gfs2: Clean up the error handling in gfs2_page_mkwrite

We're setting an error number so that block_page_mkwrite_return
translates it into the corresponding VM_FAULT_* code in several places,
but this is getting confusing, so set the VM_FAULT_* codes directly
instead.  (No change in functionality.)

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index 37041873bb954acdd71dbeaa5522b6a06a6f28ac..cf16d61f46ec359f26966914dfbe8b083c890975 100644 (file)
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -427,22 +427,25 @@ static vm_fault_t gfs2_page_mkwrite(struct vm_fault *vmf)
        struct gfs2_alloc_parms ap = { .aflags = 0, };
        u64 offset = page_offset(page);
        unsigned int data_blocks, ind_blocks, rblocks;
+       vm_fault_t ret = VM_FAULT_LOCKED;
        struct gfs2_holder gh;
        unsigned int length;
        loff_t size;
-       int ret;
+       int err;
 
        sb_start_pagefault(inode->i_sb);
 
        gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
-       ret = gfs2_glock_nq(&gh);
-       if (ret)
+       err = gfs2_glock_nq(&gh);
+       if (err) {
+               ret = block_page_mkwrite_return(err);
                goto out_uninit;
+       }
 
        /* Check page index against inode size */
        size = i_size_read(inode);
        if (offset >= size) {
-               ret = -EINVAL;
+               ret = VM_FAULT_SIGBUS;
                goto out_unlock;
        }
 
@@ -469,24 +472,30 @@ static vm_fault_t gfs2_page_mkwrite(struct vm_fault *vmf)
            !gfs2_write_alloc_required(ip, offset, length)) {
                lock_page(page);
                if (!PageUptodate(page) || page->mapping != inode->i_mapping) {
-                       ret = -EAGAIN;
+                       ret = VM_FAULT_NOPAGE;
                        unlock_page(page);
                }
                goto out_unlock;
        }
 
-       ret = gfs2_rindex_update(sdp);
-       if (ret)
+       err = gfs2_rindex_update(sdp);
+       if (err) {
+               ret = block_page_mkwrite_return(err);
                goto out_unlock;
+       }
 
        gfs2_write_calc_reserv(ip, length, &data_blocks, &ind_blocks);
        ap.target = data_blocks + ind_blocks;
-       ret = gfs2_quota_lock_check(ip, &ap);
-       if (ret)
+       err = gfs2_quota_lock_check(ip, &ap);
+       if (err) {
+               ret = block_page_mkwrite_return(err);
                goto out_unlock;
-       ret = gfs2_inplace_reserve(ip, &ap);
-       if (ret)
+       }
+       err = gfs2_inplace_reserve(ip, &ap);
+       if (err) {
+               ret = block_page_mkwrite_return(err);
                goto out_quota_unlock;
+       }
 
        rblocks = RES_DINODE + ind_blocks;
        if (gfs2_is_jdata(ip))
@@ -495,27 +504,35 @@ static vm_fault_t gfs2_page_mkwrite(struct vm_fault *vmf)
                rblocks += RES_STATFS + RES_QUOTA;
                rblocks += gfs2_rg_blocks(ip, data_blocks + ind_blocks);
        }
-       ret = gfs2_trans_begin(sdp, rblocks, 0);
-       if (ret)
+       err = gfs2_trans_begin(sdp, rblocks, 0);
+       if (err) {
+               ret = block_page_mkwrite_return(err);
                goto out_trans_fail;
+       }
 
        lock_page(page);
-       ret = -EAGAIN;
        /* If truncated, we must retry the operation, we may have raced
         * with the glock demotion code.
         */
-       if (!PageUptodate(page) || page->mapping != inode->i_mapping)
+       if (!PageUptodate(page) || page->mapping != inode->i_mapping) {
+               ret = VM_FAULT_NOPAGE;
                goto out_trans_end;
+       }
 
        /* Unstuff, if required, and allocate backing blocks for page */
-       ret = 0;
-       if (gfs2_is_stuffed(ip))
-               ret = gfs2_unstuff_dinode(ip, page);
-       if (ret == 0)
-               ret = gfs2_allocate_page_backing(page, length);
+       if (gfs2_is_stuffed(ip)) {
+               err = gfs2_unstuff_dinode(ip, page);
+               if (err) {
+                       ret = block_page_mkwrite_return(err);
+                       goto out_trans_end;
+               }
+       }
+       err = gfs2_allocate_page_backing(page, length);
+       if (err)
+               ret = block_page_mkwrite_return(err);
 
 out_trans_end:
-       if (ret)
+       if (ret != VM_FAULT_LOCKED)
                unlock_page(page);
        gfs2_trans_end(sdp);
 out_trans_fail:
@@ -526,12 +543,12 @@ out_unlock:
        gfs2_glock_dq(&gh);
 out_uninit:
        gfs2_holder_uninit(&gh);
-       if (ret == 0) {
+       if (ret == VM_FAULT_LOCKED) {
                set_page_dirty(page);
                wait_for_stable_page(page);
        }
        sb_end_pagefault(inode->i_sb);
-       return block_page_mkwrite_return(ret);
+       return ret;
 }
 
 static vm_fault_t gfs2_fault(struct vm_fault *vmf)