xfs: remove wrappers for read/write file operations

Currently the aio_read, aio_write, splice_read and splice_write file
operations are divided into a low-level routine doing all the work
and one that implements the Linux file operations and does minimal
argument wrapping.  This is a leftover from the days of the vnode
operations layer and can be removed to simplify the code a lot.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Alex Elder <aelder@sgi.com>

1 files changed, 114 insertions, 171 deletions

diff --git a/fs/xfs/linux-2.6/xfs_file.c b/fs/xfs/linux-2.6/xfs_file.c
index 51fc510828a4..1eb561a10e26 100644
--- a/fs/xfs/linux-2.6/xfs_file.c
+++ b/fs/xfs/linux-2.6/xfs_file.c
@@ -96,28 +96,34 @@ xfs_iozero(
         return (-status);
 }
 
-ssize_t                 /* bytes read, or (-)  error */
-xfs_read(
-        xfs_inode_t             *ip,
+STATIC ssize_t
+xfs_file_aio_read(
         struct kiocb            *iocb,
         const struct iovec      *iovp,
-        unsigned int            segs,
-        loff_t                  *offset,
-        int                     ioflags)
+        unsigned long           nr_segs,
+        loff_t                  pos)
 {
         struct file             *file = iocb->ki_filp;
         struct inode            *inode = file->f_mapping->host;
-        xfs_mount_t             *mp = ip->i_mount;
+        struct xfs_inode        *ip = XFS_I(inode);
+        struct xfs_mount        *mp = ip->i_mount;
         size_t                  size = 0;
         ssize_t                 ret = 0;
+        int                     ioflags = 0;
         xfs_fsize_t             n;
         unsigned long           seg;
 
-
         XFS_STATS_INC(xs_read_calls);
 
+        BUG_ON(iocb->ki_pos != pos);
+
+        if (unlikely(file->f_flags & O_DIRECT))
+                ioflags |= IO_ISDIRECT;
+        if (file->f_mode & FMODE_NOCMTIME)
+                ioflags |= IO_INVIS;
+
         /* START copy & waste from filemap.c */
-        for (seg = 0; seg < segs; seg++) {
+        for (seg = 0; seg < nr_segs; seg++) {
                 const struct iovec *iv = &iovp[seg];
 
                 /*
@@ -134,17 +140,16 @@ xfs_read(
                 xfs_buftarg_t   *target =
                         XFS_IS_REALTIME_INODE(ip) ?
                                 mp->m_rtdev_targp : mp->m_ddev_targp;
-                if ((*offset & target->bt_smask) ||
+                if ((iocb->ki_pos & target->bt_smask) ||
                     (size & target->bt_smask)) {
-                        if (*offset == ip->i_size) {
-                                return (0);
-                        }
+                        if (iocb->ki_pos == ip->i_size)
+                                return 0;
                         return -XFS_ERROR(EINVAL);
                 }
         }
 
-        n = XFS_MAXIOFFSET(mp) - *offset;
-        if ((n <= 0) || (size == 0))
+        n = XFS_MAXIOFFSET(mp) - iocb->ki_pos;
+        if (n <= 0 || size == 0)
                 return 0;
 
         if (n < size)
@@ -161,7 +166,7 @@ xfs_read(
                 int dmflags = FILP_DELAY_FLAG(file) | DM_SEM_FLAG_RD(ioflags);
                 int iolock = XFS_IOLOCK_SHARED;
 
-                ret = -XFS_SEND_DATA(mp, DM_EVENT_READ, ip, *offset, size,
+                ret = -XFS_SEND_DATA(mp, DM_EVENT_READ, ip, iocb->ki_pos, size,
                                         dmflags, &iolock);
                 if (ret) {
                         xfs_iunlock(ip, XFS_IOLOCK_SHARED);
@@ -172,9 +177,11 @@ xfs_read(
         }
 
         if (unlikely(ioflags & IO_ISDIRECT)) {
-                if (inode->i_mapping->nrpages)
-                        ret = -xfs_flushinval_pages(ip, (*offset & PAGE_CACHE_MASK),
-                                                    -1, FI_REMAPF_LOCKED);
+                if (inode->i_mapping->nrpages) {
+                        ret = -xfs_flushinval_pages(ip,
+                                        (iocb->ki_pos & PAGE_CACHE_MASK),
+                                        -1, FI_REMAPF_LOCKED);
+                }
                 mutex_unlock(&inode->i_mutex);
                 if (ret) {
                         xfs_iunlock(ip, XFS_IOLOCK_SHARED);
@@ -182,10 +189,9 @@ xfs_read(
                 }
         }
 
-        trace_xfs_file_read(ip, size, *offset, ioflags);
+        trace_xfs_file_read(ip, size, iocb->ki_pos, ioflags);
 
-        iocb->ki_pos = *offset;
-        ret = generic_file_aio_read(iocb, iovp, segs, *offset);
+        ret = generic_file_aio_read(iocb, iovp, nr_segs, iocb->ki_pos);
         if (ret > 0)
                 XFS_STATS_ADD(xs_read_bytes, ret);
 
@@ -193,20 +199,24 @@ xfs_read(
         return ret;
 }
 
-ssize_t
-xfs_splice_read(
-        xfs_inode_t             *ip,
+STATIC ssize_t
+xfs_file_splice_read(
         struct file             *infilp,
         loff_t                  *ppos,
         struct pipe_inode_info  *pipe,
         size_t                  count,
-        int                     flags,
-        int                     ioflags)
+        unsigned int            flags)
 {
-        xfs_mount_t             *mp = ip->i_mount;
+        struct xfs_inode        *ip = XFS_I(infilp->f_mapping->host);
+        struct xfs_mount        *mp = ip->i_mount;
+        int                     ioflags = 0;
         ssize_t                 ret;
 
         XFS_STATS_INC(xs_read_calls);
+
+        if (infilp->f_mode & FMODE_NOCMTIME)
+                ioflags |= IO_INVIS;
+
         if (XFS_FORCED_SHUTDOWN(ip->i_mount))
                 return -EIO;
 
@@ -234,22 +244,26 @@ xfs_splice_read(
         return ret;
 }
 
-ssize_t
-xfs_splice_write(
-        xfs_inode_t             *ip,
+STATIC ssize_t
+xfs_file_splice_write(
         struct pipe_inode_info  *pipe,
         struct file             *outfilp,
         loff_t                  *ppos,
         size_t                  count,
-        int                     flags,
-        int                     ioflags)
+        unsigned int            flags)
 {
-        xfs_mount_t             *mp = ip->i_mount;
-        ssize_t                 ret;
         struct inode            *inode = outfilp->f_mapping->host;
+        struct xfs_inode        *ip = XFS_I(inode);
+        struct xfs_mount        *mp = ip->i_mount;
         xfs_fsize_t             isize, new_size;
+        int                     ioflags = 0;
+        ssize_t                 ret;
 
         XFS_STATS_INC(xs_write_calls);
+
+        if (outfilp->f_mode & FMODE_NOCMTIME)
+                ioflags |= IO_INVIS;
+
         if (XFS_FORCED_SHUTDOWN(ip->i_mount))
                 return -EIO;
 
@@ -484,42 +498,43 @@ out_lock:
         return error;
 }
 
-ssize_t                         /* bytes written, or (-) error */
-xfs_write(
-        struct xfs_inode        *xip,
+STATIC ssize_t
+xfs_file_aio_write(
         struct kiocb            *iocb,
         const struct iovec      *iovp,
-        unsigned int            nsegs,
-        loff_t                  *offset,
-        int                     ioflags)
+        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;
-        unsigned long           segs = nsegs;
-        xfs_mount_t             *mp;
+        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;
         int                     eventsent = 0;
         size_t                  ocount = 0, count;
-        loff_t                  pos;
         int                     need_i_mutex;
 
         XFS_STATS_INC(xs_write_calls);
 
-        error = generic_segment_checks(iovp, &segs, &ocount, VERIFY_READ);
+        BUG_ON(iocb->ki_pos != pos);
+
+        if (unlikely(file->f_flags & O_DIRECT))
+                ioflags |= IO_ISDIRECT;
+        if (file->f_mode & FMODE_NOCMTIME)
+                ioflags |= IO_INVIS;
+
+        error = generic_segment_checks(iovp, &nr_segs, &ocount, VERIFY_READ);
         if (error)
                 return error;
 
         count = ocount;
-        pos = *offset;
-
         if (count == 0)
                 return 0;
 
-        mp = xip->i_mount;
-
         xfs_wait_for_freeze(mp, SB_FREEZE_WRITE);
 
         if (XFS_FORCED_SHUTDOWN(mp))
@@ -535,30 +550,30 @@ relock:
                 mutex_lock(&inode->i_mutex);
         }
 
-        xfs_ilock(xip, XFS_ILOCK_EXCL|iolock);
+        xfs_ilock(ip, XFS_ILOCK_EXCL|iolock);
 
 start:
         error = -generic_write_checks(file, &pos, &count,
                                         S_ISBLK(inode->i_mode));
         if (error) {
-                xfs_iunlock(xip, XFS_ILOCK_EXCL|iolock);
+                xfs_iunlock(ip, XFS_ILOCK_EXCL|iolock);
                 goto out_unlock_mutex;
         }
 
-        if ((DM_EVENT_ENABLED(xip, DM_EVENT_WRITE) &&
+        if ((DM_EVENT_ENABLED(ip, DM_EVENT_WRITE) &&
             !(ioflags & IO_INVIS) && !eventsent)) {
                 int             dmflags = FILP_DELAY_FLAG(file);
 
                 if (need_i_mutex)
                         dmflags |= DM_FLAGS_IMUX;
 
-                xfs_iunlock(xip, XFS_ILOCK_EXCL);
-                error = XFS_SEND_DATA(xip->i_mount, DM_EVENT_WRITE, xip,
+                xfs_iunlock(ip, XFS_ILOCK_EXCL);
+                error = XFS_SEND_DATA(ip->i_mount, DM_EVENT_WRITE, ip,
                                       pos, count, dmflags, &iolock);
                 if (error) {
                         goto out_unlock_internal;
                 }
-                xfs_ilock(xip, XFS_ILOCK_EXCL);
+                xfs_ilock(ip, XFS_ILOCK_EXCL);
                 eventsent = 1;
 
                 /*
@@ -568,33 +583,33 @@ start:
                  * event prevents another call to XFS_SEND_DATA, which is
                  * what allows the size to change in the first place.
                  */
-                if ((file->f_flags & O_APPEND) && pos != xip->i_size)
+                if ((file->f_flags & O_APPEND) && pos != ip->i_size)
                         goto start;
         }
 
         if (ioflags & IO_ISDIRECT) {
                 xfs_buftarg_t   *target =
-                        XFS_IS_REALTIME_INODE(xip) ?
+                        XFS_IS_REALTIME_INODE(ip) ?
                                 mp->m_rtdev_targp : mp->m_ddev_targp;
 
                 if ((pos & target->bt_smask) || (count & target->bt_smask)) {
-                        xfs_iunlock(xip, XFS_ILOCK_EXCL|iolock);
+                        xfs_iunlock(ip, XFS_ILOCK_EXCL|iolock);
                         return XFS_ERROR(-EINVAL);
                 }
 
-                if (!need_i_mutex && (mapping->nrpages || pos > xip->i_size)) {
-                        xfs_iunlock(xip, XFS_ILOCK_EXCL|iolock);
+                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(xip, XFS_ILOCK_EXCL|iolock);
+                        xfs_ilock(ip, XFS_ILOCK_EXCL|iolock);
                         goto start;
                 }
         }
 
         new_size = pos + count;
-        if (new_size > xip->i_size)
-                xip->i_new_size = new_size;
+        if (new_size > ip->i_size)
+                ip->i_new_size = new_size;
 
         if (likely(!(ioflags & IO_INVIS)))
                 file_update_time(file);
@@ -608,14 +623,14 @@ start:
          * to zero it out up to the new size.
          */
 
-        if (pos > xip->i_size) {
-                error = xfs_zero_eof(xip, pos, xip->i_size);
+        if (pos > ip->i_size) {
+                error = xfs_zero_eof(ip, pos, ip->i_size);
                 if (error) {
-                        xfs_iunlock(xip, XFS_ILOCK_EXCL);
+                        xfs_iunlock(ip, XFS_ILOCK_EXCL);
                         goto out_unlock_internal;
                 }
         }
-        xfs_iunlock(xip, XFS_ILOCK_EXCL);
+        xfs_iunlock(ip, XFS_ILOCK_EXCL);
 
         /*
          * If we're writing the file then make sure to clear the
@@ -633,7 +648,7 @@ start:
         if ((ioflags & IO_ISDIRECT)) {
                 if (mapping->nrpages) {
                         WARN_ON(need_i_mutex == 0);
-                        error = xfs_flushinval_pages(xip,
+                        error = xfs_flushinval_pages(ip,
                                         (pos & PAGE_CACHE_MASK),
                                         -1, FI_REMAPF_LOCKED);
                         if (error)
@@ -642,16 +657,16 @@ start:
 
                 if (need_i_mutex) {
                         /* demote the lock now the cached pages are gone */
-                        xfs_ilock_demote(xip, XFS_IOLOCK_EXCL);
+                        xfs_ilock_demote(ip, XFS_IOLOCK_EXCL);
                         mutex_unlock(&inode->i_mutex);
 
                         iolock = XFS_IOLOCK_SHARED;
                         need_i_mutex = 0;
                 }
 
-                trace_xfs_file_direct_write(xip, count, *offset, ioflags);
+                trace_xfs_file_direct_write(ip, count, iocb->ki_pos, ioflags);
                 ret = generic_file_direct_write(iocb, iovp,
-                                &segs, pos, offset, count, ocount);
+                                &nr_segs, pos, &iocb->ki_pos, count, ocount);
 
                 /*
                  * direct-io write to a hole: fall through to buffered I/O
@@ -664,7 +679,7 @@ start:
                         count -= ret;
 
                         ioflags &= ~IO_ISDIRECT;
-                        xfs_iunlock(xip, iolock);
+                        xfs_iunlock(ip, iolock);
                         goto relock;
                 }
         } else {
@@ -672,15 +687,15 @@ start:
                 ssize_t ret2 = 0;
 
 write_retry:
-                trace_xfs_file_buffered_write(xip, count, *offset, ioflags);
-                ret2 = generic_file_buffered_write(iocb, iovp, segs,
-                                pos, offset, count, ret);
+                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(xip, 0, -1, 0, FI_NONE);
+                        error = xfs_flush_pages(ip, 0, -1, 0, FI_NONE);
                         if (error)
                                 goto out_unlock_internal;
                         enospc = 1;
@@ -692,27 +707,27 @@ write_retry:
         current->backing_dev_info = NULL;
 
         isize = i_size_read(inode);
-        if (unlikely(ret < 0 && ret != -EFAULT && *offset > isize))
-                *offset = isize;
-
-        if (*offset > xip->i_size) {
-                xfs_ilock(xip, XFS_ILOCK_EXCL);
-                if (*offset > xip->i_size)
-                        xip->i_size = *offset;
-                xfs_iunlock(xip, XFS_ILOCK_EXCL);
+        if (unlikely(ret < 0 && ret != -EFAULT && iocb->ki_pos > isize))
+                iocb->ki_pos = isize;
+
+        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);
         }
 
         if (ret == -ENOSPC &&
-            DM_EVENT_ENABLED(xip, DM_EVENT_NOSPACE) && !(ioflags & IO_INVIS)) {
-                xfs_iunlock(xip, iolock);
+            DM_EVENT_ENABLED(ip, DM_EVENT_NOSPACE) && !(ioflags & IO_INVIS)) {
+                xfs_iunlock(ip, iolock);
                 if (need_i_mutex)
                         mutex_unlock(&inode->i_mutex);
-                error = XFS_SEND_NAMESP(xip->i_mount, DM_EVENT_NOSPACE, xip,
-                                DM_RIGHT_NULL, xip, DM_RIGHT_NULL, NULL, NULL,
+                error = XFS_SEND_NAMESP(ip->i_mount, DM_EVENT_NOSPACE, ip,
+                                DM_RIGHT_NULL, ip, DM_RIGHT_NULL, NULL, NULL,
                                 0, 0, 0); /* Delay flag intentionally  unused */
                 if (need_i_mutex)
                         mutex_lock(&inode->i_mutex);
-                xfs_ilock(xip, iolock);
+                xfs_ilock(ip, iolock);
                 if (error)
                         goto out_unlock_internal;
                 goto start;
@@ -729,7 +744,7 @@ write_retry:
                 loff_t end = pos + ret - 1;
                 int error2;
 
-                xfs_iunlock(xip, iolock);
+                xfs_iunlock(ip, iolock);
                 if (need_i_mutex)
                         mutex_unlock(&inode->i_mutex);
 
@@ -738,17 +753,17 @@ write_retry:
                         error = error2;
                 if (need_i_mutex)
                         mutex_lock(&inode->i_mutex);
-                xfs_ilock(xip, iolock);
+                xfs_ilock(ip, iolock);
 
-                error2 = xfs_fsync(xip);
+                error2 = xfs_fsync(ip);
                 if (!error)
                         error = error2;
         }
 
  out_unlock_internal:
-        if (xip->i_new_size) {
-                xfs_ilock(xip, XFS_ILOCK_EXCL);
-                xip->i_new_size = 0;
+        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
@@ -756,89 +771,17 @@ write_retry:
                  * file size may have been adjusted beyond the in-memory file
                  * size and now needs to be truncated back.
                  */
-                if (xip->i_d.di_size > xip->i_size)
-                        xip->i_d.di_size = xip->i_size;
-                xfs_iunlock(xip, XFS_ILOCK_EXCL);
+                if (ip->i_d.di_size > ip->i_size)
+                        ip->i_d.di_size = ip->i_size;
+                xfs_iunlock(ip, XFS_ILOCK_EXCL);
         }
-        xfs_iunlock(xip, iolock);
+        xfs_iunlock(ip, iolock);
  out_unlock_mutex:
         if (need_i_mutex)
                 mutex_unlock(&inode->i_mutex);
         return -error;
 }
 
-STATIC ssize_t
-xfs_file_aio_read(
-        struct kiocb            *iocb,
-        const struct iovec      *iov,
-        unsigned long           nr_segs,
-        loff_t                  pos)
-{
-        struct file             *file = iocb->ki_filp;
-        int                     ioflags = 0;
-
-        BUG_ON(iocb->ki_pos != pos);
-        if (unlikely(file->f_flags & O_DIRECT))
-                ioflags |= IO_ISDIRECT;
-        if (file->f_mode & FMODE_NOCMTIME)
-                ioflags |= IO_INVIS;
-        return xfs_read(XFS_I(file->f_path.dentry->d_inode), iocb, iov,
-                                nr_segs, &iocb->ki_pos, ioflags);
-}
-
-STATIC ssize_t
-xfs_file_aio_write(
-        struct kiocb            *iocb,
-        const struct iovec      *iov,
-        unsigned long           nr_segs,
-        loff_t                  pos)
-{
-        struct file             *file = iocb->ki_filp;
-        int                     ioflags = 0;
-
-        BUG_ON(iocb->ki_pos != pos);
-        if (unlikely(file->f_flags & O_DIRECT))
-                ioflags |= IO_ISDIRECT;
-        if (file->f_mode & FMODE_NOCMTIME)
-                ioflags |= IO_INVIS;
-        return xfs_write(XFS_I(file->f_mapping->host), iocb, iov, nr_segs,
-                                &iocb->ki_pos, ioflags);
-}
-
-STATIC ssize_t
-xfs_file_splice_read(
-        struct file             *infilp,
-        loff_t                  *ppos,
-        struct pipe_inode_info  *pipe,
-        size_t                  len,
-        unsigned int            flags)
-{
-        int                     ioflags = 0;
-
-        if (infilp->f_mode & FMODE_NOCMTIME)
-                ioflags |= IO_INVIS;
-
-        return xfs_splice_read(XFS_I(infilp->f_path.dentry->d_inode),
-                                   infilp, ppos, pipe, len, flags, ioflags);
-}
-
-STATIC ssize_t
-xfs_file_splice_write(
-        struct pipe_inode_info  *pipe,
-        struct file             *outfilp,
-        loff_t                  *ppos,
-        size_t                  len,
-        unsigned int            flags)
-{
-        int                     ioflags = 0;
-
-        if (outfilp->f_mode & FMODE_NOCMTIME)
-                ioflags |= IO_INVIS;
-
-        return xfs_splice_write(XFS_I(outfilp->f_path.dentry->d_inode),
-                                    pipe, outfilp, ppos, len, flags, ioflags);
-}
-
 STATIC int
 xfs_file_open(
         struct inode    *inode,