It looks like this one has gone un-noticed for a little while. On 3/26/19 5:17 PM, Daniel Henrique Barboza wrote: > Adding to Block Drivers the capability of being able to clean up > its created files can be useful in certain situations. For the > LUKS driver, for instance, a failure in one of its authentication > steps can leave files in the host that weren't there before. > > This patch adds the 'bdrv_co_delete_file' interface to block > drivers and add it to the 'file' driver in file-posix.c. The > implementation is given by 'raw_co_delete_file'. The helper > 'bdrv_path_is_regular_file' is being used only in raw_co_delete_file > at this moment, but it will be used inside LUKS in a later patch. > Foreseeing this future use, let's put it in block.c and make it > public. > > Suggested-by: Daniel P. Berrangé <berra...@redhat.com> > Signed-off-by: Daniel Henrique Barboza <danielhb...@gmail.com> > --- > block.c | 11 +++++++++++ > block/file-posix.c | 28 ++++++++++++++++++++++++++++ > include/block/block.h | 1 + > include/block/block_int.h | 6 ++++++ > 4 files changed, 46 insertions(+) > > diff --git a/block.c b/block.c > index 0a93ee9ac8..227362b282 100644 > --- a/block.c > +++ b/block.c > @@ -621,6 +621,17 @@ int get_tmp_filename(char *filename, int size) > #endif > } > > +/** > + * Helper that checks if a given string represents a regular > + * local file. > + */ > +bool bdrv_path_is_regular_file(const char *path) > +{ > + struct stat st; > + > + return (stat(path, &st) == 0) && S_ISREG(st.st_mode); > +} > + > /* > * Detect host devices. By convention, /dev/cdrom[N] is always > * recognized as a host CDROM. > diff --git a/block/file-posix.c b/block/file-posix.c > index d102f3b222..09d84bab37 100644 > --- a/block/file-posix.c > +++ b/block/file-posix.c > @@ -2342,6 +2342,33 @@ static int coroutine_fn raw_co_create_opts(const char > *filename, QemuOpts *opts, > return raw_co_create(&options, errp); > } > > +/** > + * Co-routine function that erases a regular file. > + */ > +static int coroutine_fn raw_co_delete_file(const char *filename, > + Error **errp)
Do we need to mark functions that make no use of coroutines as coroutine_fn? I guess this way the interface is *allowed* to be a coroutine if other drivers need to make use of that. > +{ > + int ret; > + > + /* Skip file: protocol prefix */ > + strstart(filename, "file:", &filename); > + This sticks out as fragile to me, but I guess that's exactly how create works, so... OK. > + if (!bdrv_path_is_regular_file(filename)) { > + ret = -ENOENT; > + error_setg_errno(errp, -ret, "%s is not a regular file", filename); > + goto done; > + } > + > + ret = unlink(filename); > + if (ret < 0) { > + ret = -errno; > + error_setg_errno(errp, -ret, "Error when deleting file %s", > filename); > + } > + > +done: > + return ret; > +} > + > /* > * Find allocation range in @bs around offset @start. > * May change underlying file descriptor's file offset. > @@ -2867,6 +2894,7 @@ BlockDriver bdrv_file = { > .bdrv_co_block_status = raw_co_block_status, > .bdrv_co_invalidate_cache = raw_co_invalidate_cache, > .bdrv_co_pwrite_zeroes = raw_co_pwrite_zeroes, > + .bdrv_co_delete_file = raw_co_delete_file, > > .bdrv_co_preadv = raw_co_preadv, > .bdrv_co_pwritev = raw_co_pwritev, > diff --git a/include/block/block.h b/include/block/block.h > index e452988b66..820643f96d 100644 > --- a/include/block/block.h > +++ b/include/block/block.h > @@ -363,6 +363,7 @@ int bdrv_freeze_backing_chain(BlockDriverState *bs, > BlockDriverState *base, > Error **errp); > void bdrv_unfreeze_backing_chain(BlockDriverState *bs, BlockDriverState > *base); > > +bool bdrv_path_is_regular_file(const char *path); > > typedef struct BdrvCheckResult { > int corruptions; > diff --git a/include/block/block_int.h b/include/block/block_int.h > index 01e855a066..74abb78ce7 100644 > --- a/include/block/block_int.h > +++ b/include/block/block_int.h > @@ -309,6 +309,12 @@ struct BlockDriver { > */ > int coroutine_fn (*bdrv_co_flush)(BlockDriverState *bs); > > + /* > + * Delete a local created file. > + */ > + int coroutine_fn (*bdrv_co_delete_file)(const char *filename, > + Error **errp); > + > /* > * Flushes all data that was already written to the OS all the way down > to > * the disk (for example file-posix.c calls fsync()). > Seems alright at a glance, if we want this interface. Kevin, do we? --js