From: Goldwyn Rodrigues <rgoldwyn@suse.de>
To: linux-fsdevel@vger.kernel.org
Cc: hch@lst.de, smfrench@gmail.com, linux-unionfs@vger.kernel.org,
david@fromorbit.com, Goldwyn Rodrigues <rgoldwyn@suse.com>
Subject: [PATCH 3/4] copy_file_range: splice with holes
Date: Tue, 8 May 2018 16:24:04 -0500 [thread overview]
Message-ID: <20180508212405.15297-4-rgoldwyn@suse.de> (raw)
In-Reply-To: <20180508212405.15297-1-rgoldwyn@suse.de>
From: Goldwyn Rodrigues <rgoldwyn@suse.com>
copy_file_range calls do_splice_direct() if fs->clone_file_range
or fs->copy_file_range() is not available. However, do_splice_direct()
converts holes to zeros. Detect holes in the file_in range, and
create them in the corresponding file_out range.
If there is already data present at the offset in file_out, attempt
to punch a hole there. If the operation is not supported, fall
back to performing splice on the whole range.
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
---
fs/read_write.c | 60 ++++++++++++++++++++++++++++++++++++++++++++++++++++-----
1 file changed, 55 insertions(+), 5 deletions(-)
diff --git a/fs/read_write.c b/fs/read_write.c
index 2c9e7a5ea806..5df9d6e8ebee 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -20,6 +20,7 @@
#include <linux/compat.h>
#include <linux/mount.h>
#include <linux/fs.h>
+#include <linux/falloc.h>
#include "internal.h"
#include <linux/uaccess.h>
@@ -1541,14 +1542,15 @@ COMPAT_SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd,
}
#endif
-ssize_t do_copy_file_range(struct file *file_in, loff_t pos_in,
+static ssize_t do_copy_file_range(struct file *file_in, loff_t pos_in,
struct file *file_out, loff_t pos_out,
size_t len, unsigned int flags,
unsigned int splice_flags)
{
struct inode *inode_in = file_inode(file_in);
struct inode *inode_out = file_inode(file_out);
- ssize_t ret = 0;
+ ssize_t ret = 0, total = 0;
+ loff_t size, end;
if (flags != 0)
return -EINVAL;
@@ -1576,10 +1578,58 @@ ssize_t do_copy_file_range(struct file *file_in, loff_t pos_in,
if (ret != -EOPNOTSUPP)
return ret;
}
+
splice:
- ret = do_splice_direct(file_in, &pos_in, file_out, &pos_out,
- len > MAX_RW_COUNT ? MAX_RW_COUNT : len, splice_flags);
- return ret;
+ while (total < len) {
+ end = vfs_llseek(file_in, pos_in, SEEK_HOLE);
+
+ /* Starting position is already in a hole */
+ if (end == pos_in)
+ goto hole;
+ size = end - pos_in;
+do_splice:
+ ret = do_splice_direct(file_in, &pos_in, file_out, &pos_out,
+ size, 0);
+ if (ret < 0)
+ goto out;
+ total += ret;
+ if (total == len)
+ break;
+hole:
+ end = vfs_llseek(file_in, pos_in, SEEK_DATA);
+ if (end < 0) {
+ ret = end;
+ goto out;
+ }
+ size = end - pos_in;
+ /* Data on offset, punch holes */
+ if (i_size_read(file_out->f_inode) > pos_out) {
+ ret = vfs_fallocate(file_out,
+ FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
+ pos_out, size);
+ if (ret < 0) {
+ /*
+ * The filesystem does not support punching
+ * holes. Perform splice on the remaining range.
+ */
+ if (ret == -EOPNOTSUPP) {
+ size = len - total;
+ goto do_splice;
+ }
+ goto out;
+ }
+ }
+ if (ret < 0) {
+ ret = end;
+ goto out;
+ }
+ pos_out += size;
+ pos_in = end;
+ total += size;
+ }
+
+out:
+ return total ? total : ret;
}
/*
--
2.16.3
next prev parent reply other threads:[~2018-05-08 21:24 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-08 21:24 [PATCH v1 0/5] Enable holes on copy_file_range() Goldwyn Rodrigues
2018-05-08 21:24 ` [PATCH 1/4] copy_file_range: refactor vfs_copy_file_range Goldwyn Rodrigues
2018-05-08 21:24 ` [PATCH 2/4] copy_file_range: Perform splice if in/out SB are not same Goldwyn Rodrigues
2018-05-08 21:57 ` Florian Weimer
2018-05-09 19:08 ` Goldwyn Rodrigues
2018-05-09 5:44 ` Amir Goldstein
2018-05-08 21:24 ` Goldwyn Rodrigues [this message]
2018-05-08 21:59 ` [PATCH 3/4] copy_file_range: splice with holes Florian Weimer
2018-05-08 23:43 ` Dave Chinner
2018-05-09 5:47 ` Amir Goldstein
2018-05-08 21:24 ` [PATCH 4/4] ovl: Use do_copy_file_range() in copy_up_data() Goldwyn Rodrigues
2018-05-09 5:50 ` Amir Goldstein
2018-05-09 19:13 ` Goldwyn Rodrigues
2018-05-10 4:52 ` Amir Goldstein
2018-05-10 1:58 [PATCH v2 0/4] Enable holes in copy_file_range() Goldwyn Rodrigues
2018-05-10 1:58 ` [PATCH 3/4] copy_file_range: splice with holes Goldwyn Rodrigues
2018-05-10 4:42 ` Amir Goldstein
2018-05-10 5:49 ` Amir Goldstein
2018-05-14 14:56 [PATCH v3 0/4] Enable holes in copy_file_range() Goldwyn Rodrigues
2018-05-14 14:56 ` [PATCH 3/4] copy_file_range: splice with holes Goldwyn Rodrigues
2018-06-14 15:12 [PATCH RESEND v3 0/4] Enable holes in copy_file_range() Goldwyn Rodrigues
2018-06-14 15:12 ` [PATCH 3/4] copy_file_range: splice with holes Goldwyn Rodrigues
2018-06-30 18:01 ` Steve French
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