Attachment 8246 Details for Bug 43049 – ext3 no_mbcache - UNTESTED!

[patch] ext3 no_mbcache - UNTESTED!

43049_linux-ext3-no_mbcache.diff (text/plain), 5.05 KB, created by Philipp Hahn on 2016-11-25 16:54:14 CET

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Creator: Philipp Hahn

Created: 2016-11-25 16:54:14 CET

Size: 5.05 KB

patch

obsolete

>Bug #43049: backport ext3
>
>mbcache provides absolutely no value for Lustre xattrs (because
>they are unique and cannot be shared between files) and as we can
>see it has a noticable overhead in some cases. In the past there
>was a CONFIG_MBCACHE option that would allow it to be disabled,
>but this was removed in newer kernels, so we will need to patch
>ldiskfs to fix this.
>
><https://bugzilla.kernel.org/show_bug.cgi?id=107301>
>
>--- a/fs/ext3/ext3.h
>+++ b/fs/ext3/ext3.h
>@@ -340,6 +340,7 @@ struct ext3_inode_info {
>  * Mount flags
>  */
> #define EXT3_MOUNT_CHECK		0x00001	/* Do mount-time checks */
>+#define EXT3_MOUNT_NO_MBCACHE		0x00002 /* Disable mbcache */
> /* EXT3_MOUNT_OLDALLOC was there */
> #define EXT3_MOUNT_GRPID		0x00004	/* Create files with directory's group */
> #define EXT3_MOUNT_DEBUG		0x00008	/* Some debugging messages */
>--- a/fs/ext3/super.c
>+++ b/fs/ext3/super.c
>@@ -814,6 +814,7 @@ enum {
> 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
> 	Opt_noquota, Opt_ignore, Opt_barrier, Opt_nobarrier, Opt_err,
> 	Opt_resize, Opt_usrquota, Opt_grpquota
>+	,Opt_no_mbcache
> };
> 
> static const match_table_t tokens = {
>@@ -871,6 +872,7 @@ static const match_table_t tokens = {
> 	{Opt_nobarrier, "nobarrier"},
> 	{Opt_resize, "resize"},
> 	{Opt_err, NULL},
>+	{Opt_no_mbcache, "no_mbcache"},
> };
> 
> static ext3_fsblk_t get_sb_block(void **data, struct super_block *sb)
>@@ -1275,6 +1277,9 @@ static inst parse_options {
> 			ext3_msg(sb, KERN_WARNING,
> 				"warning: ignoring deprecated bh option");
> 			break;
>+		case Opt_no_mbcache:
>+			set_opt(sbi->s_mount_opt, EXT3_MOUNT_NO_MBCACHE);
>+			break;
> 		default:
> 			ext3_msg(sb, KERN_ERR,
> 				"error: unrecognized mount option \"%s\" "
>--- a/fs/ext3/xattr.c
>+++ b/fs/ext3/xattr.c
>@@ -88,7 +88,7 @@
> # define ea_bdebug(f...)
> #endif
> 
>-static void ext3_xattr_cache_insert(struct buffer_head *);
>+static void ext3_xattr_cache_insert(struct inode *, struct buffer_head *);
> static struct buffer_head *ext3_xattr_cache_find(struct inode *,
> 						 struct ext3_xattr_header *,
> 						 struct mb_cache_entry **);
>@@ -235,7 +234,7 @@ bad_block:
> 		error = -EIO;
> 		goto cleanup;
> 	}
>-	ext3_xattr_cache_insert(bh);
>+	ext3_xattr_cache_insert(inode, bh);
> 	entry = BFIRST(bh);
> 	error = ext3_xattr_find_entry(&entry, name_index, name, bh->b_size, 1);
> 	if (error == -EIO)
>@@ -379,7 +377,7 @@ ext3_xattr_block_list(struct dentry *den
> 		error = -EIO;
> 		goto cleanup;
> 	}
>-	ext3_xattr_cache_insert(bh);
>+	ext3_xattr_cache_insert(inode, bh);
> 	error = ext3_xattr_list_entries(dentry, BFIRST(bh), buffer, buffer_size);
> 
> cleanup:
>@@ -476,7 +474,8 @@ ext3_xattr_release_block(handle_t *handl
> 	struct mb_cache_entry *ce = NULL;
> 	int error = 0;
> 
>-	ce = mb_cache_entry_get(ext3_xattr_cache, bh->b_bdev, bh->b_blocknr);
>+	if (!test_opt(inode->i_sb, NO_MBCACHE))
>+		ce = mb_cache_entry_get(ext3_xattr_cache, bh->b_bdev, bh->b_blocknr);
> 	error = ext3_journal_get_write_access(handle, bh);
> 	if (error)
> 		 goto out;
>@@ -687,8 +686,9 @@ ext3_xattr_block_set(handle_t *handle, s
> 	if (i->value && i->value_len > sb->s_blocksize)
> 		return -ENOSPC;
> 	if (s->base) {
>-		ce = mb_cache_entry_get(ext3_xattr_cache, bs->bh->b_bdev,
>-					bs->bh->b_blocknr);
>+		if (!test_opt(inode->i_sb, NO_MBCACHE))
>+			ce = mb_cache_entry_get(ext3_xattr_cache, bs->bh->b_bdev,
>+						bs->bh->b_blocknr);
> 		error = ext3_journal_get_write_access(handle, bs->bh);
> 		if (error)
> 			goto cleanup;
>@@ -705,7 +705,7 @@ ext3_xattr_block_set(handle_t *handle, s
> 				if (!IS_LAST_ENTRY(s->first))
> 					ext3_xattr_rehash(header(s->base),
> 							  s->here);
>-				ext3_xattr_cache_insert(bs->bh);
>+				ext3_xattr_cache_insert(inode, bs->bh);
> 			}
> 			unlock_buffer(bs->bh);
> 			if (error == -EIO)
>@@ -787,7 +787,8 @@ inserted:
> 				if (error)
> 					goto cleanup_dquot;
> 			}
>-			mb_cache_entry_release(ce);
>+			if (ce)
>+				mb_cache_entry_release(ce);
> 			ce = NULL;
> 		} else if (bs->bh && s->base == bs->bh->b_data) {
> 			/* We were modifying this block in-place. */
>@@ -828,7 +828,7 @@ getblk_failed:
> 			memcpy(new_bh->b_data, s->base, new_bh->b_size);
> 			set_buffer_uptodate(new_bh);
> 			unlock_buffer(new_bh);
>-			ext3_xattr_cache_insert(new_bh);
>+			ext3_xattr_cache_insert(inode, new_bh);
> 			error = ext3_journal_dirty_metadata(handle, new_bh);
> 			if (error)
> 				goto cleanup;
>@@ -1131,12 +1132,16 @@ ext3_xattr_put_super(struct super_block
>  * Returns 0, or a negative error number on failure.
>  */
> static void
>-ext3_xattr_cache_insert(struct buffer_head *bh)
>+ext3_xattr_cache_insert(struct inode *inode, struct buffer_head *bh)
> {
>+	struct super_block *sb = inode->i_sb;
> 	__u32 hash = le32_to_cpu(BHDR(bh)->h_hash);
> 	struct mb_cache_entry *ce;
> 	int error;
> 
>+	if (test_opt(sb, NO_MBCACHE))
>+		return;
>+
> 	ce = mb_cache_entry_alloc(ext3_xattr_cache, GFP_NOFS);
> 	if (!ce) {
> 		ea_bdebug(bh, "out of memory");
>@@ -1210,6 +1216,8 @@ ext3_xattr_cache_find(struct inode *inod
> 	__u32 hash = le32_to_cpu(header->h_hash);
> 	struct mb_cache_entry *ce;
> 
>+	if (test_opt(inode->i_sb, NO_MBCACHE))
>+		return NULL;
> 	if (!header->h_hash)
> 		return NULL;  /* never share */
> 	ea_idebug(inode, "looking for cached blocks [%x]", (int)hash);

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Attachments on bug 43049: 8246