From 4b5397dc24ab12afaac85be3d0863b7f6eb8b0f0 Mon Sep 17 00:00:00 2001 From: Phillip Lougher Date: Fri, 14 May 2010 20:48:47 +0100 Subject: squashfs: add xattr id support This patch adds support for mapping xattr ids (stored in inodes) into the on-disk location of the xattrs themselves. Signed-off-by: Phillip Lougher --- fs/squashfs/Makefile | 2 + fs/squashfs/squashfs.h | 6 +++ fs/squashfs/squashfs_fs.h | 32 +++++++++++++- fs/squashfs/squashfs_fs_sb.h | 3 ++ fs/squashfs/super.c | 22 ++++++++-- fs/squashfs/xattr_id.c | 100 +++++++++++++++++++++++++++++++++++++++++++ 6 files changed, 161 insertions(+), 4 deletions(-) create mode 100644 fs/squashfs/xattr_id.c (limited to 'fs/squashfs') diff --git a/fs/squashfs/Makefile b/fs/squashfs/Makefile index df8a19e..c0da4a1 100644 --- a/fs/squashfs/Makefile +++ b/fs/squashfs/Makefile @@ -5,3 +5,5 @@ obj-$(CONFIG_SQUASHFS) += squashfs.o squashfs-y += block.o cache.o dir.o export.o file.o fragment.o id.o inode.o squashfs-y += namei.o super.o symlink.o zlib_wrapper.o decompressor.o +squashfs-y += xattr_id.o + diff --git a/fs/squashfs/squashfs.h b/fs/squashfs/squashfs.h index fe2587a..133befe 100644 --- a/fs/squashfs/squashfs.h +++ b/fs/squashfs/squashfs.h @@ -73,6 +73,12 @@ extern struct inode *squashfs_iget(struct super_block *, long long, unsigned int); extern int squashfs_read_inode(struct inode *, long long); +/* xattr_id.c */ +extern int squashfs_xattr_lookup(struct super_block *, unsigned int, int *, + int *, long long *); +extern __le64 *squashfs_read_xattr_id_table(struct super_block *, u64, + u64 *, int *); + /* * Inodes, files and decompressor operations */ diff --git a/fs/squashfs/squashfs_fs.h b/fs/squashfs/squashfs_fs.h index 7902424..c654e86 100644 --- a/fs/squashfs/squashfs_fs.h +++ b/fs/squashfs/squashfs_fs.h @@ -174,6 +174,24 @@ #define SQUASHFS_ID_BLOCK_BYTES(A) (SQUASHFS_ID_BLOCKS(A) *\ sizeof(u64)) +/* xattr id lookup table defines */ +#define SQUASHFS_XATTR_BYTES(A) ((A) * sizeof(struct squashfs_xattr_id)) + +#define SQUASHFS_XATTR_BLOCK(A) (SQUASHFS_XATTR_BYTES(A) / \ + SQUASHFS_METADATA_SIZE) + +#define SQUASHFS_XATTR_BLOCK_OFFSET(A) (SQUASHFS_XATTR_BYTES(A) % \ + SQUASHFS_METADATA_SIZE) + +#define SQUASHFS_XATTR_BLOCKS(A) ((SQUASHFS_XATTR_BYTES(A) + \ + SQUASHFS_METADATA_SIZE - 1) / \ + SQUASHFS_METADATA_SIZE) + +#define SQUASHFS_XATTR_BLOCK_BYTES(A) (SQUASHFS_XATTR_BLOCKS(A) *\ + sizeof(u64)) +#define SQUASHFS_XATTR_BLK(A) ((unsigned int) ((A) >> 16)) + +#define SQUASHFS_XATTR_OFFSET(A) ((unsigned int) ((A) & 0xffff)) /* cached data constants for filesystem */ #define SQUASHFS_CACHED_BLKS 8 @@ -228,7 +246,7 @@ struct squashfs_super_block { __le64 root_inode; __le64 bytes_used; __le64 id_table_start; - __le64 xattr_table_start; + __le64 xattr_id_table_start; __le64 inode_table_start; __le64 directory_table_start; __le64 fragment_table_start; @@ -377,4 +395,16 @@ struct squashfs_fragment_entry { unsigned int unused; }; +struct squashfs_xattr_id { + __le64 xattr; + __le32 count; + __le32 size; +}; + +struct squashfs_xattr_id_table { + __le64 xattr_table_start; + __le32 xattr_ids; + __le32 unused; +}; + #endif diff --git a/fs/squashfs/squashfs_fs_sb.h b/fs/squashfs/squashfs_fs_sb.h index 2e77dc5..d9037a5 100644 --- a/fs/squashfs/squashfs_fs_sb.h +++ b/fs/squashfs/squashfs_fs_sb.h @@ -61,6 +61,7 @@ struct squashfs_sb_info { int next_meta_index; __le64 *id_table; __le64 *fragment_index; + __le64 *xattr_id_table; struct mutex read_data_mutex; struct mutex meta_index_mutex; struct meta_index *meta_index; @@ -68,9 +69,11 @@ struct squashfs_sb_info { __le64 *inode_lookup_table; u64 inode_table; u64 directory_table; + u64 xattr_table; unsigned int block_size; unsigned short block_log; long long bytes_used; unsigned int inodes; + int xattr_ids; }; #endif diff --git a/fs/squashfs/super.c b/fs/squashfs/super.c index 48b6f4a..c4dfc39 100644 --- a/fs/squashfs/super.c +++ b/fs/squashfs/super.c @@ -36,6 +36,7 @@ #include #include #include +#include #include "squashfs_fs.h" #include "squashfs_fs_sb.h" @@ -82,7 +83,7 @@ static int squashfs_fill_super(struct super_block *sb, void *data, int silent) long long root_inode; unsigned short flags; unsigned int fragments; - u64 lookup_table_start; + u64 lookup_table_start, xattr_id_table_start; int err; TRACE("Entered squashfs_fill_superblock\n"); @@ -143,7 +144,7 @@ static int squashfs_fill_super(struct super_block *sb, void *data, int silent) * Check if there's xattrs in the filesystem. These are not * supported in this version, so warn that they will be ignored. */ - if (le64_to_cpu(sblk->xattr_table_start) != SQUASHFS_INVALID_BLK) + if (le64_to_cpu(sblk->xattr_id_table_start) != SQUASHFS_INVALID_BLK) ERROR("Xattrs in filesystem, these will be ignored\n"); /* Check the filesystem does not extend beyond the end of the @@ -253,7 +254,7 @@ static int squashfs_fill_super(struct super_block *sb, void *data, int silent) allocate_lookup_table: lookup_table_start = le64_to_cpu(sblk->lookup_table_start); if (lookup_table_start == SQUASHFS_INVALID_BLK) - goto allocate_root; + goto allocate_xattr_table; /* Allocate and read inode lookup table */ msblk->inode_lookup_table = squashfs_read_inode_lookup_table(sb, @@ -266,6 +267,19 @@ allocate_lookup_table: sb->s_export_op = &squashfs_export_ops; +allocate_xattr_table: + xattr_id_table_start = le64_to_cpu(sblk->xattr_id_table_start); + if (xattr_id_table_start == SQUASHFS_INVALID_BLK) + goto allocate_root; + + /* Allocate and read xattr id lookup table */ + msblk->xattr_id_table = squashfs_read_xattr_id_table(sb, + xattr_id_table_start, &msblk->xattr_table, &msblk->xattr_ids); + if (IS_ERR(msblk->xattr_id_table)) { + err = PTR_ERR(msblk->xattr_id_table); + msblk->xattr_id_table = NULL; + goto failed_mount; + } allocate_root: root = new_inode(sb); if (!root) { @@ -301,6 +315,7 @@ failed_mount: kfree(msblk->inode_lookup_table); kfree(msblk->fragment_index); kfree(msblk->id_table); + kfree(msblk->xattr_id_table); kfree(sb->s_fs_info); sb->s_fs_info = NULL; kfree(sblk); @@ -355,6 +370,7 @@ static void squashfs_put_super(struct super_block *sb) kfree(sbi->fragment_index); kfree(sbi->meta_index); kfree(sbi->inode_lookup_table); + kfree(sbi->xattr_id_table); kfree(sb->s_fs_info); sb->s_fs_info = NULL; } diff --git a/fs/squashfs/xattr_id.c b/fs/squashfs/xattr_id.c new file mode 100644 index 0000000..a741012 --- /dev/null +++ b/fs/squashfs/xattr_id.c @@ -0,0 +1,100 @@ +/* + * 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_fs_i.h" +#include "squashfs.h" + +/* + * Map xattr id using the xattr id look up table + */ +int squashfs_xattr_lookup(struct super_block *sb, unsigned int index, + int *count, int *size, 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; + __le64 *xid_table; + struct squashfs_xattr_id_table id_table; + int err; + + err = squashfs_read_table(sb, &id_table, start, sizeof(id_table)); + if (err < 0) { + ERROR("unable to read xattr id table\n"); + return ERR_PTR(err); + } + *xattr_table_start = le64_to_cpu(id_table.xattr_table_start); + *xattr_ids = le32_to_cpu(id_table.xattr_ids); + len = SQUASHFS_XATTR_BLOCK_BYTES(*xattr_ids); + + TRACE("In read_xattr_index_table, length %d\n", len); + + /* Allocate xattr id lookup table indexes */ + xid_table = kmalloc(len, GFP_KERNEL); + if (xid_table == NULL) { + ERROR("Failed to allocate xattr id index table\n"); + return ERR_PTR(-ENOMEM); + } + + err = squashfs_read_table(sb, xid_table, start + sizeof(id_table), len); + if (err < 0) { + ERROR("unable to read xattr id index table\n"); + kfree(xid_table); + return ERR_PTR(err); + } + + return xid_table; +} -- cgit v1.1