diff options
Diffstat (limited to 'fs/ntfs/attrib.c')
| -rw-r--r-- | fs/ntfs/attrib.c | 300 |
1 files changed, 300 insertions, 0 deletions
diff --git a/fs/ntfs/attrib.c b/fs/ntfs/attrib.c index 6de5e04e97a..3b9de404021 100644 --- a/fs/ntfs/attrib.c +++ b/fs/ntfs/attrib.c @@ -25,6 +25,8 @@ #include "attrib.h" #include "debug.h" #include "layout.h" +#include "lcnalloc.h" +#include "malloc.h" #include "mft.h" #include "ntfs.h" #include "types.h" @@ -1227,6 +1229,304 @@ int ntfs_attr_record_resize(MFT_RECORD *m, ATTR_RECORD *a, u32 new_size) } /** + * ntfs_attr_make_non_resident - convert a resident to a non-resident attribute + * @ni: ntfs inode describing the attribute to convert + * + * Convert the resident ntfs attribute described by the ntfs inode @ni to a + * non-resident one. + * + * Return 0 on success and -errno on error. The following error return codes + * are defined: + * -EPERM - The attribute is not allowed to be non-resident. + * -ENOMEM - Not enough memory. + * -ENOSPC - Not enough disk space. + * -EINVAL - Attribute not defined on the volume. + * -EIO - I/o error or other error. + * + * NOTE to self: No changes in the attribute list are required to move from + * a resident to a non-resident attribute. + * + * Locking: - The caller must hold i_sem on the inode. + */ +int ntfs_attr_make_non_resident(ntfs_inode *ni) +{ + s64 new_size; + struct inode *vi = VFS_I(ni); + ntfs_volume *vol = ni->vol; + ntfs_inode *base_ni; + MFT_RECORD *m; + ATTR_RECORD *a; + ntfs_attr_search_ctx *ctx; + struct page *page; + runlist_element *rl; + u8 *kaddr; + unsigned long flags; + int mp_size, mp_ofs, name_ofs, arec_size, err, err2; + u32 attr_size; + u8 old_res_attr_flags; + + /* Check that the attribute is allowed to be non-resident. */ + err = ntfs_attr_can_be_non_resident(vol, ni->type); + if (unlikely(err)) { + if (err == -EPERM) + ntfs_debug("Attribute is not allowed to be " + "non-resident."); + else + ntfs_debug("Attribute not defined on the NTFS " + "volume!"); + return err; + } + /* + * The size needs to be aligned to a cluster boundary for allocation + * purposes. + */ + new_size = (i_size_read(vi) + vol->cluster_size - 1) & + ~(vol->cluster_size - 1); + if (new_size > 0) { + /* + * Will need the page later and since the page lock nests + * outside all ntfs locks, we need to get the page now. + */ + page = find_or_create_page(vi->i_mapping, 0, + mapping_gfp_mask(vi->i_mapping)); + if (unlikely(!page)) + return -ENOMEM; + /* Start by allocating clusters to hold the attribute value. */ + rl = ntfs_cluster_alloc(vol, 0, new_size >> + vol->cluster_size_bits, -1, DATA_ZONE); + if (IS_ERR(rl)) { + err = PTR_ERR(rl); + ntfs_debug("Failed to allocate cluster%s, error code " + "%i.\n", (new_size >> + vol->cluster_size_bits) > 1 ? "s" : "", + err); + goto page_err_out; + } + } else { + rl = NULL; + page = NULL; + } + /* Determine the size of the mapping pairs array. */ + mp_size = ntfs_get_size_for_mapping_pairs(vol, rl, 0); + if (unlikely(mp_size < 0)) { + err = mp_size; + ntfs_debug("Failed to get size for mapping pairs array, error " + "code %i.", err); + goto rl_err_out; + } + down_write(&ni->runlist.lock); + if (!NInoAttr(ni)) + base_ni = ni; + else + base_ni = ni->ext.base_ntfs_ino; + m = map_mft_record(base_ni); + if (IS_ERR(m)) { + err = PTR_ERR(m); + m = NULL; + ctx = NULL; + goto err_out; + } + ctx = ntfs_attr_get_search_ctx(base_ni, m); + if (unlikely(!ctx)) { + err = -ENOMEM; + goto err_out; + } + err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len, + CASE_SENSITIVE, 0, NULL, 0, ctx); + if (unlikely(err)) { + if (err == -ENOENT) + err = -EIO; + goto err_out; + } + m = ctx->mrec; + a = ctx->attr; + BUG_ON(NInoNonResident(ni)); + BUG_ON(a->non_resident); + /* + * Calculate new offsets for the name and the mapping pairs array. + * We assume the attribute is not compressed or sparse. + */ + name_ofs = (offsetof(ATTR_REC, + data.non_resident.compressed_size) + 7) & ~7; + mp_ofs = (name_ofs + a->name_length * sizeof(ntfschar) + 7) & ~7; + /* + * Determine the size of the resident part of the now non-resident + * attribute record. + */ + arec_size = (mp_ofs + mp_size + 7) & ~7; + /* + * If the page is not uptodate bring it uptodate by copying from the + * attribute value. + */ + attr_size = le32_to_cpu(a->data.resident.value_length); + BUG_ON(attr_size != i_size_read(vi)); + if (page && !PageUptodate(page)) { + kaddr = kmap_atomic(page, KM_USER0); + memcpy(kaddr, (u8*)a + + le16_to_cpu(a->data.resident.value_offset), + attr_size); + memset(kaddr + attr_size, 0, PAGE_CACHE_SIZE - attr_size); + kunmap_atomic(kaddr, KM_USER0); + flush_dcache_page(page); + SetPageUptodate(page); + } + /* Backup the attribute flag. */ + old_res_attr_flags = a->data.resident.flags; + /* Resize the resident part of the attribute record. */ + err = ntfs_attr_record_resize(m, a, arec_size); + if (unlikely(err)) + goto err_out; + /* Setup the in-memory attribute structure to be non-resident. */ + NInoSetNonResident(ni); + ni->runlist.rl = rl; + write_lock_irqsave(&ni->size_lock, flags); + ni->allocated_size = new_size; + write_unlock_irqrestore(&ni->size_lock, flags); + /* + * FIXME: For now just clear all of these as we do not support them + * when writing. + */ + NInoClearCompressed(ni); + NInoClearSparse(ni); + NInoClearEncrypted(ni); + /* + * Convert the resident part of the attribute record to describe a + * non-resident attribute. + */ + a->non_resident = 1; + /* Move the attribute name if it exists and update the offset. */ + if (a->name_length) + memmove((u8*)a + name_ofs, (u8*)a + le16_to_cpu(a->name_offset), + a->name_length * sizeof(ntfschar)); + a->name_offset = cpu_to_le16(name_ofs); + /* Update the flags to match the in-memory ones. */ + a->flags &= cpu_to_le16(0xffff & ~le16_to_cpu(ATTR_IS_SPARSE | + ATTR_IS_ENCRYPTED | ATTR_COMPRESSION_MASK)); + /* Setup the fields specific to non-resident attributes. */ + a->data.non_resident.lowest_vcn = 0; + a->data.non_resident.highest_vcn = cpu_to_sle64((new_size - 1) >> + vol->cluster_size_bits); + a->data.non_resident.mapping_pairs_offset = cpu_to_le16(mp_ofs); + a->data.non_resident.compression_unit = 0; + memset(&a->data.non_resident.reserved, 0, + sizeof(a->data.non_resident.reserved)); + a->data.non_resident.allocated_size = cpu_to_sle64(new_size); + a->data.non_resident.data_size = + a->data.non_resident.initialized_size = + cpu_to_sle64(attr_size); + /* Generate the mapping pairs array into the attribute record. */ + err = ntfs_mapping_pairs_build(vol, (u8*)a + mp_ofs, + arec_size - mp_ofs, rl, 0, NULL); + if (unlikely(err)) { + ntfs_debug("Failed to build mapping pairs, error code %i.", + err); + goto undo_err_out; + } + /* Mark the mft record dirty, so it gets written back. */ + flush_dcache_mft_record_page(ctx->ntfs_ino); + mark_mft_record_dirty(ctx->ntfs_ino); + ntfs_attr_put_search_ctx(ctx); + unmap_mft_record(base_ni); + up_write(&ni->runlist.lock); + if (page) { + set_page_dirty(page); + unlock_page(page); + page_cache_release(page); + } + ntfs_debug("Done."); + return 0; +undo_err_out: + /* Convert the attribute back into a resident attribute. */ + a->non_resident = 0; + /* Move the attribute name if it exists and update the offset. */ + name_ofs = (offsetof(ATTR_RECORD, data.resident.reserved) + + sizeof(a->data.resident.reserved) + 7) & ~7; + if (a->name_length) + memmove((u8*)a + name_ofs, (u8*)a + le16_to_cpu(a->name_offset), + a->name_length * sizeof(ntfschar)); + mp_ofs = (name_ofs + a->name_length * sizeof(ntfschar) + 7) & ~7; + a->name_offset = cpu_to_le16(name_ofs); + arec_size = (mp_ofs + attr_size + 7) & ~7; + /* Resize the resident part of the attribute record. */ + err2 = ntfs_attr_record_resize(m, a, arec_size); + if (unlikely(err2)) { + /* + * This cannot happen (well if memory corruption is at work it + * could happen in theory), but deal with it as well as we can. + * If the old size is too small, truncate the attribute, + * otherwise simply give it a larger allocated size. + * FIXME: Should check whether chkdsk complains when the + * allocated size is much bigger than the resident value size. + */ + arec_size = le32_to_cpu(a->length); + if ((mp_ofs + attr_size) > arec_size) { + err2 = attr_size; + attr_size = arec_size - mp_ofs; + ntfs_error(vol->sb, "Failed to undo partial resident " + "to non-resident attribute " + "conversion. Truncating inode 0x%lx, " + "attribute type 0x%x from %i bytes to " + "%i bytes to maintain metadata " + "consistency. THIS MEANS YOU ARE " + "LOSING %i BYTES DATA FROM THIS %s.", + vi->i_ino, + (unsigned)le32_to_cpu(ni->type), + err2, attr_size, err2 - attr_size, + ((ni->type == AT_DATA) && + !ni->name_len) ? "FILE": "ATTRIBUTE"); + write_lock_irqsave(&ni->size_lock, flags); + ni->initialized_size = attr_size; + i_size_write(vi, attr_size); + write_unlock_irqrestore(&ni->size_lock, flags); + } + } + /* Setup the fields specific to resident attributes. */ + a->data.resident.value_length = cpu_to_le32(attr_size); + a->data.resident.value_offset = cpu_to_le16(mp_ofs); + a->data.resident.flags = old_res_attr_flags; + memset(&a->data.resident.reserved, 0, + sizeof(a->data.resident.reserved)); + /* Copy the data from the page back to the attribute value. */ + if (page) { + kaddr = kmap_atomic(page, KM_USER0); + memcpy((u8*)a + mp_ofs, kaddr, attr_size); + kunmap_atomic(kaddr, KM_USER0); + } + /* Finally setup the ntfs inode appropriately. */ + write_lock_irqsave(&ni->size_lock, flags); + ni->allocated_size = arec_size - mp_ofs; + write_unlock_irqrestore(&ni->size_lock, flags); + NInoClearNonResident(ni); + /* Mark the mft record dirty, so it gets written back. */ + flush_dcache_mft_record_page(ctx->ntfs_ino); + mark_mft_record_dirty(ctx->ntfs_ino); +err_out: + if (ctx) + ntfs_attr_put_search_ctx(ctx); + if (m) + unmap_mft_record(base_ni); + ni->runlist.rl = NULL; + up_write(&ni->runlist.lock); +rl_err_out: + if (rl) { + if (ntfs_cluster_free_from_rl(vol, rl) < 0) { + ntfs_free(rl); + ntfs_error(vol->sb, "Failed to release allocated " + "cluster(s) in error code path. Run " + "chkdsk to recover the lost " + "cluster(s)."); + NVolSetErrors(vol); + } +page_err_out: + unlock_page(page); + page_cache_release(page); + } + if (err == -EINVAL) + err = -EIO; + return err; +} + +/** * ntfs_attr_set - fill (a part of) an attribute with a byte * @ni: ntfs inode describing the attribute to fill * @ofs: offset inside the attribute at which to start to fill |