![Theodore Ts'o](/assets/img/avatar_default.png)
The function ext4_handle_dirty_super() was calculating the superblock on the wrong block data. As a result, when the superblock is modified while it is mounted (most commonly, when inodes are added or removed from the orphan list), the superblock checksum would be wrong. We didn't notice because the superblock *was* being correctly calculated in ext4_commit_super(), and this would get called when the file system was unmounted. So the problem only became obvious if the system crashed while the file system was mounted. Fix this by removing the poorly designed function signature for ext4_superblock_csum_set(); if it only took a single argument, the pointer to a struct superblock, the ambiguity which caused this mistake would have been impossible. Reported-by: George Spelvin <linux@horizon.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: stable@vger.kernel.org
156 lines
4 KiB
C
156 lines
4 KiB
C
/*
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* Interface between ext4 and JBD
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*/
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#include "ext4_jbd2.h"
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#include <trace/events/ext4.h>
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int __ext4_journal_get_write_access(const char *where, unsigned int line,
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handle_t *handle, struct buffer_head *bh)
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{
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int err = 0;
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if (ext4_handle_valid(handle)) {
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err = jbd2_journal_get_write_access(handle, bh);
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if (err)
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ext4_journal_abort_handle(where, line, __func__, bh,
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handle, err);
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}
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return err;
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}
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/*
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* The ext4 forget function must perform a revoke if we are freeing data
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* which has been journaled. Metadata (eg. indirect blocks) must be
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* revoked in all cases.
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*
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* "bh" may be NULL: a metadata block may have been freed from memory
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* but there may still be a record of it in the journal, and that record
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* still needs to be revoked.
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*
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* If the handle isn't valid we're not journaling, but we still need to
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* call into ext4_journal_revoke() to put the buffer head.
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*/
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int __ext4_forget(const char *where, unsigned int line, handle_t *handle,
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int is_metadata, struct inode *inode,
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struct buffer_head *bh, ext4_fsblk_t blocknr)
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{
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int err;
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might_sleep();
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trace_ext4_forget(inode, is_metadata, blocknr);
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BUFFER_TRACE(bh, "enter");
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jbd_debug(4, "forgetting bh %p: is_metadata = %d, mode %o, "
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"data mode %x\n",
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bh, is_metadata, inode->i_mode,
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test_opt(inode->i_sb, DATA_FLAGS));
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/* In the no journal case, we can just do a bforget and return */
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if (!ext4_handle_valid(handle)) {
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bforget(bh);
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return 0;
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}
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/* Never use the revoke function if we are doing full data
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* journaling: there is no need to, and a V1 superblock won't
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* support it. Otherwise, only skip the revoke on un-journaled
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* data blocks. */
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if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA ||
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(!is_metadata && !ext4_should_journal_data(inode))) {
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if (bh) {
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BUFFER_TRACE(bh, "call jbd2_journal_forget");
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err = jbd2_journal_forget(handle, bh);
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if (err)
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ext4_journal_abort_handle(where, line, __func__,
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bh, handle, err);
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return err;
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}
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return 0;
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}
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/*
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* data!=journal && (is_metadata || should_journal_data(inode))
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*/
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BUFFER_TRACE(bh, "call jbd2_journal_revoke");
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err = jbd2_journal_revoke(handle, blocknr, bh);
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if (err) {
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ext4_journal_abort_handle(where, line, __func__,
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bh, handle, err);
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__ext4_abort(inode->i_sb, where, line,
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"error %d when attempting revoke", err);
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}
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BUFFER_TRACE(bh, "exit");
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return err;
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}
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int __ext4_journal_get_create_access(const char *where, unsigned int line,
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handle_t *handle, struct buffer_head *bh)
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{
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int err = 0;
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if (ext4_handle_valid(handle)) {
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err = jbd2_journal_get_create_access(handle, bh);
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if (err)
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ext4_journal_abort_handle(where, line, __func__,
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bh, handle, err);
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}
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return err;
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}
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int __ext4_handle_dirty_metadata(const char *where, unsigned int line,
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handle_t *handle, struct inode *inode,
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struct buffer_head *bh)
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{
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int err = 0;
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if (ext4_handle_valid(handle)) {
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err = jbd2_journal_dirty_metadata(handle, bh);
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if (err) {
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/* Errors can only happen if there is a bug */
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handle->h_err = err;
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__ext4_journal_stop(where, line, handle);
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}
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} else {
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if (inode)
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mark_buffer_dirty_inode(bh, inode);
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else
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mark_buffer_dirty(bh);
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if (inode && inode_needs_sync(inode)) {
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sync_dirty_buffer(bh);
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if (buffer_req(bh) && !buffer_uptodate(bh)) {
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struct ext4_super_block *es;
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es = EXT4_SB(inode->i_sb)->s_es;
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es->s_last_error_block =
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cpu_to_le64(bh->b_blocknr);
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ext4_error_inode(inode, where, line,
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bh->b_blocknr,
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"IO error syncing itable block");
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err = -EIO;
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}
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}
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}
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return err;
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}
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int __ext4_handle_dirty_super(const char *where, unsigned int line,
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handle_t *handle, struct super_block *sb)
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{
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struct buffer_head *bh = EXT4_SB(sb)->s_sbh;
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int err = 0;
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ext4_superblock_csum_set(sb);
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if (ext4_handle_valid(handle)) {
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err = jbd2_journal_dirty_metadata(handle, bh);
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if (err)
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ext4_journal_abort_handle(where, line, __func__,
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bh, handle, err);
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} else
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mark_buffer_dirty(bh);
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return err;
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}
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