linux-ext4 - [PATCH 2/2] ext4: Convert to generic reserved quota's space management.

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Date:	Thu, 10 Dec 2009 04:44:07 +0300
From:	Dmitry Monakhov <dmonakhov@...nvz.org>
To:	linux-ext4@...r.kernel.org
Cc:	aneesh.kumar@...ux.vnet.ibm.com, jack@...e.cz, cmm@...ibm.com,
	Dmitry Monakhov <dmonakhov@...nvz.org>
Subject: [PATCH 2/2] ext4: Convert to generic reserved quota's space management.

This patch solves write vs chown race condition.

Signed-off-by: Dmitry Monakhov <dmonakhov@...nvz.org>
---
 fs/ext4/ext4.h  |    6 +++++-
 fs/ext4/inode.c |   13 ++++---------
 2 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 26d3cf8..992cecd 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -705,6 +705,10 @@ struct ext4_inode_info {
 	struct list_head i_aio_dio_complete_list;
 	/* current io_end structure for async DIO write*/
 	ext4_io_end_t *cur_aio_dio;
+#ifdef CONFIG_QUOTA
+	/* quota space reservation, managed internally by quota code */
+	qsize_t i_reserved_quota;
+#endif
 };
 
 /*
@@ -1427,7 +1431,7 @@ extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);
 extern int ext4_block_truncate_page(handle_t *handle,
 		struct address_space *mapping, loff_t from);
 extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
-extern qsize_t ext4_get_reserved_space(struct inode *inode);
+extern qsize_t* ext4_get_reserved_space(struct inode *inode);
 extern int flush_aio_dio_completed_IO(struct inode *inode);
 /* ioctl.c */
 extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index f693768..d833e5a 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1048,17 +1048,12 @@ out:
 	return err;
 }
 
-qsize_t ext4_get_reserved_space(struct inode *inode)
+#ifdef CONFIG_QUOTA
+qsize_t* ext4_get_reserved_space(struct inode *inode)
 {
-	unsigned long long total;
-
-	spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
-	total = EXT4_I(inode)->i_reserved_data_blocks +
-		EXT4_I(inode)->i_reserved_meta_blocks;
-	spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
-
-	return (total << inode->i_blkbits);
+	return &EXT4_I(inode)->i_reserved_quota;
 }
+#endif
 /*
  * Calculate the number of metadata blocks need to reserve
  * to allocate @blocks for non extent file based file
-- 
1.6.0.4

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