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authorSteven Whitehouse <swhiteho@redhat.com>2007-10-15 15:40:33 +0100
committerSteven Whitehouse <swhiteho@redhat.com>2008-01-25 08:07:13 +0000
commit3cc3f710ce0effe397b830826a1a081fa81f11c7 (patch)
tree53f69f1b8d1cbc2849c6bac08ce7786f3ecd7447 /fs/gfs2/ops_address.c
parent51ff87bdd9f21a5d3672517b75d25ab5842d94a8 (diff)
[GFS2] Use ->page_mkwrite() for mmap()
This cleans up the mmap() code path for GFS2 by implementing the page_mkwrite function for GFS2. We are thus able to use the generic filemap_fault function for our ->fault() implementation. This now means that shared writable mappings will be much more efficiently shared across the cluster if there is a reasonable proportion of read activity (the greater proportion, the better). As a side effect, it also reduces the size of the code, removes special cases from readpage and readpages, and makes the code path easier to follow. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Diffstat (limited to 'fs/gfs2/ops_address.c')
-rw-r--r--fs/gfs2/ops_address.c45
1 files changed, 8 insertions, 37 deletions
diff --git a/fs/gfs2/ops_address.c b/fs/gfs2/ops_address.c
index 9bb24b1d9c05..1696e5d9d112 100644
--- a/fs/gfs2/ops_address.c
+++ b/fs/gfs2/ops_address.c
@@ -265,9 +265,7 @@ static int __gfs2_readpage(void *file, struct page *page)
* @file: The file to read
* @page: The page of the file
*
- * This deals with the locking required. If the GFF_EXLOCK flags is set
- * then we already hold the glock (due to page fault) and thus we call
- * __gfs2_readpage() directly. Otherwise we use a trylock in order to
+ * This deals with the locking required. We use a trylock in order to
* avoid the page lock / glock ordering problems returning AOP_TRUNCATED_PAGE
* in the event that we are unable to get the lock.
*/
@@ -278,12 +276,6 @@ static int gfs2_readpage(struct file *file, struct page *page)
struct gfs2_holder gh;
int error;
- if (file) {
- struct gfs2_file *gf = file->private_data;
- if (test_bit(GFF_EXLOCK, &gf->f_flags))
- return __gfs2_readpage(file, page);
- }
-
gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME|LM_FLAG_TRY_1CB, &gh);
error = gfs2_glock_nq_atime(&gh);
if (unlikely(error)) {
@@ -354,9 +346,8 @@ int gfs2_internal_read(struct gfs2_inode *ip, struct file_ra_state *ra_state,
* 2. We don't handle stuffed files here we let readpage do the honours.
* 3. mpage_readpages() does most of the heavy lifting in the common case.
* 4. gfs2_get_block() is relied upon to set BH_Boundary in the right places.
- * 5. We use LM_FLAG_TRY_1CB here, effectively we then have lock-ahead as
- * well as read-ahead.
*/
+
static int gfs2_readpages(struct file *file, struct address_space *mapping,
struct list_head *pages, unsigned nr_pages)
{
@@ -364,40 +355,20 @@ static int gfs2_readpages(struct file *file, struct address_space *mapping,
struct gfs2_inode *ip = GFS2_I(inode);
struct gfs2_sbd *sdp = GFS2_SB(inode);
struct gfs2_holder gh;
- int ret = 0;
- int do_unlock = 0;
+ int ret;
- if (file) {
- struct gfs2_file *gf = file->private_data;
- if (test_bit(GFF_EXLOCK, &gf->f_flags))
- goto skip_lock;
- }
- gfs2_holder_init(ip->i_gl, LM_ST_SHARED,
- LM_FLAG_TRY_1CB|GL_ATIME, &gh);
- do_unlock = 1;
+ gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME, &gh);
ret = gfs2_glock_nq_atime(&gh);
- if (ret == GLR_TRYFAILED)
- goto out_noerror;
if (unlikely(ret))
- goto out_unlock;
-skip_lock:
+ goto out_uninit;
if (!gfs2_is_stuffed(ip))
ret = mpage_readpages(mapping, pages, nr_pages, gfs2_get_block);
-
- if (do_unlock) {
- gfs2_glock_dq_m(1, &gh);
- gfs2_holder_uninit(&gh);
- }
-out:
+ gfs2_glock_dq(&gh);
+out_uninit:
+ gfs2_holder_uninit(&gh);
if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
ret = -EIO;
return ret;
-out_noerror:
- ret = 0;
-out_unlock:
- if (do_unlock)
- gfs2_holder_uninit(&gh);
- goto out;
}
/**