Merge branch 'mpi-master' into wip-k-fmlpwip-k-fmlp

Conflicts:
	litmus/sched_cedf.c

1 files changed, 125 insertions, 4 deletions

diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index ee92b66d4558..2c0972322009 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -55,11 +55,47 @@ static int ext4_release_file(struct inode *inode, struct file *filp)
         return 0;
 }
 
+static void ext4_aiodio_wait(struct inode *inode)
+{
+        wait_queue_head_t *wq = ext4_ioend_wq(inode);
+
+        wait_event(*wq, (atomic_read(&EXT4_I(inode)->i_aiodio_unwritten) == 0));
+}
+
+/*
+ * This tests whether the IO in question is block-aligned or not.
+ * Ext4 utilizes unwritten extents when hole-filling during direct IO, and they
+ * are converted to written only after the IO is complete.  Until they are
+ * mapped, these blocks appear as holes, so dio_zero_block() will assume that
+ * it needs to zero out portions of the start and/or end block.  If 2 AIO
+ * threads are at work on the same unwritten block, they must be synchronized
+ * or one thread will zero the other's data, causing corruption.
+ */
+static int
+ext4_unaligned_aio(struct inode *inode, const struct iovec *iov,
+                   unsigned long nr_segs, loff_t pos)
+{
+        struct super_block *sb = inode->i_sb;
+        int blockmask = sb->s_blocksize - 1;
+        size_t count = iov_length(iov, nr_segs);
+        loff_t final_size = pos + count;
+
+        if (pos >= inode->i_size)
+                return 0;
+
+        if ((pos & blockmask) || (final_size & blockmask))
+                return 1;
+
+        return 0;
+}
+
 static ssize_t
 ext4_file_write(struct kiocb *iocb, const struct iovec *iov,
                 unsigned long nr_segs, loff_t pos)
 {
         struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode;
+        int unaligned_aio = 0;
+        int ret;
 
         /*
          * If we have encountered a bitmap-format file, the size limit
@@ -78,9 +114,31 @@ ext4_file_write(struct kiocb *iocb, const struct iovec *iov,
                         nr_segs = iov_shorten((struct iovec *)iov, nr_segs,
                                               sbi->s_bitmap_maxbytes - pos);
                 }
+        } else if (unlikely((iocb->ki_filp->f_flags & O_DIRECT) &&
+                   !is_sync_kiocb(iocb))) {
+                unaligned_aio = ext4_unaligned_aio(inode, iov, nr_segs, pos);
+        }
+
+        /* Unaligned direct AIO must be serialized; see comment above */
+        if (unaligned_aio) {
+                static unsigned long unaligned_warn_time;
+
+                /* Warn about this once per day */
+                if (printk_timed_ratelimit(&unaligned_warn_time, 60*60*24*HZ))
+                        ext4_msg(inode->i_sb, KERN_WARNING,
+                                 "Unaligned AIO/DIO on inode %ld by %s; "
+                                 "performance will be poor.",
+                                 inode->i_ino, current->comm);
+                mutex_lock(ext4_aio_mutex(inode));
+                ext4_aiodio_wait(inode);
         }
 
-        return generic_file_aio_write(iocb, iov, nr_segs, pos);
+        ret = generic_file_aio_write(iocb, iov, nr_segs, pos);
+
+        if (unaligned_aio)
+                mutex_unlock(ext4_aio_mutex(inode));
+
+        return ret;
 }
 
 static const struct vm_operations_struct ext4_file_vm_ops = {
@@ -104,6 +162,7 @@ static int ext4_file_open(struct inode * inode, struct file * filp)
 {
         struct super_block *sb = inode->i_sb;
         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+        struct ext4_inode_info *ei = EXT4_I(inode);
         struct vfsmount *mnt = filp->f_path.mnt;
         struct path path;
         char buf[64], *cp;
@@ -127,11 +186,74 @@ static int ext4_file_open(struct inode * inode, struct file * filp)
                         ext4_mark_super_dirty(sb);
                 }
         }
+        /*
+         * Set up the jbd2_inode if we are opening the inode for
+         * writing and the journal is present
+         */
+        if (sbi->s_journal && !ei->jinode && (filp->f_mode & FMODE_WRITE)) {
+                struct jbd2_inode *jinode = jbd2_alloc_inode(GFP_KERNEL);
+
+                spin_lock(&inode->i_lock);
+                if (!ei->jinode) {
+                        if (!jinode) {
+                                spin_unlock(&inode->i_lock);
+                                return -ENOMEM;
+                        }
+                        ei->jinode = jinode;
+                        jbd2_journal_init_jbd_inode(ei->jinode, inode);
+                        jinode = NULL;
+                }
+                spin_unlock(&inode->i_lock);
+                if (unlikely(jinode != NULL))
+                        jbd2_free_inode(jinode);
+        }
         return dquot_file_open(inode, filp);
 }
 
+/*
+ * ext4_llseek() copied from generic_file_llseek() to handle both
+ * block-mapped and extent-mapped maxbytes values. This should
+ * otherwise be identical with generic_file_llseek().
+ */
+loff_t ext4_llseek(struct file *file, loff_t offset, int origin)
+{
+        struct inode *inode = file->f_mapping->host;
+        loff_t maxbytes;
+
+        if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
+                maxbytes = EXT4_SB(inode->i_sb)->s_bitmap_maxbytes;
+        else
+                maxbytes = inode->i_sb->s_maxbytes;
+        mutex_lock(&inode->i_mutex);
+        switch (origin) {
+        case SEEK_END:
+                offset += inode->i_size;
+                break;
+        case SEEK_CUR:
+                if (offset == 0) {
+                        mutex_unlock(&inode->i_mutex);
+                        return file->f_pos;
+                }
+                offset += file->f_pos;
+                break;
+        }
+
+        if (offset < 0 || offset > maxbytes) {
+                mutex_unlock(&inode->i_mutex);
+                return -EINVAL;
+        }
+
+        if (offset != file->f_pos) {
+                file->f_pos = offset;
+                file->f_version = 0;
+        }
+        mutex_unlock(&inode->i_mutex);
+
+        return offset;
+}
+
 const struct file_operations ext4_file_operations = {
-        .llseek         = generic_file_llseek,
+        .llseek         = ext4_llseek,
         .read           = do_sync_read,
         .write          = do_sync_write,
         .aio_read       = generic_file_aio_read,
@@ -146,10 +268,10 @@ const struct file_operations ext4_file_operations = {
         .fsync          = ext4_sync_file,
         .splice_read    = generic_file_splice_read,
         .splice_write   = generic_file_splice_write,
+        .fallocate      = ext4_fallocate,
 };
 
 const struct inode_operations ext4_file_inode_operations = {
-        .truncate       = ext4_truncate,
         .setattr        = ext4_setattr,
         .getattr        = ext4_getattr,
 #ifdef CONFIG_EXT4_FS_XATTR
@@ -159,7 +281,6 @@ const struct inode_operations ext4_file_inode_operations = {
         .removexattr    = generic_removexattr,
 #endif
         .check_acl      = ext4_check_acl,
-        .fallocate      = ext4_fallocate,
         .fiemap         = ext4_fiemap,
 };