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| author | Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> | 2008-02-15 20:47:21 +0300 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2008-02-15 20:47:21 +0300 |
| commit | 55bd725aa3a83b3935988f37275b5a80e10d4169 (patch) | |
| tree | 9e4c092830eafbb0036892d578d4075689ef81df | |
| parent | 642be6ec218b956fbae88304449720f76ba0d578 (diff) | |
| download | linux-55bd725aa3a83b3935988f37275b5a80e10d4169.tar.xz | |
ext4: Fix locking hierarchy violation in ext4_fallocate()
ext4_fallocate() was trying to acquire i_data_sem outside of
jbd2_start_transaction/jbd2_journal_stop, which violates ext4's locking
hierarchy. So we take i_mutex to prevent writes and truncates during
the complete fallocate operation, and use ext4_get_block_wrap() which
acquires and releases i_data_sem for each block allocation.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
| -rw-r--r-- | fs/ext4/extents.c | 10 |
1 files changed, 3 insertions, 7 deletions
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index bc7081f1fbe8..e856f660fc30 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -2623,7 +2623,7 @@ long ext4_fallocate(struct inode *inode, int mode, loff_t offset, loff_t len) * modify 1 super block, 1 block bitmap and 1 group descriptor. */ credits = EXT4_DATA_TRANS_BLOCKS(inode->i_sb) + 3; - down_write((&EXT4_I(inode)->i_data_sem)); + mutex_lock(&inode->i_mutex); retry: while (ret >= 0 && ret < max_blocks) { block = block + ret; @@ -2634,7 +2634,7 @@ retry: break; } - ret = ext4_ext_get_blocks(handle, inode, block, + ret = ext4_get_blocks_wrap(handle, inode, block, max_blocks, &map_bh, EXT4_CREATE_UNINITIALIZED_EXT, 0); WARN_ON(ret <= 0); @@ -2680,7 +2680,6 @@ retry: if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries)) goto retry; - up_write((&EXT4_I(inode)->i_data_sem)); /* * Time to update the file size. * Update only when preallocation was requested beyond the file size. @@ -2692,21 +2691,18 @@ retry: * if no error, we assume preallocation succeeded * completely */ - mutex_lock(&inode->i_mutex); i_size_write(inode, offset + len); EXT4_I(inode)->i_disksize = i_size_read(inode); - mutex_unlock(&inode->i_mutex); } else if (ret < 0 && nblocks) { /* Handle partial allocation scenario */ loff_t newsize; - mutex_lock(&inode->i_mutex); newsize = (nblocks << blkbits) + i_size_read(inode); i_size_write(inode, EXT4_BLOCK_ALIGN(newsize, blkbits)); EXT4_I(inode)->i_disksize = i_size_read(inode); - mutex_unlock(&inode->i_mutex); } } + mutex_unlock(&inode->i_mutex); return ret > 0 ? ret2 : ret; } |