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author | David Disseldorp <ddiss@suse.de> | 2014-02-06 15:29:18 +0100 |
---|---|---|
committer | Chris Mason <clm@fb.com> | 2014-03-21 06:23:10 -0700 |
commit | 1484081f6113cd33ad538a4a50f332754dbcc873 (patch) | |
tree | 62d47e56dee80d985ef6fd0f9237f6194577e882 | |
parent | afb47079fa1e57c63c0ae0cfcb90817f3abf6830 (diff) |
ioctl: add note regarding CLONE_RANGE(len=0) behaviour
A BTRFS_IOC_CLONE_RANGE request with a src_length value of zero has the
effect of cloning all data from src_offset through to end-of-file.
Document this behaviour in the header file for those who (like me)
incorrectly assume that no data is cloned in such a case.
Signed-off-by: David Disseldorp <ddiss@suse.de>
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
-rw-r--r-- | ioctl.h | 1 |
1 files changed, 1 insertions, 0 deletions
@@ -506,6 +506,7 @@ static inline char *btrfs_err_str(enum btrfs_err_code err_code) #define BTRFS_IOC_SCAN_DEV _IOW(BTRFS_IOCTL_MAGIC, 4, \ struct btrfs_ioctl_vol_args) +/* With a @src_length of zero, the range from @src_offset->EOF is cloned! */ struct btrfs_ioctl_clone_range_args { __s64 src_fd; __u64 src_offset, src_length; |