diff options
Diffstat (limited to 'fs/ntfs/aops.c')
| -rw-r--r-- | fs/ntfs/aops.c | 104 |
1 files changed, 47 insertions, 57 deletions
diff --git a/fs/ntfs/aops.c b/fs/ntfs/aops.c index f3ad36d8b8c..6f2954aac5a 100644 --- a/fs/ntfs/aops.c +++ b/fs/ntfs/aops.c @@ -1301,38 +1301,42 @@ retry_writepage: ntfs_debug("Write outside i_size - truncated?"); return 0; } + /* + * Only $DATA attributes can be encrypted and only unnamed $DATA + * attributes can be compressed. Index root can have the flags set but + * this means to create compressed/encrypted files, not that the + * attribute is compressed/encrypted. + */ + if (ni->type != AT_INDEX_ROOT) { + /* If file is encrypted, deny access, just like NT4. */ + if (NInoEncrypted(ni)) { + unlock_page(page); + BUG_ON(ni->type != AT_DATA); + ntfs_debug("Denying write access to encrypted " + "file."); + return -EACCES; + } + /* Compressed data streams are handled in compress.c. */ + if (NInoNonResident(ni) && NInoCompressed(ni)) { + BUG_ON(ni->type != AT_DATA); + BUG_ON(ni->name_len); + // TODO: Implement and replace this with + // return ntfs_write_compressed_block(page); + unlock_page(page); + ntfs_error(vi->i_sb, "Writing to compressed files is " + "not supported yet. Sorry."); + return -EOPNOTSUPP; + } + // TODO: Implement and remove this check. + if (NInoNonResident(ni) && NInoSparse(ni)) { + unlock_page(page); + ntfs_error(vi->i_sb, "Writing to sparse files is not " + "supported yet. Sorry."); + return -EOPNOTSUPP; + } + } /* NInoNonResident() == NInoIndexAllocPresent() */ if (NInoNonResident(ni)) { - /* - * Only unnamed $DATA attributes can be compressed, encrypted, - * and/or sparse. - */ - if (ni->type == AT_DATA && !ni->name_len) { - /* If file is encrypted, deny access, just like NT4. */ - if (NInoEncrypted(ni)) { - unlock_page(page); - ntfs_debug("Denying write access to encrypted " - "file."); - return -EACCES; - } - /* Compressed data streams are handled in compress.c. */ - if (NInoCompressed(ni)) { - // TODO: Implement and replace this check with - // return ntfs_write_compressed_block(page); - unlock_page(page); - ntfs_error(vi->i_sb, "Writing to compressed " - "files is not supported yet. " - "Sorry."); - return -EOPNOTSUPP; - } - // TODO: Implement and remove this check. - if (NInoSparse(ni)) { - unlock_page(page); - ntfs_error(vi->i_sb, "Writing to sparse files " - "is not supported yet. Sorry."); - return -EOPNOTSUPP; - } - } /* We have to zero every time due to mmap-at-end-of-file. */ if (page->index >= (i_size >> PAGE_CACHE_SHIFT)) { /* The page straddles i_size. */ @@ -1345,14 +1349,16 @@ retry_writepage: /* Handle mst protected attributes. */ if (NInoMstProtected(ni)) return ntfs_write_mst_block(page, wbc); - /* Normal data stream. */ + /* Normal, non-resident data stream. */ return ntfs_write_block(page, wbc); } /* - * Attribute is resident, implying it is not compressed, encrypted, - * sparse, or mst protected. This also means the attribute is smaller - * than an mft record and hence smaller than a page, so can simply - * return error on any pages with index above 0. + * Attribute is resident, implying it is not compressed, encrypted, or + * mst protected. This also means the attribute is smaller than an mft + * record and hence smaller than a page, so can simply return error on + * any pages with index above 0. Note the attribute can actually be + * marked compressed but if it is resident the actual data is not + * compressed so we are ok to ignore the compressed flag here. */ BUG_ON(page_has_buffers(page)); BUG_ON(!PageUptodate(page)); @@ -1401,30 +1407,14 @@ retry_writepage: BUG_ON(PageWriteback(page)); set_page_writeback(page); unlock_page(page); - /* - * Here, we don't need to zero the out of bounds area everytime because - * the below memcpy() already takes care of the mmap-at-end-of-file - * requirements. If the file is converted to a non-resident one, then - * the code path use is switched to the non-resident one where the - * zeroing happens on each ntfs_writepage() invocation. - * - * The above also applies nicely when i_size is decreased. - * - * When i_size is increased, the memory between the old and new i_size - * _must_ be zeroed (or overwritten with new data). Otherwise we will - * expose data to userspace/disk which should never have been exposed. - * - * FIXME: Ensure that i_size increases do the zeroing/overwriting and - * if we cannot guarantee that, then enable the zeroing below. If the - * zeroing below is enabled, we MUST move the unlock_page() from above - * to after the kunmap_atomic(), i.e. just before the - * end_page_writeback(). - * UPDATE: ntfs_prepare/commit_write() do the zeroing on i_size - * increases for resident attributes so those are ok. - * TODO: ntfs_truncate(), others? + * Here, we do not need to zero the out of bounds area everytime + * because the below memcpy() already takes care of the + * mmap-at-end-of-file requirements. If the file is converted to a + * non-resident one, then the code path use is switched to the + * non-resident one where the zeroing happens on each ntfs_writepage() + * invocation. */ - attr_len = le32_to_cpu(ctx->attr->data.resident.value_length); i_size = i_size_read(vi); if (unlikely(attr_len > i_size)) { |