Re: [PATCH 1/2] Make orphan functions no-op in no-journal mode
From: Theodore Ts'o <tytso@mit.edu>
Date: 2012-09-18 03:32:08
On Mon, Sep 17, 2012 at 10:47:16AM -0700, Anatol Pomozov wrote:
This avoids using shared mutext and thus improves scalability of no-journal mode. The goal of this change is similar to 3d287de3b828 but it avoids mutex usage for all ext4_orphan_del(NULL,..) calls.
It doesn't really improve scalability in no-journal except in the error case. This is because....
quoted hunk ↗ jump to hunk
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index 2a42cc0..6863cdf 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c@@ -2362,6 +2362,8 @@ int ext4_orphan_add(handle_t *handle, struct inode *inode) struct ext4_iloc iloc; int err = 0, rc; + if (!EXT4_SB(sb)->s_journal) + return 0; if (!ext4_handle_valid(handle)) return 0;
The two checks above are equivalent. If (!EXT4_SB(sb)->s_journal), then ext4_journal_start() will return return an "invalid" handle. So this change is purely cosmetic. I don't object to making the change for consistency with the change to be made in ext4_orphan_del() below, but we should remove the !ext4_handle_valid(handle) call in that case.
quoted hunk ↗ jump to hunk
@@ -2436,6 +2438,8 @@ int ext4_orphan_del(handle_t *handle, struct inode *inode) struct ext4_iloc iloc; int err = 0; + if (!EXT4_SB(inode->i_sb)->s_journal) + return 0; /* ext4_handle_valid() assumes a valid handle_t pointer */ if (handle && !ext4_handle_valid(handle)) return 0;
We can remove the (handle && !ext4_handle_valid(handle)) conditional here too. - Ted