fs/ufs: use ktime_get_real_seconds for sb and cg timestamps

get_seconds() is deprecated because of the 32-bit overflow and will be
removed.  All callers in ufs also truncate to a 32-bit number, so
nothing changes during the conversion, but this should be harmless as
the superblock and cylinder group timestamps are not visible to user
space, except for checking the fs-dirty state, wich works fine across
the overflow.

This moves the call to get_seconds() into a new inline function, with a
comment explaining the constraints, while converting it to
ktime_get_real_seconds().

Link: http://lkml.kernel.org/r/20180718115017.742609-1-arnd@arndb.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/ufs/balloc.c b/fs/ufs/balloc.c
index e727ee07dbe4ac1a824d8626f917d4a561e3eb0a..075d3d9114c8fa961df937fb80d9d8a1cb4eb417 100644 (file)
--- a/fs/ufs/balloc.c
+++ b/fs/ufs/balloc.c
@@ -547,7 +547,7 @@ static u64 ufs_add_fragments(struct inode *inode, u64 fragment,
        /*
         * Block can be extended
         */
-       ucg->cg_time = cpu_to_fs32(sb, get_seconds());
+       ucg->cg_time = ufs_get_seconds(sb);
        for (i = newcount; i < (uspi->s_fpb - fragoff); i++)
                if (ubh_isclr (UCPI_UBH(ucpi), ucpi->c_freeoff, fragno + i))
                        break;
@@ -639,7 +639,7 @@ cg_found:
        if (!ufs_cg_chkmagic(sb, ucg)) 
                ufs_panic (sb, "ufs_alloc_fragments",
                        "internal error, bad magic number on cg %u", cgno);
-       ucg->cg_time = cpu_to_fs32(sb, get_seconds());
+       ucg->cg_time = ufs_get_seconds(sb);
 
        if (count == uspi->s_fpb) {
                result = ufs_alloccg_block (inode, ucpi, goal, err);

diff --git a/fs/ufs/ialloc.c b/fs/ufs/ialloc.c
index 02c0a4be421295c3d8ad28368eaba90ed4449e7c..969fd60436d395ec6fbf8606aa1308e05748c25a 100644 (file)
--- a/fs/ufs/ialloc.c
+++ b/fs/ufs/ialloc.c
@@ -89,7 +89,7 @@ void ufs_free_inode (struct inode * inode)
        if (!ufs_cg_chkmagic(sb, ucg))
                ufs_panic (sb, "ufs_free_fragments", "internal error, bad cg magic number");
 
-       ucg->cg_time = cpu_to_fs32(sb, get_seconds());
+       ucg->cg_time = ufs_get_seconds(sb);
 
        is_directory = S_ISDIR(inode->i_mode);
 

diff --git a/fs/ufs/super.c b/fs/ufs/super.c
index 488088141451ba6c9dab80dd0c96a1502100b3f7..a4e07e910f1b4c7d679645c2d3941c8e19f75ee4 100644 (file)
--- a/fs/ufs/super.c
+++ b/fs/ufs/super.c
@@ -698,7 +698,7 @@ static int ufs_sync_fs(struct super_block *sb, int wait)
        usb1 = ubh_get_usb_first(uspi);
        usb3 = ubh_get_usb_third(uspi);
 
-       usb1->fs_time = cpu_to_fs32(sb, get_seconds());
+       usb1->fs_time = ufs_get_seconds(sb);
        if ((flags & UFS_ST_MASK) == UFS_ST_SUN  ||
            (flags & UFS_ST_MASK) == UFS_ST_SUNOS ||
            (flags & UFS_ST_MASK) == UFS_ST_SUNx86)
@@ -1342,7 +1342,7 @@ static int ufs_remount (struct super_block *sb, int *mount_flags, char *data)
         */
        if (*mount_flags & SB_RDONLY) {
                ufs_put_super_internal(sb);
-               usb1->fs_time = cpu_to_fs32(sb, get_seconds());
+               usb1->fs_time = ufs_get_seconds(sb);
                if ((flags & UFS_ST_MASK) == UFS_ST_SUN
                  || (flags & UFS_ST_MASK) == UFS_ST_SUNOS
                  || (flags & UFS_ST_MASK) == UFS_ST_SUNx86) 

diff --git a/fs/ufs/util.h b/fs/ufs/util.h
index 1907be6d580855bf595f169ea82e7abca2d7df76..1fd3011ea6236b6f0bcb04bd52051c0ffd930cda 100644 (file)
--- a/fs/ufs/util.h
+++ b/fs/ufs/util.h
@@ -590,3 +590,17 @@ static inline int ufs_is_data_ptr_zero(struct ufs_sb_private_info *uspi,
        else
                return *(__fs32 *)p == 0;
 }
+
+static inline __fs32 ufs_get_seconds(struct super_block *sbp)
+{
+       time64_t now = ktime_get_real_seconds();
+
+       /* Signed 32-bit interpretation wraps around in 2038, which
+        * happens in ufs1 inode stamps but not ufs2 using 64-bits
+        * stamps. For superblock and blockgroup, let's assume
+        * unsigned 32-bit stamps, which are good until y2106.
+        * Wrap around rather than clamp here to make the dirty
+        * file system detection work in the superblock stamp.
+        */
+       return cpu_to_fs32(sbp, lower_32_bits(now));
+}