Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
diff --git a/fs/ntfs/index.c b/fs/ntfs/index.c
new file mode 100644
index 0000000..71bd2cd
--- /dev/null
+++ b/fs/ntfs/index.c
@@ -0,0 +1,461 @@
+/*
+ * index.c - NTFS kernel index handling. Part of the Linux-NTFS project.
+ *
+ * Copyright (c) 2004 Anton Altaparmakov
+ *
+ * This program/include file is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as published
+ * by the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program/include file is distributed in the hope that it will be
+ * useful, but WITHOUT ANY WARRANTY; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program (in the main directory of the Linux-NTFS
+ * distribution in the file COPYING); if not, write to the Free Software
+ * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include "aops.h"
+#include "collate.h"
+#include "debug.h"
+#include "index.h"
+#include "ntfs.h"
+
+/**
+ * ntfs_index_ctx_get - allocate and initialize a new index context
+ * @idx_ni: ntfs index inode with which to initialize the context
+ *
+ * Allocate a new index context, initialize it with @idx_ni and return it.
+ * Return NULL if allocation failed.
+ *
+ * Locking: Caller must hold i_sem on the index inode.
+ */
+ntfs_index_context *ntfs_index_ctx_get(ntfs_inode *idx_ni)
+{
+ ntfs_index_context *ictx;
+
+ ictx = kmem_cache_alloc(ntfs_index_ctx_cache, SLAB_NOFS);
+ if (ictx) {
+ ictx->idx_ni = idx_ni;
+ ictx->entry = NULL;
+ ictx->data = NULL;
+ ictx->data_len = 0;
+ ictx->is_in_root = 0;
+ ictx->ir = NULL;
+ ictx->actx = NULL;
+ ictx->base_ni = NULL;
+ ictx->ia = NULL;
+ ictx->page = NULL;
+ }
+ return ictx;
+}
+
+/**
+ * ntfs_index_ctx_put - release an index context
+ * @ictx: index context to free
+ *
+ * Release the index context @ictx, releasing all associated resources.
+ *
+ * Locking: Caller must hold i_sem on the index inode.
+ */
+void ntfs_index_ctx_put(ntfs_index_context *ictx)
+{
+ if (ictx->entry) {
+ if (ictx->is_in_root) {
+ if (ictx->actx)
+ ntfs_attr_put_search_ctx(ictx->actx);
+ if (ictx->base_ni)
+ unmap_mft_record(ictx->base_ni);
+ } else {
+ struct page *page = ictx->page;
+ if (page) {
+ BUG_ON(!PageLocked(page));
+ unlock_page(page);
+ ntfs_unmap_page(page);
+ }
+ }
+ }
+ kmem_cache_free(ntfs_index_ctx_cache, ictx);
+ return;
+}
+
+/**
+ * ntfs_index_lookup - find a key in an index and return its index entry
+ * @key: [IN] key for which to search in the index
+ * @key_len: [IN] length of @key in bytes
+ * @ictx: [IN/OUT] context describing the index and the returned entry
+ *
+ * Before calling ntfs_index_lookup(), @ictx must have been obtained from a
+ * call to ntfs_index_ctx_get().
+ *
+ * Look for the @key in the index specified by the index lookup context @ictx.
+ * ntfs_index_lookup() walks the contents of the index looking for the @key.
+ *
+ * If the @key is found in the index, 0 is returned and @ictx is setup to
+ * describe the index entry containing the matching @key. @ictx->entry is the
+ * index entry and @ictx->data and @ictx->data_len are the index entry data and
+ * its length in bytes, respectively.
+ *
+ * If the @key is not found in the index, -ENOENT is returned and @ictx is
+ * setup to describe the index entry whose key collates immediately after the
+ * search @key, i.e. this is the position in the index at which an index entry
+ * with a key of @key would need to be inserted.
+ *
+ * If an error occurs return the negative error code and @ictx is left
+ * untouched.
+ *
+ * When finished with the entry and its data, call ntfs_index_ctx_put() to free
+ * the context and other associated resources.
+ *
+ * If the index entry was modified, call flush_dcache_index_entry_page()
+ * immediately after the modification and either ntfs_index_entry_mark_dirty()
+ * or ntfs_index_entry_write() before the call to ntfs_index_ctx_put() to
+ * ensure that the changes are written to disk.
+ *
+ * Locking: - Caller must hold i_sem on the index inode.
+ * - Each page cache page in the index allocation mapping must be
+ * locked whilst being accessed otherwise we may find a corrupt
+ * page due to it being under ->writepage at the moment which
+ * applies the mst protection fixups before writing out and then
+ * removes them again after the write is complete after which it
+ * unlocks the page.
+ */
+int ntfs_index_lookup(const void *key, const int key_len,
+ ntfs_index_context *ictx)
+{
+ VCN vcn, old_vcn;
+ ntfs_inode *idx_ni = ictx->idx_ni;
+ ntfs_volume *vol = idx_ni->vol;
+ struct super_block *sb = vol->sb;
+ ntfs_inode *base_ni = idx_ni->ext.base_ntfs_ino;
+ MFT_RECORD *m;
+ INDEX_ROOT *ir;
+ INDEX_ENTRY *ie;
+ INDEX_ALLOCATION *ia;
+ u8 *index_end, *kaddr;
+ ntfs_attr_search_ctx *actx;
+ struct address_space *ia_mapping;
+ struct page *page;
+ int rc, err = 0;
+
+ ntfs_debug("Entering.");
+ BUG_ON(!NInoAttr(idx_ni));
+ BUG_ON(idx_ni->type != AT_INDEX_ALLOCATION);
+ BUG_ON(idx_ni->nr_extents != -1);
+ BUG_ON(!base_ni);
+ BUG_ON(!key);
+ BUG_ON(key_len <= 0);
+ if (!ntfs_is_collation_rule_supported(
+ idx_ni->itype.index.collation_rule)) {
+ ntfs_error(sb, "Index uses unsupported collation rule 0x%x. "
+ "Aborting lookup.", le32_to_cpu(
+ idx_ni->itype.index.collation_rule));
+ return -EOPNOTSUPP;
+ }
+ /* Get hold of the mft record for the index inode. */
+ m = map_mft_record(base_ni);
+ if (IS_ERR(m)) {
+ ntfs_error(sb, "map_mft_record() failed with error code %ld.",
+ -PTR_ERR(m));
+ return PTR_ERR(m);
+ }
+ actx = ntfs_attr_get_search_ctx(base_ni, m);
+ if (unlikely(!actx)) {
+ err = -ENOMEM;
+ goto err_out;
+ }
+ /* Find the index root attribute in the mft record. */
+ err = ntfs_attr_lookup(AT_INDEX_ROOT, idx_ni->name, idx_ni->name_len,
+ CASE_SENSITIVE, 0, NULL, 0, actx);
+ if (unlikely(err)) {
+ if (err == -ENOENT) {
+ ntfs_error(sb, "Index root attribute missing in inode "
+ "0x%lx.", idx_ni->mft_no);
+ err = -EIO;
+ }
+ goto err_out;
+ }
+ /* Get to the index root value (it has been verified in read_inode). */
+ ir = (INDEX_ROOT*)((u8*)actx->attr +
+ le16_to_cpu(actx->attr->data.resident.value_offset));
+ index_end = (u8*)&ir->index + le32_to_cpu(ir->index.index_length);
+ /* The first index entry. */
+ ie = (INDEX_ENTRY*)((u8*)&ir->index +
+ le32_to_cpu(ir->index.entries_offset));
+ /*
+ * Loop until we exceed valid memory (corruption case) or until we
+ * reach the last entry.
+ */
+ for (;; ie = (INDEX_ENTRY*)((u8*)ie + le16_to_cpu(ie->length))) {
+ /* Bounds checks. */
+ if ((u8*)ie < (u8*)actx->mrec || (u8*)ie +
+ sizeof(INDEX_ENTRY_HEADER) > index_end ||
+ (u8*)ie + le16_to_cpu(ie->length) > index_end)
+ goto idx_err_out;
+ /*
+ * The last entry cannot contain a key. It can however contain
+ * a pointer to a child node in the B+tree so we just break out.
+ */
+ if (ie->flags & INDEX_ENTRY_END)
+ break;
+ /* Further bounds checks. */
+ if ((u32)sizeof(INDEX_ENTRY_HEADER) +
+ le16_to_cpu(ie->key_length) >
+ le16_to_cpu(ie->data.vi.data_offset) ||
+ (u32)le16_to_cpu(ie->data.vi.data_offset) +
+ le16_to_cpu(ie->data.vi.data_length) >
+ le16_to_cpu(ie->length))
+ goto idx_err_out;
+ /* If the keys match perfectly, we setup @ictx and return 0. */
+ if ((key_len == le16_to_cpu(ie->key_length)) && !memcmp(key,
+ &ie->key, key_len)) {
+ir_done:
+ ictx->is_in_root = TRUE;
+ ictx->actx = actx;
+ ictx->base_ni = base_ni;
+ ictx->ia = NULL;
+ ictx->page = NULL;
+done:
+ ictx->entry = ie;
+ ictx->data = (u8*)ie +
+ le16_to_cpu(ie->data.vi.data_offset);
+ ictx->data_len = le16_to_cpu(ie->data.vi.data_length);
+ ntfs_debug("Done.");
+ return err;
+ }
+ /*
+ * Not a perfect match, need to do full blown collation so we
+ * know which way in the B+tree we have to go.
+ */
+ rc = ntfs_collate(vol, idx_ni->itype.index.collation_rule, key,
+ key_len, &ie->key, le16_to_cpu(ie->key_length));
+ /*
+ * If @key collates before the key of the current entry, there
+ * is definitely no such key in this index but we might need to
+ * descend into the B+tree so we just break out of the loop.
+ */
+ if (rc == -1)
+ break;
+ /*
+ * A match should never happen as the memcmp() call should have
+ * cought it, but we still treat it correctly.
+ */
+ if (!rc)
+ goto ir_done;
+ /* The keys are not equal, continue the search. */
+ }
+ /*
+ * We have finished with this index without success. Check for the
+ * presence of a child node and if not present setup @ictx and return
+ * -ENOENT.
+ */
+ if (!(ie->flags & INDEX_ENTRY_NODE)) {
+ ntfs_debug("Entry not found.");
+ err = -ENOENT;
+ goto ir_done;
+ } /* Child node present, descend into it. */
+ /* Consistency check: Verify that an index allocation exists. */
+ if (!NInoIndexAllocPresent(idx_ni)) {
+ ntfs_error(sb, "No index allocation attribute but index entry "
+ "requires one. Inode 0x%lx is corrupt or "
+ "driver bug.", idx_ni->mft_no);
+ goto err_out;
+ }
+ /* Get the starting vcn of the index_block holding the child node. */
+ vcn = sle64_to_cpup((sle64*)((u8*)ie + le16_to_cpu(ie->length) - 8));
+ ia_mapping = VFS_I(idx_ni)->i_mapping;
+ /*
+ * We are done with the index root and the mft record. Release them,
+ * otherwise we deadlock with ntfs_map_page().
+ */
+ ntfs_attr_put_search_ctx(actx);
+ unmap_mft_record(base_ni);
+ m = NULL;
+ actx = NULL;
+descend_into_child_node:
+ /*
+ * Convert vcn to index into the index allocation attribute in units
+ * of PAGE_CACHE_SIZE and map the page cache page, reading it from
+ * disk if necessary.
+ */
+ page = ntfs_map_page(ia_mapping, vcn <<
+ idx_ni->itype.index.vcn_size_bits >> PAGE_CACHE_SHIFT);
+ if (IS_ERR(page)) {
+ ntfs_error(sb, "Failed to map index page, error %ld.",
+ -PTR_ERR(page));
+ err = PTR_ERR(page);
+ goto err_out;
+ }
+ lock_page(page);
+ kaddr = (u8*)page_address(page);
+fast_descend_into_child_node:
+ /* Get to the index allocation block. */
+ ia = (INDEX_ALLOCATION*)(kaddr + ((vcn <<
+ idx_ni->itype.index.vcn_size_bits) & ~PAGE_CACHE_MASK));
+ /* Bounds checks. */
+ if ((u8*)ia < kaddr || (u8*)ia > kaddr + PAGE_CACHE_SIZE) {
+ ntfs_error(sb, "Out of bounds check failed. Corrupt inode "
+ "0x%lx or driver bug.", idx_ni->mft_no);
+ goto unm_err_out;
+ }
+ /* Catch multi sector transfer fixup errors. */
+ if (unlikely(!ntfs_is_indx_record(ia->magic))) {
+ ntfs_error(sb, "Index record with vcn 0x%llx is corrupt. "
+ "Corrupt inode 0x%lx. Run chkdsk.",
+ (long long)vcn, idx_ni->mft_no);
+ goto unm_err_out;
+ }
+ if (sle64_to_cpu(ia->index_block_vcn) != vcn) {
+ ntfs_error(sb, "Actual VCN (0x%llx) of index buffer is "
+ "different from expected VCN (0x%llx). Inode "
+ "0x%lx is corrupt or driver bug.",
+ (unsigned long long)
+ sle64_to_cpu(ia->index_block_vcn),
+ (unsigned long long)vcn, idx_ni->mft_no);
+ goto unm_err_out;
+ }
+ if (le32_to_cpu(ia->index.allocated_size) + 0x18 !=
+ idx_ni->itype.index.block_size) {
+ ntfs_error(sb, "Index buffer (VCN 0x%llx) of inode 0x%lx has "
+ "a size (%u) differing from the index "
+ "specified size (%u). Inode is corrupt or "
+ "driver bug.", (unsigned long long)vcn,
+ idx_ni->mft_no,
+ le32_to_cpu(ia->index.allocated_size) + 0x18,
+ idx_ni->itype.index.block_size);
+ goto unm_err_out;
+ }
+ index_end = (u8*)ia + idx_ni->itype.index.block_size;
+ if (index_end > kaddr + PAGE_CACHE_SIZE) {
+ ntfs_error(sb, "Index buffer (VCN 0x%llx) of inode 0x%lx "
+ "crosses page boundary. Impossible! Cannot "
+ "access! This is probably a bug in the "
+ "driver.", (unsigned long long)vcn,
+ idx_ni->mft_no);
+ goto unm_err_out;
+ }
+ index_end = (u8*)&ia->index + le32_to_cpu(ia->index.index_length);
+ if (index_end > (u8*)ia + idx_ni->itype.index.block_size) {
+ ntfs_error(sb, "Size of index buffer (VCN 0x%llx) of inode "
+ "0x%lx exceeds maximum size.",
+ (unsigned long long)vcn, idx_ni->mft_no);
+ goto unm_err_out;
+ }
+ /* The first index entry. */
+ ie = (INDEX_ENTRY*)((u8*)&ia->index +
+ le32_to_cpu(ia->index.entries_offset));
+ /*
+ * Iterate similar to above big loop but applied to index buffer, thus
+ * loop until we exceed valid memory (corruption case) or until we
+ * reach the last entry.
+ */
+ for (;; ie = (INDEX_ENTRY*)((u8*)ie + le16_to_cpu(ie->length))) {
+ /* Bounds checks. */
+ if ((u8*)ie < (u8*)ia || (u8*)ie +
+ sizeof(INDEX_ENTRY_HEADER) > index_end ||
+ (u8*)ie + le16_to_cpu(ie->length) > index_end) {
+ ntfs_error(sb, "Index entry out of bounds in inode "
+ "0x%lx.", idx_ni->mft_no);
+ goto unm_err_out;
+ }
+ /*
+ * The last entry cannot contain a key. It can however contain
+ * a pointer to a child node in the B+tree so we just break out.
+ */
+ if (ie->flags & INDEX_ENTRY_END)
+ break;
+ /* Further bounds checks. */
+ if ((u32)sizeof(INDEX_ENTRY_HEADER) +
+ le16_to_cpu(ie->key_length) >
+ le16_to_cpu(ie->data.vi.data_offset) ||
+ (u32)le16_to_cpu(ie->data.vi.data_offset) +
+ le16_to_cpu(ie->data.vi.data_length) >
+ le16_to_cpu(ie->length)) {
+ ntfs_error(sb, "Index entry out of bounds in inode "
+ "0x%lx.", idx_ni->mft_no);
+ goto unm_err_out;
+ }
+ /* If the keys match perfectly, we setup @ictx and return 0. */
+ if ((key_len == le16_to_cpu(ie->key_length)) && !memcmp(key,
+ &ie->key, key_len)) {
+ia_done:
+ ictx->is_in_root = FALSE;
+ ictx->actx = NULL;
+ ictx->base_ni = NULL;
+ ictx->ia = ia;
+ ictx->page = page;
+ goto done;
+ }
+ /*
+ * Not a perfect match, need to do full blown collation so we
+ * know which way in the B+tree we have to go.
+ */
+ rc = ntfs_collate(vol, idx_ni->itype.index.collation_rule, key,
+ key_len, &ie->key, le16_to_cpu(ie->key_length));
+ /*
+ * If @key collates before the key of the current entry, there
+ * is definitely no such key in this index but we might need to
+ * descend into the B+tree so we just break out of the loop.
+ */
+ if (rc == -1)
+ break;
+ /*
+ * A match should never happen as the memcmp() call should have
+ * cought it, but we still treat it correctly.
+ */
+ if (!rc)
+ goto ia_done;
+ /* The keys are not equal, continue the search. */
+ }
+ /*
+ * We have finished with this index buffer without success. Check for
+ * the presence of a child node and if not present return -ENOENT.
+ */
+ if (!(ie->flags & INDEX_ENTRY_NODE)) {
+ ntfs_debug("Entry not found.");
+ err = -ENOENT;
+ goto ia_done;
+ }
+ if ((ia->index.flags & NODE_MASK) == LEAF_NODE) {
+ ntfs_error(sb, "Index entry with child node found in a leaf "
+ "node in inode 0x%lx.", idx_ni->mft_no);
+ goto unm_err_out;
+ }
+ /* Child node present, descend into it. */
+ old_vcn = vcn;
+ vcn = sle64_to_cpup((sle64*)((u8*)ie + le16_to_cpu(ie->length) - 8));
+ if (vcn >= 0) {
+ /*
+ * If vcn is in the same page cache page as old_vcn we recycle
+ * the mapped page.
+ */
+ if (old_vcn << vol->cluster_size_bits >>
+ PAGE_CACHE_SHIFT == vcn <<
+ vol->cluster_size_bits >>
+ PAGE_CACHE_SHIFT)
+ goto fast_descend_into_child_node;
+ unlock_page(page);
+ ntfs_unmap_page(page);
+ goto descend_into_child_node;
+ }
+ ntfs_error(sb, "Negative child node vcn in inode 0x%lx.",
+ idx_ni->mft_no);
+unm_err_out:
+ unlock_page(page);
+ ntfs_unmap_page(page);
+err_out:
+ if (!err)
+ err = -EIO;
+ if (actx)
+ ntfs_attr_put_search_ctx(actx);
+ if (m)
+ unmap_mft_record(base_ni);
+ return err;
+idx_err_out:
+ ntfs_error(sb, "Corrupt index. Aborting lookup.");
+ goto err_out;
+}