The patch titled
jbd: check for error returned by kthread_create on creating journal thread
has been added to the -mm tree. Its filename is
jbd-check-for-error-returned-by-kthread_create-on-creating-journal-thread.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: jbd: check for error returned by kthread_create on creating journal thread
From: Pavel Emelianov <xemul@xxxxx>
If the thread failed to create the subsequent wait_event will hang forever.
This is likely to happen if kernel hits max_threads limit.
Will be critical for virtualization systems that limit the number of tasks
and kernel memory usage within the container.
(akpm: JBD should be converted fully to the kthread API: kthread_should_stop()
and kthread_stop()).
Cc: <linux-ext4@xxxxxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/jbd/journal.c | 13 +++++++++----
fs/jbd2/journal.c | 13 +++++++++----
2 files changed, 18 insertions(+), 8 deletions(-)
diff -puN fs/jbd/journal.c~jbd-check-for-error-returned-by-kthread_create-on-creating-journal-thread fs/jbd/journal.c
--- a/fs/jbd/journal.c~jbd-check-for-error-returned-by-kthread_create-on-creating-journal-thread
+++ a/fs/jbd/journal.c
@@ -210,10 +210,16 @@ end_loop:
return 0;
}
-static void journal_start_thread(journal_t *journal)
+static int journal_start_thread(journal_t *journal)
{
- kthread_run(kjournald, journal, "kjournald");
+ struct task_struct *t;
+
+ t = kthread_run(kjournald, journal, "kjournald");
+ if (IS_ERR(t))
+ return PTR_ERR(t);
+
wait_event(journal->j_wait_done_commit, journal->j_task != 0);
+ return 0;
}
static void journal_kill_thread(journal_t *journal)
@@ -839,8 +845,7 @@ static int journal_reset(journal_t *jour
/* Add the dynamic fields and write it to disk. */
journal_update_superblock(journal, 1);
- journal_start_thread(journal);
- return 0;
+ return journal_start_thread(journal);
}
/**
diff -puN fs/jbd2/journal.c~jbd-check-for-error-returned-by-kthread_create-on-creating-journal-thread fs/jbd2/journal.c
--- a/fs/jbd2/journal.c~jbd-check-for-error-returned-by-kthread_create-on-creating-journal-thread
+++ a/fs/jbd2/journal.c
@@ -210,10 +210,16 @@ end_loop:
return 0;
}
-static void jbd2_journal_start_thread(journal_t *journal)
+static int jbd2_journal_start_thread(journal_t *journal)
{
- kthread_run(kjournald2, journal, "kjournald2");
+ struct task_struct *t;
+
+ t = kthread_run(kjournald2, journal, "kjournald2");
+ if (IS_ERR(t))
+ return PTR_ERR(t);
+
wait_event(journal->j_wait_done_commit, journal->j_task != 0);
+ return 0;
}
static void journal_kill_thread(journal_t *journal)
@@ -839,8 +845,7 @@ static int journal_reset(journal_t *jour
/* Add the dynamic fields and write it to disk. */
jbd2_journal_update_superblock(journal, 1);
- jbd2_journal_start_thread(journal);
- return 0;
+ return jbd2_journal_start_thread(journal);
}
/**
_
Patches currently in -mm which might be from xemul@xxxxx are
origin.patch
lockdep-treats-down_write_trylock-like-regular-down_write.patch
introduce-a-handy-list_first_entry-macro-v2.patch
report-that-kernel-is-tainted-if-there-were-an-oops-before.patch
jbd-check-for-error-returned-by-kthread_create-on-creating-journal-thread.patch
-
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