NTFS: Add fs/ntfs/attrib.[hc]::ntfs_attr_make_non_resident().
Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
diff --git a/fs/ntfs/attrib.c b/fs/ntfs/attrib.c
index 6de5e04..3b9de40 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 @@
}
/**
+ * 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