* Re: ext4 fallocate related crash on 2.6.26
2008-07-15 4:06 ext4 fallocate related crash on 2.6.26 Shehjar Tikoo
@ 2008-07-18 12:00 ` Aneesh Kumar K.V
2008-07-18 13:07 ` Aneesh Kumar K.V
0 siblings, 1 reply; 3+ messages in thread
From: Aneesh Kumar K.V @ 2008-07-18 12:00 UTC (permalink / raw)
To: Shehjar Tikoo, Mingming Cao; +Cc: linux-fsdevel, linux-ext4, linux-kernel
On Tue, Jul 15, 2008 at 02:06:21PM +1000, Shehjar Tikoo wrote:
> Hi all
>
> I've observed the following kernel crash during tests against ext4
> fallocate'ion support on 2.6.26.
>
> Stack trace is at:
> http://www.gelato.unsw.edu.au/~shehjart/docs/ext4_fallocate_test_trace_2.6.26.txt
>
> The test involved running the following program which fallocates a given
> length in bytes then writes to it. The above crash was seen when writing
> to an ext4 disk, 2G file, in blocks of 64k with fallocate requests of
> 1mb. After each 1mb of data is written to the fallocated space, another
> 1mb is requested. This write-fallocate cycle continues till the requested
> file size is reached. The trace is from one of the crashes from the
> various runs(all crashed). I must emphasise that after one of the runs,
> the test disk could not be mounted as the filesystem was unrecognized.
> ext4dev was mounted in data=ordered mode.
>
> See the test code at:
> http://www.gelato.unsw.edu.au/~shehjart/docs/writefallocate.c
>
> The command line arguments are self-explanatory. Run without any
> arguments to see the usage message. Do change the _NR_fallocate define
> at the beginning of the file to your architecture's syscall number for
> sys_fallocate.
>
> I can run a few more tests if more info is needed.
Can you try this patch ?
commit 1ebfca565bb06763e14dd468ce84aa55eecb1122
Author: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Date: Fri Jul 18 17:25:18 2008 +0530
falloc fix
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 7bdaeec..9c8541e 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -2462,7 +2462,10 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
unsigned int newdepth;
/* If extent has less than EXT4_EXT_ZERO_LEN zerout directly */
if (allocated <= EXT4_EXT_ZERO_LEN) {
- /* Mark first half uninitialized.
+ /*
+ * iblock == ee_block is handled by the zerouout
+ * at the beginning.
+ * Mark first half uninitialized.
* Mark second half initialized and zero out the
* initialized extent
*/
@@ -2485,7 +2488,7 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
ex->ee_len = orig_ex.ee_len;
ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
ext4_ext_dirty(handle, inode, path + depth);
- /* zeroed the full extent */
+ /* blocks available from iblock */
return allocated;
} else if (err)
@@ -2513,6 +2516,7 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
err = PTR_ERR(path);
return err;
}
+ /* get the second half extent details */
ex = path[depth].p_ext;
err = ext4_ext_get_access(handle, inode,
path + depth);
@@ -2542,6 +2546,7 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
ext4_ext_dirty(handle, inode, path + depth);
/* zeroed the full extent */
+ /* blocks available from iblock */
return allocated;
} else if (err)
@@ -2557,23 +2562,22 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
*/
orig_ex.ee_len = cpu_to_le16(ee_len -
ext4_ext_get_actual_len(ex3));
- if (newdepth != depth) {
- depth = newdepth;
- ext4_ext_drop_refs(path);
- path = ext4_ext_find_extent(inode, iblock, path);
- if (IS_ERR(path)) {
- err = PTR_ERR(path);
- goto out;
- }
- eh = path[depth].p_hdr;
- ex = path[depth].p_ext;
- if (ex2 != &newex)
- ex2 = ex;
-
- err = ext4_ext_get_access(handle, inode, path + depth);
- if (err)
- goto out;
+ depth = newdepth;
+ ext4_ext_drop_refs(path);
+ path = ext4_ext_find_extent(inode, iblock, path);
+ if (IS_ERR(path)) {
+ err = PTR_ERR(path);
+ goto out;
}
+ eh = path[depth].p_hdr;
+ ex = path[depth].p_ext;
+ if (ex2 != &newex)
+ ex2 = ex;
+
+ err = ext4_ext_get_access(handle, inode, path + depth);
+ if (err)
+ goto out;
+
allocated = max_blocks;
/* If extent has less than EXT4_EXT_ZERO_LEN and we are trying
@@ -2591,6 +2595,7 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
ext4_ext_dirty(handle, inode, path + depth);
/* zero out the first half */
+ /* blocks available from iblock */
return allocated;
}
}
-aneesh
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