From: Lukas Czerner Subject: Re: [PATCH RFC 05/30] ext4: snapshot hooks - delete blocks Date: Tue, 7 Jun 2011 13:24:39 +0200 (CEST) Message-ID: References: <1304959308-11122-1-git-send-email-amir73il@users.sourceforge.net> <1304959308-11122-6-git-send-email-amir73il@users.sourceforge.net> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: linux-ext4@vger.kernel.org, tytso@mit.edu, Amir Goldstein , Yongqiang Yang To: amir73il@users.sourceforge.net Return-path: Received: from mx1.redhat.com ([209.132.183.28]:18067 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751913Ab1FGLYx (ORCPT ); Tue, 7 Jun 2011 07:24:53 -0400 In-Reply-To: <1304959308-11122-6-git-send-email-amir73il@users.sourceforge.net> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Mon, 9 May 2011, amir73il@users.sourceforge.net wrote: > From: Amir Goldstein > > Before deleting file blocks in ext4_free_blocks(), > we call the snapshot API ext4_snapshot_get_delete_access(), > to optionally move the block to the snapshot file instead of > freeing them. > > Signed-off-by: Amir Goldstein > Signed-off-by: Yongqiang Yang > --- > fs/ext4/ext4.h | 10 +++++++--- > fs/ext4/mballoc.c | 30 +++++++++++++++++++++++++++--- > 2 files changed, 34 insertions(+), 6 deletions(-) > > diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h > index ca25e67..4e9e46a 100644 > --- a/fs/ext4/ext4.h > +++ b/fs/ext4/ext4.h > @@ -1729,9 +1729,13 @@ extern int ext4_mb_reserve_blocks(struct super_block *, int); > extern void ext4_discard_preallocations(struct inode *); > extern int __init ext4_init_mballoc(void); > extern void ext4_exit_mballoc(void); > -extern void ext4_free_blocks(handle_t *handle, struct inode *inode, > - struct buffer_head *bh, ext4_fsblk_t block, > - unsigned long count, int flags); > +extern void __ext4_free_blocks(const char *where, unsigned int line, > + handle_t *handle, struct inode *inode, > + struct buffer_head *bh, ext4_fsblk_t block, > + unsigned long count, int flags); > +#define ext4_free_blocks(handle, inode, bh, block, count, flags) \ > + __ext4_free_blocks(__func__, __LINE__ , (handle), (inode), (bh), \ > + (block), (count), (flags)) > extern int ext4_mb_add_groupinfo(struct super_block *sb, > ext4_group_t i, struct ext4_group_desc *desc); > extern int ext4_trim_fs(struct super_block *, struct fstrim_range *); > diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c > index e8bfd8d..3b1c6d1 100644 > --- a/fs/ext4/mballoc.c > +++ b/fs/ext4/mballoc.c > @@ -4445,9 +4445,9 @@ ext4_mb_free_metadata(handle_t *handle, struct ext4_buddy *e4b, > * @count: number of blocks to count > * @metadata: Are these metadata blocks > */ > -void ext4_free_blocks(handle_t *handle, struct inode *inode, > - struct buffer_head *bh, ext4_fsblk_t block, > - unsigned long count, int flags) > +void __ext4_free_blocks(const char *where, unsigned int line, handle_t *handle, > + struct inode *inode, struct buffer_head *bh, > + ext4_fsblk_t block, unsigned long count, int flags) > { > struct buffer_head *bitmap_bh = NULL; > struct super_block *sb = inode->i_sb; > @@ -4461,6 +4461,7 @@ void ext4_free_blocks(handle_t *handle, struct inode *inode, > struct ext4_buddy e4b; > int err = 0; > int ret; > + int maxblocks; > > if (bh) { > if (block) > @@ -4543,6 +4544,29 @@ do_more: > goto error_return; > } > > + maxblocks = count; > + ret = ext4_snapshot_get_delete_access(handle, inode, > + block, &maxblocks); It would be nice to have this defined in the same commit, so I know what is it doing. > + if (ret < 0) { > + ext4_journal_abort_handle(where, line, __func__, > + NULL, handle, ret); > + err = ret; > + goto error_return; > + } > + if (ret > 0) { > + /* 'ret' blocks were moved to snapshot - skip them */ > + block += maxblocks; > + count -= maxblocks; > + count += overflow; > + cond_resched(); > + if (count > 0) > + goto do_more; > + /* no more blocks to free/move to snapshot */ > + ext4_mark_super_dirty(sb); > + goto error_return; > + } > + overflow += count - maxblocks; > + count = maxblocks; > BUFFER_TRACE(bitmap_bh, "getting write access"); > err = ext4_handle_get_bitmap_access(handle, sb, block_group, bitmap_bh); > if (err) >