diff options
| -rw-r--r-- | block/raw-posix.c | 127 |
1 files changed, 77 insertions, 50 deletions
diff --git a/block/raw-posix.c b/block/raw-posix.c index 3ce026db58..6586a0c9e1 100644 --- a/block/raw-posix.c +++ b/block/raw-posix.c @@ -146,6 +146,9 @@ typedef struct BDRVRawState { bool has_discard:1; bool has_write_zeroes:1; bool discard_zeroes:1; +#ifdef CONFIG_FIEMAP + bool skip_fiemap; +#endif } BDRVRawState; typedef struct BDRVRawReopenState { @@ -1272,53 +1275,29 @@ static int raw_create(const char *filename, QEMUOptionParameter *options, return result; } -/* - * Returns true iff the specified sector is present in the disk image. Drivers - * not implementing the functionality are assumed to not support backing files, - * hence all their sectors are reported as allocated. - * - * If 'sector_num' is beyond the end of the disk image the return value is 0 - * and 'pnum' is set to 0. - * - * 'pnum' is set to the number of sectors (including and immediately following - * the specified sector) that are known to be in the same - * allocated/unallocated state. - * - * 'nb_sectors' is the max value 'pnum' should be set to. If nb_sectors goes - * beyond the end of the disk image it will be clamped. - */ -static int64_t coroutine_fn raw_co_get_block_status(BlockDriverState *bs, - int64_t sector_num, - int nb_sectors, int *pnum) +static int64_t try_fiemap(BlockDriverState *bs, off_t start, off_t *data, + off_t *hole, int nb_sectors, int *pnum) { - off_t start, data, hole; - int64_t ret; - - ret = fd_open(bs); - if (ret < 0) { - return ret; - } - - start = sector_num * BDRV_SECTOR_SIZE; - ret = BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID | start; - #ifdef CONFIG_FIEMAP - BDRVRawState *s = bs->opaque; + int64_t ret = BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID | start; struct { struct fiemap fm; struct fiemap_extent fe; } f; + if (s->skip_fiemap) { + return -ENOTSUP; + } + f.fm.fm_start = start; f.fm.fm_length = (int64_t)nb_sectors * BDRV_SECTOR_SIZE; f.fm.fm_flags = 0; f.fm.fm_extent_count = 1; f.fm.fm_reserved = 0; if (ioctl(s->fd, FS_IOC_FIEMAP, &f) == -1) { - /* Assume everything is allocated. */ - *pnum = nb_sectors; - return ret; + s->skip_fiemap = true; + return -errno; } if (f.fm.fm_mapped_extents == 0) { @@ -1326,44 +1305,92 @@ static int64_t coroutine_fn raw_co_get_block_status(BlockDriverState *bs, * f.fm.fm_start + f.fm.fm_length must be clamped to the file size! */ off_t length = lseek(s->fd, 0, SEEK_END); - hole = f.fm.fm_start; - data = MIN(f.fm.fm_start + f.fm.fm_length, length); + *hole = f.fm.fm_start; + *data = MIN(f.fm.fm_start + f.fm.fm_length, length); } else { - data = f.fe.fe_logical; - hole = f.fe.fe_logical + f.fe.fe_length; + *data = f.fe.fe_logical; + *hole = f.fe.fe_logical + f.fe.fe_length; if (f.fe.fe_flags & FIEMAP_EXTENT_UNWRITTEN) { ret |= BDRV_BLOCK_ZERO; } } -#elif defined SEEK_HOLE && defined SEEK_DATA + return ret; +#else + return -ENOTSUP; +#endif +} +static int64_t try_seek_hole(BlockDriverState *bs, off_t start, off_t *data, + off_t *hole, int *pnum) +{ +#if defined SEEK_HOLE && defined SEEK_DATA BDRVRawState *s = bs->opaque; - hole = lseek(s->fd, start, SEEK_HOLE); - if (hole == -1) { + *hole = lseek(s->fd, start, SEEK_HOLE); + if (*hole == -1) { /* -ENXIO indicates that sector_num was past the end of the file. * There is a virtual hole there. */ assert(errno != -ENXIO); - /* Most likely EINVAL. Assume everything is allocated. */ - *pnum = nb_sectors; - return ret; + return -errno; } - if (hole > start) { - data = start; + if (*hole > start) { + *data = start; } else { /* On a hole. We need another syscall to find its end. */ - data = lseek(s->fd, start, SEEK_DATA); - if (data == -1) { - data = lseek(s->fd, 0, SEEK_END); + *data = lseek(s->fd, start, SEEK_DATA); + if (*data == -1) { + *data = lseek(s->fd, 0, SEEK_END); } } + + return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID | start; #else - data = 0; - hole = start + nb_sectors * BDRV_SECTOR_SIZE; + return -ENOTSUP; #endif +} + +/* + * Returns true iff the specified sector is present in the disk image. Drivers + * not implementing the functionality are assumed to not support backing files, + * hence all their sectors are reported as allocated. + * + * If 'sector_num' is beyond the end of the disk image the return value is 0 + * and 'pnum' is set to 0. + * + * 'pnum' is set to the number of sectors (including and immediately following + * the specified sector) that are known to be in the same + * allocated/unallocated state. + * + * 'nb_sectors' is the max value 'pnum' should be set to. If nb_sectors goes + * beyond the end of the disk image it will be clamped. + */ +static int64_t coroutine_fn raw_co_get_block_status(BlockDriverState *bs, + int64_t sector_num, + int nb_sectors, int *pnum) +{ + off_t start, data = 0, hole = 0; + int64_t ret; + + ret = fd_open(bs); + if (ret < 0) { + return ret; + } + + start = sector_num * BDRV_SECTOR_SIZE; + + ret = try_fiemap(bs, start, &data, &hole, nb_sectors, pnum); + if (ret < 0) { + ret = try_seek_hole(bs, start, &data, &hole, pnum); + if (ret < 0) { + /* Assume everything is allocated. */ + data = 0; + hole = start + nb_sectors * BDRV_SECTOR_SIZE; + ret = BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID | start; + } + } if (data <= start) { /* On a data extent, compute sectors to the end of the extent. */ |