[Libguestfs] [PATCH] lib: Add optional 'append' parameter to copy-(device|file)-to-file APIs.
Pino Toscano
ptoscano at redhat.com
Tue Jun 23 17:40:57 UTC 2015
In data martedì 23 giugno 2015 13:25:28, Richard W.M. Jones ha scritto:
> This allows you to append one file to another:
>
> copy-file-to-file /input.txt /output.txt append:true
>
> will append the contents of /input.txt to /output.txt.
> ---
> daemon/copy.c | 38 +++++++++++++++++++++++++++++++-------
> generator/actions.ml | 29 +++++++++++++++++++++--------
> 2 files changed, 52 insertions(+), 15 deletions(-)
>
> diff --git a/daemon/copy.c b/daemon/copy.c
> index bab00fe..6f3e844 100644
> --- a/daemon/copy.c
> +++ b/daemon/copy.c
> @@ -30,7 +30,6 @@
> #include "actions.h"
>
> /* wrflags */
> -#define DEST_FILE_FLAGS O_WRONLY|O_CREAT|O_TRUNC|O_NOCTTY|O_CLOEXEC, 0666
> #define DEST_DEVICE_FLAGS O_WRONLY|O_CLOEXEC, 0
>
> /* flags */
> @@ -210,8 +209,13 @@ copy (const char *src, const char *src_display,
> int
> do_copy_device_to_device (const char *src, const char *dest,
> int64_t srcoffset, int64_t destoffset, int64_t size,
> - int sparse)
> + int sparse, int append)
> {
> + if ((optargs_bitmask & GUESTFS_COPY_DEVICE_TO_DEVICE_APPEND_BITMASK) &&
> + append) {
> + reply_with_error ("the append flag cannot be set for this call");
> + return -1;
> + }
> return copy (src, src, dest, dest, DEST_DEVICE_FLAGS, 0,
> srcoffset, destoffset, size, sparse);
> }
> @@ -219,23 +223,30 @@ do_copy_device_to_device (const char *src, const char *dest,
> int
> do_copy_device_to_file (const char *src, const char *dest,
> int64_t srcoffset, int64_t destoffset, int64_t size,
> - int sparse)
> + int sparse, int append)
> {
> CLEANUP_FREE char *dest_buf = sysroot_path (dest);
> + int wrflags = O_WRONLY|O_CREAT|O_NOCTTY|O_CLOEXEC;
Cannot DEST_FILE_FLAGS (without O_TRUNC, of course) be used here (and
below) to avoid copying&pasting these attributes?
>
> if (!dest_buf) {
> reply_with_perror ("malloc");
> return -1;
> }
>
> - return copy (src, src, dest_buf, dest, DEST_FILE_FLAGS, 0,
> + if ((optargs_bitmask & GUESTFS_COPY_DEVICE_TO_FILE_APPEND_BITMASK) &&
> + append)
> + wrflags |= O_APPEND;
> + else
> + wrflags |= O_TRUNC;
> +
> + return copy (src, src, dest_buf, dest, wrflags, 0666, 0,
> srcoffset, destoffset, size, sparse);
> }
>
> int
> do_copy_file_to_device (const char *src, const char *dest,
> int64_t srcoffset, int64_t destoffset, int64_t size,
> - int sparse)
> + int sparse, int append)
> {
> CLEANUP_FREE char *src_buf = sysroot_path (src);
>
> @@ -244,6 +255,12 @@ do_copy_file_to_device (const char *src, const char *dest,
> return -1;
> }
>
> + if ((optargs_bitmask & GUESTFS_COPY_FILE_TO_DEVICE_APPEND_BITMASK) &&
> + append) {
> + reply_with_error ("the append flag cannot be set for this call");
> + return -1;
> + }
> +
> return copy (src_buf, src, dest, dest, DEST_DEVICE_FLAGS, 0,
> srcoffset, destoffset, size, sparse);
> }
> @@ -251,9 +268,10 @@ do_copy_file_to_device (const char *src, const char *dest,
> int
> do_copy_file_to_file (const char *src, const char *dest,
> int64_t srcoffset, int64_t destoffset, int64_t size,
> - int sparse)
> + int sparse, int append)
> {
> CLEANUP_FREE char *src_buf = NULL, *dest_buf = NULL;
> + int wrflags = O_WRONLY|O_CREAT|O_NOCTTY|O_CLOEXEC;
>
> src_buf = sysroot_path (src);
> if (!src_buf) {
> @@ -267,7 +285,13 @@ do_copy_file_to_file (const char *src, const char *dest,
> return -1;
> }
>
> - return copy (src_buf, src, dest_buf, dest, DEST_FILE_FLAGS,
> + if ((optargs_bitmask & GUESTFS_COPY_FILE_TO_FILE_APPEND_BITMASK) &&
> + append)
> + wrflags |= O_APPEND;
> + else
> + wrflags |= O_TRUNC;
> +
> + return copy (src_buf, src, dest_buf, dest, wrflags, 0666,
> COPY_UNLINK_DEST_ON_FAILURE,
> srcoffset, destoffset, size, sparse);
> }
> diff --git a/generator/actions.ml b/generator/actions.ml
> index d5e5ccf..11b8652 100644
> --- a/generator/actions.ml
> +++ b/generator/actions.ml
> @@ -9424,7 +9424,7 @@ See also C<guestfs_part_to_dev>." };
>
> { defaults with
> name = "copy_device_to_device"; added = (1, 13, 25);
> - style = RErr, [Device "src"; Device "dest"], [OInt64 "srcoffset"; OInt64 "destoffset"; OInt64 "size"; OBool "sparse"];
> + style = RErr, [Device "src"; Device "dest"], [OInt64 "srcoffset"; OInt64 "destoffset"; OInt64 "size"; OBool "sparse"; OBool "append"];
> proc_nr = Some 294;
> progress = true;
> shortdesc = "copy from source device to destination device";
> @@ -9448,6 +9448,11 @@ overlapping regions may not be copied correctly.
> If the destination is a file, it is created if required. If
> the destination file is not large enough, it is extended.
>
> +If the destination is a file and the C<append> flag is not set,
> +then the destination file is truncated. If the C<append> flag is
> +set, then the copy appends to the destination file. The C<append>
> +flag currently cannot be set for devices.
> +
> If the C<sparse> flag is true then the call avoids writing
> blocks that contain only zeroes, which can help in some situations
> where the backing disk is thin-provisioned. Note that unless
> @@ -9456,7 +9461,7 @@ in incorrect copying." };
>
> { defaults with
> name = "copy_device_to_file"; added = (1, 13, 25);
> - style = RErr, [Device "src"; Pathname "dest"], [OInt64 "srcoffset"; OInt64 "destoffset"; OInt64 "size"; OBool "sparse"];
> + style = RErr, [Device "src"; Pathname "dest"], [OInt64 "srcoffset"; OInt64 "destoffset"; OInt64 "size"; OBool "sparse"; OBool "append"];
> proc_nr = Some 295;
> progress = true;
> shortdesc = "copy from source device to destination file";
> @@ -9466,7 +9471,7 @@ of this call." };
>
> { defaults with
> name = "copy_file_to_device"; added = (1, 13, 25);
> - style = RErr, [Pathname "src"; Device "dest"], [OInt64 "srcoffset"; OInt64 "destoffset"; OInt64 "size"; OBool "sparse"];
> + style = RErr, [Pathname "src"; Device "dest"], [OInt64 "srcoffset"; OInt64 "destoffset"; OInt64 "size"; OBool "sparse"; OBool "append"];
> proc_nr = Some 296;
> progress = true;
> shortdesc = "copy from source file to destination device";
> @@ -9476,24 +9481,32 @@ of this call." };
>
> { defaults with
> name = "copy_file_to_file"; added = (1, 13, 25);
> - style = RErr, [Pathname "src"; Pathname "dest"], [OInt64 "srcoffset"; OInt64 "destoffset"; OInt64 "size"; OBool "sparse"];
> + style = RErr, [Pathname "src"; Pathname "dest"], [OInt64 "srcoffset"; OInt64 "destoffset"; OInt64 "size"; OBool "sparse"; OBool "append"];
> proc_nr = Some 297;
> progress = true;
> tests = [
> InitScratchFS, Always, TestResult (
> [["mkdir"; "/copyff"];
> ["write"; "/copyff/src"; "hello, world"];
> - ["copy_file_to_file"; "/copyff/src"; "/copyff/dest"; ""; ""; ""; ""];
> + ["copy_file_to_file"; "/copyff/src"; "/copyff/dest"; ""; ""; ""; ""; "false"];
> ["read_file"; "/copyff/dest"]],
> "compare_buffers (ret, size, \"hello, world\", 12) == 0"), [];
> - let size = 1024 * 1024 in
> InitScratchFS, Always, TestResultTrue (
> + let size = 1024 * 1024 in
This seems unused? Or is it supposed to be used and its usage has been
forgotten?
> [["mkdir"; "/copyff2"];
> ["fill"; "0"; string_of_int size; "/copyff2/src"];
> ["touch"; "/copyff2/dest"];
> ["truncate_size"; "/copyff2/dest"; string_of_int size];
> - ["copy_file_to_file"; "/copyff2/src"; "/copyff2/dest"; ""; ""; ""; "true"];
> - ["is_zero"; "/copyff2/dest"]]), []
> + ["copy_file_to_file"; "/copyff2/src"; "/copyff2/dest"; ""; ""; ""; "true"; "false"];
> + ["is_zero"; "/copyff2/dest"]]), [];
> + InitScratchFS, Always, TestResult (
> + [["mkdir"; "/copyff3"];
> + ["write"; "/copyff3/src"; "hello, world"];
> + ["copy_file_to_file"; "/copyff3/src"; "/copyff3/dest"; ""; ""; ""; ""; "true"];
> + ["copy_file_to_file"; "/copyff3/src"; "/copyff3/dest"; ""; ""; ""; ""; "true"];
> + ["copy_file_to_file"; "/copyff3/src"; "/copyff3/dest"; ""; ""; ""; ""; "true"];
> + ["read_file"; "/copyff3/dest"]],
> + "compare_buffers (ret, size, \"hello, worldhello, worldhello, world\", 12*3) == 0"), [];
> ];
> shortdesc = "copy from source file to destination file";
> longdesc = "\
It would seem okay for me, although maybe we should decouple the enums
for flags, so there's no need to add non-functional append flags to the
*_to_device variants.
--
Pino Toscano
More information about the Libguestfs
mailing list