1 files changed, 361 insertions, 226 deletions

diff --git a/fs/xfs/linux-2.6/xfs_file.c b/fs/xfs/linux-2.6/xfs_file.c
index ba8ad422a165..a55c1b46b219 100644
--- a/fs/xfs/linux-2.6/xfs_file.c
+++ b/fs/xfs/linux-2.6/xfs_file.c
@@ -37,10 +37,45 @@
 #include "xfs_trace.h"
 
 #include <linux/dcache.h>
+#include <linux/falloc.h>
 
 static const struct vm_operations_struct xfs_file_vm_ops;
 
 /*
+ * Locking primitives for read and write IO paths to ensure we consistently use
+ * and order the inode->i_mutex, ip->i_lock and ip->i_iolock.
+ */
+static inline void
+xfs_rw_ilock(
+        struct xfs_inode        *ip,
+        int                     type)
+{
+        if (type & XFS_IOLOCK_EXCL)
+                mutex_lock(&VFS_I(ip)->i_mutex);
+        xfs_ilock(ip, type);
+}
+
+static inline void
+xfs_rw_iunlock(
+        struct xfs_inode        *ip,
+        int                     type)
+{
+        xfs_iunlock(ip, type);
+        if (type & XFS_IOLOCK_EXCL)
+                mutex_unlock(&VFS_I(ip)->i_mutex);
+}
+
+static inline void
+xfs_rw_ilock_demote(
+        struct xfs_inode        *ip,
+        int                     type)
+{
+        xfs_ilock_demote(ip, type);
+        if (type & XFS_IOLOCK_EXCL)
+                mutex_unlock(&VFS_I(ip)->i_mutex);
+}
+
+/*
  *      xfs_iozero
  *
  *      xfs_iozero clears the specified range of buffer supplied,
@@ -262,22 +297,21 @@ xfs_file_aio_read(
         if (XFS_FORCED_SHUTDOWN(mp))
                 return -EIO;
 
-        if (unlikely(ioflags & IO_ISDIRECT))
-                mutex_lock(&inode->i_mutex);
-        xfs_ilock(ip, XFS_IOLOCK_SHARED);
-
         if (unlikely(ioflags & IO_ISDIRECT)) {
+                xfs_rw_ilock(ip, XFS_IOLOCK_EXCL);
+
                 if (inode->i_mapping->nrpages) {
                         ret = -xfs_flushinval_pages(ip,
                                         (iocb->ki_pos & PAGE_CACHE_MASK),
                                         -1, FI_REMAPF_LOCKED);
+                        if (ret) {
+                                xfs_rw_iunlock(ip, XFS_IOLOCK_EXCL);
+                                return ret;
+                        }
                 }
-                mutex_unlock(&inode->i_mutex);
-                if (ret) {
-                        xfs_iunlock(ip, XFS_IOLOCK_SHARED);
-                        return ret;
-                }
-        }
+                xfs_rw_ilock_demote(ip, XFS_IOLOCK_EXCL);
+        } else
+                xfs_rw_ilock(ip, XFS_IOLOCK_SHARED);
 
         trace_xfs_file_read(ip, size, iocb->ki_pos, ioflags);
 
@@ -285,7 +319,7 @@ xfs_file_aio_read(
         if (ret > 0)
                 XFS_STATS_ADD(xs_read_bytes, ret);
 
-        xfs_iunlock(ip, XFS_IOLOCK_SHARED);
+        xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED);
         return ret;
 }
 
@@ -309,7 +343,7 @@ xfs_file_splice_read(
         if (XFS_FORCED_SHUTDOWN(ip->i_mount))
                 return -EIO;
 
-        xfs_ilock(ip, XFS_IOLOCK_SHARED);
+        xfs_rw_ilock(ip, XFS_IOLOCK_SHARED);
 
         trace_xfs_file_splice_read(ip, count, *ppos, ioflags);
 
@@ -317,10 +351,61 @@ xfs_file_splice_read(
         if (ret > 0)
                 XFS_STATS_ADD(xs_read_bytes, ret);
 
-        xfs_iunlock(ip, XFS_IOLOCK_SHARED);
+        xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED);
         return ret;
 }
 
+STATIC void
+xfs_aio_write_isize_update(
+        struct inode    *inode,
+        loff_t          *ppos,
+        ssize_t         bytes_written)
+{
+        struct xfs_inode        *ip = XFS_I(inode);
+        xfs_fsize_t             isize = i_size_read(inode);
+
+        if (bytes_written > 0)
+                XFS_STATS_ADD(xs_write_bytes, bytes_written);
+
+        if (unlikely(bytes_written < 0 && bytes_written != -EFAULT &&
+                                        *ppos > isize))
+                *ppos = isize;
+
+        if (*ppos > ip->i_size) {
+                xfs_rw_ilock(ip, XFS_ILOCK_EXCL);
+                if (*ppos > ip->i_size)
+                        ip->i_size = *ppos;
+                xfs_rw_iunlock(ip, XFS_ILOCK_EXCL);
+        }
+}
+
+/*
+ * If this was a direct or synchronous I/O that failed (such as ENOSPC) then
+ * part of the I/O may have been written to disk before the error occured.  In
+ * this case the on-disk file size may have been adjusted beyond the in-memory
+ * file size and now needs to be truncated back.
+ */
+STATIC void
+xfs_aio_write_newsize_update(
+        struct xfs_inode        *ip)
+{
+        if (ip->i_new_size) {
+                xfs_rw_ilock(ip, XFS_ILOCK_EXCL);
+                ip->i_new_size = 0;
+                if (ip->i_d.di_size > ip->i_size)
+                        ip->i_d.di_size = ip->i_size;
+                xfs_rw_iunlock(ip, XFS_ILOCK_EXCL);
+        }
+}
+
+/*
+ * xfs_file_splice_write() does not use xfs_rw_ilock() because
+ * generic_file_splice_write() takes the i_mutex itself. This, in theory,
+ * couuld cause lock inversions between the aio_write path and the splice path
+ * if someone is doing concurrent splice(2) based writes and write(2) based
+ * writes to the same inode. The only real way to fix this is to re-implement
+ * the generic code here with correct locking orders.
+ */
 STATIC ssize_t
 xfs_file_splice_write(
         struct pipe_inode_info  *pipe,
@@ -331,7 +416,7 @@ xfs_file_splice_write(
 {
         struct inode            *inode = outfilp->f_mapping->host;
         struct xfs_inode        *ip = XFS_I(inode);
-        xfs_fsize_t             isize, new_size;
+        xfs_fsize_t             new_size;
         int                     ioflags = 0;
         ssize_t                 ret;
 
@@ -355,27 +440,9 @@ xfs_file_splice_write(
         trace_xfs_file_splice_write(ip, count, *ppos, ioflags);
 
         ret = generic_file_splice_write(pipe, outfilp, ppos, count, flags);
-        if (ret > 0)
-                XFS_STATS_ADD(xs_write_bytes, ret);
-
-        isize = i_size_read(inode);
-        if (unlikely(ret < 0 && ret != -EFAULT && *ppos > isize))
-                *ppos = isize;
-
-        if (*ppos > ip->i_size) {
-                xfs_ilock(ip, XFS_ILOCK_EXCL);
-                if (*ppos > ip->i_size)
-                        ip->i_size = *ppos;
-                xfs_iunlock(ip, XFS_ILOCK_EXCL);
-        }
 
-        if (ip->i_new_size) {
-                xfs_ilock(ip, XFS_ILOCK_EXCL);
-                ip->i_new_size = 0;
-                if (ip->i_d.di_size > ip->i_size)
-                        ip->i_d.di_size = ip->i_size;
-                xfs_iunlock(ip, XFS_ILOCK_EXCL);
-        }
+        xfs_aio_write_isize_update(inode, ppos, ret);
+        xfs_aio_write_newsize_update(ip);
         xfs_iunlock(ip, XFS_IOLOCK_EXCL);
         return ret;
 }
@@ -562,247 +629,314 @@ out_lock:
         return error;
 }
 
+/*
+ * Common pre-write limit and setup checks.
+ *
+ * Returns with iolock held according to @iolock.
+ */
 STATIC ssize_t
-xfs_file_aio_write(
-        struct kiocb            *iocb,
-        const struct iovec      *iovp,
-        unsigned long           nr_segs,
-        loff_t                  pos)
+xfs_file_aio_write_checks(
+        struct file             *file,
+        loff_t                  *pos,
+        size_t                  *count,
+        int                     *iolock)
 {
-        struct file             *file = iocb->ki_filp;
-        struct address_space    *mapping = file->f_mapping;
-        struct inode            *inode = mapping->host;
+        struct inode            *inode = file->f_mapping->host;
         struct xfs_inode        *ip = XFS_I(inode);
-        struct xfs_mount        *mp = ip->i_mount;
-        ssize_t                 ret = 0, error = 0;
-        int                     ioflags = 0;
-        xfs_fsize_t             isize, new_size;
-        int                     iolock;
-        size_t                  ocount = 0, count;
-        int                     need_i_mutex;
+        xfs_fsize_t             new_size;
+        int                     error = 0;
 
-        XFS_STATS_INC(xs_write_calls);
+        error = generic_write_checks(file, pos, count, S_ISBLK(inode->i_mode));
+        if (error) {
+                xfs_rw_iunlock(ip, XFS_ILOCK_EXCL | *iolock);
+                *iolock = 0;
+                return error;
+        }
 
-        BUG_ON(iocb->ki_pos != pos);
+        new_size = *pos + *count;
+        if (new_size > ip->i_size)
+                ip->i_new_size = new_size;
 
-        if (unlikely(file->f_flags & O_DIRECT))
-                ioflags |= IO_ISDIRECT;
-        if (file->f_mode & FMODE_NOCMTIME)
-                ioflags |= IO_INVIS;
+        if (likely(!(file->f_mode & FMODE_NOCMTIME)))
+                file_update_time(file);
+
+        /*
+         * If the offset is beyond the size of the file, we need to zero any
+         * blocks that fall between the existing EOF and the start of this
+         * write.
+         */
+        if (*pos > ip->i_size)
+                error = -xfs_zero_eof(ip, *pos, ip->i_size);
 
-        error = generic_segment_checks(iovp, &nr_segs, &ocount, VERIFY_READ);
+        xfs_rw_iunlock(ip, XFS_ILOCK_EXCL);
         if (error)
                 return error;
 
-        count = ocount;
-        if (count == 0)
-                return 0;
-
-        xfs_wait_for_freeze(mp, SB_FREEZE_WRITE);
+        /*
+         * If we're writing the file then make sure to clear the setuid and
+         * setgid bits if the process is not being run by root.  This keeps
+         * people from modifying setuid and setgid binaries.
+         */
+        return file_remove_suid(file);
 
-        if (XFS_FORCED_SHUTDOWN(mp))
-                return -EIO;
+}
 
-relock:
-        if (ioflags & IO_ISDIRECT) {
-                iolock = XFS_IOLOCK_SHARED;
-                need_i_mutex = 0;
-        } else {
-                iolock = XFS_IOLOCK_EXCL;
-                need_i_mutex = 1;
-                mutex_lock(&inode->i_mutex);
+/*
+ * xfs_file_dio_aio_write - handle direct IO writes
+ *
+ * Lock the inode appropriately to prepare for and issue a direct IO write.
+ * By separating it from the buffered write path we remove all the tricky to
+ * follow locking changes and looping.
+ *
+ * If there are cached pages or we're extending the file, we need IOLOCK_EXCL
+ * until we're sure the bytes at the new EOF have been zeroed and/or the cached
+ * pages are flushed out.
+ *
+ * In most cases the direct IO writes will be done holding IOLOCK_SHARED
+ * allowing them to be done in parallel with reads and other direct IO writes.
+ * However, if the IO is not aligned to filesystem blocks, the direct IO layer
+ * needs to do sub-block zeroing and that requires serialisation against other
+ * direct IOs to the same block. In this case we need to serialise the
+ * submission of the unaligned IOs so that we don't get racing block zeroing in
+ * the dio layer.  To avoid the problem with aio, we also need to wait for
+ * outstanding IOs to complete so that unwritten extent conversion is completed
+ * before we try to map the overlapping block. This is currently implemented by
+ * hitting it with a big hammer (i.e. xfs_ioend_wait()).
+ *
+ * Returns with locks held indicated by @iolock and errors indicated by
+ * negative return values.
+ */
+STATIC ssize_t
+xfs_file_dio_aio_write(
+        struct kiocb            *iocb,
+        const struct iovec      *iovp,
+        unsigned long           nr_segs,
+        loff_t                  pos,
+        size_t                  ocount,
+        int                     *iolock)
+{
+        struct file             *file = iocb->ki_filp;
+        struct address_space    *mapping = file->f_mapping;
+        struct inode            *inode = mapping->host;
+        struct xfs_inode        *ip = XFS_I(inode);
+        struct xfs_mount        *mp = ip->i_mount;
+        ssize_t                 ret = 0;
+        size_t                  count = ocount;
+        int                     unaligned_io = 0;
+        struct xfs_buftarg      *target = XFS_IS_REALTIME_INODE(ip) ?
+                                        mp->m_rtdev_targp : mp->m_ddev_targp;
+
+        *iolock = 0;
+        if ((pos & target->bt_smask) || (count & target->bt_smask))
+                return -XFS_ERROR(EINVAL);
+
+        if ((pos & mp->m_blockmask) || ((pos + count) & mp->m_blockmask))
+                unaligned_io = 1;
+
+        if (unaligned_io || mapping->nrpages || pos > ip->i_size)
+                *iolock = XFS_IOLOCK_EXCL;
+        else
+                *iolock = XFS_IOLOCK_SHARED;
+        xfs_rw_ilock(ip, XFS_ILOCK_EXCL | *iolock);
+
+        ret = xfs_file_aio_write_checks(file, &pos, &count, iolock);
+        if (ret)
+                return ret;
+
+        if (mapping->nrpages) {
+                WARN_ON(*iolock != XFS_IOLOCK_EXCL);
+                ret = -xfs_flushinval_pages(ip, (pos & PAGE_CACHE_MASK), -1,
+                                                        FI_REMAPF_LOCKED);
+                if (ret)
+                        return ret;
         }
 
-        xfs_ilock(ip, XFS_ILOCK_EXCL|iolock);
-
-start:
-        error = -generic_write_checks(file, &pos, &count,
-                                        S_ISBLK(inode->i_mode));
-        if (error) {
-                xfs_iunlock(ip, XFS_ILOCK_EXCL|iolock);
-                goto out_unlock_mutex;
+        /*
+         * If we are doing unaligned IO, wait for all other IO to drain,
+         * otherwise demote the lock if we had to flush cached pages
+         */
+        if (unaligned_io)
+                xfs_ioend_wait(ip);
+        else if (*iolock == XFS_IOLOCK_EXCL) {
+                xfs_rw_ilock_demote(ip, XFS_IOLOCK_EXCL);
+                *iolock = XFS_IOLOCK_SHARED;
         }
 
-        if (ioflags & IO_ISDIRECT) {
-                xfs_buftarg_t   *target =
-                        XFS_IS_REALTIME_INODE(ip) ?
-                                mp->m_rtdev_targp : mp->m_ddev_targp;
+        trace_xfs_file_direct_write(ip, count, iocb->ki_pos, 0);
+        ret = generic_file_direct_write(iocb, iovp,
+                        &nr_segs, pos, &iocb->ki_pos, count, ocount);
 
-                if ((pos & target->bt_smask) || (count & target->bt_smask)) {
-                        xfs_iunlock(ip, XFS_ILOCK_EXCL|iolock);
-                        return XFS_ERROR(-EINVAL);
-                }
+        /* No fallback to buffered IO on errors for XFS. */
+        ASSERT(ret < 0 || ret == count);
+        return ret;
+}
 
-                if (!need_i_mutex && (mapping->nrpages || pos > ip->i_size)) {
-                        xfs_iunlock(ip, XFS_ILOCK_EXCL|iolock);
-                        iolock = XFS_IOLOCK_EXCL;
-                        need_i_mutex = 1;
-                        mutex_lock(&inode->i_mutex);
-                        xfs_ilock(ip, XFS_ILOCK_EXCL|iolock);
-                        goto start;
-                }
-        }
+STATIC ssize_t
+xfs_file_buffered_aio_write(
+        struct kiocb            *iocb,
+        const struct iovec      *iovp,
+        unsigned long           nr_segs,
+        loff_t                  pos,
+        size_t                  ocount,
+        int                     *iolock)
+{
+        struct file             *file = iocb->ki_filp;
+        struct address_space    *mapping = file->f_mapping;
+        struct inode            *inode = mapping->host;
+        struct xfs_inode        *ip = XFS_I(inode);
+        ssize_t                 ret;
+        int                     enospc = 0;
+        size_t                  count = ocount;
 
-        new_size = pos + count;
-        if (new_size > ip->i_size)
-                ip->i_new_size = new_size;
+        *iolock = XFS_IOLOCK_EXCL;
+        xfs_rw_ilock(ip, XFS_ILOCK_EXCL | *iolock);
 
-        if (likely(!(ioflags & IO_INVIS)))
-                file_update_time(file);
+        ret = xfs_file_aio_write_checks(file, &pos, &count, iolock);
+        if (ret)
+                return ret;
 
+        /* We can write back this queue in page reclaim */
+        current->backing_dev_info = mapping->backing_dev_info;
+
+write_retry:
+        trace_xfs_file_buffered_write(ip, count, iocb->ki_pos, 0);
+        ret = generic_file_buffered_write(iocb, iovp, nr_segs,
+                        pos, &iocb->ki_pos, count, ret);
         /*
-         * If the offset is beyond the size of the file, we have a couple
-         * of things to do. First, if there is already space allocated
-         * we need to either create holes or zero the disk or ...
-         *
-         * If there is a page where the previous size lands, we need
-         * to zero it out up to the new size.
+         * if we just got an ENOSPC, flush the inode now we aren't holding any
+         * page locks and retry *once*
          */
-
-        if (pos > ip->i_size) {
-                error = xfs_zero_eof(ip, pos, ip->i_size);
-                if (error) {
-                        xfs_iunlock(ip, XFS_ILOCK_EXCL);
-                        goto out_unlock_internal;
-                }
+        if (ret == -ENOSPC && !enospc) {
+                ret = -xfs_flush_pages(ip, 0, -1, 0, FI_NONE);
+                if (ret)
+                        return ret;
+                enospc = 1;
+                goto write_retry;
         }
-        xfs_iunlock(ip, XFS_ILOCK_EXCL);
+        current->backing_dev_info = NULL;
+        return ret;
+}
 
-        /*
-         * If we're writing the file then make sure to clear the
-         * setuid and setgid bits if the process is not being run
-         * by root.  This keeps people from modifying setuid and
-         * setgid binaries.
-         */
-        error = -file_remove_suid(file);
-        if (unlikely(error))
-                goto out_unlock_internal;
+STATIC ssize_t
+xfs_file_aio_write(
+        struct kiocb            *iocb,
+        const struct iovec      *iovp,
+        unsigned long           nr_segs,
+        loff_t                  pos)
+{
+        struct file             *file = iocb->ki_filp;
+        struct address_space    *mapping = file->f_mapping;
+        struct inode            *inode = mapping->host;
+        struct xfs_inode        *ip = XFS_I(inode);
+        ssize_t                 ret;
+        int                     iolock;
+        size_t                  ocount = 0;
 
-        /* We can write back this queue in page reclaim */
-        current->backing_dev_info = mapping->backing_dev_info;
+        XFS_STATS_INC(xs_write_calls);
 
-        if ((ioflags & IO_ISDIRECT)) {
-                if (mapping->nrpages) {
-                        WARN_ON(need_i_mutex == 0);
-                        error = xfs_flushinval_pages(ip,
-                                        (pos & PAGE_CACHE_MASK),
-                                        -1, FI_REMAPF_LOCKED);
-                        if (error)
-                                goto out_unlock_internal;
-                }
+        BUG_ON(iocb->ki_pos != pos);
 
-                if (need_i_mutex) {
-                        /* demote the lock now the cached pages are gone */
-                        xfs_ilock_demote(ip, XFS_IOLOCK_EXCL);
-                        mutex_unlock(&inode->i_mutex);
+        ret = generic_segment_checks(iovp, &nr_segs, &ocount, VERIFY_READ);
+        if (ret)
+                return ret;
 
-                        iolock = XFS_IOLOCK_SHARED;
-                        need_i_mutex = 0;
-                }
+        if (ocount == 0)
+                return 0;
 
-                trace_xfs_file_direct_write(ip, count, iocb->ki_pos, ioflags);
-                ret = generic_file_direct_write(iocb, iovp,
-                                &nr_segs, pos, &iocb->ki_pos, count, ocount);
+        xfs_wait_for_freeze(ip->i_mount, SB_FREEZE_WRITE);
 
-                /*
-                 * direct-io write to a hole: fall through to buffered I/O
-                 * for completing the rest of the request.
-                 */
-                if (ret >= 0 && ret != count) {
-                        XFS_STATS_ADD(xs_write_bytes, ret);
+        if (XFS_FORCED_SHUTDOWN(ip->i_mount))
+                return -EIO;
 
-                        pos += ret;
-                        count -= ret;
+        if (unlikely(file->f_flags & O_DIRECT))
+                ret = xfs_file_dio_aio_write(iocb, iovp, nr_segs, pos,
+                                                ocount, &iolock);
+        else
+                ret = xfs_file_buffered_aio_write(iocb, iovp, nr_segs, pos,
+                                                ocount, &iolock);
 
-                        ioflags &= ~IO_ISDIRECT;
-                        xfs_iunlock(ip, iolock);
-                        goto relock;
-                }
-        } else {
-                int enospc = 0;
-                ssize_t ret2 = 0;
+        xfs_aio_write_isize_update(inode, &iocb->ki_pos, ret);
 
-write_retry:
-                trace_xfs_file_buffered_write(ip, count, iocb->ki_pos, ioflags);
-                ret2 = generic_file_buffered_write(iocb, iovp, nr_segs,
-                                pos, &iocb->ki_pos, count, ret);
-                /*
-                 * if we just got an ENOSPC, flush the inode now we
-                 * aren't holding any page locks and retry *once*
-                 */
-                if (ret2 == -ENOSPC && !enospc) {
-                        error = xfs_flush_pages(ip, 0, -1, 0, FI_NONE);
-                        if (error)
-                                goto out_unlock_internal;
-                        enospc = 1;
-                        goto write_retry;
-                }
-                ret = ret2;
-        }
+        if (ret <= 0)
+                goto out_unlock;
 
-        current->backing_dev_info = NULL;
+        /* Handle various SYNC-type writes */
+        if ((file->f_flags & O_DSYNC) || IS_SYNC(inode)) {
+                loff_t end = pos + ret - 1;
+                int error, error2;
 
-        isize = i_size_read(inode);
-        if (unlikely(ret < 0 && ret != -EFAULT && iocb->ki_pos > isize))
-                iocb->ki_pos = isize;
+                xfs_rw_iunlock(ip, iolock);
+                error = filemap_write_and_wait_range(mapping, pos, end);
+                xfs_rw_ilock(ip, iolock);
 
-        if (iocb->ki_pos > ip->i_size) {
-                xfs_ilock(ip, XFS_ILOCK_EXCL);
-                if (iocb->ki_pos > ip->i_size)
-                        ip->i_size = iocb->ki_pos;
-                xfs_iunlock(ip, XFS_ILOCK_EXCL);
+                error2 = -xfs_file_fsync(file,
+                                         (file->f_flags & __O_SYNC) ? 0 : 1);
+                if (error)
+                        ret = error;
+                else if (error2)
+                        ret = error2;
         }
 
-        error = -ret;
-        if (ret <= 0)
-                goto out_unlock_internal;
+out_unlock:
+        xfs_aio_write_newsize_update(ip);
+        xfs_rw_iunlock(ip, iolock);
+        return ret;
+}
 
-        XFS_STATS_ADD(xs_write_bytes, ret);
+STATIC long
+xfs_file_fallocate(
+        struct file     *file,
+        int             mode,
+        loff_t          offset,
+        loff_t          len)
+{
+        struct inode    *inode = file->f_path.dentry->d_inode;
+        long            error;
+        loff_t          new_size = 0;
+        xfs_flock64_t   bf;
+        xfs_inode_t     *ip = XFS_I(inode);
+        int             cmd = XFS_IOC_RESVSP;
 
-        /* Handle various SYNC-type writes */
-        if ((file->f_flags & O_DSYNC) || IS_SYNC(inode)) {
-                loff_t end = pos + ret - 1;
-                int error2;
+        if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
+                return -EOPNOTSUPP;
 
-                xfs_iunlock(ip, iolock);
-                if (need_i_mutex)
-                        mutex_unlock(&inode->i_mutex);
+        bf.l_whence = 0;
+        bf.l_start = offset;
+        bf.l_len = len;
 
-                error2 = filemap_write_and_wait_range(mapping, pos, end);
-                if (!error)
-                        error = error2;
-                if (need_i_mutex)
-                        mutex_lock(&inode->i_mutex);
-                xfs_ilock(ip, iolock);
+        xfs_ilock(ip, XFS_IOLOCK_EXCL);
 
-                error2 = -xfs_file_fsync(file,
-                                         (file->f_flags & __O_SYNC) ? 0 : 1);
-                if (!error)
-                        error = error2;
+        if (mode & FALLOC_FL_PUNCH_HOLE)
+                cmd = XFS_IOC_UNRESVSP;
+
+        /* check the new inode size is valid before allocating */
+        if (!(mode & FALLOC_FL_KEEP_SIZE) &&
+            offset + len > i_size_read(inode)) {
+                new_size = offset + len;
+                error = inode_newsize_ok(inode, new_size);
+                if (error)
+                        goto out_unlock;
         }
 
- out_unlock_internal:
-        if (ip->i_new_size) {
-                xfs_ilock(ip, XFS_ILOCK_EXCL);
-                ip->i_new_size = 0;
-                /*
-                 * If this was a direct or synchronous I/O that failed (such
-                 * as ENOSPC) then part of the I/O may have been written to
-                 * disk before the error occured.  In this case the on-disk
-                 * file size may have been adjusted beyond the in-memory file
-                 * size and now needs to be truncated back.
-                 */
-                if (ip->i_d.di_size > ip->i_size)
-                        ip->i_d.di_size = ip->i_size;
-                xfs_iunlock(ip, XFS_ILOCK_EXCL);
+        error = -xfs_change_file_space(ip, cmd, &bf, 0, XFS_ATTR_NOLOCK);
+        if (error)
+                goto out_unlock;
+
+        /* Change file size if needed */
+        if (new_size) {
+                struct iattr iattr;
+
+                iattr.ia_valid = ATTR_SIZE;
+                iattr.ia_size = new_size;
+                error = -xfs_setattr(ip, &iattr, XFS_ATTR_NOLOCK);
         }
-        xfs_iunlock(ip, iolock);
- out_unlock_mutex:
-        if (need_i_mutex)
-                mutex_unlock(&inode->i_mutex);
-        return -error;
+
+out_unlock:
+        xfs_iunlock(ip, XFS_IOLOCK_EXCL);
+        return error;
 }
 
+
 STATIC int
 xfs_file_open(
         struct inode    *inode,
@@ -921,6 +1055,7 @@ const struct file_operations xfs_file_operations = {
         .open           = xfs_file_open,
         .release        = xfs_file_release,
         .fsync          = xfs_file_fsync,
+        .fallocate      = xfs_file_fallocate,
 };
 
 const struct file_operations xfs_dir_file_operations = {