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SubjectRe: [PATCH 12/16] ext4: Calculate and verify checksums of directory leaf blocks
On Fri, Sep 02, 2011 at 02:52:32PM -0600, Andreas Dilger wrote:
> On 2011-09-02, at 12:57 PM, Darrick J. Wong wrote:
> > On Thu, Sep 01, 2011 at 01:36:50AM -0600, Andreas Dilger wrote:
> >> On 2011-08-31, at 6:31 PM, Darrick J. Wong wrote:
> >>> /*
> >>> + * This is a bogus directory entry at the end of each leaf block that
> >>> + * records checksums.
> >>> + */
> >>> +struct ext4_dir_entry_tail {
> >>> + __le32 reserved_zero1; /* Pretend to be unused */
> >>> + __le16 rec_len; /* 12 */
> >>> + __le16 reserved_zero2; /* Zero name length */
> >>> + __le32 checksum; /* crc32c(uuid+inum+dirblock) */
> >>> +};
> >>
> >> Since this field is stored inline with existing directory entries, it
> >> may make sense to also add a magic value to this entry (preferably one
> >> with non-ASCII values) so that it can be distinguished from an empty
> >> dirent that happens to be at the end of the block.
> >
> > I could set the file type to 0xDE since currently there's only 8 file types
> > defined.
>
> This seems possible, since the dirent is empty the value stored in
> file_type is largely irrelevant.
>
> It also definitely makes sense to declare this as an "ext4_dir_entry_2"
> style structure, since this is the only dirent that is used in the ext4
> code. I'd be happy if you also deleted the ext4_dir_entry structure
> definition from ext4.h, since it is unused and only serves to potentially
> cause confusion if used accidentally.

Perhaps, but as a separate patchset.

> You could do the whole sanity check for this tail dirent by treating
> it as a 64-bit magic number:
>
> struct ext4_dirent_tail {
> union {
> struct {
> __le32 inode_zero; /* Pretend to be unused */
> __le16 rec_len; /* 12 */
> __u8 name_zero; /* Zero name length */
> __u8 file_type; /* 0xde */
> };
> __le64 det_magic;
> };
> __le32 det_checksum;
> };
>
> #define EXT4_DIRENT_TAIL_MAGIC 0xde000c000000
>
> That said, looking at this magic number doesn't give me a world of
> confidence that it will not be accidentally duplicated, though at
> the same time consecutive NUL bytes do not happen in filenames, so
> maybe it is OK.

det_checksum sits where the filename usually goes, so that won't be the case.
On the other hand, there are very few zero-length directory entries, so we're
probably ok.

--D
>
> >>> /* checksumming functions */
> >>> +static struct ext4_dir_entry_tail *get_dirent_tail(struct inode *inode,
> >>> + struct ext4_dir_entry *de)
> >>> +{
> >>> + struct ext4_dir_entry *d, *top;
> >>> + struct ext4_dir_entry_tail *t;
> >>> +
> >>> + d = de;
> >>> + top = (struct ext4_dir_entry *)(((void *)de) +
> >>> + (EXT4_BLOCK_SIZE(inode->i_sb) -
> >>> + sizeof(struct ext4_dir_entry_tail)));
> >>> + while (d < top && d->rec_len)
> >>> + d = (struct ext4_dir_entry *)(((void *)d) +
> >>> + le16_to_cpu(d->rec_len));
> >>
> >> Calling get_dirent_tail() is fairly expensive, because it has to walk
> >> the whole directory block each time. When filling a block it would
> >> be O(n^2) for the number of entries in the block.
> >>
> >> It would be more efficient to just cast the end of the directory block
> >> to the ext4_dir_entry_tail and check its validity, which is especially
> >> easy if there is a magic value in it.
> >>
> >>> + if (d != top)
> >>> + return NULL;
> >>> +
> >>> + t = (struct ext4_dir_entry_tail *)d;
> >>> + if (t->reserved_zero1 ||
> >>> + le16_to_cpu(t->rec_len) != sizeof(struct ext4_dir_entry_tail) ||
> >>> + t->reserved_zero2)
> >>
> >> I'd prefer these reserved_zero[12] fields be explicitly compared to zero
> >> instead of treated as boolean values.
> >
> > Ok.
> >
> >>> + return NULL;
> >>> +
> >>> + return t;
> >>> +}
> >>> +
> >>> +static __le32 ext4_dirent_csum(struct inode *inode,
> >>> + struct ext4_dir_entry *dirent)
> >>> +{
> >>> + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
> >>> + struct ext4_dir_entry_tail *t;
> >>> + __le32 inum = cpu_to_le32(inode->i_ino);
> >>> + int size;
> >>> + __u32 crc = 0;
> >>> +
> >>> + if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
> >>> + EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
> >>> + return 0;
> >>> +
> >>> + t = get_dirent_tail(inode, dirent);
> >>
> >>> + if (!t)
> >>> + return 0;
> >>> +
> >>> + size = (void *)t - (void *)dirent;
> >>> + crc = crc32c_le(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
> >>> + crc = crc32c_le(crc, (__u8 *)&inum, sizeof(inum));
> >>
> >> Based on the number of times that the s_uuid+inum checksum is used in this
> >> code, and since it is constant for the life of the inode, it probably
> >> makes sense to precompute it and store it in ext4_inode_info.
> >
> > Agreed.
> >
> >> Also, now that I think about it, these checksums that contain the inum
> >> should also contain i_generation, so that there is no confusion with
> >> accessing old blocks on disk.
> >
> > i_generation only gets updated when inodes are created or SETVERSION ioctl is
> > called, correct? I guess it wouldn't be too difficult to rewrite all file
> > metadata, though it could get a little expensive.
>
> I don't think SETVERSION is used in any regular cases (at least I'm not
> aware of any applications/tools that use it). Note that, despite the
> name, this sets the i_generation field and not the NFSv4 i_version field,
> so it should be constant for the life of the inode. In the short term you
> could just disable SETVERSION on an inode if checksums are enabled, and
> see if anyone complains about it at all.
>
> Cheers, Andreas
>
> >>> + crc = crc32c_le(crc, (__u8 *)dirent, size);
> >>> + return cpu_to_le32(crc);
> >>> +}
> >>> +
> >>> +int ext4_dirent_csum_verify(struct inode *inode, struct ext4_dir_entry *dirent)
> >>> +{
> >>> + struct ext4_dir_entry_tail *t;
> >>> +
> >>> + if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
> >>> + EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
> >>> + return 1;
> >>> +
> >>> + t = get_dirent_tail(inode, dirent);
> >>> + if (!t) {
> >>> + EXT4_ERROR_INODE(inode, "metadata_csum set but no space in dir "
> >>> + "leaf for checksum. Please run e2fsck -D.");
> >>> + return 0;
> >>> + }
> >>
> >> I don't think this should necessarily be considered an error. That
> >> there is no space in the directory block is not a sign of corruption.
> >
> > I was trying to steer users towards running fsck, which will notice the
> > lack of space and rebuild the dir. With a somewhat large mallet. :)
>
> Yes, but this would cause a service interruption because the filesystem
> will be mounted read-only and/or panic the kernel, which is not justified
> for a situation which is legitimately possible and does not indicate data
> corruption of the filesystem.
>
> >>> +
> >>> + if (t->checksum != ext4_dirent_csum(inode, dirent))
> >>> + return 0;
> >>> +
> >>> + return 1;
> >>> +}
> >>> +
> >>> +static void ext4_dirent_csum_set(struct inode *inode,
> >>> + struct ext4_dir_entry *dirent)
> >>> +{
> >>> + struct ext4_dir_entry_tail *t;
> >>> +
> >>> + if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
> >>> + EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
> >>> + return;
> >>> +
> >>> + t = get_dirent_tail(inode, dirent);
> >>> + if (!t) {
> >>> + EXT4_ERROR_INODE(inode, "metadata_csum set but no space in dir "
> >>> + "leaf for checksum. Please run e2fsck -D.");
> >>> + return;
> >>> + }
> >>> +
> >>> + t->checksum = ext4_dirent_csum(inode, dirent);
> >>> +}
> >>> +
> >>> +static inline int ext4_handle_dirty_dirent_node(handle_t *handle,
> >>> + struct inode *inode,
> >>> + struct buffer_head *bh)
> >>> +{
> >>> + ext4_dirent_csum_set(inode, (struct ext4_dir_entry *)bh->b_data);
> >>> + return ext4_handle_dirty_metadata(handle, inode, bh);
> >>> +}
> >>> +
> >>> static struct dx_countlimit *get_dx_countlimit(struct inode *inode,
> >>> struct ext4_dir_entry *dirent,
> >>> int *offset)
> >>> @@ -748,6 +846,11 @@ static int htree_dirblock_to_tree(struct file *dir_file,
> >>> if (!(bh = ext4_bread (NULL, dir, block, 0, &err)))
> >>> return err;
> >>>
> >>> + if (!buffer_verified(bh) &&
> >>> + !ext4_dirent_csum_verify(dir, (struct ext4_dir_entry *)bh->b_data))
> >>> + return -EIO;
> >>> + set_buffer_verified(bh);
> >>> +
> >>> de = (struct ext4_dir_entry_2 *) bh->b_data;
> >>
> >> You might as well set de before calling ext4_dirent_csum_verify() to avoid
> >> having another unsightly cast.
> >
> > Ok.
> >
> >>> top = (struct ext4_dir_entry_2 *) ((char *) de +
> >>> dir->i_sb->s_blocksize -
> >>> @@ -1106,6 +1209,15 @@ restart:
> >>> brelse(bh);
> >>> goto next;
> >>> }
> >>> + if (!buffer_verified(bh) &&
> >>> + !ext4_dirent_csum_verify(dir,
> >>> + (struct ext4_dir_entry *)bh->b_data)) {
> >>> + EXT4_ERROR_INODE(dir, "checksumming directory "
> >>> + "block %lu", (unsigned long)block);
> >>> + brelse(bh);
> >>> + goto next;
> >>> + }
> >>> + set_buffer_verified(bh);
> >>> i = search_dirblock(bh, dir, d_name,
> >>> block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
> >>> if (i == 1) {
> >>> @@ -1157,6 +1269,16 @@ static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct q
> >>> if (!(bh = ext4_bread(NULL, dir, block, 0, err)))
> >>> goto errout;
> >>>
> >>> + if (!buffer_verified(bh) &&
> >>> + !ext4_dirent_csum_verify(dir,
> >>> + (struct ext4_dir_entry *)bh->b_data)) {
> >>> + EXT4_ERROR_INODE(dir, "checksumming directory "
> >>> + "block %lu", (unsigned long)block);
> >>> + brelse(bh);
> >>> + *err = -EIO;
> >>> + goto errout;
> >>> + }
> >>> + set_buffer_verified(bh);
> >>> retval = search_dirblock(bh, dir, d_name,
> >>> block << EXT4_BLOCK_SIZE_BITS(sb),
> >>> res_dir);
> >>> @@ -1329,8 +1451,14 @@ static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
> >>> char *data1 = (*bh)->b_data, *data2;
> >>> unsigned split, move, size;
> >>> struct ext4_dir_entry_2 *de = NULL, *de2;
> >>> + struct ext4_dir_entry_tail *t;
> >>> + int csum_size = 0;
> >>> int err = 0, i;
> >>>
> >>> + if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
> >>> + EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
> >>> + csum_size = sizeof(struct ext4_dir_entry_tail);
> >>> +
> >>> bh2 = ext4_append (handle, dir, &newblock, &err);
> >>> if (!(bh2)) {
> >>> brelse(*bh);
> >>> @@ -1377,10 +1505,24 @@ static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
> >>> /* Fancy dance to stay within two buffers */
> >>> de2 = dx_move_dirents(data1, data2, map + split, count - split, blocksize);
> >>> de = dx_pack_dirents(data1, blocksize);
> >>> - de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de,
> >>> + de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
> >>> + (char *) de,
> >>> blocksize);
> >>
> >> (style) This should be "(char *)de, blocksize);"
> >>
> >>> - de2->rec_len = ext4_rec_len_to_disk(data2 + blocksize - (char *) de2,
> >>> + de2->rec_len = ext4_rec_len_to_disk(data2 + (blocksize - csum_size) -
> >>> + (char *) de2,
> >>> blocksize);
> >>
> >> (style) likewise
> >>
> >>> + if (csum_size) {
> >>> + t = (struct ext4_dir_entry_tail *)(data2 +
> >>> + (blocksize - csum_size));
> >>> + memset(t, 0, csum_size);
> >>> + t->rec_len = ext4_rec_len_to_disk(csum_size, blocksize);
> >>> +
> >>> + t = (struct ext4_dir_entry_tail *)(data1 +
> >>> + (blocksize - csum_size));
> >>> + memset(t, 0, csum_size);
> >>> + t->rec_len = ext4_rec_len_to_disk(csum_size, blocksize);
> >>> + }
> >>> +
> >>> dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data1, blocksize, 1));
> >>> dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data2, blocksize, 1));
> >>>
> >>> @@ -1391,7 +1533,7 @@ static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
> >>> de = de2;
> >>> }
> >>> dx_insert_block(frame, hash2 + continued, newblock);
> >>> - err = ext4_handle_dirty_metadata(handle, dir, bh2);
> >>> + err = ext4_handle_dirty_dirent_node(handle, dir, bh2);
> >>> if (err)
> >>> goto journal_error;
> >>> err = ext4_handle_dirty_dx_node(handle, dir, frame->bh);
> >>> @@ -1431,11 +1573,16 @@ static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
> >>> unsigned short reclen;
> >>> int nlen, rlen, err;
> >>> char *top;
> >>> + int csum_size = 0;
> >>> +
> >>> + if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
> >>> + EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
> >>> + csum_size = sizeof(struct ext4_dir_entry_tail);
> >>>
> >>> reclen = EXT4_DIR_REC_LEN(namelen);
> >>> if (!de) {
> >>> de = (struct ext4_dir_entry_2 *)bh->b_data;
> >>> - top = bh->b_data + blocksize - reclen;
> >>> + top = bh->b_data + (blocksize - csum_size) - reclen;
> >>> while ((char *) de <= top) {
> >>> if (ext4_check_dir_entry(dir, NULL, de, bh, offset))
> >>> return -EIO;
> >>> @@ -1491,7 +1638,7 @@ static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
> >>> dir->i_version++;
> >>> ext4_mark_inode_dirty(handle, dir);
> >>> BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
> >>> - err = ext4_handle_dirty_metadata(handle, dir, bh);
> >>> + err = ext4_handle_dirty_dirent_node(handle, dir, bh);
> >>> if (err)
> >>> ext4_std_error(dir->i_sb, err);
> >>> return 0;
> >>> @@ -1512,6 +1659,7 @@ static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
> >>> struct dx_frame frames[2], *frame;
> >>> struct dx_entry *entries;
> >>> struct ext4_dir_entry_2 *de, *de2;
> >>> + struct ext4_dir_entry_tail *t;
> >>> char *data1, *top;
> >>> unsigned len;
> >>> int retval;
> >>> @@ -1519,6 +1667,11 @@ static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
> >>> struct dx_hash_info hinfo;
> >>> ext4_lblk_t block;
> >>> struct fake_dirent *fde;
> >>> + int csum_size = 0;
> >>> +
> >>> + if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
> >>> + EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
> >>> + csum_size = sizeof(struct ext4_dir_entry_tail);
> >>>
> >>> blocksize = dir->i_sb->s_blocksize;
> >>> dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
> >>> @@ -1539,7 +1692,7 @@ static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
> >>> brelse(bh);
> >>> return -EIO;
> >>> }
> >>> - len = ((char *) root) + blocksize - (char *) de;
> >>> + len = ((char *) root) + (blocksize - csum_size) - (char *) de;
> >>
> >> (style) "(char *)root)" and "(char *)de".
> >>
> >>> /* Allocate new block for the 0th block's dirents */
> >>> bh2 = ext4_append(handle, dir, &block, &retval);
> >>> @@ -1555,8 +1708,17 @@ static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
> >>> top = data1 + len;
> >>> while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
> >>> de = de2;
> >>> - de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de,
> >>> + de->rec_len = ext4_rec_len_to_disk(data1 + (blocksize - csum_size) -
> >>> + (char *) de,
> >>> blocksize);
> >>
> >> Likewise.
> >
> > Ok, I'll fix the style complaints. Should checkpatch find these things?
> >
> > --D
> >
> >>> +
> >>> + if (csum_size) {
> >>> + t = (struct ext4_dir_entry_tail *)(data1 +
> >>> + (blocksize - csum_size));
> >>> + memset(t, 0, csum_size);
> >>> + t->rec_len = ext4_rec_len_to_disk(csum_size, blocksize);
> >>> + }
> >>> +
> >>> /* Initialize the root; the dot dirents already exist */
> >>> de = (struct ext4_dir_entry_2 *) (&root->dotdot);
> >>> de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
> >>> @@ -1582,7 +1744,7 @@ static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
> >>> bh = bh2;
> >>>
> >>> ext4_handle_dirty_dx_node(handle, dir, frame->bh);
> >>> - ext4_handle_dirty_metadata(handle, dir, bh);
> >>> + ext4_handle_dirty_dirent_node(handle, dir, bh);
> >>>
> >>> de = do_split(handle,dir, &bh, frame, &hinfo, &retval);
> >>> if (!de) {
> >>> @@ -1618,11 +1780,17 @@ static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
> >>> struct inode *dir = dentry->d_parent->d_inode;
> >>> struct buffer_head *bh;
> >>> struct ext4_dir_entry_2 *de;
> >>> + struct ext4_dir_entry_tail *t;
> >>> struct super_block *sb;
> >>> int retval;
> >>> int dx_fallback=0;
> >>> unsigned blocksize;
> >>> ext4_lblk_t block, blocks;
> >>> + int csum_size = 0;
> >>> +
> >>> + if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
> >>> + EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
> >>> + csum_size = sizeof(struct ext4_dir_entry_tail);
> >>>
> >>> sb = dir->i_sb;
> >>> blocksize = sb->s_blocksize;
> >>> @@ -1641,6 +1809,11 @@ static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
> >>> bh = ext4_bread(handle, dir, block, 0, &retval);
> >>> if(!bh)
> >>> return retval;
> >>> + if (!buffer_verified(bh) &&
> >>> + !ext4_dirent_csum_verify(dir,
> >>> + (struct ext4_dir_entry *)bh->b_data))
> >>> + return -EIO;
> >>> + set_buffer_verified(bh);
> >>> retval = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
> >>> if (retval != -ENOSPC) {
> >>> brelse(bh);
> >>> @@ -1657,7 +1830,15 @@ static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
> >>> return retval;
> >>> de = (struct ext4_dir_entry_2 *) bh->b_data;
> >>> de->inode = 0;
> >>> - de->rec_len = ext4_rec_len_to_disk(blocksize, blocksize);
> >>> + de->rec_len = ext4_rec_len_to_disk(blocksize - csum_size, blocksize);
> >>> +
> >>> + if (csum_size) {
> >>> + t = (struct ext4_dir_entry_tail *)(((void *)bh->b_data) +
> >>> + (blocksize - csum_size));
> >>> + memset(t, 0, csum_size);
> >>> + t->rec_len = ext4_rec_len_to_disk(csum_size, blocksize);
> >>> + }
> >>> +
> >>> retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
> >>> brelse(bh);
> >>> if (retval == 0)
> >>> @@ -1689,6 +1870,11 @@ static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
> >>> if (!(bh = ext4_bread(handle,dir, dx_get_block(frame->at), 0, &err)))
> >>> goto cleanup;
> >>>
> >>> + if (!buffer_verified(bh) &&
> >>> + !ext4_dirent_csum_verify(dir, (struct ext4_dir_entry *)bh->b_data))
> >>> + goto journal_error;
> >>> + set_buffer_verified(bh);
> >>> +
> >>> BUFFER_TRACE(bh, "get_write_access");
> >>> err = ext4_journal_get_write_access(handle, bh);
> >>> if (err)
> >>> @@ -1814,12 +2000,17 @@ static int ext4_delete_entry(handle_t *handle,
> >>> {
> >>> struct ext4_dir_entry_2 *de, *pde;
> >>> unsigned int blocksize = dir->i_sb->s_blocksize;
> >>> + int csum_size = 0;
> >>> int i, err;
> >>>
> >>> + if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
> >>> + EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
> >>> + csum_size = sizeof(struct ext4_dir_entry_tail);
> >>> +
> >>> i = 0;
> >>> pde = NULL;
> >>> de = (struct ext4_dir_entry_2 *) bh->b_data;
> >>> - while (i < bh->b_size) {
> >>> + while (i < bh->b_size - csum_size) {
> >>> if (ext4_check_dir_entry(dir, NULL, de, bh, i))
> >>> return -EIO;
> >>> if (de == de_del) {
> >>> @@ -1840,7 +2031,7 @@ static int ext4_delete_entry(handle_t *handle,
> >>> de->inode = 0;
> >>> dir->i_version++;
> >>> BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
> >>> - err = ext4_handle_dirty_metadata(handle, dir, bh);
> >>> + err = ext4_handle_dirty_dirent_node(handle, dir, bh);
> >>> if (unlikely(err)) {
> >>> ext4_std_error(dir->i_sb, err);
> >>> return err;
> >>> @@ -1983,9 +2174,15 @@ static int ext4_mkdir(struct inode *dir, struct dentry *dentry, int mode)
> >>> struct inode *inode;
> >>> struct buffer_head *dir_block = NULL;
> >>> struct ext4_dir_entry_2 *de;
> >>> + struct ext4_dir_entry_tail *t;
> >>> unsigned int blocksize = dir->i_sb->s_blocksize;
> >>> + int csum_size = 0;
> >>> int err, retries = 0;
> >>>
> >>> + if (EXT4_HAS_RO_COMPAT_FEATURE(dir->i_sb,
> >>> + EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
> >>> + csum_size = sizeof(struct ext4_dir_entry_tail);
> >>> +
> >>> if (EXT4_DIR_LINK_MAX(dir))
> >>> return -EMLINK;
> >>>
> >>> @@ -2026,16 +2223,26 @@ retry:
> >>> ext4_set_de_type(dir->i_sb, de, S_IFDIR);
> >>> de = ext4_next_entry(de, blocksize);
> >>> de->inode = cpu_to_le32(dir->i_ino);
> >>> - de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(1),
> >>> + de->rec_len = ext4_rec_len_to_disk(blocksize -
> >>> + (csum_size + EXT4_DIR_REC_LEN(1)),
> >>> blocksize);
> >>> de->name_len = 2;
> >>> strcpy(de->name, "..");
> >>> ext4_set_de_type(dir->i_sb, de, S_IFDIR);
> >>> inode->i_nlink = 2;
> >>> +
> >>> + if (csum_size) {
> >>> + t = (struct ext4_dir_entry_tail *)(((void *)dir_block->b_data) +
> >>> + (blocksize - csum_size));
> >>> + memset(t, 0, csum_size);
> >>> + t->rec_len = ext4_rec_len_to_disk(csum_size, blocksize);
> >>> + }
> >>> +
> >>> BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
> >>> - err = ext4_handle_dirty_metadata(handle, inode, dir_block);
> >>> + err = ext4_handle_dirty_dirent_node(handle, inode, dir_block);
> >>> if (err)
> >>> goto out_clear_inode;
> >>> + set_buffer_verified(dir_block);
> >>> err = ext4_mark_inode_dirty(handle, inode);
> >>> if (!err)
> >>> err = ext4_add_entry(handle, dentry, inode);
> >>> @@ -2085,6 +2292,14 @@ static int empty_dir(struct inode *inode)
> >>> inode->i_ino);
> >>> return 1;
> >>> }
> >>> + if (!buffer_verified(bh) &&
> >>> + !ext4_dirent_csum_verify(inode,
> >>> + (struct ext4_dir_entry *)bh->b_data)) {
> >>> + EXT4_ERROR_INODE(inode, "checksum error reading directory "
> >>> + "lblock 0");
> >>> + return -EIO;
> >>> + }
> >>> + set_buffer_verified(bh);
> >>> de = (struct ext4_dir_entry_2 *) bh->b_data;
> >>> de1 = ext4_next_entry(de, sb->s_blocksize);
> >>> if (le32_to_cpu(de->inode) != inode->i_ino ||
> >>> @@ -2116,6 +2331,14 @@ static int empty_dir(struct inode *inode)
> >>> offset += sb->s_blocksize;
> >>> continue;
> >>> }
> >>> + if (!buffer_verified(bh) &&
> >>> + !ext4_dirent_csum_verify(inode,
> >>> + (struct ext4_dir_entry *)bh->b_data)) {
> >>> + EXT4_ERROR_INODE(inode, "checksum error "
> >>> + "reading directory lblock 0");
> >>> + return -EIO;
> >>> + }
> >>> + set_buffer_verified(bh);
> >>> de = (struct ext4_dir_entry_2 *) bh->b_data;
> >>> }
> >>> if (ext4_check_dir_entry(inode, NULL, de, bh, offset)) {
> >>> @@ -2616,6 +2839,11 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
> >>> dir_bh = ext4_bread(handle, old_inode, 0, 0, &retval);
> >>> if (!dir_bh)
> >>> goto end_rename;
> >>> + if (!buffer_verified(dir_bh) &&
> >>> + !ext4_dirent_csum_verify(old_inode,
> >>> + (struct ext4_dir_entry *)dir_bh->b_data))
> >>> + goto end_rename;
> >>> + set_buffer_verified(dir_bh);
> >>> if (le32_to_cpu(PARENT_INO(dir_bh->b_data,
> >>> old_dir->i_sb->s_blocksize)) != old_dir->i_ino)
> >>> goto end_rename;
> >>> @@ -2646,7 +2874,7 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
> >>> ext4_current_time(new_dir);
> >>> ext4_mark_inode_dirty(handle, new_dir);
> >>> BUFFER_TRACE(new_bh, "call ext4_handle_dirty_metadata");
> >>> - retval = ext4_handle_dirty_metadata(handle, new_dir, new_bh);
> >>> + retval = ext4_handle_dirty_dirent_node(handle, new_dir, new_bh);
> >>> if (unlikely(retval)) {
> >>> ext4_std_error(new_dir->i_sb, retval);
> >>> goto end_rename;
> >>> @@ -2700,7 +2928,8 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
> >>> PARENT_INO(dir_bh->b_data, new_dir->i_sb->s_blocksize) =
> >>> cpu_to_le32(new_dir->i_ino);
> >>> BUFFER_TRACE(dir_bh, "call ext4_handle_dirty_metadata");
> >>> - retval = ext4_handle_dirty_metadata(handle, old_inode, dir_bh);
> >>> + retval = ext4_handle_dirty_dirent_node(handle, old_inode,
> >>> + dir_bh);
> >>> if (retval) {
> >>> ext4_std_error(old_dir->i_sb, retval);
> >>> goto end_rename;
> >>>
> >>
>
> --
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  Last update: 2011-09-05 20:33    [from the cache]
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