Commit 99128add authored by Jan Kara's avatar Jan Kara
Browse files

ext3: Update PF_MEMALLOC handling in ext3_write_inode() 



The special handling of PF_MEMALLOC callers in ext3_write_inode()
shouldn't be necessary as there shouldn't be any. Warn about it. Also
update comment before the function as it seems somewhat outdated.

Signed-off-by: default avatarJan Kara <jack@suse.cz>
parent e878167a

fs/ext3/inode.c

+11 −12
Original line number Diff line number Diff line
@@ -3209,21 +3209,20 @@ static int ext3_do_update_inode(handle_t *handle, 
 *

 * We are called from a few places:

 *

 * - Within generic_file_write() for O_SYNC files.

 * - Within generic_file_aio_write() -> generic_write_sync() for O_SYNC files.

 *   Here, there will be no transaction running. We wait for any running

 *   transaction to commit.

 *

 * - Within sys_sync(), kupdate and such.

 *   We wait on commit, if tol to.

 * - Within flush work (for sys_sync(), kupdate and such).

 *   We wait on commit, if told to.

 *

 * - Within prune_icache() (PF_MEMALLOC == true)

 *   Here we simply return.  We can't afford to block kswapd on the

 *   journal commit.

 * - Within iput_final() -> write_inode_now()

 *   We wait on commit, if told to.

 *

 * In all cases it is actually safe for us to return without doing anything,

 * because the inode has been copied into a raw inode buffer in

 * ext3_mark_inode_dirty().  This is a correctness thing for O_SYNC and for

 * knfsd.

 * ext3_mark_inode_dirty().  This is a correctness thing for WB_SYNC_ALL

 * writeback.

 *

 * Note that we are absolutely dependent upon all inode dirtiers doing the

 * right thing: they *must* call mark_inode_dirty() after dirtying info in
@@ -3235,13 +3234,13 @@ static int ext3_do_update_inode(handle_t *handle, 
 *	stuff();

 *	inode->i_size = expr;

 *

 * is in error because a kswapd-driven write_inode() could occur while

 * `stuff()' is running, and the new i_size will be lost.  Plus the inode

 * will no longer be on the superblock's dirty inode list.

 * is in error because write_inode() could occur while `stuff()' is running,

 * and the new i_size will be lost.  Plus the inode will no longer be on the

 * superblock's dirty inode list.

 */

int ext3_write_inode(struct inode *inode, struct writeback_control *wbc)

{

	if (current->flags & PF_MEMALLOC)

	if (WARN_ON_ONCE(current->flags & PF_MEMALLOC))

		return 0;



	if (ext3_journal_current_handle()) {