[PATCH 2/3] man2/ioctl_fideduperange.2: clarify operation some more
From: Darrick J. Wong <hidden>
Date: 2016-08-25 23:26:43
Also in:
linux-api, linux-fsdevel
Subsystem:
the rest · Maintainer:
Linus Torvalds
Signed-off-by: Darrick J. Wong <redacted> --- man2/ioctl_ficlonerange.2 | 2 +- man2/ioctl_fideduperange.2 | 26 ++++++++++++++++++++++---- 2 files changed, 23 insertions(+), 5 deletions(-)
diff --git a/man2/ioctl_ficlonerange.2 b/man2/ioctl_ficlonerange.2
index ac0738a..0e3ae0e 100644
--- a/man2/ioctl_ficlonerange.2
+++ b/man2/ioctl_ficlonerange.2@@ -114,7 +114,7 @@ regions in directories. .TP .B EOPNOTSUPP This can appear if the filesystem does not support reflinking either file -descriptor. +descriptor, or if either file descriptor refers to special inodes. .TP .B EPERM .IR dest_fd
diff --git a/man2/ioctl_fideduperange.2 b/man2/ioctl_fideduperange.2
index c52fa2a..2112d10 100644
--- a/man2/ioctl_fideduperange.2
+++ b/man2/ioctl_fideduperange.2@@ -99,21 +99,39 @@ Each deduplication operation targets bytes in file descriptor .IR dest_fd at offset -.IR logical_offset ". +.IR dest_offset ". The field .IR reserved must be zero. +During the call, +.IR src_fd +must be open for reading and +.IR dest_fd +must be open for writing. +For any call to this ioctl, there may not be more than 65,536 +requests attached; each request may not exceed 16MiB. +By convention, the storage used by +.IR src_fd +is mapped into +.IR dest_fd +and the previous contents in +.IR dest_fd +are freed. Upon successful completion of this ioctl, the number of bytes successfully deduplicated is returned in .IR bytes_deduped and a status code for the deduplication operation is returned in .IR status ". - +If even a single byte in the range does not match, the deduplication +request will be ignored and +.IR status +set to +.BR FILE_DEDUPE_RANGE_DIFFERS . The .IR status code is set to -.B 0 +.B FILE_DEDUPE_RANGE_SAME for success, a negative error code in case of error, or .B FILE_DEDUPE_RANGE_DIFFERS if the data did not match.
@@ -150,7 +168,7 @@ regions in directories. .TP .B EOPNOTSUPP This can appear if the filesystem does not support deduplicating either file -descriptor. +descriptor, or if either file descriptor refers to special inodes. .TP .B EPERM .IR dest_fd