Linux-2.6.12-rc2v2.6.12-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!

1 files changed, 461 insertions, 0 deletions

diff --git a/fs/ntfs/index.c b/fs/ntfs/index.c
new file mode 100644
index 000000000000..71bd2cd7a4d9
--- /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;
+}