The patch titled
remove sb->s_files and file_list_lock usage in dquot.c
has been added to the -mm tree. Its filename is
remove-sb-s_files-and-file_list_lock-usage-in-dquotc.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: remove sb->s_files and file_list_lock usage in dquot.c
From: Christoph Hellwig <hch@xxxxxx>
Iterate over sb->s_inodes instead of sb->s_files in add_dquot_ref. This
reduces list search and lock hold time aswell as getting rid of one of the
few uses of file_list_lock which Ingo identified as a scalability problem.
Previously we called dq_op->initialize for every inode handing of a
writeable file that wasn't initialized before. Now we're calling it for
every inode that has a non-zero i_writecount, aka a writeable file
descriptor refering to it.
Thanks a lot to Jan Kara for running this patch through his quota test
harness.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/dquot.c | 32 ++++++++++++++++++--------------
1 files changed, 18 insertions(+), 14 deletions(-)
diff -puN fs/dquot.c~remove-sb-s_files-and-file_list_lock-usage-in-dquotc fs/dquot.c
--- a/fs/dquot.c~remove-sb-s_files-and-file_list_lock-usage-in-dquotc
+++ a/fs/dquot.c
@@ -688,23 +688,27 @@ static int dqinit_needed(struct inode *i
/* This routine is guarded by dqonoff_mutex mutex */
static void add_dquot_ref(struct super_block *sb, int type)
{
- struct list_head *p;
+ struct inode *inode;
restart:
- file_list_lock();
- list_for_each(p, &sb->s_files) {
- struct file *filp = list_entry(p, struct file, f_u.fu_list);
- struct inode *inode = filp->f_path.dentry->d_inode;
- if (filp->f_mode & FMODE_WRITE && dqinit_needed(inode, type)) {
- struct dentry *dentry = dget(filp->f_path.dentry);
- file_list_unlock();
- sb->dq_op->initialize(inode, type);
- dput(dentry);
- /* As we may have blocked we had better restart... */
- goto restart;
- }
+ spin_lock(&inode_lock);
+ list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
+ if (!atomic_read(&inode->i_writecount))
+ continue;
+ if (!dqinit_needed(inode, type))
+ continue;
+ if (inode->i_state & (I_FREEING|I_WILL_FREE))
+ continue;
+
+ __iget(inode);
+ spin_unlock(&inode_lock);
+
+ sb->dq_op->initialize(inode, type);
+ iput(inode);
+ /* As we may have blocked we had better restart... */
+ goto restart;
}
- file_list_unlock();
+ spin_unlock(&inode_lock);
}
/* Return 0 if dqput() won't block (note that 1 doesn't necessarily mean blocking) */
_
Patches currently in -mm which might be from hch@xxxxxx are
git-drm.patch
git-scsi-misc.patch
slab-cache-alloc-cleanups.patch
simplify-the-stacktrace-code.patch
make-bh_unwritten-a-first-class-bufferhead-flag-v2.patch
make-xfs-use-bh_unwritten-and-bh_delay-correctly.patch
tty-cleanup-release_mem.patch
allow-access-to-proc-pid-fd-after-setuid.patch
allow-access-to-proc-pid-fd-after-setuid-fix.patch
allow-access-to-proc-pid-fd-after-setuid-update.patch
fix-d_path-for-lazy-unmounts.patch
move-remove_dquot_ref-to-dqoutc.patch
remove-sb-s_files-and-file_list_lock-usage-in-dquotc.patch
make-static-counters-in-new_inode-and-iunique-be-32-bits.patch
change-libfs-sb-creation-routines-to-avoid-collisions-with-their-root-inodes.patch
aio-is-unlikely.patch
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