| Message ID | 20161215140715.12732-7-mhocko@kernel.org |
|---|---|
| State | Superseded, archived |
| Headers | show |
On Thu 15-12-16 15:07:12, Michal Hocko wrote: > From: Michal Hocko <mhocko@suse.com> > > now that we have memalloc_nofs_{save,restore} api we can mark the whole > transaction context as implicitly GFP_NOFS. All allocations will > automatically inherit GFP_NOFS this way. This means that we do not have > to mark any of those requests with GFP_NOFS and moreover all the > ext4_kv[mz]alloc(GFP_NOFS) are also safe now because even the hardcoded > GFP_KERNEL allocations deep inside the vmalloc will be NOFS now. > > Signed-off-by: Michal Hocko <mhocko@suse.com> Looks good to me. You can add: Reviewed-by: Jan Kara <jack@suse.cz> Honza > --- > fs/jbd2/transaction.c | 11 +++++++++++ > include/linux/jbd2.h | 2 ++ > 2 files changed, 13 insertions(+) > > diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c > index e1652665bd93..35a5d3d76182 100644 > --- a/fs/jbd2/transaction.c > +++ b/fs/jbd2/transaction.c > @@ -388,6 +388,11 @@ static int start_this_handle(journal_t *journal, handle_t *handle, > > rwsem_acquire_read(&journal->j_trans_commit_map, 0, 0, _THIS_IP_); > jbd2_journal_free_transaction(new_transaction); > + /* > + * Make sure that no allocations done while the transaction is > + * open is going to recurse back to the fs layer. > + */ > + handle->saved_alloc_context = memalloc_nofs_save(); > return 0; > } > > @@ -466,6 +471,7 @@ handle_t *jbd2__journal_start(journal_t *journal, int nblocks, int rsv_blocks, > trace_jbd2_handle_start(journal->j_fs_dev->bd_dev, > handle->h_transaction->t_tid, type, > line_no, nblocks); > + > return handle; > } > EXPORT_SYMBOL(jbd2__journal_start); > @@ -1760,6 +1766,11 @@ int jbd2_journal_stop(handle_t *handle) > if (handle->h_rsv_handle) > jbd2_journal_free_reserved(handle->h_rsv_handle); > free_and_exit: > + /* > + * scope of th GFP_NOFS context is over here and so we can > + * restore the original alloc context. > + */ > + memalloc_nofs_restore(handle->saved_alloc_context); > jbd2_free_handle(handle); > return err; > } > diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h > index dfaa1f4dcb0c..606b6bce3a5b 100644 > --- a/include/linux/jbd2.h > +++ b/include/linux/jbd2.h > @@ -491,6 +491,8 @@ struct jbd2_journal_handle > > unsigned long h_start_jiffies; > unsigned int h_requested_credits; > + > + unsigned int saved_alloc_context; > }; > > > -- > 2.10.2 >
diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c index e1652665bd93..35a5d3d76182 100644 --- a/fs/jbd2/transaction.c +++ b/fs/jbd2/transaction.c @@ -388,6 +388,11 @@ static int start_this_handle(journal_t *journal, handle_t *handle, rwsem_acquire_read(&journal->j_trans_commit_map, 0, 0, _THIS_IP_); jbd2_journal_free_transaction(new_transaction); + /* + * Make sure that no allocations done while the transaction is + * open is going to recurse back to the fs layer. + */ + handle->saved_alloc_context = memalloc_nofs_save(); return 0; } @@ -466,6 +471,7 @@ handle_t *jbd2__journal_start(journal_t *journal, int nblocks, int rsv_blocks, trace_jbd2_handle_start(journal->j_fs_dev->bd_dev, handle->h_transaction->t_tid, type, line_no, nblocks); + return handle; } EXPORT_SYMBOL(jbd2__journal_start); @@ -1760,6 +1766,11 @@ int jbd2_journal_stop(handle_t *handle) if (handle->h_rsv_handle) jbd2_journal_free_reserved(handle->h_rsv_handle); free_and_exit: + /* + * scope of th GFP_NOFS context is over here and so we can + * restore the original alloc context. + */ + memalloc_nofs_restore(handle->saved_alloc_context); jbd2_free_handle(handle); return err; } diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h index dfaa1f4dcb0c..606b6bce3a5b 100644 --- a/include/linux/jbd2.h +++ b/include/linux/jbd2.h @@ -491,6 +491,8 @@ struct jbd2_journal_handle unsigned long h_start_jiffies; unsigned int h_requested_credits; + + unsigned int saved_alloc_context; };