051,12 @@ int generic_remap_checks(struct file *file_in, loff_t pos_in,
if (pos_in + count == size_in) {
bcount = ALIGN(size_in, bs) - pos_in;
} else {
- if (!IS_ALIGNED(count, bs))
- return -EINVAL;
+ if (!IS_ALIGNED(count, bs)) {
+ if (remap_flags & RFR_CAN_SHORTEN)
+ count = ALIGN_DOWN(count, bs);
+ else
+ return -EINVAL;
+ }
bcount = count;
}
@@ -3063,10 +3067,14 @@ int generic_remap_checks(struct file *file_in, loff_t pos_in,
pos_out < pos_in + bcount)
return -EINVAL;
- /* For now we don't support changing the length. */
- if (*req_count != count)
+ /*
+ * We shortened the request but the caller can't deal with that, so
+ * bounce the request back to userspace.
+ */
+ if (*req_count != count && !(remap_flags & RFR_CAN_SHORTEN))
return -EINVAL;
+ *req_count = count;
return 0;
}
next prev parent reply other threads:[~2018-10-11 4:14 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-11 4:12 [PATCH v3 00/25] fs: fixes for serious clone/dedupe problems Darrick J. Wong
2018-10-11 4:12 ` [PATCH 01/25] xfs: add a per-xfs trace_printk macro Darrick J. Wong
2018-10-11 13:39 ` Christoph Hellwig
2018-10-11 23:34 ` Darrick J. Wong
2018-10-11 4:12 ` [PATCH 02/25] vfs: vfs_clone_file_prep_inodes should return EINVAL for a clone from beyond EOF Darrick J. Wong
2018-10-11 13:40 ` Christoph Hellwig
2018-10-11 4:12 ` [PATCH 03/25] vfs: check file ranges before cloning files Darrick J. Wong
2018-10-11 13:42 ` Christoph Hellwig
2018-10-11 14:13 ` Amir Goldstein
2018-10-11 4:12 ` [PATCH 04/25] vfs: strengthen checking of file range inputs to generic_remap_checks Darrick J. Wong
2018-10-11 13:43 ` Christoph Hellwig
2018-10-11 4:12 ` [PATCH 05/25] vfs: avoid problematic remapping requests into partial EOF block Darrick J. Wong
2018-10-12 0:16 ` Dave Chinner
2018-10-12 16:07 ` Darrick J. Wong
2018-10-12 20:22 ` Filipe Manana
2018-10-15 0:31 ` Dave Chinner
2018-11-02 12:04 ` Filipe Manana
2018-11-02 17:42 ` Darrick J. Wong
2018-11-02 18:18 ` Filipe Manana
2018-11-02 19:05 ` Filipe Manana
2018-10-11 4:13 ` [PATCH 06/25] vfs: skip zero-length dedupe requests Darrick J. Wong
2018-10-11 4:13 ` [PATCH 07/25] vfs: combine the clone and dedupe into a single remap_file_range Darrick J. Wong
2018-10-11 4:13 ` [PATCH 08/25] vfs: rename vfs_clone_file_prep to be more descriptive Darrick J. Wong
2018-10-11 4:13 ` [PATCH 09/25] vfs: rename clone_verify_area to remap_verify_area Darrick J. Wong
2018-10-11 4:13 ` [PATCH 10/25] vfs: create generic_remap_file_range_touch to update inode metadata Darrick J. Wong
2018-10-11 4:13 ` [PATCH 11/25] vfs: pass remap flags to generic_remap_file_range_prep Darrick J. Wong
2018-10-11 4:13 ` [PATCH 12/25] vfs: pass remap flags to generic_remap_checks Darrick J. Wong
2018-10-11 4:13 ` [PATCH 13/25] vfs: make remap_file_range functions take and return bytes completed Darrick J. Wong
2018-10-11 4:14 ` [PATCH 14/25] vfs: plumb RFR_* remap flags through the vfs clone functions Darrick J. Wong
2018-10-11 4:14 ` [PATCH 15/25] vfs: plumb RFR_* remap flags through the vfs dedupe functions Darrick J. Wong
2018-10-11 4:14 ` [PATCH 16/25] vfs: make remapping to source file eof more explicit Darrick J. Wong
2018-10-11 4:14 ` Darrick J. Wong [this message]
2018-10-11 5:15 ` [PATCH 17/25] vfs: enable remap callers that can handle short operations Amir Goldstein
2018-10-11 16:04 ` Darrick J. Wong
2018-10-11 16:05 ` [PATCH v2 " Darrick J. Wong
2018-10-11 4:14 ` [PATCH 18/25] vfs: hide file range comparison function Darrick J. Wong
2018-10-11 4:14 ` [PATCH 19/25] vfs: implement opportunistic short dedupe Darrick J. Wong
2018-10-11 4:14 ` [PATCH 20/25] ocfs2: truncate page cache for clone destination file before remapping Darrick J. Wong
2018-10-11 4:14 ` [PATCH 21/25] ocfs2: fix pagecache truncation prior to reflink Darrick J. Wong
2018-10-11 4:15 ` [PATCH 22/25] ocfs2: support partial clone range and dedupe range Darrick J. Wong
2018-10-11 4:15 ` [PATCH 23/25] xfs: fix pagecache truncation prior to reflink Darrick J. Wong
2018-10-12 1:15 ` Dave Chinner
2018-10-11 4:15 ` [PATCH 24/25] xfs: support returning partial reflink results Darrick J. Wong
2018-10-12 1:22 ` Dave Chinner
2018-10-12 16:06 ` Darrick J. Wong
2018-10-11 4:15 ` [PATCH 25/25] xfs: remove redundant remap partial EOF block checks Darrick J. Wong
2018-10-12 1:22 ` Dave Chinner
2018-10-11 8:33 ` [PATCH v3 00/25] fs: fixes for serious clone/dedupe problems Amir Goldstein
2018-10-11 15:55 ` Darrick J. Wong
2018-10-13 0:05 [PATCH v4 " Darrick J. Wong
2018-10-13 0:07 ` [PATCH 17/25] vfs: enable remap callers that can handle short operations Darrick J. Wong
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