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Message-Id: <1503080382-37376-1-git-send-email-adilger@dilger.ca>
Date: Fri, 18 Aug 2017 12:19:42 -0600
From: Andreas Dilger <adilger@...ger.ca>
To: tytso@....edu
Cc: linux-ext4@...r.kernel.org, Andreas Dilger <adilger@...ger.ca>
Subject: [PATCH] e2fsck: set dir_nlink feature if large dir exists
If there is a directory with more than EXT2_LINK_MAX (65000)
subdirectories, but the DIR_NLINK feature is not set in the
superblock, the feature should be set before continuing on
to change the on-disk directory link count to 1.
While most filesystems should have DIR_NLINK set (it was set
by default for all ext4 filesystems, and the kernel before
4.12 automatically set it if the directory link count grew
too large), it is possible that this flag is lost due to disk
corruption or for an upgraded filesystem. We no longer want
the kernel to automatically enable this feature.
Addresses: https://bugzilla.kernel.org/show_bug.cgi?id=196405
Signed-off-by: Andreas Dilger <adilger@...ger.ca>
---
e2fsck/pass4.c | 12 +++++++++-
e2fsck/problem.c | 5 ++++
e2fsck/problem.h | 3 +++
tests/f_large_dir/expect | 7 ++++--
tests/f_large_dir/script | 60 ++++++++++++++++++++++++++++++------------------
5 files changed, 62 insertions(+), 25 deletions(-)
diff --git a/e2fsck/pass4.c b/e2fsck/pass4.c
index 663f87a..d0ff8e9 100644
--- a/e2fsck/pass4.c
+++ b/e2fsck/pass4.c
@@ -170,6 +170,7 @@ void e2fsck_pass4(e2fsck_t ctx)
#endif
struct problem_context pctx;
__u16 link_count, link_counted;
+ int dir_nlink_fs;
char *buf = 0;
dgrp_t group, maxgroup;
@@ -193,6 +194,8 @@ void e2fsck_pass4(e2fsck_t ctx)
if (!(ctx->options & E2F_OPT_PREEN))
fix_problem(ctx, PR_4_PASS_HEADER, &pctx);
+ dir_nlink_fs = ext2fs_has_feature_dir_nlink(fs->super);
+
group = 0;
maxgroup = fs->group_desc_count;
if (ctx->progress)
@@ -249,8 +252,15 @@ void e2fsck_pass4(e2fsck_t ctx)
&link_counted);
}
isdir = ext2fs_test_inode_bitmap2(ctx->inode_dir_map, i);
- if (isdir && (link_counted > EXT2_LINK_MAX))
+ if (isdir && (link_counted > EXT2_LINK_MAX)) {
+ if (!dir_nlink_fs &&
+ fix_problem(ctx, PR_4_DIR_NLINK_FEATURE, &pctx)) {
+ ext2fs_set_feature_dir_nlink(fs->super);
+ ext2fs_mark_super_dirty(fs);
+ dir_nlink_fs = 1;
+ }
link_counted = 1;
+ }
if (link_counted != link_count) {
e2fsck_read_inode_full(ctx, i, EXT2_INODE(inode),
inode_size, "pass4");
diff --git a/e2fsck/problem.c b/e2fsck/problem.c
index 9706933..25c1de9 100644
--- a/e2fsck/problem.c
+++ b/e2fsck/problem.c
@@ -1873,6 +1873,11 @@ static struct e2fsck_problem problem_table[] = {
N_("@a @i %i ref count is %N, @s %n. "),
PROMPT_FIX, PR_PREEN_OK },
+ /* directory exceeds max links, but no DIR_NLINK feature in superblock*/
+ { PR_4_DIR_NLINK_FEATURE,
+ N_("@d exceeds max links, but no DIR_NLINK feature in @S.\n"),
+ PROMPT_FIX, 0 },
+
/* Pass 5 errors */
/* Pass 5: Checking group summary information */
diff --git a/e2fsck/problem.h b/e2fsck/problem.h
index f30f8f0..07ed0a7 100644
--- a/e2fsck/problem.h
+++ b/e2fsck/problem.h
@@ -1134,6 +1134,9 @@ struct problem_context {
/* Extended attribute inode ref count wrong */
#define PR_4_EA_INODE_REF_COUNT 0x040005
+/* directory exceeds max links, but no DIR_NLINK feature in superblock */
+#define PR_4_DIR_NLINK_FEATURE 0x040006
+
/*
* Pass 5 errors
*/
diff --git a/tests/f_large_dir/expect b/tests/f_large_dir/expect
index b099460..4b9ca6f 100644
--- a/tests/f_large_dir/expect
+++ b/tests/f_large_dir/expect
@@ -3,10 +3,13 @@ Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 3A: Optimizing directories
Pass 4: Checking reference counts
-Inode 13 ref count is 1, should be 47245. Fix? yes
+Directory exceeds max links, but no DIR_NLINK feature in superblock.
+Fix? yes
+
+Inode 12 ref count is 65012, should be 1. Fix? yes
Pass 5: Checking group summary information
test.img: ***** FILE SYSTEM WAS MODIFIED *****
-test.img: 13/115368 files (0.0% non-contiguous), 32817/460800 blocks
+test.img: 65023/65104 files (0.0% non-contiguous), 96668/100937 blocks
Exit status is 1
diff --git a/tests/f_large_dir/script b/tests/f_large_dir/script
index 0b5fdff..a10fe16 100644
--- a/tests/f_large_dir/script
+++ b/tests/f_large_dir/script
@@ -5,43 +5,59 @@ E2FSCK=../e2fsck/e2fsck
NAMELEN=255
DIRENT_SZ=8
BLOCKSZ=1024
+INODESZ=128
DIRENT_PER_LEAF=$((BLOCKSZ / (NAMELEN + DIRENT_SZ)))
HEADER=32
INDEX_SZ=8
INDEX_L1=$(((BLOCKSZ - HEADER) / INDEX_SZ))
INDEX_L2=$(((BLOCKSZ - DIRENT_SZ) / INDEX_SZ))
ENTRIES=$((INDEX_L1 * INDEX_L2 * DIRENT_PER_LEAF))
+DIRBLK=$((2 + INDEX_L1 * INDEX_L2))
+EXT4_LINK_MAX=65000
+[ $ENTRIES -lt $((EXT4_LINK_MAX + 10)) ] && ENTRIES=$((EXT4_LINK_MAX + 10))
+FSIZE=$(((DIRBLK + EXT4_LINK_MAX * ((BLOCKSZ + INODESZ) / BLOCKSZ)) * 5 / 4))
-cp /dev/null $OUT
-$MKE2FS -b 1024 -O large_dir,uninit_bg,dir_nlink -F $TMPFILE 460800 \
- > /dev/null 2>&1
+> $OUT
+$MKE2FS -b 1024 -O large_dir,uninit_bg -N $((ENTRIES + 50)) \
+ -I $INODESZ -F $TMPFILE $FSIZE > $OUT 2>&1
+RC=$?
+if [ $RC -eq 0 ]; then
{
- echo "feature large_dir"
+ START=$SECONDS
echo "mkdir /foo"
echo "cd /foo"
- touch foofile
- echo "write foofile foofile"
+ touch $TMPFILE.tmp
+ echo "write $TMPFILE.tmp foofile"
i=0
- while test $i -lt $ENTRIES ; do
- if test $(( i % DIRENT_PER_LEAF )) -eq 0 ; then
- echo "expand ./"
+ while test $i -lt $ENTRIES ; do
+ if test $((i % DIRENT_PER_LEAF)) -eq 0; then
+ echo "expand ./"
fi
- if test $(( i % 5000 )) -eq 0 -a $i -gt 0 ; then
- >&2 echo "$test_name: $i processed"
+ if test $((i % 5000)) -eq 0 -a $i -gt 0; then
+ ELAPSED=$((SECONDS - START))
+ RATE=$((i / ELAPSED))
+ >&2 echo "$test_name: $i processed in ${ELAPSED}s @ $RATE/s"
fi
- printf "ln foofile %0255X\n" $i
- i=$(($i + 1))
+ if test $i -lt $((EXT4_LINK_MAX + 10)); then
+ printf "mkdir d%0254u\n" $i
+ else
+ printf "ln foofile f%0254u\n" $i
+ fi
+ i=$((i + 1))
done
-} | $DEBUGFS -w -f /dev/stdin $TMPFILE > /dev/null 2>&1
-
-$E2FSCK -yfD $TMPFILE > $OUT.new 2>&1
-status=$?
-echo Exit status is $status >> $OUT.new
-sed -f $cmd_dir/filter.sed -e "s;$TMPFILE;test.img;" $OUT.new >> $OUT
-rm -f $OUT.new
+} | $DEBUGFS -w -f /dev/stdin $TMPFILE > $OUT
+ RC=$?
+fi
+if [ $RC -eq 0 ]; then
+ $E2FSCK -yfD $TMPFILE > $OUT.new 2>&1
+ status=$?
+ echo "Exit status is $status" >> $OUT.new
+ sed -f $cmd_dir/filter.sed -e "s;$TMPFILE;test.img;" $OUT.new > $OUT
+ rm -f $OUT.new
-cmp -s $OUT $EXP
-RC=$?
+ cmp -s $OUT $EXP
+ RC=$?
+fi
if [ $RC -eq 0 ]; then
echo "$test_name: $test_description: ok"
touch $test_name.ok
--
1.8.0
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