Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 updates from Ted Ts'o:

 - Add support for online resizing of file systems with bigalloc

 - Fix a two data corruption bugs involving DAX, as well as a corruption
   bug after a crash during a racing fallocate and delayed allocation.

 - Finally, a number of cleanups and optimizations.

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: improve smp scalability for inode generation
  ext4: add support for online resizing with bigalloc
  ext4: mention noload when recovering on read-only device
  Documentation: fix little inconsistencies
  ext4: convert timers to use timer_setup()
  jbd2: convert timers to use timer_setup()
  ext4: remove duplicate extended attributes defs
  ext4: add ext4_should_use_dax()
  ext4: add sanity check for encryption + DAX
  ext4: prevent data corruption with journaling + DAX
  ext4: prevent data corruption with inline data + DAX
  ext4: fix interaction between i_size, fallocate, and delalloc after a crash
  ext4: retry allocations conservatively
  ext4: Switch to iomap for SEEK_HOLE / SEEK_DATA
  ext4: Add iomap support for inline data
  iomap: Add IOMAP_F_DATA_INLINE flag
  iomap: Switch from blkno to disk offset

1 files changed, 16 insertions, 14 deletions

diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index 75d83471f65c..b7558f292420 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -15,6 +15,7 @@
 #include <linux/mount.h>
 #include <linux/file.h>
 #include <linux/quotaops.h>
+#include <linux/random.h>
 #include <linux/uuid.h>
 #include <linux/uaccess.h>
 #include <linux/delay.h>
@@ -99,7 +100,6 @@ static long swap_inode_boot_loader(struct super_block *sb,
         int err;
         struct inode *inode_bl;
         struct ext4_inode_info *ei_bl;
-        struct ext4_sb_info *sbi = EXT4_SB(sb);
 
         if (inode->i_nlink != 1 || !S_ISREG(inode->i_mode))
                 return -EINVAL;
@@ -158,10 +158,8 @@ static long swap_inode_boot_loader(struct super_block *sb,
 
         inode->i_ctime = inode_bl->i_ctime = current_time(inode);
 
-        spin_lock(&sbi->s_next_gen_lock);
-        inode->i_generation = sbi->s_next_generation++;
-        inode_bl->i_generation = sbi->s_next_generation++;
-        spin_unlock(&sbi->s_next_gen_lock);
+        inode->i_generation = prandom_u32();
+        inode_bl->i_generation = prandom_u32();
 
         ext4_discard_preallocations(inode);
 
@@ -291,10 +289,20 @@ flags_err:
         if (err)
                 goto flags_out;
 
-        if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL))
+        if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL)) {
+                /*
+                 * Changes to the journaling mode can cause unsafe changes to
+                 * S_DAX if we are using the DAX mount option.
+                 */
+                if (test_opt(inode->i_sb, DAX)) {
+                        err = -EBUSY;
+                        goto flags_out;
+                }
+
                 err = ext4_change_inode_journal_flag(inode, jflag);
-        if (err)
-                goto flags_out;
+                if (err)
+                        goto flags_out;
+        }
         if (migrate) {
                 if (flags & EXT4_EXTENTS_FL)
                         err = ext4_ext_migrate(inode);
@@ -862,12 +870,6 @@ group_add_out:
                 int err = 0, err2 = 0;
                 ext4_group_t o_group = EXT4_SB(sb)->s_groups_count;
 
-                if (ext4_has_feature_bigalloc(sb)) {
-                        ext4_msg(sb, KERN_ERR,
-                                 "Online resizing not (yet) supported with bigalloc");
-                        return -EOPNOTSUPP;
-                }
-
                 if (copy_from_user(&n_blocks_count, (__u64 __user *)arg,
                                    sizeof(__u64))) {
                         return -EFAULT;