/* * Squashfs - a compressed read only filesystem for Linux * * Copyright (c) 2010 * Phillip Lougher * * This program 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, * or (at your option) any later version. * * This program 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; if not, write to the Free Software * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. * * xattr_id.c */ /* * This file implements code to map the 32-bit xattr id stored in the inode * into the on disk location of the xattr data. */ #include #include #include #include "squashfs_fs.h" #include "squashfs_fs_sb.h" #include "squashfs.h" #include "xattr.h" /* * Map xattr id using the xattr id look up table */ int squashfs_xattr_lookup(struct super_block *sb, unsigned int index, int *count, unsigned int *size, unsigned long long *xattr) { struct squashfs_sb_info *msblk = sb->s_fs_info; int block = SQUASHFS_XATTR_BLOCK(index); int offset = SQUASHFS_XATTR_BLOCK_OFFSET(index); u64 start_block = le64_to_cpu(msblk->xattr_id_table[block]); struct squashfs_xattr_id id; int err; err = squashfs_read_metadata(sb, &id, &start_block, &offset, sizeof(id)); if (err < 0) return err; *xattr = le64_to_cpu(id.xattr); *size = le32_to_cpu(id.size); *count = le32_to_cpu(id.count); return 0; } /* * Read uncompressed xattr id lookup table indexes from disk into memory */ __le64 *squashfs_read_xattr_id_table(struct super_block *sb, u64 start, u64 *xattr_table_start, int *xattr_ids) { unsigned int len; struct squashfs_xattr_id_table *id_table; id_table = squashfs_read_table(sb, start, sizeof(*id_table)); if (IS_ERR(id_table)) return (__le64 *) id_table; *xattr_table_start = le64_to_cpu(id_table->xattr_table_start); *xattr_ids = le32_to_cpu(id_table->xattr_ids); kfree(id_table); /* Sanity check values */ /* there is always at least one xattr id */ if (*xattr_ids == 0) return ERR_PTR(-EINVAL); /* xattr_table should be less than start */ if (*xattr_table_start >= start) return ERR_PTR(-EINVAL); len = SQUASHFS_XATTR_BLOCK_BYTES(*xattr_ids); TRACE("In read_xattr_index_table, length %d\n", len); return squashfs_read_table(sb, start + sizeof(*id_table), len); } >
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