diff options
| -rw-r--r-- | fs/cifs/smb2ops.c | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index 21ef51d338e0..b68ba92893b6 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -3601,6 +3601,119 @@ static long smb3_punch_hole(struct file *file, struct cifs_tcon *tcon, return rc; } +static int smb3_simple_fallocate_write_range(unsigned int xid, + struct cifs_tcon *tcon, + struct cifsFileInfo *cfile, + loff_t off, loff_t len, + char *buf) +{ + struct cifs_io_parms io_parms = {0}; + int nbytes; + struct kvec iov[2]; + + io_parms.netfid = cfile->fid.netfid; + io_parms.pid = current->tgid; + io_parms.tcon = tcon; + io_parms.persistent_fid = cfile->fid.persistent_fid; + io_parms.volatile_fid = cfile->fid.volatile_fid; + io_parms.offset = off; + io_parms.length = len; + + /* iov[0] is reserved for smb header */ + iov[1].iov_base = buf; + iov[1].iov_len = io_parms.length; + return SMB2_write(xid, &io_parms, &nbytes, iov, 1); +} + +static int smb3_simple_fallocate_range(unsigned int xid, + struct cifs_tcon *tcon, + struct cifsFileInfo *cfile, + loff_t off, loff_t len) +{ + struct file_allocated_range_buffer in_data, *out_data = NULL, *tmp_data; + u32 out_data_len; + char *buf = NULL; + loff_t l; + int rc; + + in_data.file_offset = cpu_to_le64(off); + in_data.length = cpu_to_le64(len); + rc = SMB2_ioctl(xid, tcon, cfile->fid.persistent_fid, + cfile->fid.volatile_fid, + FSCTL_QUERY_ALLOCATED_RANGES, true, + (char *)&in_data, sizeof(in_data), + 1024 * sizeof(struct file_allocated_range_buffer), + (char **)&out_data, &out_data_len); + if (rc) + goto out; + /* + * It is already all allocated + */ + if (out_data_len == 0) + goto out; + + buf = kzalloc(1024 * 1024, GFP_KERNEL); + if (buf == NULL) { + rc = -ENOMEM; + goto out; + } + + tmp_data = out_data; + while (len) { + /* + * The rest of the region is unmapped so write it all. + */ + if (out_data_len == 0) { + rc = smb3_simple_fallocate_write_range(xid, tcon, + cfile, off, len, buf); + goto out; + } + + if (out_data_len < sizeof(struct file_allocated_range_buffer)) { + rc = -EINVAL; + goto out; + } + + if (off < le64_to_cpu(tmp_data->file_offset)) { + /* + * We are at a hole. Write until the end of the region + * or until the next allocated data, + * whichever comes next. + */ + l = le64_to_cpu(tmp_data->file_offset) - off; + if (len < l) + l = len; + rc = smb3_simple_fallocate_write_range(xid, tcon, + cfile, off, l, buf); + if (rc) + goto out; + off = off + l; + len = len - l; + if (len == 0) + goto out; + } + /* + * We are at a section of allocated data, just skip forward + * until the end of the data or the end of the region + * we are supposed to fallocate, whichever comes first. + */ + l = le64_to_cpu(tmp_data->length); + if (len < l) + l = len; + off += l; + len -= l; + + tmp_data = &tmp_data[1]; + out_data_len -= sizeof(struct file_allocated_range_buffer); + } + + out: + kfree(out_data); + kfree(buf); + return rc; +} + + static long smb3_simple_falloc(struct file *file, struct cifs_tcon *tcon, loff_t off, loff_t len, bool keep_size) { @@ -3662,6 +3775,26 @@ static long smb3_simple_falloc(struct file *file, struct cifs_tcon *tcon, if ((keep_size == true) || (i_size_read(inode) >= off + len)) { /* + * At this point, we are trying to fallocate an internal + * regions of a sparse file. Since smb2 does not have a + * fallocate command we have two otions on how to emulate this. + * We can either turn the entire file to become non-sparse + * which we only do if the fallocate is for virtually + * the whole file, or we can overwrite the region with zeroes + * using SMB2_write, which could be prohibitevly expensive + * if len is large. + */ + /* + * We are only trying to fallocate a small region so + * just write it with zero. + */ + if (len <= 1024 * 1024) { + rc = smb3_simple_fallocate_range(xid, tcon, cfile, + off, len); + goto out; + } + + /* * Check if falloc starts within first few pages of file * and ends within a few pages of the end of file to * ensure that most of file is being forced to be |