diff options
Diffstat (limited to 'block/export')
-rw-r--r-- | block/export/fuse.c | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/block/export/fuse.c b/block/export/fuse.c index 92d2f50bcc..0b9d226b2f 100644 --- a/block/export/fuse.c +++ b/block/export/fuse.c @@ -522,6 +522,89 @@ static void fuse_write(fuse_req_t req, fuse_ino_t inode, const char *buf, } /** + * Let clients perform various fallocate() operations. + */ +static void fuse_fallocate(fuse_req_t req, fuse_ino_t inode, int mode, + off_t offset, off_t length, + struct fuse_file_info *fi) +{ + FuseExport *exp = fuse_req_userdata(req); + int64_t blk_len; + int ret; + + if (!exp->writable) { + fuse_reply_err(req, EACCES); + return; + } + + blk_len = blk_getlength(exp->common.blk); + if (blk_len < 0) { + fuse_reply_err(req, -blk_len); + return; + } + + if (mode & FALLOC_FL_KEEP_SIZE) { + length = MIN(length, blk_len - offset); + } + + if (mode & FALLOC_FL_PUNCH_HOLE) { + if (!(mode & FALLOC_FL_KEEP_SIZE)) { + fuse_reply_err(req, EINVAL); + return; + } + + do { + int size = MIN(length, BDRV_REQUEST_MAX_BYTES); + + ret = blk_pdiscard(exp->common.blk, offset, size); + offset += size; + length -= size; + } while (ret == 0 && length > 0); + } else if (mode & FALLOC_FL_ZERO_RANGE) { + if (!(mode & FALLOC_FL_KEEP_SIZE) && offset + length > blk_len) { + /* No need for zeroes, we are going to write them ourselves */ + ret = fuse_do_truncate(exp, offset + length, false, + PREALLOC_MODE_OFF); + if (ret < 0) { + fuse_reply_err(req, -ret); + return; + } + } + + do { + int size = MIN(length, BDRV_REQUEST_MAX_BYTES); + + ret = blk_pwrite_zeroes(exp->common.blk, + offset, size, 0); + offset += size; + length -= size; + } while (ret == 0 && length > 0); + } else if (!mode) { + /* We can only fallocate at the EOF with a truncate */ + if (offset < blk_len) { + fuse_reply_err(req, EOPNOTSUPP); + return; + } + + if (offset > blk_len) { + /* No preallocation needed here */ + ret = fuse_do_truncate(exp, offset, true, PREALLOC_MODE_OFF); + if (ret < 0) { + fuse_reply_err(req, -ret); + return; + } + } + + ret = fuse_do_truncate(exp, offset + length, true, + PREALLOC_MODE_FALLOC); + } else { + ret = -EOPNOTSUPP; + } + + fuse_reply_err(req, ret < 0 ? -ret : 0); +} + +/** * Let clients fsync the exported image. */ static void fuse_fsync(fuse_req_t req, fuse_ino_t inode, int datasync, @@ -552,6 +635,7 @@ static const struct fuse_lowlevel_ops fuse_ops = { .open = fuse_open, .read = fuse_read, .write = fuse_write, + .fallocate = fuse_fallocate, .flush = fuse_flush, .fsync = fuse_fsync, }; |