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Message-Id: <1372009468-11651-1-git-send-email-tytso@mit.edu>
Date: Sun, 23 Jun 2013 13:44:28 -0400
From: Theodore Ts'o <tytso@....edu>
To: Ext4 Developers List <linux-ext4@...r.kernel.org>
Cc: jbacik@...ionio.com, younger.liu@...wei.com,
Theodore Ts'o <tytso@....edu>, Jan Kara <jack@...e.cz>
Subject: [PATCH] jbd2: invalidate handle if jbd2_journal_restart() fails
If jbd2_journal_restart() fails the handle will have been disconnected
from the current transaction. In this situation, the handle must not
be used for for any jbd2 function other than jbd2_journal_stop().
Enforce this with by treating a handle which has a NULL transaction
pointer as an aborted handle, and issue a kernel warning if
jbd2_journal_extent(), jbd2_journal_get_write_access(),
jbd2_journal_dirty_metadata(), etc. is called with an invalid handle.
This commit also fixes a bug where jbd2_journal_stop() would trip over
a kernel jbd2 assertion check when trying to free an invalid handle.
Also move the responsibility of setting current->journal_info to
start_this_handle(), simplifying the three users of this function.
Signed-off-by: "Theodore Ts'o" <tytso@....edu>
Reported-by: Younger Liu <younger.liu@...wei.com>
Cc: Jan Kara <jack@...e.cz>
---
fs/jbd2/transaction.c | 27 ++++++++++++++++-----------
include/linux/jbd2.h | 2 +-
2 files changed, 17 insertions(+), 12 deletions(-)
diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c
index 7391456..8ac8306 100644
--- a/fs/jbd2/transaction.c
+++ b/fs/jbd2/transaction.c
@@ -368,6 +368,7 @@ repeat:
atomic_read(&transaction->t_outstanding_credits),
jbd2_log_space_left(journal));
read_unlock(&journal->j_state_lock);
+ current->journal_info = handle;
lock_map_acquire(&handle->h_lockdep_map);
jbd2_journal_free_transaction(new_transaction);
@@ -442,14 +443,11 @@ handle_t *jbd2__journal_start(journal_t *journal, int nblocks, int rsv_blocks,
handle->h_rsv_handle = rsv_handle;
}
- current->journal_info = handle;
-
err = start_this_handle(journal, handle, gfp_mask);
if (err < 0) {
if (handle->h_rsv_handle)
jbd2_free_handle(handle->h_rsv_handle);
jbd2_free_handle(handle);
- current->journal_info = NULL;
return ERR_PTR(err);
}
handle->h_type = type;
@@ -511,16 +509,13 @@ int jbd2_journal_start_reserved(handle_t *handle, unsigned int type,
}
handle->h_journal = NULL;
- current->journal_info = handle;
/*
* GFP_NOFS is here because callers are likely from writeback or
* similarly constrained call sites
*/
ret = start_this_handle(journal, handle, GFP_NOFS);
- if (ret < 0) {
- current->journal_info = NULL;
+ if (ret < 0)
jbd2_journal_free_reserved(handle);
- }
handle->h_type = type;
handle->h_line_no = line_no;
return ret;
@@ -555,6 +550,7 @@ int jbd2_journal_extend(handle_t *handle, int nblocks)
int wanted;
result = -EIO;
+ WARN_ON(!handle->h_transaction);
if (is_handle_aborted(handle))
goto out;
@@ -630,6 +626,7 @@ int jbd2__journal_restart(handle_t *handle, int nblocks, gfp_t gfp_mask)
tid_t tid;
int need_to_start, ret;
+ WARN_ON(!handle->h_transaction);
/* If we've had an abort of any type, don't even think about
* actually doing the restart! */
if (is_handle_aborted(handle))
@@ -654,6 +651,8 @@ int jbd2__journal_restart(handle_t *handle, int nblocks, gfp_t gfp_mask)
wake_up(&journal->j_wait_updates);
tid = transaction->t_tid;
spin_unlock(&transaction->t_handle_lock);
+ handle->h_transaction = NULL;
+ current->journal_info = NULL;
jbd_debug(2, "restarting handle %p\n", handle);
need_to_start = !tid_geq(journal->j_commit_request, tid);
@@ -790,6 +789,7 @@ do_get_write_access(handle_t *handle, struct journal_head *jh,
int need_copy = 0;
unsigned long start_lock, time_lock;
+ WARN_ON(!handle->h_transaction);
if (is_handle_aborted(handle))
return -EROFS;
@@ -1057,6 +1057,7 @@ int jbd2_journal_get_create_access(handle_t *handle, struct buffer_head *bh)
int err;
jbd_debug(5, "journal_head %p\n", jh);
+ WARN_ON(!handle->h_transaction);
err = -EROFS;
if (is_handle_aborted(handle))
goto out;
@@ -1269,6 +1270,7 @@ int jbd2_journal_dirty_metadata(handle_t *handle, struct buffer_head *bh)
struct journal_head *jh;
int ret = 0;
+ WARN_ON(!handle->h_transaction);
if (is_handle_aborted(handle))
goto out;
jh = jbd2_journal_grab_journal_head(bh);
@@ -1523,18 +1525,19 @@ int jbd2_journal_stop(handle_t *handle)
{
transaction_t *transaction = handle->h_transaction;
journal_t *journal = transaction->t_journal;
- int err, wait_for_commit = 0;
+ int err = 0, wait_for_commit = 0;
tid_t tid;
pid_t pid;
+ if (!handle->h_transaction)
+ goto free_and_exit;
+
J_ASSERT(journal_current_handle() == handle);
if (is_handle_aborted(handle))
err = -EIO;
- else {
+ else
J_ASSERT(atomic_read(&transaction->t_updates) > 0);
- err = 0;
- }
if (--handle->h_ref > 0) {
jbd_debug(4, "h_ref %d -> %d\n", handle->h_ref + 1,
@@ -1657,6 +1660,7 @@ int jbd2_journal_stop(handle_t *handle)
if (handle->h_rsv_handle)
jbd2_journal_free_reserved(handle->h_rsv_handle);
+free_and_exit:
jbd2_free_handle(handle);
return err;
}
@@ -2364,6 +2368,7 @@ int jbd2_journal_file_inode(handle_t *handle, struct jbd2_inode *jinode)
transaction_t *transaction = handle->h_transaction;
journal_t *journal = transaction->t_journal;
+ WARN_ON(!handle->h_transaction);
if (is_handle_aborted(handle))
return -EIO;
diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h
index 5f3c094..1891112 100644
--- a/include/linux/jbd2.h
+++ b/include/linux/jbd2.h
@@ -1295,7 +1295,7 @@ static inline int is_journal_aborted(journal_t *journal)
static inline int is_handle_aborted(handle_t *handle)
{
- if (handle->h_aborted)
+ if (handle->h_aborted || !handle->h_transaction)
return 1;
return is_journal_aborted(handle->h_transaction->t_journal);
}
--
1.7.12.rc0.22.gcdd159b
--
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