[Libguestfs] [PATCH 2/2] New API: write for creating files with fixed content (RHBZ#501889).
Richard W.M. Jones
rjones at redhat.com
Tue May 18 21:04:03 UTC 2010
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
virt-df lists disk usage of guests without needing to install any
software inside the virtual machine. Supports Linux and Windows.
http://et.redhat.com/~rjones/virt-df/
-------------- next part --------------
>From 40a88c206f7759bcd13f8e483b23373d49958056 Mon Sep 17 00:00:00 2001
From: Richard Jones <rjones at redhat.com>
Date: Tue, 18 May 2010 21:51:05 +0100
Subject: [PATCH 2/2] New API: write for creating files with fixed content (RHBZ#501889).
The guestfs_write call can be used to create small files with
arbitrary 8 bit content, including \0 bytes.
This replaces and deprecates write-file, which cannot be modified
to use BufferIn because of an unfortunate choice in the ABI: the
size parameter to write-file, if zero, means that the daemon tries
to calculate the length of the buffer using strlen. However this
fails if we pass a zero-length buffer using BufferIn because then
the daemon tries to do strlen on a (really) zero length buffer, not
even containing a terminating \0 character, thus segfaulting.
---
daemon/file.c | 28 +++++++++++++
fish/edit.c | 2 +-
fish/fish.c | 2 +-
fish/guestfish.pod | 4 +-
fuse/test-fuse.sh | 4 +-
recipes/clone.sh | 4 +-
src/MAX_PROC_NR | 2 +-
src/generator.ml | 99 +++++++++++++++++++++++++-----------------------
src/guestfs.pod | 4 +-
tools/make-test-img.sh | 12 +++---
10 files changed, 96 insertions(+), 65 deletions(-)
diff --git a/daemon/file.c b/daemon/file.c
index 2399828..7d37f56 100644
--- a/daemon/file.c
+++ b/daemon/file.c
@@ -314,6 +314,34 @@ do_write_file (const char *path, const char *content, int size)
return 0;
}
+int
+do_write (const char *path, const char *content, size_t size)
+{
+ int fd;
+
+ CHROOT_IN;
+ fd = open (path, O_WRONLY | O_TRUNC | O_CREAT | O_NOCTTY, 0666);
+ CHROOT_OUT;
+
+ if (fd == -1) {
+ reply_with_perror ("open: %s", path);
+ return -1;
+ }
+
+ if (xwrite (fd, content, size) == -1) {
+ reply_with_perror ("write");
+ close (fd);
+ return -1;
+ }
+
+ if (close (fd) == -1) {
+ reply_with_perror ("close: %s", path);
+ return -1;
+ }
+
+ return 0;
+}
+
char *
do_read_file (const char *path, size_t *size_r)
{
diff --git a/fish/edit.c b/fish/edit.c
index 3fc41fb..a010057 100644
--- a/fish/edit.c
+++ b/fish/edit.c
@@ -156,7 +156,7 @@ do_edit (const char *cmd, int argc, char *argv[])
}
/* Write new content. */
- if (guestfs_write_file (g, argv[0], content_new, size) == -1) {
+ if (guestfs_write (g, argv[0], content_new, size) == -1) {
free (content);
free (content_new);
return -1;
diff --git a/fish/fish.c b/fish/fish.c
index a630cdc..5d89d60 100644
--- a/fish/fish.c
+++ b/fish/fish.c
@@ -1091,7 +1091,7 @@ display_builtin_command (const char *cmd)
" This is used to edit a file.\n"
"\n"
" It is the equivalent of (and is implemented by)\n"
- " running \"cat\", editing locally, and then \"write-file\".\n"
+ " running \"cat\", editing locally, and then \"write\".\n"
"\n"
" Normally it uses $EDITOR, but if you use the aliases\n"
" \"vi\" or \"emacs\" you will get those editors.\n"
diff --git a/fish/guestfish.pod b/fish/guestfish.pod
index 7260caf..274f1d4 100644
--- a/fish/guestfish.pod
+++ b/fish/guestfish.pod
@@ -41,7 +41,7 @@ Create a new C</etc/motd> file in a guest:
add disk.img
run
mount /dev/vg_guest/lv_root /
- write_file /etc/motd "Welcome, new users" 0
+ write /etc/motd "Welcome, new users"
_EOF_
List the LVM logical volumes in a guest:
@@ -57,7 +57,7 @@ Update C</etc/resolv.conf> in a guest:
guestfish \
add disk.img : run : mount /dev/vg_guest/lv_root / : \
- write-file /etc/resolv.conf "nameserver 1.2.3.4" 0
+ write /etc/resolv.conf "nameserver 1.2.3.4"
Edit C</boot/grub/grub.conf> interactively:
diff --git a/fuse/test-fuse.sh b/fuse/test-fuse.sh
index 7dc8e4b..e31ea9d 100755
--- a/fuse/test-fuse.sh
+++ b/fuse/test-fuse.sh
@@ -93,8 +93,8 @@ $guestfish <<EOF
part-disk /dev/sda mbr
mkfs ext2 /dev/sda1
mount /dev/sda1 /
- write-file /hello.txt hello 0
- write-file /world.txt "hello world" 0
+ write /hello.txt hello
+ write /world.txt "hello world"
touch /empty
EOF
diff --git a/recipes/clone.sh b/recipes/clone.sh
index e3fc11c..d2b9d99 100755
--- a/recipes/clone.sh
+++ b/recipes/clone.sh
@@ -9,7 +9,7 @@ hostname="$5"
dd if="$preimage" of="$newimage"
guestfish -a "$newimage" -m "$root" <<EOF
-write-file /etc/resolv.conf "nameserver $nameserver" 0
-write-file /etc/HOSTNAME "$hostname" 0
+write /etc/resolv.conf "nameserver $nameserver"
+write /etc/HOSTNAME "$hostname"
sync
EOF
diff --git a/src/MAX_PROC_NR b/src/MAX_PROC_NR
index 2c2b1af..5d165ff 100644
--- a/src/MAX_PROC_NR
+++ b/src/MAX_PROC_NR
@@ -1 +1 @@
-245
+246
diff --git a/src/generator.ml b/src/generator.ml
index 090c280..dfab8dc 100755
--- a/src/generator.ml
+++ b/src/generator.ml
@@ -938,7 +938,7 @@ let daemon_functions = [
[["part_disk"; "/dev/sda"; "mbr"];
["mkfs"; "ext2"; "/dev/sda1"];
["mount"; "/dev/sda1"; "/"];
- ["write_file"; "/new"; "new file contents"; "0"];
+ ["write"; "/new"; "new file contents"];
["cat"; "/new"]], "new file contents")],
"mount a guest disk at a position in the filesystem",
"\
@@ -1500,7 +1500,7 @@ on the volume group C<volgroup>, with C<size> megabytes.");
[["part_disk"; "/dev/sda"; "mbr"];
["mkfs"; "ext2"; "/dev/sda1"];
["mount_options"; ""; "/dev/sda1"; "/"];
- ["write_file"; "/new"; "new file contents"; "0"];
+ ["write"; "/new"; "new file contents"];
["cat"; "/new"]], "new file contents")],
"make a filesystem",
"\
@@ -1537,25 +1537,8 @@ the string C<,> (comma).
See also: C<guestfs_sfdisk_l>, C<guestfs_sfdisk_N>,
C<guestfs_part_init>");
- ("write_file", (RErr, [Pathname "path"; String "content"; Int "size"]), 44, [ProtocolLimitWarning],
- [InitBasicFS, Always, TestOutput (
- [["write_file"; "/new"; "new file contents"; "0"];
- ["cat"; "/new"]], "new file contents");
- InitBasicFS, Always, TestOutput (
- [["write_file"; "/new"; "\nnew file contents\n"; "0"];
- ["cat"; "/new"]], "\nnew file contents\n");
- InitBasicFS, Always, TestOutput (
- [["write_file"; "/new"; "\n\n"; "0"];
- ["cat"; "/new"]], "\n\n");
- InitBasicFS, Always, TestOutput (
- [["write_file"; "/new"; ""; "0"];
- ["cat"; "/new"]], "");
- InitBasicFS, Always, TestOutput (
- [["write_file"; "/new"; "\n\n\n"; "0"];
- ["cat"; "/new"]], "\n\n\n");
- InitBasicFS, Always, TestOutput (
- [["write_file"; "/new"; "\n"; "0"];
- ["cat"; "/new"]], "\n")],
+ ("write_file", (RErr, [Pathname "path"; String "content"; Int "size"]), 44, [ProtocolLimitWarning; DeprecatedBy "write"],
+ [],
"create a file",
"\
This call creates a file called C<path>. The contents of the
@@ -1567,9 +1550,7 @@ then the length is calculated using C<strlen> (so in this case
the content cannot contain embedded ASCII NULs).
I<NB.> Owing to a bug, writing content containing ASCII NUL
-characters does I<not> work, even if the length is specified.
-We hope to resolve this bug in a future version. In the meantime
-use C<guestfs_upload>.");
+characters does I<not> work, even if the length is specified.");
("umount", (RErr, [String "pathordevice"]), 45, [FishAlias "unmount"],
[InitEmpty, Always, TestOutputListOfDevices (
@@ -2088,7 +2069,7 @@ To download an uncompressed tarball, use C<guestfs_tar_out>.");
["mount_ro"; "/dev/sda1"; "/"];
["touch"; "/new"]]);
InitBasicFS, Always, TestOutput (
- [["write_file"; "/new"; "data"; "0"];
+ [["write"; "/new"; "data"];
["umount"; "/"];
["mount_ro"; "/dev/sda1"; "/"];
["cat"; "/new"]], "data")],
@@ -2340,15 +2321,15 @@ C<device>, with the root directory being C<root>.");
("cp", (RErr, [Pathname "src"; Pathname "dest"]), 87, [],
[InitBasicFS, Always, TestOutput (
- [["write_file"; "/old"; "file content"; "0"];
+ [["write"; "/old"; "file content"];
["cp"; "/old"; "/new"];
["cat"; "/new"]], "file content");
InitBasicFS, Always, TestOutputTrue (
- [["write_file"; "/old"; "file content"; "0"];
+ [["write"; "/old"; "file content"];
["cp"; "/old"; "/new"];
["is_file"; "/old"]]);
InitBasicFS, Always, TestOutput (
- [["write_file"; "/old"; "file content"; "0"];
+ [["write"; "/old"; "file content"];
["mkdir"; "/dir"];
["cp"; "/old"; "/dir/new"];
["cat"; "/dir/new"]], "file content")],
@@ -2361,7 +2342,7 @@ either a destination filename or destination directory.");
[InitBasicFS, Always, TestOutput (
[["mkdir"; "/olddir"];
["mkdir"; "/newdir"];
- ["write_file"; "/olddir/file"; "file content"; "0"];
+ ["write"; "/olddir/file"; "file content"];
["cp_a"; "/olddir"; "/newdir"];
["cat"; "/newdir/olddir/file"]], "file content")],
"copy a file or directory recursively",
@@ -2371,11 +2352,11 @@ recursively using the C<cp -a> command.");
("mv", (RErr, [Pathname "src"; Pathname "dest"]), 89, [],
[InitBasicFS, Always, TestOutput (
- [["write_file"; "/old"; "file content"; "0"];
+ [["write"; "/old"; "file content"];
["mv"; "/old"; "/new"];
["cat"; "/new"]], "file content");
InitBasicFS, Always, TestOutputFalse (
- [["write_file"; "/old"; "file content"; "0"];
+ [["write"; "/old"; "file content"];
["mv"; "/old"; "/new"];
["is_file"; "/old"]])],
"move a file",
@@ -2424,12 +2405,12 @@ or attached block device(s) in any other way.");
("equal", (RBool "equality", [Pathname "file1"; Pathname "file2"]), 93, [],
[InitBasicFS, Always, TestOutputTrue (
- [["write_file"; "/file1"; "contents of a file"; "0"];
+ [["write"; "/file1"; "contents of a file"];
["cp"; "/file1"; "/file2"];
["equal"; "/file1"; "/file2"]]);
InitBasicFS, Always, TestOutputFalse (
- [["write_file"; "/file1"; "contents of a file"; "0"];
- ["write_file"; "/file2"; "contents of another file"; "0"];
+ [["write"; "/file1"; "contents of a file"];
+ ["write"; "/file2"; "contents of another file"];
["equal"; "/file1"; "/file2"]]);
InitBasicFS, Always, TestLastFail (
[["equal"; "/file1"; "/file2"]])],
@@ -2456,8 +2437,8 @@ the list of printable strings found.");
("strings_e", (RStringList "stringsout", [String "encoding"; Pathname "path"]), 95, [ProtocolLimitWarning],
[InitISOFS, Always, TestOutputList (
[["strings_e"; "b"; "/known-5"]], []);
- InitBasicFS, Disabled, TestOutputList (
- [["write_file"; "/new"; "\000h\000e\000l\000l\000o\000\n\000w\000o\000r\000l\000d\000\n"; "24"];
+ InitBasicFS, Always, TestOutputList (
+ [["write"; "/new"; "\000h\000e\000l\000l\000o\000\n\000w\000o\000r\000l\000d\000\n"];
["strings_e"; "b"; "/new"]], ["hello"; "world"])],
"print the printable strings in a file",
"\
@@ -2521,7 +2502,7 @@ the human-readable, canonical hex dump of the file.");
[["part_disk"; "/dev/sda"; "mbr"];
["mkfs"; "ext3"; "/dev/sda1"];
["mount_options"; ""; "/dev/sda1"; "/"];
- ["write_file"; "/new"; "test file"; "0"];
+ ["write"; "/new"; "test file"];
["umount"; "/dev/sda1"];
["zerofree"; "/dev/sda1"];
["mount_options"; ""; "/dev/sda1"; "/"];
@@ -2626,7 +2607,7 @@ are activated or deactivated.");
["lvcreate"; "LV"; "VG"; "10"];
["mkfs"; "ext2"; "/dev/VG/LV"];
["mount_options"; ""; "/dev/VG/LV"; "/"];
- ["write_file"; "/new"; "test content"; "0"];
+ ["write"; "/new"; "test content"];
["umount"; "/"];
["lvresize"; "/dev/VG/LV"; "20"];
["e2fsck_f"; "/dev/VG/LV"];
@@ -2813,7 +2794,7 @@ manual page for more details.");
("scrub_file", (RErr, [Pathname "file"]), 115, [Optional "scrub"],
[InitBasicFS, Always, TestRun (
- [["write_file"; "/file"; "content"; "0"];
+ [["write"; "/file"; "content"];
["scrub_file"; "/file"]])],
"scrub (securely wipe) a file",
"\
@@ -3721,7 +3702,7 @@ and C<guestfs_setcon>");
[["part_disk"; "/dev/sda"; "mbr"];
["mkfs_b"; "ext2"; "4096"; "/dev/sda1"];
["mount_options"; ""; "/dev/sda1"; "/"];
- ["write_file"; "/new"; "new file contents"; "0"];
+ ["write"; "/new"; "new file contents"];
["cat"; "/new"]], "new file contents")],
"make a filesystem with block size",
"\
@@ -3736,7 +3717,7 @@ are C<1024>, C<2048> or C<4096> only.");
["mke2journal"; "4096"; "/dev/sda1"];
["mke2fs_J"; "ext2"; "4096"; "/dev/sda2"; "/dev/sda1"];
["mount_options"; ""; "/dev/sda2"; "/"];
- ["write_file"; "/new"; "new file contents"; "0"];
+ ["write"; "/new"; "new file contents"];
["cat"; "/new"]], "new file contents")],
"make ext2/3/4 external journal",
"\
@@ -3751,7 +3732,7 @@ to the command:
["mke2journal_L"; "4096"; "JOURNAL"; "/dev/sda1"];
["mke2fs_JL"; "ext2"; "4096"; "/dev/sda2"; "JOURNAL"];
["mount_options"; ""; "/dev/sda2"; "/"];
- ["write_file"; "/new"; "new file contents"; "0"];
+ ["write"; "/new"; "new file contents"];
["cat"; "/new"]], "new file contents")],
"make ext2/3/4 external journal with label",
"\
@@ -3764,7 +3745,7 @@ This creates an ext2 external journal on C<device> with label C<label>.");
["mke2journal_U"; "4096"; uuid; "/dev/sda1"];
["mke2fs_JU"; "ext2"; "4096"; "/dev/sda2"; uuid];
["mount_options"; ""; "/dev/sda2"; "/"];
- ["write_file"; "/new"; "new file contents"; "0"];
+ ["write"; "/new"; "new file contents"];
["cat"; "/new"]], "new file contents")]),
"make ext2/3/4 external journal with UUID",
"\
@@ -3927,7 +3908,7 @@ if you used the C<guestfs_mount> call).");
("truncate", (RErr, [Pathname "path"]), 199, [],
[InitBasicFS, Always, TestOutputStruct (
- [["write_file"; "/test"; "some stuff so size is not zero"; "0"];
+ [["write"; "/test"; "some stuff so size is not zero"];
["truncate"; "/test"];
["stat"; "/test"]], [CompareWithInt ("size", 0)])],
"truncate a file to zero size",
@@ -4345,7 +4326,7 @@ See also C<guestfs_version>.
("dd", (RErr, [Dev_or_Path "src"; Dev_or_Path "dest"]), 217, [],
[InitBasicFS, Always, TestOutputBuffer (
- [["write_file"; "/src"; "hello, world"; "0"];
+ [["write"; "/src"; "hello, world"];
["dd"; "/src"; "/dest"];
["read_file"; "/dest"]], "hello, world")],
"copy from source to destination using dd",
@@ -4361,7 +4342,7 @@ This command cannot do partial copies (see C<guestfs_copy_size>).");
("filesize", (RInt64 "size", [Pathname "file"]), 218, [],
[InitBasicFS, Always, TestOutputInt (
- [["write_file"; "/file"; "hello, world"; "0"];
+ [["write"; "/file"; "hello, world"];
["filesize"; "/file"]], 12)],
"return the size of the file in bytes",
"\
@@ -4452,7 +4433,7 @@ See also C<guestfs_vgpvuuids>.");
("copy_size", (RErr, [Dev_or_Path "src"; Dev_or_Path "dest"; Int64 "size"]), 227, [],
[InitBasicFS, Always, TestOutputBuffer (
- [["write_file"; "/src"; "hello, world"; "0"];
+ [["write"; "/src"; "hello, world"];
["copy_size"; "/src"; "/dest"; "5"];
["read_file"; "/dest"]], "hello")],
"copy size bytes from source to destination using dd",
@@ -4653,6 +4634,30 @@ a new file of length C<len> containing the repeating pattern
of bytes in C<pattern>. The pattern is truncated if necessary
to ensure the length of the file is exactly C<len> bytes.");
+ ("write", (RErr, [Pathname "path"; BufferIn "content"]), 246, [ProtocolLimitWarning],
+ [InitBasicFS, Always, TestOutput (
+ [["write"; "/new"; "new file contents"];
+ ["cat"; "/new"]], "new file contents");
+ InitBasicFS, Always, TestOutput (
+ [["write"; "/new"; "\nnew file contents\n"];
+ ["cat"; "/new"]], "\nnew file contents\n");
+ InitBasicFS, Always, TestOutput (
+ [["write"; "/new"; "\n\n"];
+ ["cat"; "/new"]], "\n\n");
+ InitBasicFS, Always, TestOutput (
+ [["write"; "/new"; ""];
+ ["cat"; "/new"]], "");
+ InitBasicFS, Always, TestOutput (
+ [["write"; "/new"; "\n\n\n"];
+ ["cat"; "/new"]], "\n\n\n");
+ InitBasicFS, Always, TestOutput (
+ [["write"; "/new"; "\n"];
+ ["cat"; "/new"]], "\n")],
+ "create a new file",
+ "\
+This call creates a file called C<path>. The content of the
+file is the string C<content> (which can contain any 8 bit data).");
+
]
let all_functions = non_daemon_functions @ daemon_functions
diff --git a/src/guestfs.pod b/src/guestfs.pod
index e1fa4f5..8404e74 100644
--- a/src/guestfs.pod
+++ b/src/guestfs.pod
@@ -258,9 +258,7 @@ L</guestfs_tgz_out>.
It's often the case that you want to write a file or files to the disk
image.
-For small, single files, use L</guestfs_write_file>. This call
-currently contains a bug which limits the call to plain text files
-(not containing ASCII NUL characters).
+For small, single files, use L</guestfs_write>.
To upload a single file, use L</guestfs_upload>. This call has no
limits on file content or size (even files larger than 4 GB).
diff --git a/tools/make-test-img.sh b/tools/make-test-img.sh
index 9752f1d..fddd8a2 100755
--- a/tools/make-test-img.sh
+++ b/tools/make-test-img.sh
@@ -68,12 +68,12 @@ mkdir /boot/grub
touch /boot/grub/grub.conf
# Test files.
-write-file /etc/test1 "abcdefg" 0
-write-file /etc/test2 "" 0
-write-file /bin/test1 "abcdefg" 0
-write-file /bin/test2 "zxcvbnm" 0
-write-file /bin/test3 "1234567" 0
-write-file /bin/test4 "" 0
+write /etc/test1 "abcdefg"
+write /etc/test2 ""
+write /bin/test1 "abcdefg"
+write /bin/test2 "zxcvbnm"
+write /bin/test3 "1234567"
+write /bin/test4 ""
ln-s /bin/test1 /bin/test5
mkfifo 0777 /bin/test6
mknod 0777 10 10 /bin/test7
--
1.6.6.1
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