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Commit 144347df authored by girish's avatar girish
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Add block map validation

b=13144
i=adilger
i=kalpak
parent 35b38cc1
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fs/ext3/balloc.c | 99 ++++++++++++++++++++++++++++++++++++++++++++----------
1 files changed, 81 insertions(+), 18 deletions(-)
diff --git a/fs/ext3/balloc.c b/fs/ext3/balloc.c
index ff3428e..a9140ea 100644
Index: linux-stage/fs/ext3/balloc.c
===================================================================
--- linux-stage.orig/fs/ext3/balloc.c
+++ linux-stage/fs/ext3/balloc.c
@@ -143,9 +143,96 @@ unsigned ext3_init_block_bitmap(struct s
return free_blocks - sbi->s_itb_per_group - 2;
}
-/*
- * Read the bitmap for a given block_group, reading into the specified
- * slot in the superblock's bitmap cache.
+/**
+* bh_uptodate_or_lock: Test whether the buffer is uptodate
+* @bh: struct buffer_head
+*
+* Return true if the buffer is up-to-date and false,
+* with the buffer locked, if not.
+*/
+int bh_uptodate_or_lock(struct buffer_head *bh)
+{
+ if (!buffer_uptodate(bh)) {
+ lock_buffer(bh);
+ if (!buffer_uptodate(bh))
+ return 0;
+ unlock_buffer(bh);
+ }
+ return 1;
+}
+
+/**
+* bh_submit_read: Submit a locked buffer for reading
+* @bh: struct buffer_head
+*
+* Returns a negative error
+*/
+int bh_submit_read(struct buffer_head *bh)
+{
+ if (!buffer_locked(bh))
+ lock_buffer(bh);
+ if (buffer_uptodate(bh))
+ return 0;
+ get_bh(bh);
+ bh->b_end_io = end_buffer_read_sync;
+ submit_bh(READ, bh);
+ wait_on_buffer(bh);
+ if (buffer_uptodate(bh))
+ return 0;
+ return -EIO;
+}
+
+static int ext3_valid_block_bitmap(struct super_block *sb,
+ struct ext3_group_desc *desc,
+ unsigned int block_group,
+ struct buffer_head *bh)
+{
+ ext3_grpblk_t offset;
+ ext3_grpblk_t next_zero_bit;
+ ext3_fsblk_t bitmap_blk;
+ ext3_fsblk_t group_first_block;
+
+ group_first_block = ext3_group_first_block_no(sb, block_group);
+
+ /* check whether block bitmap block number is set */
+ bitmap_blk = le32_to_cpu(desc->bg_block_bitmap);
+ offset = bitmap_blk - group_first_block;
+ if (!ext3_test_bit(offset, bh->b_data))
+ /* bad block bitmap */
+ goto err_out;
+
+ /* check whether the inode bitmap block number is set */
+ bitmap_blk = le32_to_cpu(desc->bg_inode_bitmap);
+ offset = bitmap_blk - group_first_block;
+ if (!ext3_test_bit(offset, bh->b_data))
+ /* bad block bitmap */
+ goto err_out;
+
+ /* check whether the inode table block number is set */
+ bitmap_blk = le32_to_cpu(desc->bg_inode_table);
+ offset = bitmap_blk - group_first_block;
+ next_zero_bit = ext3_find_next_zero_bit(bh->b_data,
+ offset + EXT3_SB(sb)->s_itb_per_group,
+ offset);
+ if (next_zero_bit >= offset + EXT3_SB(sb)->s_itb_per_group)
+ /* good bitmap for inode tables */
+ return 1;
+
+err_out:
+ ext3_error(sb, __FUNCTION__,
+ "Invalid block bitmap - "
+ "block_group = %d, block = %lu",
+ (int)block_group, bitmap_blk);
+ return 0;
+}
+
+/**
+ * read_block_bitmap()
+ * @sb: super block
+ * @block_group: given block group
+ *
+ * Read the bitmap for a given block_group,and validate the
+ * bits for block/inode/inode tables are set in the bitmaps.
*
* Return buffer_head on success or NULL in case of failure.
*/
@@ -154,29 +241,42 @@ read_block_bitmap(struct super_block *sb
{
struct ext3_group_desc * desc;
struct buffer_head * bh = NULL;
+ ext3_fsblk_t bitmap_blk;
desc = ext3_get_group_desc (sb, block_group, NULL);
if (!desc)
- goto error_out;
+ return NULL;
+ bitmap_blk = desc->bg_block_bitmap;
+ bh = sb_getblk(sb, bitmap_blk);
+ if (unlikely(!bh)) {
+ ext3_error(sb, __FUNCTION__,
+ "Can not read block bitmap - "
+ "block group = %d, block_bitmap = %lu",
+ (int)block_group, bitmap_blk);
+ return NULL;
+ }
+ if (bh_uptodate_or_lock(bh))
+ return bh;
+
if (desc->bg_flags & cpu_to_le16(EXT3_BG_BLOCK_UNINIT)) {
- bh = sb_getblk(sb, le32_to_cpu(desc->bg_block_bitmap));
- if (!buffer_uptodate(bh)) {
- lock_buffer(bh);
- if (!buffer_uptodate(bh)) {
- ext3_init_block_bitmap(sb, bh,block_group,desc);
- set_buffer_uptodate(bh);
- }
- unlock_buffer(bh);
- }
- } else {
- bh = sb_bread(sb, le32_to_cpu(desc->bg_block_bitmap));
+ ext3_init_block_bitmap(sb, bh, block_group, desc);
+ set_buffer_uptodate(bh);
+ unlock_buffer(bh);
+ return bh;
+ }
+ if (bh_submit_read(bh) < 0) {
+ brelse(bh);
+ ext3_error(sb, __FUNCTION__,
+ "Cannot read block bitmap - "
+ "block group = %d block_bitmap = %lu",
+ (int)block_group, bitmap_blk);
+ return NULL;
+ }
+ if (!ext3_valid_block_bitmap(sb, desc, block_group, bh)) {
+ brelse(bh);
+ return NULL;
}
- if (!bh)
- ext3_error (sb, "read_block_bitmap",
- "Cannot read block bitmap - "
- "block_group = %d, block_bitmap = %u",
- block_group, le32_to_cpu(desc->bg_block_bitmap));
-error_out:
+
return bh;
}
/*
fs/ext3/balloc.c | 99 ++++++++++++++++++++++++++++++++++++++++++++----------
1 files changed, 81 insertions(+), 18 deletions(-)
diff --git a/fs/ext3/balloc.c b/fs/ext3/balloc.c
index ff3428e..a9140ea 100644
Index: linux-stage/fs/ext3/balloc.c
===================================================================
--- linux-stage.orig/fs/ext3/balloc.c
+++ linux-stage/fs/ext3/balloc.c
@@ -144,9 +144,96 @@ unsigned ext3_init_block_bitmap(struct s
return free_blocks - sbi->s_itb_per_group - 2;
}
-/*
- * Read the bitmap for a given block_group, reading into the specified
- * slot in the superblock's bitmap cache.
+/**
+* bh_uptodate_or_lock: Test whether the buffer is uptodate
+* @bh: struct buffer_head
+*
+* Return true if the buffer is up-to-date and false,
+* with the buffer locked, if not.
+*/
+int bh_uptodate_or_lock(struct buffer_head *bh)
+{
+ if (!buffer_uptodate(bh)) {
+ lock_buffer(bh);
+ if (!buffer_uptodate(bh))
+ return 0;
+ unlock_buffer(bh);
+ }
+ return 1;
+}
+
+/**
+* bh_submit_read: Submit a locked buffer for reading
+* @bh: struct buffer_head
+*
+* Returns a negative error
+*/
+int bh_submit_read(struct buffer_head *bh)
+{
+ if (!buffer_locked(bh))
+ lock_buffer(bh);
+ if (buffer_uptodate(bh))
+ return 0;
+ get_bh(bh);
+ bh->b_end_io = end_buffer_read_sync;
+ submit_bh(READ, bh);
+ wait_on_buffer(bh);
+ if (buffer_uptodate(bh))
+ return 0;
+ return -EIO;
+}
+
+static int ext3_valid_block_bitmap(struct super_block *sb,
+ struct ext3_group_desc *desc,
+ unsigned int block_group,
+ struct buffer_head *bh)
+{
+ unsigned long long offset;
+ unsigned long long next_zero_bit;
+ unsigned long long bitmap_blk;
+ unsigned long long group_first_block;
+
+ group_first_block = ext3_group_first_block_no(sb, block_group);
+
+ /* check whether block bitmap block number is set */
+ bitmap_blk = le32_to_cpu(desc->bg_block_bitmap);
+ offset = bitmap_blk - group_first_block;
+ if (!ext3_test_bit(offset, bh->b_data))
+ /* bad block bitmap */
+ goto err_out;
+
+ /* check whether the inode bitmap block number is set */
+ bitmap_blk = le32_to_cpu(desc->bg_inode_bitmap);
+ offset = bitmap_blk - group_first_block;
+ if (!ext3_test_bit(offset, bh->b_data))
+ /* bad block bitmap */
+ goto err_out;
+
+ /* check whether the inode table block number is set */
+ bitmap_blk = le32_to_cpu(desc->bg_inode_table);
+ offset = bitmap_blk - group_first_block;
+ next_zero_bit = ext3_find_next_zero_bit(bh->b_data,
+ offset + EXT3_SB(sb)->s_itb_per_group,
+ offset);
+ if (next_zero_bit >= offset + EXT3_SB(sb)->s_itb_per_group)
+ /* good bitmap for inode tables */
+ return 1;
+
+err_out:
+ ext3_error(sb, __FUNCTION__,
+ "Invalid block bitmap - "
+ "block_group = %d, block = %llu",
+ block_group, bitmap_blk);
+ return 0;
+}
+
+/**
+ * read_block_bitmap()
+ * @sb: super block
+ * @block_group: given block group
+ *
+ * Read the bitmap for a given block_group,and validate the
+ * bits for block/inode/inode tables are set in the bitmaps.
*
* Return buffer_head on success or NULL in case of failure.
*/
@@ -155,29 +242,42 @@ read_block_bitmap(struct super_block *sb
{
struct ext3_group_desc * desc;
struct buffer_head * bh = NULL;
+ unsigned long long bitmap_blk;
desc = ext3_get_group_desc (sb, block_group, NULL);
if (!desc)
- goto error_out;
+ return NULL;
+ bitmap_blk = desc->bg_block_bitmap;
+ bh = sb_getblk(sb, bitmap_blk);
+ if (unlikely(!bh)) {
+ ext3_error(sb, __FUNCTION__,
+ "Can not read block bitmap - "
+ "block group = %d, block_bitmap = %llu",
+ (int)block_group, bitmap_blk);
+ return NULL;
+ }
+ if (bh_uptodate_or_lock(bh))
+ return bh;
+
if (desc->bg_flags & cpu_to_le16(EXT3_BG_BLOCK_UNINIT)) {
- bh = sb_getblk(sb, le32_to_cpu(desc->bg_block_bitmap));
- if (!buffer_uptodate(bh)) {
- lock_buffer(bh);
- if (!buffer_uptodate(bh)) {
- ext3_init_block_bitmap(sb, bh,block_group,desc);
- set_buffer_uptodate(bh);
- }
- unlock_buffer(bh);
- }
- } else {
- bh = sb_bread(sb, le32_to_cpu(desc->bg_block_bitmap));
+ ext3_init_block_bitmap(sb, bh, block_group, desc);
+ set_buffer_uptodate(bh);
+ unlock_buffer(bh);
+ return bh;
+ }
+ if (bh_submit_read(bh) < 0) {
+ brelse(bh);
+ ext3_error(sb, __FUNCTION__,
+ "Cannot read block bitmap - "
+ "block group = %d block_bitmap = %llu",
+ (int)block_group, bitmap_blk);
+ return NULL;
}
- if (!bh)
- ext3_error (sb, "read_block_bitmap",
- "Cannot read block bitmap - "
- "block_group = %d, block_bitmap = %u",
- block_group, le32_to_cpu(desc->bg_block_bitmap));
-error_out:
+ if (!ext3_valid_block_bitmap(sb, desc, block_group, bh)) {
+ brelse(bh);
+ return NULL;
+ }
+
return bh;
}
/*
Index: linux-stage/include/linux/ext3_fs.h
===================================================================
--- linux-stage.orig/include/linux/ext3_fs.h
+++ linux-stage/include/linux/ext3_fs.h
@@ -872,6 +872,14 @@ struct dir_private_info {
__u32 next_hash;
};
+/* calculate the first block number of the group */
+static inline long long
+ext3_group_first_block_no(struct super_block *sb, unsigned long group_no)
+{
+ return group_no * (long long)EXT3_BLOCKS_PER_GROUP(sb) +
+ le32_to_cpu(EXT3_SB(sb)->s_es->s_first_data_block);
+}
+
/*
* Special error return code only used by dx_probe() and its callers.
*/
......@@ -21,3 +21,4 @@ ext3-statfs-2.6-rhel5.patch
ext3-lookup-dotdot-2.6.9.patch
ext3-max-dir-size.patch
ext3-print-inum-in-htree-warning.patch
ext3-block-bitmap-validation-2.6-rhel5.patch
......@@ -25,3 +25,4 @@ ext3-statfs-2.6-sles10.patch
ext3-lookup-dotdot-2.6.9.patch
ext3-max-dir-size.patch
ext3-print-inum-in-htree-warning.patch
ext3-block-bitmap-validation-2.6-sles10.patch
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