From: amir73il@users.sourceforge.net Subject: [PATCH v1 05/36] ext4: snapshot hooks - delete blocks Date: Tue, 7 Jun 2011 18:07:32 +0300 Message-ID: <1307459283-22130-6-git-send-email-amir73il@users.sourceforge.net> References: <1307459283-22130-1-git-send-email-amir73il@users.sourceforge.net> Cc: tytso@mit.edu, lczerner@redhat.com, Amir Goldstein , Yongqiang Yang To: linux-ext4@vger.kernel.org Return-path: Received: from mail-ww0-f44.google.com ([74.125.82.44]:41767 "EHLO mail-ww0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754072Ab1FGPJI (ORCPT ); Tue, 7 Jun 2011 11:09:08 -0400 Received: by mail-ww0-f44.google.com with SMTP id 36so5035787wwa.1 for ; Tue, 07 Jun 2011 08:09:07 -0700 (PDT) In-Reply-To: <1307459283-22130-1-git-send-email-amir73il@users.sourceforge.net> Sender: linux-ext4-owner@vger.kernel.org List-ID: 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 +++++++++++++++++++++++++++--- fs/ext4/snapshot.h | 26 ++++++++++++++++++++++++++ 3 files changed, 60 insertions(+), 6 deletions(-) diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 756848f..b910dcb 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -1731,9 +1731,13 @@ 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 6b400f2..f878449 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -4451,9 +4451,9 @@ 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; @@ -4467,6 +4467,7 @@ 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) @@ -4549,6 +4550,29 @@ do_more: goto error_return; } + maxblocks = count; + ret = ext4_snapshot_get_delete_access(handle, inode, + block, &maxblocks); + 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) diff --git a/fs/ext4/snapshot.h b/fs/ext4/snapshot.h index 008f4a9..504dfd5 100644 --- a/fs/ext4/snapshot.h +++ b/fs/ext4/snapshot.h @@ -227,6 +227,32 @@ static inline int ext4_snapshot_get_bitmap_access(handle_t *handle, return ext4_snapshot_cow(handle, NULL, bh->b_blocknr, bh, 1); } +/* + * get_delete_access() - move blocks to snapshot or approve to free them + * @handle: JBD handle + * @inode: owner of blocks if known (or NULL otherwise) + * @block: address of start @block + * @pcount: pointer to no. of blocks about to move or approve + * + * Called from ext4_free_blocks() before deleting blocks with + * i_data_sem held + * + * Return values: + * > 0 - blocks were moved to snapshot and may not be freed + * = 0 - blocks may be freed + * < 0 - error + */ +static inline int ext4_snapshot_get_delete_access(handle_t *handle, + struct inode *inode, ext4_fsblk_t block, int *pcount) +{ + struct super_block *sb; + + sb = handle->h_transaction->t_journal->j_private; + if (!EXT4_SNAPSHOTS(sb)) + return 0; + + return ext4_snapshot_move(handle, inode, block, pcount, 1); +} /* snapshot_ctl.c */ -- 1.7.4.1