Merge branch 'master' into for-next

Conflicts:
	drivers/devfreq/exynos4_bus.c

Sync with Linus' tree to be able to apply patches that are
against newer code (mvneta).

1 files changed, 381 insertions, 59 deletions

diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 2778258fcfa2..66282dcb821b 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -45,6 +45,7 @@
 #include "xfs_filestream.h"
 #include "xfs_vnodeops.h"
 #include "xfs_trace.h"
+#include "xfs_icache.h"
 
 kmem_zone_t *xfs_ifork_zone;
 kmem_zone_t *xfs_inode_zone;
@@ -74,6 +75,256 @@ xfs_get_extsz_hint(
         return 0;
 }
 
+/*
+ * This is a wrapper routine around the xfs_ilock() routine used to centralize
+ * some grungy code.  It is used in places that wish to lock the inode solely
+ * for reading the extents.  The reason these places can't just call
+ * xfs_ilock(SHARED) is that the inode lock also guards to bringing in of the
+ * extents from disk for a file in b-tree format.  If the inode is in b-tree
+ * format, then we need to lock the inode exclusively until the extents are read
+ * in.  Locking it exclusively all the time would limit our parallelism
+ * unnecessarily, though.  What we do instead is check to see if the extents
+ * have been read in yet, and only lock the inode exclusively if they have not.
+ *
+ * The function returns a value which should be given to the corresponding
+ * xfs_iunlock_map_shared().  This value is the mode in which the lock was
+ * actually taken.
+ */
+uint
+xfs_ilock_map_shared(
+        xfs_inode_t     *ip)
+{
+        uint    lock_mode;
+
+        if ((ip->i_d.di_format == XFS_DINODE_FMT_BTREE) &&
+            ((ip->i_df.if_flags & XFS_IFEXTENTS) == 0)) {
+                lock_mode = XFS_ILOCK_EXCL;
+        } else {
+                lock_mode = XFS_ILOCK_SHARED;
+        }
+
+        xfs_ilock(ip, lock_mode);
+
+        return lock_mode;
+}
+
+/*
+ * This is simply the unlock routine to go with xfs_ilock_map_shared().
+ * All it does is call xfs_iunlock() with the given lock_mode.
+ */
+void
+xfs_iunlock_map_shared(
+        xfs_inode_t     *ip,
+        unsigned int    lock_mode)
+{
+        xfs_iunlock(ip, lock_mode);
+}
+
+/*
+ * The xfs inode contains 2 locks: a multi-reader lock called the
+ * i_iolock and a multi-reader lock called the i_lock.  This routine
+ * allows either or both of the locks to be obtained.
+ *
+ * The 2 locks should always be ordered so that the IO lock is
+ * obtained first in order to prevent deadlock.
+ *
+ * ip -- the inode being locked
+ * lock_flags -- this parameter indicates the inode's locks
+ *       to be locked.  It can be:
+ *              XFS_IOLOCK_SHARED,
+ *              XFS_IOLOCK_EXCL,
+ *              XFS_ILOCK_SHARED,
+ *              XFS_ILOCK_EXCL,
+ *              XFS_IOLOCK_SHARED | XFS_ILOCK_SHARED,
+ *              XFS_IOLOCK_SHARED | XFS_ILOCK_EXCL,
+ *              XFS_IOLOCK_EXCL | XFS_ILOCK_SHARED,
+ *              XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL
+ */
+void
+xfs_ilock(
+        xfs_inode_t             *ip,
+        uint                    lock_flags)
+{
+        trace_xfs_ilock(ip, lock_flags, _RET_IP_);
+
+        /*
+         * You can't set both SHARED and EXCL for the same lock,
+         * and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED,
+         * and XFS_ILOCK_EXCL are valid values to set in lock_flags.
+         */
+        ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) !=
+               (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL));
+        ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) !=
+               (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
+        ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_LOCK_DEP_MASK)) == 0);
+
+        if (lock_flags & XFS_IOLOCK_EXCL)
+                mrupdate_nested(&ip->i_iolock, XFS_IOLOCK_DEP(lock_flags));
+        else if (lock_flags & XFS_IOLOCK_SHARED)
+                mraccess_nested(&ip->i_iolock, XFS_IOLOCK_DEP(lock_flags));
+
+        if (lock_flags & XFS_ILOCK_EXCL)
+                mrupdate_nested(&ip->i_lock, XFS_ILOCK_DEP(lock_flags));
+        else if (lock_flags & XFS_ILOCK_SHARED)
+                mraccess_nested(&ip->i_lock, XFS_ILOCK_DEP(lock_flags));
+}
+
+/*
+ * This is just like xfs_ilock(), except that the caller
+ * is guaranteed not to sleep.  It returns 1 if it gets
+ * the requested locks and 0 otherwise.  If the IO lock is
+ * obtained but the inode lock cannot be, then the IO lock
+ * is dropped before returning.
+ *
+ * ip -- the inode being locked
+ * lock_flags -- this parameter indicates the inode's locks to be
+ *       to be locked.  See the comment for xfs_ilock() for a list
+ *       of valid values.
+ */
+int
+xfs_ilock_nowait(
+        xfs_inode_t             *ip,
+        uint                    lock_flags)
+{
+        trace_xfs_ilock_nowait(ip, lock_flags, _RET_IP_);
+
+        /*
+         * You can't set both SHARED and EXCL for the same lock,
+         * and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED,
+         * and XFS_ILOCK_EXCL are valid values to set in lock_flags.
+         */
+        ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) !=
+               (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL));
+        ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) !=
+               (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
+        ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_LOCK_DEP_MASK)) == 0);
+
+        if (lock_flags & XFS_IOLOCK_EXCL) {
+                if (!mrtryupdate(&ip->i_iolock))
+                        goto out;
+        } else if (lock_flags & XFS_IOLOCK_SHARED) {
+                if (!mrtryaccess(&ip->i_iolock))
+                        goto out;
+        }
+        if (lock_flags & XFS_ILOCK_EXCL) {
+                if (!mrtryupdate(&ip->i_lock))
+                        goto out_undo_iolock;
+        } else if (lock_flags & XFS_ILOCK_SHARED) {
+                if (!mrtryaccess(&ip->i_lock))
+                        goto out_undo_iolock;
+        }
+        return 1;
+
+ out_undo_iolock:
+        if (lock_flags & XFS_IOLOCK_EXCL)
+                mrunlock_excl(&ip->i_iolock);
+        else if (lock_flags & XFS_IOLOCK_SHARED)
+                mrunlock_shared(&ip->i_iolock);
+ out:
+        return 0;
+}
+
+/*
+ * xfs_iunlock() is used to drop the inode locks acquired with
+ * xfs_ilock() and xfs_ilock_nowait().  The caller must pass
+ * in the flags given to xfs_ilock() or xfs_ilock_nowait() so
+ * that we know which locks to drop.
+ *
+ * ip -- the inode being unlocked
+ * lock_flags -- this parameter indicates the inode's locks to be
+ *       to be unlocked.  See the comment for xfs_ilock() for a list
+ *       of valid values for this parameter.
+ *
+ */
+void
+xfs_iunlock(
+        xfs_inode_t             *ip,
+        uint                    lock_flags)
+{
+        /*
+         * You can't set both SHARED and EXCL for the same lock,
+         * and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED,
+         * and XFS_ILOCK_EXCL are valid values to set in lock_flags.
+         */
+        ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) !=
+               (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL));
+        ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) !=
+               (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
+        ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_LOCK_DEP_MASK)) == 0);
+        ASSERT(lock_flags != 0);
+
+        if (lock_flags & XFS_IOLOCK_EXCL)
+                mrunlock_excl(&ip->i_iolock);
+        else if (lock_flags & XFS_IOLOCK_SHARED)
+                mrunlock_shared(&ip->i_iolock);
+
+        if (lock_flags & XFS_ILOCK_EXCL)
+                mrunlock_excl(&ip->i_lock);
+        else if (lock_flags & XFS_ILOCK_SHARED)
+                mrunlock_shared(&ip->i_lock);
+
+        trace_xfs_iunlock(ip, lock_flags, _RET_IP_);
+}
+
+/*
+ * give up write locks.  the i/o lock cannot be held nested
+ * if it is being demoted.
+ */
+void
+xfs_ilock_demote(
+        xfs_inode_t             *ip,
+        uint                    lock_flags)
+{
+        ASSERT(lock_flags & (XFS_IOLOCK_EXCL|XFS_ILOCK_EXCL));
+        ASSERT((lock_flags & ~(XFS_IOLOCK_EXCL|XFS_ILOCK_EXCL)) == 0);
+
+        if (lock_flags & XFS_ILOCK_EXCL)
+                mrdemote(&ip->i_lock);
+        if (lock_flags & XFS_IOLOCK_EXCL)
+                mrdemote(&ip->i_iolock);
+
+        trace_xfs_ilock_demote(ip, lock_flags, _RET_IP_);
+}
+
+#ifdef DEBUG
+int
+xfs_isilocked(
+        xfs_inode_t             *ip,
+        uint                    lock_flags)
+{
+        if (lock_flags & (XFS_ILOCK_EXCL|XFS_ILOCK_SHARED)) {
+                if (!(lock_flags & XFS_ILOCK_SHARED))
+                        return !!ip->i_lock.mr_writer;
+                return rwsem_is_locked(&ip->i_lock.mr_lock);
+        }
+
+        if (lock_flags & (XFS_IOLOCK_EXCL|XFS_IOLOCK_SHARED)) {
+                if (!(lock_flags & XFS_IOLOCK_SHARED))
+                        return !!ip->i_iolock.mr_writer;
+                return rwsem_is_locked(&ip->i_iolock.mr_lock);
+        }
+
+        ASSERT(0);
+        return 0;
+}
+#endif
+
+void
+__xfs_iflock(
+        struct xfs_inode        *ip)
+{
+        wait_queue_head_t *wq = bit_waitqueue(&ip->i_flags, __XFS_IFLOCK_BIT);
+        DEFINE_WAIT_BIT(wait, &ip->i_flags, __XFS_IFLOCK_BIT);
+
+        do {
+                prepare_to_wait_exclusive(wq, &wait.wait, TASK_UNINTERRUPTIBLE);
+                if (xfs_isiflocked(ip))
+                        io_schedule();
+        } while (!xfs_iflock_nowait(ip));
+
+        finish_wait(wq, &wait.wait);
+}
+
 #ifdef DEBUG
 /*
  * Make sure that the extents in the given memory buffer
@@ -131,6 +382,65 @@ xfs_inobp_check(
 }
 #endif
 
+static void
+xfs_inode_buf_verify(
+        struct xfs_buf  *bp)
+{
+        struct xfs_mount *mp = bp->b_target->bt_mount;
+        int             i;
+        int             ni;
+
+        /*
+         * Validate the magic number and version of every inode in the buffer
+         */
+        ni = XFS_BB_TO_FSB(mp, bp->b_length) * mp->m_sb.sb_inopblock;
+        for (i = 0; i < ni; i++) {
+                int             di_ok;
+                xfs_dinode_t    *dip;
+
+                dip = (struct xfs_dinode *)xfs_buf_offset(bp,
+                                        (i << mp->m_sb.sb_inodelog));
+                di_ok = dip->di_magic == cpu_to_be16(XFS_DINODE_MAGIC) &&
+                            XFS_DINODE_GOOD_VERSION(dip->di_version);
+                if (unlikely(XFS_TEST_ERROR(!di_ok, mp,
+                                                XFS_ERRTAG_ITOBP_INOTOBP,
+                                                XFS_RANDOM_ITOBP_INOTOBP))) {
+                        xfs_buf_ioerror(bp, EFSCORRUPTED);
+                        XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_HIGH,
+                                             mp, dip);
+#ifdef DEBUG
+                        xfs_emerg(mp,
+                                "bad inode magic/vsn daddr %lld #%d (magic=%x)",
+                                (unsigned long long)bp->b_bn, i,
+                                be16_to_cpu(dip->di_magic));
+                        ASSERT(0);
+#endif
+                }
+        }
+        xfs_inobp_check(mp, bp);
+}
+
+
+static void
+xfs_inode_buf_read_verify(
+        struct xfs_buf  *bp)
+{
+        xfs_inode_buf_verify(bp);
+}
+
+static void
+xfs_inode_buf_write_verify(
+        struct xfs_buf  *bp)
+{
+        xfs_inode_buf_verify(bp);
+}
+
+const struct xfs_buf_ops xfs_inode_buf_ops = {
+        .verify_read = xfs_inode_buf_read_verify,
+        .verify_write = xfs_inode_buf_write_verify,
+};
+
+
 /*
  * This routine is called to map an inode to the buffer containing the on-disk
  * version of the inode.  It returns a pointer to the buffer containing the
@@ -145,71 +455,33 @@ xfs_imap_to_bp(
         struct xfs_mount        *mp,
         struct xfs_trans        *tp,
         struct xfs_imap         *imap,
-        struct xfs_dinode       **dipp,
+        struct xfs_dinode       **dipp,
         struct xfs_buf          **bpp,
         uint                    buf_flags,
         uint                    iget_flags)
 {
         struct xfs_buf          *bp;
         int                     error;
-        int                     i;
-        int                     ni;
 
         buf_flags |= XBF_UNMAPPED;
         error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, imap->im_blkno,
-                                   (int)imap->im_len, buf_flags, &bp);
+                                   (int)imap->im_len, buf_flags, &bp,
+                                   &xfs_inode_buf_ops);
         if (error) {
-                if (error != EAGAIN) {
-                        xfs_warn(mp,
-                                "%s: xfs_trans_read_buf() returned error %d.",
-                                __func__, error);
-                } else {
+                if (error == EAGAIN) {
                         ASSERT(buf_flags & XBF_TRYLOCK);
+                        return error;
                 }
-                return error;
-        }
-
-        /*
-         * Validate the magic number and version of every inode in the buffer
-         * (if DEBUG kernel) or the first inode in the buffer, otherwise.
-         */
-#ifdef DEBUG
-        ni = BBTOB(imap->im_len) >> mp->m_sb.sb_inodelog;
-#else   /* usual case */
-        ni = 1;
-#endif
 
-        for (i = 0; i < ni; i++) {
-                int             di_ok;
-                xfs_dinode_t    *dip;
+                if (error == EFSCORRUPTED &&
+                    (iget_flags & XFS_IGET_UNTRUSTED))
+                        return XFS_ERROR(EINVAL);
 
-                dip = (xfs_dinode_t *)xfs_buf_offset(bp,
-                                        (i << mp->m_sb.sb_inodelog));
-                di_ok = dip->di_magic == cpu_to_be16(XFS_DINODE_MAGIC) &&
-                            XFS_DINODE_GOOD_VERSION(dip->di_version);
-                if (unlikely(XFS_TEST_ERROR(!di_ok, mp,
-                                                XFS_ERRTAG_ITOBP_INOTOBP,
-                                                XFS_RANDOM_ITOBP_INOTOBP))) {
-                        if (iget_flags & XFS_IGET_UNTRUSTED) {
-                                xfs_trans_brelse(tp, bp);
-                                return XFS_ERROR(EINVAL);
-                        }
-                        XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_HIGH,
-                                             mp, dip);
-#ifdef DEBUG
-                        xfs_emerg(mp,
-                                "bad inode magic/vsn daddr %lld #%d (magic=%x)",
-                                (unsigned long long)imap->im_blkno, i,
-                                be16_to_cpu(dip->di_magic));
-                        ASSERT(0);
-#endif
-                        xfs_trans_brelse(tp, bp);
-                        return XFS_ERROR(EFSCORRUPTED);
-                }
+                xfs_warn(mp, "%s: xfs_trans_read_buf() returned error %d.",
+                        __func__, error);
+                return error;
         }
 
-        xfs_inobp_check(mp, bp);
-
         *bpp = bp;
         *dipp = (struct xfs_dinode *)xfs_buf_offset(bp, imap->im_boffset);
         return 0;
@@ -853,16 +1125,16 @@ xfs_iread_extents(
  * set according to the contents of the given cred structure.
  *
  * Use xfs_dialloc() to allocate the on-disk inode. If xfs_dialloc()
- * has a free inode available, call xfs_iget()
- * to obtain the in-core version of the allocated inode.  Finally,
- * fill in the inode and log its initial contents.  In this case,
- * ialloc_context would be set to NULL and call_again set to false.
+ * has a free inode available, call xfs_iget() to obtain the in-core
+ * version of the allocated inode.  Finally, fill in the inode and
+ * log its initial contents.  In this case, ialloc_context would be
+ * set to NULL.
  *
- * If xfs_dialloc() does not have an available inode,
- * it will replenish its supply by doing an allocation. Since we can
- * only do one allocation within a transaction without deadlocks, we
- * must commit the current transaction before returning the inode itself.
- * In this case, therefore, we will set call_again to true and return.
+ * If xfs_dialloc() does not have an available inode, it will replenish
+ * its supply by doing an allocation. Since we can only do one
+ * allocation within a transaction without deadlocks, we must commit
+ * the current transaction before returning the inode itself.
+ * In this case, therefore, we will set ialloc_context and return.
  * The caller should then commit the current transaction, start a new
  * transaction, and call xfs_ialloc() again to actually get the inode.
  *
@@ -1509,10 +1781,23 @@ xfs_ifree_cluster(
                  * to mark all the active inodes on the buffer stale.
                  */
                 bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, blkno,
-                                        mp->m_bsize * blks_per_cluster, 0);
+                                        mp->m_bsize * blks_per_cluster,
+                                        XBF_UNMAPPED);
 
                 if (!bp)
                         return ENOMEM;
+
+                /*
+                 * This buffer may not have been correctly initialised as we
+                 * didn't read it from disk. That's not important because we are
+                 * only using to mark the buffer as stale in the log, and to
+                 * attach stale cached inodes on it. That means it will never be
+                 * dispatched for IO. If it is, we want to know about it, and we
+                 * want it to fail. We can acheive this by adding a write
+                 * verifier to the buffer.
+                 */
+                 bp->b_ops = &xfs_inode_buf_ops;
+
                 /*
                  * Walk the inodes already attached to the buffer and mark them
                  * stale. These will all have the flush locks held, so an
@@ -3660,3 +3945,40 @@ xfs_iext_irec_update_extoffs(
                 ifp->if_u1.if_ext_irec[i].er_extoff += ext_diff;
         }
 }
+
+/*
+ * Test whether it is appropriate to check an inode for and free post EOF
+ * blocks. The 'force' parameter determines whether we should also consider
+ * regular files that are marked preallocated or append-only.
+ */
+bool
+xfs_can_free_eofblocks(struct xfs_inode *ip, bool force)
+{
+        /* prealloc/delalloc exists only on regular files */
+        if (!S_ISREG(ip->i_d.di_mode))
+                return false;
+
+        /*
+         * Zero sized files with no cached pages and delalloc blocks will not
+         * have speculative prealloc/delalloc blocks to remove.
+         */
+        if (VFS_I(ip)->i_size == 0 &&
+            VN_CACHED(VFS_I(ip)) == 0 &&
+            ip->i_delayed_blks == 0)
+                return false;
+
+        /* If we haven't read in the extent list, then don't do it now. */
+        if (!(ip->i_df.if_flags & XFS_IFEXTENTS))
+                return false;
+
+        /*
+         * Do not free real preallocated or append-only files unless the file
+         * has delalloc blocks and we are forced to remove them.
+         */
+        if (ip->i_d.di_flags & (XFS_DIFLAG_PREALLOC | XFS_DIFLAG_APPEND))
+                if (!force || ip->i_delayed_blks == 0)
+                        return false;
+
+        return true;
+}
+