summaryrefslogtreecommitdiffstats
path: root/fs/ext4/mmp.c
diff options
context:
space:
mode:
authorDaniel Vetter <daniel.vetter@ffwll.ch>2012-06-25 19:06:12 +0200
committerDaniel Vetter <daniel.vetter@ffwll.ch>2012-06-25 19:10:36 +0200
commit7b0cfee1a24efdfe0235bac62e53f686fe8a8e24 (patch)
treeeeeb8cc3bf7be5ec0e54b7c4f3808ef88ecca012 /fs/ext4/mmp.c
parent9756fe38d10b2bf90c81dc4d2f17d5632e135364 (diff)
parent6b16351acbd415e66ba16bf7d473ece1574cf0bc (diff)
downloadlinux-7b0cfee1a24efdfe0235bac62e53f686fe8a8e24.tar.bz2
Merge tag 'v3.5-rc4' into drm-intel-next-queued
I want to merge the "no more fake agp on gen6+" patches into drm-intel-next (well, the last pieces). But a patch in 3.5-rc4 also adds a new use of dev->agp. Hence the backmarge to sort this out, for otherwise drm-intel-next merged into Linus' tree would conflict in the relevant code, things would compile but nicely OOPS at driver load :( Conflicts in this merge are just simple cases of "both branches changed/added lines at the same place". The only tricky part is to keep the order correct wrt the unwind code in case of errors in intel_ringbuffer.c (and the MI_DISPLAY_FLIP #defines in i915_reg.h together, obviously). Conflicts: drivers/gpu/drm/i915/i915_reg.h drivers/gpu/drm/i915/intel_ringbuffer.c Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Diffstat (limited to 'fs/ext4/mmp.c')
-rw-r--r--fs/ext4/mmp.c44
1 files changed, 39 insertions, 5 deletions
diff --git a/fs/ext4/mmp.c b/fs/ext4/mmp.c
index ed6548d89165..f99a1311e847 100644
--- a/fs/ext4/mmp.c
+++ b/fs/ext4/mmp.c
@@ -6,12 +6,45 @@
#include "ext4.h"
+/* Checksumming functions */
+static __u32 ext4_mmp_csum(struct super_block *sb, struct mmp_struct *mmp)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ int offset = offsetof(struct mmp_struct, mmp_checksum);
+ __u32 csum;
+
+ csum = ext4_chksum(sbi, sbi->s_csum_seed, (char *)mmp, offset);
+
+ return cpu_to_le32(csum);
+}
+
+int ext4_mmp_csum_verify(struct super_block *sb, struct mmp_struct *mmp)
+{
+ if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
+ EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+ return 1;
+
+ return mmp->mmp_checksum == ext4_mmp_csum(sb, mmp);
+}
+
+void ext4_mmp_csum_set(struct super_block *sb, struct mmp_struct *mmp)
+{
+ if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
+ EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
+ return;
+
+ mmp->mmp_checksum = ext4_mmp_csum(sb, mmp);
+}
+
/*
* Write the MMP block using WRITE_SYNC to try to get the block on-disk
* faster.
*/
-static int write_mmp_block(struct buffer_head *bh)
+static int write_mmp_block(struct super_block *sb, struct buffer_head *bh)
{
+ struct mmp_struct *mmp = (struct mmp_struct *)(bh->b_data);
+
+ ext4_mmp_csum_set(sb, mmp);
mark_buffer_dirty(bh);
lock_buffer(bh);
bh->b_end_io = end_buffer_write_sync;
@@ -59,7 +92,8 @@ static int read_mmp_block(struct super_block *sb, struct buffer_head **bh,
}
mmp = (struct mmp_struct *)((*bh)->b_data);
- if (le32_to_cpu(mmp->mmp_magic) != EXT4_MMP_MAGIC)
+ if (le32_to_cpu(mmp->mmp_magic) != EXT4_MMP_MAGIC ||
+ !ext4_mmp_csum_verify(sb, mmp))
return -EINVAL;
return 0;
@@ -120,7 +154,7 @@ static int kmmpd(void *data)
mmp->mmp_time = cpu_to_le64(get_seconds());
last_update_time = jiffies;
- retval = write_mmp_block(bh);
+ retval = write_mmp_block(sb, bh);
/*
* Don't spew too many error messages. Print one every
* (s_mmp_update_interval * 60) seconds.
@@ -200,7 +234,7 @@ static int kmmpd(void *data)
mmp->mmp_seq = cpu_to_le32(EXT4_MMP_SEQ_CLEAN);
mmp->mmp_time = cpu_to_le64(get_seconds());
- retval = write_mmp_block(bh);
+ retval = write_mmp_block(sb, bh);
failed:
kfree(data);
@@ -299,7 +333,7 @@ skip:
seq = mmp_new_seq();
mmp->mmp_seq = cpu_to_le32(seq);
- retval = write_mmp_block(bh);
+ retval = write_mmp_block(sb, bh);
if (retval)
goto failed;