xfs: simplify the xfs_iomap_write_direct calling

Move the EOF alignment and checking for the next allocated extent into
the callers to avoid the need to pass the byte based offset and count
as well as looking at the incoming imap.  The added benefit is that
the caller can unlock the incoming ilock and the function doesn't have
funny unbalanced locking contexts.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
index 7615ddf0ddba1fc1b09003ba101bb2454c32a071..153262c76051798a2012d0b9b84c10f2bde7680f 100644 (file)
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c
@@ -148,7 +148,7 @@ xfs_eof_alignment(
  * Check if last_fsb is outside the last extent, and if so grow it to the next
  * stripe unit boundary.
  */
-static xfs_fileoff_t
+xfs_fileoff_t
 xfs_iomap_eof_align_last_fsb(
        struct xfs_inode        *ip,
        xfs_fileoff_t           end_fsb)
@@ -185,61 +185,36 @@ xfs_iomap_eof_align_last_fsb(
 
 int
 xfs_iomap_write_direct(
-       xfs_inode_t     *ip,
-       xfs_off_t       offset,
-       size_t          count,
-       xfs_bmbt_irec_t *imap,
-       int             nmaps)
+       struct xfs_inode        *ip,
+       xfs_fileoff_t           offset_fsb,
+       xfs_fileoff_t           count_fsb,
+       struct xfs_bmbt_irec    *imap)
 {
-       xfs_mount_t     *mp = ip->i_mount;
-       xfs_fileoff_t   offset_fsb = XFS_B_TO_FSBT(mp, offset);
-       xfs_fileoff_t   last_fsb = xfs_iomap_end_fsb(mp, offset, count);
-       xfs_filblks_t   count_fsb, resaligned;
-       xfs_extlen_t    extsz;
-       int             nimaps;
-       int             quota_flag;
-       int             rt;
-       xfs_trans_t     *tp;
-       uint            qblocks, resblks, resrtextents;
-       int             error;
-       int             lockmode;
-       int             bmapi_flags = XFS_BMAPI_PREALLOC;
-       uint            tflags = 0;
-
-       rt = XFS_IS_REALTIME_INODE(ip);
-       extsz = xfs_get_extsz_hint(ip);
-       lockmode = XFS_ILOCK_SHARED;    /* locked by caller */
-
-       ASSERT(xfs_isilocked(ip, lockmode));
+       struct xfs_mount        *mp = ip->i_mount;
+       struct xfs_trans        *tp;
+       xfs_filblks_t           resaligned;
+       int                     nimaps;
+       int                     quota_flag;
+       uint                    qblocks, resblks;
+       unsigned int            resrtextents = 0;
+       int                     error;
+       int                     bmapi_flags = XFS_BMAPI_PREALLOC;
+       uint                    tflags = 0;
 
-       if (offset + count > XFS_ISIZE(ip)) {
-               last_fsb = xfs_iomap_eof_align_last_fsb(ip, last_fsb);
-       } else {
-               if (nmaps && (imap->br_startblock == HOLESTARTBLOCK))
-                       last_fsb = min(last_fsb, (xfs_fileoff_t)
-                                       imap->br_blockcount +
-                                       imap->br_startoff);
-       }
-       count_fsb = last_fsb - offset_fsb;
        ASSERT(count_fsb > 0);
-       resaligned = xfs_aligned_fsb_count(offset_fsb, count_fsb, extsz);
 
-       if (unlikely(rt)) {
+       resaligned = xfs_aligned_fsb_count(offset_fsb, count_fsb,
+                                          xfs_get_extsz_hint(ip));
+       if (unlikely(XFS_IS_REALTIME_INODE(ip))) {
                resrtextents = qblocks = resaligned;
                resrtextents /= mp->m_sb.sb_rextsize;
                resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
                quota_flag = XFS_QMOPT_RES_RTBLKS;
        } else {
-               resrtextents = 0;
                resblks = qblocks = XFS_DIOSTRAT_SPACE_RES(mp, resaligned);
                quota_flag = XFS_QMOPT_RES_REGBLKS;
        }
 
-       /*
-        * Drop the shared lock acquired by the caller, attach the dquot if
-        * necessary and move on to transaction setup.
-        */
-       xfs_iunlock(ip, lockmode);
        error = xfs_qm_dqattach(ip);
        if (error)
                return error;
@@ -269,8 +244,7 @@ xfs_iomap_write_direct(
        if (error)
                return error;
 
-       lockmode = XFS_ILOCK_EXCL;
-       xfs_ilock(ip, lockmode);
+       xfs_ilock(ip, XFS_ILOCK_EXCL);
 
        error = xfs_trans_reserve_quota_nblks(tp, ip, qblocks, 0, quota_flag);
        if (error)
@@ -307,7 +281,7 @@ xfs_iomap_write_direct(
                error = xfs_alert_fsblock_zero(ip, imap);
 
 out_unlock:
-       xfs_iunlock(ip, lockmode);
+       xfs_iunlock(ip, XFS_ILOCK_EXCL);
        return error;
 
 out_res_cancel:
@@ -807,14 +781,16 @@ xfs_direct_write_iomap_begin(
         * lower level functions are updated.
         */
        length = min_t(loff_t, length, 1024 * PAGE_SIZE);
+       end_fsb = xfs_iomap_end_fsb(mp, offset, length);
 
-       /*
-        * xfs_iomap_write_direct() expects the shared lock. It is unlocked on
-        * return.
-        */
-       if (lockmode == XFS_ILOCK_EXCL)
-               xfs_ilock_demote(ip, lockmode);
-       error = xfs_iomap_write_direct(ip, offset, length, &imap, nimaps);
+       if (offset + length > XFS_ISIZE(ip))
+               end_fsb = xfs_iomap_eof_align_last_fsb(ip, end_fsb);
+       else if (nimaps && imap.br_startblock == HOLESTARTBLOCK)
+               end_fsb = min(end_fsb, imap.br_startoff + imap.br_blockcount);
+       xfs_iunlock(ip, lockmode);
+
+       error = xfs_iomap_write_direct(ip, offset_fsb, end_fsb - offset_fsb,
+                       &imap);
        if (error)
                return error;
 

diff --git a/fs/xfs/xfs_iomap.h b/fs/xfs/xfs_iomap.h
index d5b292bdaf82fec106a51c6b1f120c470d30696f..7d3703556d0e082271ccfd6b06b915fe11c34425 100644 (file)
--- a/fs/xfs/xfs_iomap.h
+++ b/fs/xfs/xfs_iomap.h
@@ -11,9 +11,11 @@
 struct xfs_inode;
 struct xfs_bmbt_irec;
 
-int xfs_iomap_write_direct(struct xfs_inode *, xfs_off_t, size_t,
-                       struct xfs_bmbt_irec *, int);
+int xfs_iomap_write_direct(struct xfs_inode *ip, xfs_fileoff_t offset_fsb,
+               xfs_fileoff_t count_fsb, struct xfs_bmbt_irec *imap);
 int xfs_iomap_write_unwritten(struct xfs_inode *, xfs_off_t, xfs_off_t, bool);
+xfs_fileoff_t xfs_iomap_eof_align_last_fsb(struct xfs_inode *ip,
+               xfs_fileoff_t end_fsb);
 
 int xfs_bmbt_to_iomap(struct xfs_inode *, struct iomap *,
                struct xfs_bmbt_irec *, u16);

diff --git a/fs/xfs/xfs_pnfs.c b/fs/xfs/xfs_pnfs.c
index ada46e9f5ff13cb74706d7f0f6ab02eb59b5d0fe..ae3f00cb6a438743b541ce3ac68d1f68d5ad087e 100644 (file)
--- a/fs/xfs/xfs_pnfs.c
+++ b/fs/xfs/xfs_pnfs.c
@@ -143,21 +143,20 @@ xfs_fs_map_blocks(
        lock_flags = xfs_ilock_data_map_shared(ip);
        error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb,
                                &imap, &nimaps, bmapi_flags);
-       xfs_iunlock(ip, lock_flags);
-
-       if (error)
-               goto out_unlock;
 
        ASSERT(!nimaps || imap.br_startblock != DELAYSTARTBLOCK);
 
-       if (write && (!nimaps || imap.br_startblock == HOLESTARTBLOCK)) {
-               /*
-                * xfs_iomap_write_direct() expects to take ownership of the
-                * shared ilock.
-                */
-               xfs_ilock(ip, XFS_ILOCK_SHARED);
-               error = xfs_iomap_write_direct(ip, offset, length, &imap,
-                                              nimaps);
+       if (!error && write &&
+           (!nimaps || imap.br_startblock == HOLESTARTBLOCK)) {
+               if (offset + length > XFS_ISIZE(ip))
+                       end_fsb = xfs_iomap_eof_align_last_fsb(ip, end_fsb);
+               else if (nimaps && imap.br_startblock == HOLESTARTBLOCK)
+                       end_fsb = min(end_fsb, imap.br_startoff +
+                                              imap.br_blockcount);
+               xfs_iunlock(ip, lock_flags);
+
+               error = xfs_iomap_write_direct(ip, offset_fsb,
+                               end_fsb - offset_fsb, &imap);
                if (error)
                        goto out_unlock;
 
@@ -170,6 +169,8 @@ xfs_fs_map_blocks(
                                XFS_PREALLOC_SET | XFS_PREALLOC_SYNC);
                if (error)
                        goto out_unlock;
+       } else {
+               xfs_iunlock(ip, lock_flags);
        }
        xfs_iunlock(ip, XFS_IOLOCK_EXCL);