This patch adds 64-bit inode version support to ext4. The lower 32 bits
are stored in the osd1.linux1.l_i_version field while the high 32 bits
are stored in the i_version_hi field newly created in the ext4_inode.
Signed-off-by: Kalpak Shah <[email protected]>
Signed-off-by: Mingming Cao <[email protected]>
Index: linux-2.6.21/fs/ext4/inode.c
===================================================================
--- linux-2.6.21.orig/fs/ext4/inode.c
+++ linux-2.6.21/fs/ext4/inode.c
@@ -2709,6 +2709,13 @@ void ext4_read_inode(struct inode * inod
EXT4_INODE_GET_XTIME(i_atime, inode, raw_inode);
EXT4_EINODE_GET_XTIME(i_crtime, ei, raw_inode);
+ inode->i_version = le32_to_cpu(raw_inode->i_disk_version);
+ if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
+ if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
+ inode->i_version |=
+ (__u64)(le32_to_cpu(raw_inode->i_version_hi)) << 32;
+ }
+
if (S_ISREG(inode->i_mode)) {
inode->i_op = &ext4_file_inode_operations;
inode->i_fop = &ext4_file_operations;
@@ -2852,8 +2859,14 @@ static int ext4_do_update_inode(handle_t
} else for (block = 0; block < EXT4_N_BLOCKS; block++)
raw_inode->i_block[block] = ei->i_data[block];
- if (ei->i_extra_isize)
+ raw_inode->i_disk_version = cpu_to_le32(inode->i_version);
+ if (ei->i_extra_isize) {
+ if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi)) {
+ raw_inode->i_version_hi =
+ cpu_to_le32(inode->i_version >> 32);
+ }
raw_inode->i_extra_isize = cpu_to_le16(ei->i_extra_isize);
+ }
BUFFER_TRACE(bh, "call ext4_journal_dirty_metadata");
rc = ext4_journal_dirty_metadata(handle, bh);
Index: linux-2.6.21/include/linux/ext4_fs.h
===================================================================
--- linux-2.6.21.orig/include/linux/ext4_fs.h
+++ linux-2.6.21/include/linux/ext4_fs.h
@@ -297,7 +297,7 @@ struct ext4_inode {
__le32 i_flags; /* File flags */
union {
struct {
- __u32 l_i_reserved1;
+ __u32 l_i_version;
} linux1;
struct {
__u32 h_i_translator;
@@ -406,6 +406,8 @@ do { \
raw_inode->xtime ## _extra); \
} while (0)
+#define i_disk_version osd1.linux1.l_i_version
+
#if defined(__KERNEL__) || defined(__linux__)
#define i_reserved1 osd1.linux1.l_i_reserved1
#define i_frag osd2.linux2.l_i_frag
On Sun, 01 Jul 2007 03:37:36 -0400
Mingming Cao <[email protected]> wrote:
> This patch adds 64-bit inode version support to ext4. The lower 32 bits
> are stored in the osd1.linux1.l_i_version field while the high 32 bits
> are stored in the i_version_hi field newly created in the ext4_inode.
So reading the code here does serve to answer the question I raised against
the earlier patch. A bit.
I'd have thought that this patch and the one which adds i_version_hi should
be folded into a single diff?
>
> Index: linux-2.6.21/fs/ext4/inode.c
> ===================================================================
> --- linux-2.6.21.orig/fs/ext4/inode.c
> +++ linux-2.6.21/fs/ext4/inode.c
> @@ -2709,6 +2709,13 @@ void ext4_read_inode(struct inode * inod
> EXT4_INODE_GET_XTIME(i_atime, inode, raw_inode);
> EXT4_EINODE_GET_XTIME(i_crtime, ei, raw_inode);
>
> + inode->i_version = le32_to_cpu(raw_inode->i_disk_version);
> + if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
> + if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
> + inode->i_version |=
> + (__u64)(le32_to_cpu(raw_inode->i_version_hi)) << 32;
<checks the precedence of "(type)" versus "<<">
<OK>
> + }
I don't quite see how the above two tests are sufficient to unambiguously
determine that the i_version_hi field is present on-disk.
I guess we're implicitly assuming that if the on-disk inode is big enough
then it _must_ have i_version_hi in there? If so, why is the comparison
with EXT4_GOOD_OLD_INODE_SIZE needed?
Some description of the overall approach to inode version identification
would be helpful here.
> if (S_ISREG(inode->i_mode)) {
> inode->i_op = &ext4_file_inode_operations;
> inode->i_fop = &ext4_file_operations;
> @@ -2852,8 +2859,14 @@ static int ext4_do_update_inode(handle_t
> } else for (block = 0; block < EXT4_N_BLOCKS; block++)
> raw_inode->i_block[block] = ei->i_data[block];
>
> - if (ei->i_extra_isize)
> + raw_inode->i_disk_version = cpu_to_le32(inode->i_version);
> + if (ei->i_extra_isize) {
> + if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi)) {
There's no comparison with EXT4_GOOD_OLD_INODE_SIZE here...
> + raw_inode->i_version_hi =
> + cpu_to_le32(inode->i_version >> 32);
> + }
> raw_inode->i_extra_isize = cpu_to_le16(ei->i_extra_isize);
> + }
>
On Jul 10, 2007 16:31 -0700, Andrew Morton wrote:
> > This patch adds 64-bit inode version support to ext4. The lower 32 bits
> > are stored in the osd1.linux1.l_i_version field while the high 32 bits
> > are stored in the i_version_hi field newly created in the ext4_inode.
>
> So reading the code here does serve to answer the question I raised against
> the earlier patch. A bit.
>
> I'd have thought that this patch and the one which adds i_version_hi should
> be folded into a single diff?
It could be - the original patch to reserve i_version_hi was submitted to
before the patches were ready to avoid that space being used by something
else.
> > + if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
> > + if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
> > + inode->i_version |=
> > + (__u64)(le32_to_cpu(raw_inode->i_version_hi)) << 32;
>
> <checks the precedence of "(type)" versus "<<">
>
> <OK>
>
> > + }
>
> I don't quite see how the above two tests are sufficient to unambiguously
> determine that the i_version_hi field is present on-disk.
>
> I guess we're implicitly assuming that if the on-disk inode is big enough
> then it _must_ have i_version_hi in there? If so, why is the comparison
> with EXT4_GOOD_OLD_INODE_SIZE needed?
The GOOT_OLD_INODE_SIZE check is needed to know if i_extra_isize is even
present or valid in the on-disk inode.
> > @@ -2852,8 +2859,14 @@ static int ext4_do_update_inode(handle_t
> > + raw_inode->i_disk_version = cpu_to_le32(inode->i_version);
> > + if (ei->i_extra_isize) {
> > + if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi)) {
>
> There's no comparison with EXT4_GOOD_OLD_INODE_SIZE here...
Because this is the in-memory version and it is always valid (set to zero
if there is extra space in the on-disk inode).
Cheers, Andreas
--
Andreas Dilger
Principal Software Engineer
Cluster File Systems, Inc.