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| author | Amir Goldstein <amir73il@gmail.com> | 2018-05-13 22:54:44 -0400 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2018-05-13 22:54:44 -0400 |
| commit | db6516a5e7ddb6dc72d167b920f2f272596ea22d (patch) | |
| tree | ce820da46d4ef3e3f6f0a688f326d408ba8c506f | |
| parent | 833a950882d33a7dfc319d5e152fdf35028936eb (diff) | |
| download | linux-db6516a5e7ddb6dc72d167b920f2f272596ea22d.tar.bz2 | |
ext4: do not update s_last_mounted of a frozen fs
If fs is frozen after mount and before the first file open, the
update of s_last_mounted bypasses freeze protection and prints out
a WARNING splat:
$ mount /vdf
$ fsfreeze -f /vdf
$ cat /vdf/foo
[ 31.578555] WARNING: CPU: 1 PID: 1415 at
fs/ext4/ext4_jbd2.c:53 ext4_journal_check_start+0x48/0x82
[ 31.614016] Call Trace:
[ 31.614997] __ext4_journal_start_sb+0xe4/0x1a4
[ 31.616771] ? ext4_file_open+0xb6/0x189
[ 31.618094] ext4_file_open+0xb6/0x189
If fs is frozen, skip s_last_mounted update.
[backport hint: to apply to stable tree, need to apply also patches
vfs: add the sb_start_intwrite_trylock() helper
ext4: factor out helper ext4_sample_last_mounted()]
Cc: stable@vger.kernel.org
Fixes: bc0b0d6d69ee ("ext4: update the s_last_mounted field in the superblock")
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
| -rw-r--r-- | fs/ext4/file.c | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/fs/ext4/file.c b/fs/ext4/file.c index c48ea76b63e4..7f8023340eb8 100644 --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -393,7 +393,7 @@ static int ext4_sample_last_mounted(struct super_block *sb, if (likely(sbi->s_mount_flags & EXT4_MF_MNTDIR_SAMPLED)) return 0; - if (sb_rdonly(sb)) + if (sb_rdonly(sb) || !sb_start_intwrite_trylock(sb)) return 0; sbi->s_mount_flags |= EXT4_MF_MNTDIR_SAMPLED; @@ -407,21 +407,25 @@ static int ext4_sample_last_mounted(struct super_block *sb, path.mnt = mnt; path.dentry = mnt->mnt_root; cp = d_path(&path, buf, sizeof(buf)); + err = 0; if (IS_ERR(cp)) - return 0; + goto out; handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1); + err = PTR_ERR(handle); if (IS_ERR(handle)) - return PTR_ERR(handle); + goto out; BUFFER_TRACE(sbi->s_sbh, "get_write_access"); err = ext4_journal_get_write_access(handle, sbi->s_sbh); if (err) - goto out; + goto out_journal; strlcpy(sbi->s_es->s_last_mounted, cp, sizeof(sbi->s_es->s_last_mounted)); ext4_handle_dirty_super(handle, sb); -out: +out_journal: ext4_journal_stop(handle); +out: + sb_end_intwrite(sb); return err; } |