Quoting Eric Blake (2015-11-25 11:37:15) > Exposing OS-specific SEEK_ constants in our qapi was a mistake > (if the host has SEEK_CUR as 1, but the guest has it as 2, then > the semantics are unclear what should happen); if we had a time > machine, we would instead expose only a symbolic enum. It's too > late to change the fact that we have an integer in qapi, but we > can at least document what mapping we want to enforce for all > qga clients (and luckily, it happens to be the mapping that both > Linux and Windows use); then fix the code to match that mapping. > It also helps us filter out unsupported SEEK_DATA and SEEK_HOLE. > > In the future, we may wish to move our QGA_SEEK_* constants into > qga/qapi-schema.json, along with updating the schema to take an > alternate type (either the integer, or the string value of the > enum name) - but that's too much risk during hard freeze. > > Signed-off-by: Eric Blake <[email protected]>
Thanks, applied to qga tree: https://github.com/mdroth/qemu/commits/qga > > --- > v2: rebase to mdroth/qga, add QGA_SEEK_* constants instead of magic > numbers > --- > qga/commands-posix.c | 19 ++++++++++++++++++- > qga/commands-win32.c | 20 +++++++++++++++++++- > qga/guest-agent-core.h | 7 +++++++ > qga/qapi-schema.json | 4 ++-- > tests/test-qga.c | 5 +++-- > 5 files changed, 49 insertions(+), 6 deletions(-) > > diff --git a/qga/commands-posix.c b/qga/commands-posix.c > index cf1d7ec..c2ff970 100644 > --- a/qga/commands-posix.c > +++ b/qga/commands-posix.c > @@ -553,17 +553,34 @@ GuestFileWrite *qmp_guest_file_write(int64_t handle, > const char *buf_b64, > } > > struct GuestFileSeek *qmp_guest_file_seek(int64_t handle, int64_t offset, > - int64_t whence, Error **errp) > + int64_t whence_code, Error **errp) > { > GuestFileHandle *gfh = guest_file_handle_find(handle, errp); > GuestFileSeek *seek_data = NULL; > FILE *fh; > int ret; > + int whence; > > if (!gfh) { > return NULL; > } > > + /* We stupidly exposed 'whence':'int' in our qapi */ > + switch (whence_code) { > + case QGA_SEEK_SET: > + whence = SEEK_SET; > + break; > + case QGA_SEEK_CUR: > + whence = SEEK_CUR; > + break; > + case QGA_SEEK_END: > + whence = SEEK_END; > + break; > + default: > + error_setg(errp, "invalid whence code %"PRId64, whence_code); > + return NULL; > + } > + > fh = gfh->fh; > ret = fseek(fh, offset, whence); > if (ret == -1) { > diff --git a/qga/commands-win32.c b/qga/commands-win32.c > index 41f6dd9..0654fe4 100644 > --- a/qga/commands-win32.c > +++ b/qga/commands-win32.c > @@ -382,7 +382,7 @@ done: > } > > GuestFileSeek *qmp_guest_file_seek(int64_t handle, int64_t offset, > - int64_t whence, Error **errp) > + int64_t whence_code, Error **errp) > { > GuestFileHandle *gfh; > GuestFileSeek *seek_data; > @@ -390,11 +390,29 @@ GuestFileSeek *qmp_guest_file_seek(int64_t handle, > int64_t offset, > LARGE_INTEGER new_pos, off_pos; > off_pos.QuadPart = offset; > BOOL res; > + int whence; > + > gfh = guest_file_handle_find(handle, errp); > if (!gfh) { > return NULL; > } > > + /* We stupidly exposed 'whence':'int' in our qapi */ > + switch (whence_code) { > + case QGA_SEEK_SET: > + whence = SEEK_SET; > + break; > + case QGA_SEEK_CUR: > + whence = SEEK_CUR; > + break; > + case QGA_SEEK_END: > + whence = SEEK_END; > + break; > + default: > + error_setg(errp, "invalid whence code %"PRId64, whence_code); > + return NULL; > + } > + > fh = gfh->fh; > res = SetFilePointerEx(fh, off_pos, &new_pos, whence); > if (!res) { > diff --git a/qga/guest-agent-core.h b/qga/guest-agent-core.h > index e92c6ab..238dc6b 100644 > --- a/qga/guest-agent-core.h > +++ b/qga/guest-agent-core.h > @@ -15,6 +15,13 @@ > > #define QGA_READ_COUNT_DEFAULT 4096 > > +/* Mapping of whence codes used by guest-file-seek. */ > +enum { > + QGA_SEEK_SET = 0, > + QGA_SEEK_CUR = 1, > + QGA_SEEK_END = 2, > +}; > + > typedef struct GAState GAState; > typedef struct GACommandState GACommandState; > extern GAState *ga_state; > diff --git a/qga/qapi-schema.json b/qga/qapi-schema.json > index 78362e0..01c9ee4 100644 > --- a/qga/qapi-schema.json > +++ b/qga/qapi-schema.json > @@ -318,13 +318,13 @@ > # > # Seek to a position in the file, as with fseek(), and return the > # current file position afterward. Also encapsulates ftell()'s > -# functionality, just Set offset=0, whence=SEEK_CUR. > +# functionality, with offset=0 and whence=1. > # > # @handle: filehandle returned by guest-file-open > # > # @offset: bytes to skip over in the file stream > # > -# @whence: SEEK_SET, SEEK_CUR, or SEEK_END, as with fseek() > +# @whence: 0 for SEEK_SET, 1 for SEEK_CUR, or 2 for SEEK_END > # > # Returns: @GuestFileSeek on success. > # > diff --git a/tests/test-qga.c b/tests/test-qga.c > index 3b99d9d..e6a84d1 100644 > --- a/tests/test-qga.c > +++ b/tests/test-qga.c > @@ -13,6 +13,7 @@ > > #include "libqtest.h" > #include "config-host.h" > +#include "qga/guest-agent-core.h" > > typedef struct { > char *test_dir; > @@ -457,7 +458,7 @@ static void test_qga_file_ops(gconstpointer fix) > cmd = g_strdup_printf("{'execute': 'guest-file-seek'," > " 'arguments': { 'handle': %" PRId64 ", " > " 'offset': %d, 'whence': %d } }", > - id, 6, SEEK_SET); > + id, 6, QGA_SEEK_SET); > ret = qmp_fd(fixture->fd, cmd); > qmp_assert_no_error(ret); > val = qdict_get_qdict(ret, "return"); > @@ -550,7 +551,7 @@ static void test_qga_file_write_read(gconstpointer fix) > cmd = g_strdup_printf("{'execute': 'guest-file-seek'," > " 'arguments': { 'handle': %" PRId64 ", " > " 'offset': %d, 'whence': %d } }", > - id, 0, SEEK_SET); > + id, 0, QGA_SEEK_SET); > ret = qmp_fd(fixture->fd, cmd); > qmp_assert_no_error(ret); > val = qdict_get_qdict(ret, "return"); > -- > 2.4.3 >
