Bug#738758: [PATCH] ext4: optimize Hurd tests when reading/writing inodes
Set a in-memory superblock flag to indicate whether the file system is
designed to support the Hurd.
Also, add a sanity check to make sure the 64-bit feature is not set
for Hurd file systems, since i_file_acl_high conflicts with a
Hurd-specific field. This is not a big deal, since Hurd doesn't
support file systems larger than 1GB[1] anyway.
[1] http://walfield.org/pub/people/neal/papers/hurd-faq/FAQ.en.html#q2-6
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
---
fs/ext4/ext4.h | 2 ++
fs/ext4/inode.c | 9 +++------
fs/ext4/super.c | 10 ++++++++++
3 files changed, 15 insertions(+), 6 deletions(-)
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index f4f889e..e01135d 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1001,6 +1001,8 @@ struct ext4_inode_info {
#define EXT4_MOUNT2_STD_GROUP_SIZE 0x00000002 /* We have standard group
size of blocksize * 8
blocks */
+#define EXT4_MOUNT2_HURD_COMPAT 0x00000004 /* Support HURD-castrated
+ file systems */
#define clear_opt(sb, opt) EXT4_SB(sb)->s_mount_opt &= \
~EXT4_MOUNT_##opt
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index ed2c13a..a3a5eb3 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4168,8 +4168,7 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
EXT4_INODE_GET_XTIME(i_atime, inode, raw_inode);
EXT4_EINODE_GET_XTIME(i_crtime, ei, raw_inode);
- if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
- cpu_to_le32(EXT4_OS_HURD)) {
+ if (!test_opt2(inode->i_sb, HURD_COMPAT)) {
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))
@@ -4345,8 +4344,7 @@ static int ext4_do_update_inode(handle_t *handle,
goto out_brelse;
raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
raw_inode->i_flags = cpu_to_le32(ei->i_flags & 0xFFFFFFFF);
- if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
- cpu_to_le32(EXT4_OS_HURD))
+ if (!test_opt2(inode->i_sb, HURD_COMPAT))
raw_inode->i_file_acl_high =
cpu_to_le16(ei->i_file_acl >> 32);
raw_inode->i_file_acl_lo = cpu_to_le32(ei->i_file_acl);
@@ -4391,8 +4389,7 @@ static int ext4_do_update_inode(handle_t *handle,
raw_inode->i_block[block] = ei->i_data[block];
}
- if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
- cpu_to_le32(EXT4_OS_HURD)) {
+ if (!test_opt2(inode->i_sb, HURD_COMPAT)) {
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))
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 3c9eadf..6adee9a 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3580,6 +3580,16 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
"feature flags set on rev 0 fs, "
"running e2fsck is recommended");
+ if (es->s_creator_os == cpu_to_le32(EXT4_OS_HURD)) {
+ set_opt2(sb, HURD_COMPAT);
+ if (EXT4_HAS_INCOMPAT_FEATURE(sb,
+ EXT4_FEATURE_INCOMPAT_64BIT)) {
+ ext4_msg(sb, KERN_ERR,
+ "The Hurd can't support 64-bit file systems");
+ goto failed_mount;
+ }
+ }
+
if (IS_EXT2_SB(sb)) {
if (ext2_feature_set_ok(sb))
ext4_msg(sb, KERN_INFO, "mounting ext2 file system "
--
1.9.0
Reply to: