hfsplus: optimize fsync
Avoid doing unessecary work in fsync. Do nothing unless the inode
was marked dirty, and only write the various metadata inodes out if
they contain any dirty state from this inode. This is archived by
adding three new dirty bits to the hfsplus-specific inode which are
set in the correct places.
Signed-off-by: Christoph Hellwig <hch@tuxera.com>
diff --git a/fs/hfsplus/extents.c b/fs/hfsplus/extents.c
index 06b4fc3..b1127ef 100644
--- a/fs/hfsplus/extents.c
+++ b/fs/hfsplus/extents.c
@@ -108,6 +108,14 @@
fd->entryoffset, fd->entrylength);
hip->extent_state &= ~HFSPLUS_EXT_DIRTY;
}
+
+ /*
+ * We can't just use hfsplus_mark_inode_dirty here, because we
+ * also get called from hfsplus_write_inode, which should not
+ * redirty the inode. Instead the callers have to be careful
+ * to explicily mark the inode dirty, too.
+ */
+ set_bit(HFSPLUS_I_EXT_DIRTY, &hip->flags);
}
static void hfsplus_ext_write_extent_locked(struct inode *inode)
@@ -197,6 +205,7 @@
struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
int res = -EIO;
u32 ablock, dblock, mask;
+ int was_dirty = 0;
int shift;
/* Convert inode block to disk allocation block */
@@ -223,14 +232,20 @@
return -EIO;
mutex_lock(&hip->extents_lock);
+
+ /*
+ * hfsplus_ext_read_extent will write out a cached extent into
+ * the extents btree. In that case we may have to mark the inode
+ * dirty even for a pure read of an extent here.
+ */
+ was_dirty = (hip->extent_state & HFSPLUS_EXT_DIRTY);
res = hfsplus_ext_read_extent(inode, ablock);
- if (!res) {
- dblock = hfsplus_ext_find_block(hip->cached_extents,
- ablock - hip->cached_start);
- } else {
+ if (res) {
mutex_unlock(&hip->extents_lock);
return -EIO;
}
+ dblock = hfsplus_ext_find_block(hip->cached_extents,
+ ablock - hip->cached_start);
mutex_unlock(&hip->extents_lock);
done:
@@ -242,8 +257,9 @@
hip->phys_size += sb->s_blocksize;
hip->fs_blocks++;
inode_add_bytes(inode, sb->s_blocksize);
- mark_inode_dirty(inode);
}
+ if (create || was_dirty)
+ mark_inode_dirty(inode);
return 0;
}
@@ -438,7 +454,7 @@
mutex_unlock(&hip->extents_lock);
if (!res) {
hip->alloc_blocks += len;
- mark_inode_dirty(inode);
+ hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY);
}
return res;
@@ -529,5 +545,5 @@
hip->phys_size = inode->i_size;
hip->fs_blocks = (inode->i_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
inode_set_bytes(inode, hip->fs_blocks << sb->s_blocksize_bits);
- mark_inode_dirty(inode);
+ hfsplus_mark_inode_dirty(inode, HFSPLUS_I_ALLOC_DIRTY);
}