Gitweb:     
http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=3cc3f710ce0effe397b830826a1a081fa81f11c7
Commit:     3cc3f710ce0effe397b830826a1a081fa81f11c7
Parent:     51ff87bdd9f21a5d3672517b75d25ab5842d94a8
Author:     Steven Whitehouse <[EMAIL PROTECTED]>
AuthorDate: Mon Oct 15 15:40:33 2007 +0100
Committer:  Steven Whitehouse <[EMAIL PROTECTED]>
CommitDate: Fri Jan 25 08:07:13 2008 +0000

    [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 <[EMAIL PROTECTED]>
---
 fs/gfs2/Makefile      |    2 +-
 fs/gfs2/glops.c       |    9 +---
 fs/gfs2/incore.h      |    8 ---
 fs/gfs2/ops_address.c |   45 +++-----------
 fs/gfs2/ops_file.c    |  131 +++++++++++++++++++++++++++++++++++---
 fs/gfs2/ops_vm.c      |  169 -------------------------------------------------
 fs/gfs2/ops_vm.h      |   18 -----
 7 files changed, 131 insertions(+), 251 deletions(-)

diff --git a/fs/gfs2/Makefile b/fs/gfs2/Makefile
index 04ad0ca..8fff110 100644
--- a/fs/gfs2/Makefile
+++ b/fs/gfs2/Makefile
@@ -2,7 +2,7 @@ obj-$(CONFIG_GFS2_FS) += gfs2.o
 gfs2-y := acl.o bmap.o daemon.o dir.o eaops.o eattr.o glock.o \
        glops.o inode.o lm.o log.o lops.o locking.o main.o meta_io.o \
        mount.o ops_address.o ops_dentry.o ops_export.o ops_file.o \
-       ops_fstype.o ops_inode.o ops_super.o ops_vm.o quota.o \
+       ops_fstype.o ops_inode.o ops_super.o quota.o \
        recovery.o rgrp.o super.o sys.o trans.o util.o
 
 obj-$(CONFIG_GFS2_FS_LOCKING_NOLOCK) += locking/nolock/
diff --git a/fs/gfs2/glops.c b/fs/gfs2/glops.c
index 4670dcb..110f03d 100644
--- a/fs/gfs2/glops.c
+++ b/fs/gfs2/glops.c
@@ -86,15 +86,10 @@ static void gfs2_pte_inval(struct gfs2_glock *gl)
        if (!ip || !S_ISREG(inode->i_mode))
                return;
 
-       if (!test_bit(GIF_PAGED, &ip->i_flags))
-               return;
-
        unmap_shared_mapping_range(inode->i_mapping, 0, 0);
-
        if (test_bit(GIF_SW_PAGED, &ip->i_flags))
                set_bit(GLF_DIRTY, &gl->gl_flags);
 
-       clear_bit(GIF_SW_PAGED, &ip->i_flags);
 }
 
 /**
@@ -234,10 +229,8 @@ static void inode_go_inval(struct gfs2_glock *gl, int 
flags)
                        set_bit(GIF_INVALID, &ip->i_flags);
        }
 
-       if (ip && S_ISREG(ip->i_inode.i_mode)) {
+       if (ip && S_ISREG(ip->i_inode.i_mode))
                truncate_inode_pages(ip->i_inode.i_mapping, 0);
-               clear_bit(GIF_PAGED, &ip->i_flags);
-       }
 }
 
 /**
diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
index 662182b..55c72f0 100644
--- a/fs/gfs2/incore.h
+++ b/fs/gfs2/incore.h
@@ -241,7 +241,6 @@ struct gfs2_alloc {
 enum {
        GIF_INVALID             = 0,
        GIF_QD_LOCKED           = 1,
-       GIF_PAGED               = 2,
        GIF_SW_PAGED            = 3,
 };
 
@@ -289,19 +288,12 @@ static inline struct gfs2_inode *GFS2_I(struct inode 
*inode)
        return container_of(inode, struct gfs2_inode, i_inode);
 }
 
-/* To be removed? */
 static inline struct gfs2_sbd *GFS2_SB(struct inode *inode)
 {
        return inode->i_sb->s_fs_info;
 }
 
-enum {
-       GFF_DID_DIRECT_ALLOC    = 0,
-       GFF_EXLOCK = 1,
-};
-
 struct gfs2_file {
-       unsigned long f_flags;          /* GFF_... */
        struct mutex f_fl_mutex;
        struct gfs2_holder f_fl_gh;
 };
diff --git a/fs/gfs2/ops_address.c b/fs/gfs2/ops_address.c
index 9bb24b1..1696e5d 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;
 }
 
 /**
diff --git a/fs/gfs2/ops_file.c b/fs/gfs2/ops_file.c
index a729c86..6f3aeb0 100644
--- a/fs/gfs2/ops_file.c
+++ b/fs/gfs2/ops_file.c
@@ -33,7 +33,6 @@
 #include "lm.h"
 #include "log.h"
 #include "meta_io.h"
-#include "ops_vm.h"
 #include "quota.h"
 #include "rgrp.h"
 #include "trans.h"
@@ -169,7 +168,7 @@ static int gfs2_get_flags(struct file *filp, u32 __user 
*ptr)
        if (put_user(fsflags, ptr))
                error = -EFAULT;
 
-       gfs2_glock_dq_m(1, &gh);
+       gfs2_glock_dq(&gh);
        gfs2_holder_uninit(&gh);
        return error;
 }
@@ -293,6 +292,125 @@ static long gfs2_ioctl(struct file *filp, unsigned int 
cmd, unsigned long arg)
        return -ENOTTY;
 }
 
+/**
+ * gfs2_allocate_page_backing - Use bmap to allocate blocks
+ * @page: The (locked) page to allocate backing for
+ *
+ * We try to allocate all the blocks required for the page in
+ * one go. This might fail for various reasons, so we keep
+ * trying until all the blocks to back this page are allocated.
+ * If some of the blocks are already allocated, thats ok too.
+ */
+
+static int gfs2_allocate_page_backing(struct page *page)
+{
+       struct inode *inode = page->mapping->host;
+       struct buffer_head bh;
+       unsigned long size = PAGE_CACHE_SIZE;
+       u64 lblock = page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
+
+       do {
+               bh.b_state = 0;
+               bh.b_size = size;
+               gfs2_block_map(inode, lblock, 1, &bh);
+               if (!buffer_mapped(&bh))
+                       return -EIO;
+               size -= bh.b_size;
+               lblock += (bh.b_size >> inode->i_blkbits);
+       } while(size > 0);
+       return 0;
+}
+
+/**
+ * gfs2_page_mkwrite - Make a shared, mmap()ed, page writable
+ * @vma: The virtual memory area
+ * @page: The page which is about to become writable
+ *
+ * When the page becomes writable, we need to ensure that we have
+ * blocks allocated on disk to back that page.
+ */
+
+static int gfs2_page_mkwrite(struct vm_area_struct *vma, struct page *page)
+{
+       struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
+       struct gfs2_inode *ip = GFS2_I(inode);
+       struct gfs2_sbd *sdp = GFS2_SB(inode);
+       unsigned long last_index;
+       u64 pos = page->index << (PAGE_CACHE_SIZE - inode->i_blkbits);
+       unsigned int data_blocks, ind_blocks, rblocks;
+       int alloc_required = 0;
+       struct gfs2_holder gh;
+       struct gfs2_alloc *al;
+       int ret;
+
+       gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_ATIME, &gh);
+       ret = gfs2_glock_nq_atime(&gh);
+       if (ret)
+               goto out;
+
+       set_bit(GIF_SW_PAGED, &ip->i_flags);
+       gfs2_write_calc_reserv(ip, PAGE_CACHE_SIZE, &data_blocks, &ind_blocks);
+       ret = gfs2_write_alloc_required(ip, pos, PAGE_CACHE_SIZE, 
&alloc_required);
+       if (ret || !alloc_required)
+               goto out_unlock;
+
+       ip->i_alloc.al_requested = 0;
+       al = gfs2_alloc_get(ip);
+       ret = gfs2_quota_lock(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
+       if (ret)
+               goto out_alloc_put;
+       ret = gfs2_quota_check(ip, ip->i_inode.i_uid, ip->i_inode.i_gid);
+       if (ret)
+               goto out_quota_unlock;
+       al->al_requested = data_blocks + ind_blocks;
+       ret = gfs2_inplace_reserve(ip);
+       if (ret)
+               goto out_quota_unlock;
+
+       rblocks = RES_DINODE + ind_blocks;
+       if (gfs2_is_jdata(ip))
+               rblocks += data_blocks ? data_blocks : 1;
+       if (ind_blocks || data_blocks)
+               rblocks += RES_STATFS + RES_QUOTA;
+       ret = gfs2_trans_begin(sdp, rblocks, 0);
+       if (ret)
+               goto out_trans_fail;
+
+       lock_page(page);
+       ret = -EINVAL;
+       last_index = ip->i_inode.i_size >> PAGE_CACHE_SHIFT;
+       if (page->index > last_index)
+               goto out_unlock_page;
+       if (!PageUptodate(page) || page->mapping != ip->i_inode.i_mapping)
+               goto out_unlock_page;
+       if (gfs2_is_stuffed(ip)) {
+               ret = gfs2_unstuff_dinode(ip, page);
+               if (ret)
+                       goto out_unlock_page;
+       }
+       ret = gfs2_allocate_page_backing(page);
+
+out_unlock_page:
+       unlock_page(page);
+       gfs2_trans_end(sdp);
+out_trans_fail:
+       gfs2_inplace_release(ip);
+out_quota_unlock:
+       gfs2_quota_unlock(ip);
+out_alloc_put:
+       gfs2_alloc_put(ip);
+out_unlock:
+       gfs2_glock_dq(&gh);
+out:
+       gfs2_holder_uninit(&gh);
+       return ret;
+}
+
+static struct vm_operations_struct gfs2_vm_ops = {
+       .fault = filemap_fault,
+       .page_mkwrite = gfs2_page_mkwrite,
+};
+
 
 /**
  * gfs2_mmap -
@@ -315,14 +433,7 @@ static int gfs2_mmap(struct file *file, struct 
vm_area_struct *vma)
                return error;
        }
 
-       /* This is VM_MAYWRITE instead of VM_WRITE because a call
-          to mprotect() can turn on VM_WRITE later. */
-
-       if ((vma->vm_flags & (VM_MAYSHARE | VM_MAYWRITE)) ==
-           (VM_MAYSHARE | VM_MAYWRITE))
-               vma->vm_ops = &gfs2_vm_ops_sharewrite;
-       else
-               vma->vm_ops = &gfs2_vm_ops_private;
+       vma->vm_ops = &gfs2_vm_ops;
 
        gfs2_glock_dq_uninit(&i_gh);
 
diff --git a/fs/gfs2/ops_vm.c b/fs/gfs2/ops_vm.c
deleted file mode 100644
index 927d739..0000000
--- a/fs/gfs2/ops_vm.c
+++ /dev/null
@@ -1,169 +0,0 @@
-/*
- * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
- * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
- *
- * This copyrighted material is made available to anyone wishing to use,
- * modify, copy, or redistribute it subject to the terms and conditions
- * of the GNU General Public License version 2.
- */
-
-#include <linux/slab.h>
-#include <linux/spinlock.h>
-#include <linux/completion.h>
-#include <linux/buffer_head.h>
-#include <linux/mm.h>
-#include <linux/pagemap.h>
-#include <linux/gfs2_ondisk.h>
-#include <linux/lm_interface.h>
-
-#include "gfs2.h"
-#include "incore.h"
-#include "bmap.h"
-#include "glock.h"
-#include "inode.h"
-#include "ops_vm.h"
-#include "quota.h"
-#include "rgrp.h"
-#include "trans.h"
-#include "util.h"
-
-static int gfs2_private_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
-{
-       struct gfs2_inode *ip = GFS2_I(vma->vm_file->f_mapping->host);
-
-       set_bit(GIF_PAGED, &ip->i_flags);
-       return filemap_fault(vma, vmf);
-}
-
-static int alloc_page_backing(struct gfs2_inode *ip, struct page *page)
-{
-       struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
-       unsigned long index = page->index;
-       u64 lblock = index << (PAGE_CACHE_SHIFT -
-                                   sdp->sd_sb.sb_bsize_shift);
-       unsigned int blocks = PAGE_CACHE_SIZE >> sdp->sd_sb.sb_bsize_shift;
-       struct gfs2_alloc *al;
-       unsigned int data_blocks, ind_blocks;
-       unsigned int x;
-       int error;
-
-       al = gfs2_alloc_get(ip);
-
-       error = gfs2_quota_lock(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
-       if (error)
-               goto out;
-
-       error = gfs2_quota_check(ip, ip->i_inode.i_uid, ip->i_inode.i_gid);
-       if (error)
-               goto out_gunlock_q;
-
-       gfs2_write_calc_reserv(ip, PAGE_CACHE_SIZE, &data_blocks, &ind_blocks);
-
-       al->al_requested = data_blocks + ind_blocks;
-
-       error = gfs2_inplace_reserve(ip);
-       if (error)
-               goto out_gunlock_q;
-
-       error = gfs2_trans_begin(sdp, al->al_rgd->rd_length +
-                                ind_blocks + RES_DINODE +
-                                RES_STATFS + RES_QUOTA, 0);
-       if (error)
-               goto out_ipres;
-
-       if (gfs2_is_stuffed(ip)) {
-               error = gfs2_unstuff_dinode(ip, NULL);
-               if (error)
-                       goto out_trans;
-       }
-
-       for (x = 0; x < blocks; ) {
-               u64 dblock;
-               unsigned int extlen;
-               int new = 1;
-
-               error = gfs2_extent_map(&ip->i_inode, lblock, &new, &dblock, 
&extlen);
-               if (error)
-                       goto out_trans;
-
-               lblock += extlen;
-               x += extlen;
-       }
-
-       gfs2_assert_warn(sdp, al->al_alloced);
-
-out_trans:
-       gfs2_trans_end(sdp);
-out_ipres:
-       gfs2_inplace_release(ip);
-out_gunlock_q:
-       gfs2_quota_unlock(ip);
-out:
-       gfs2_alloc_put(ip);
-       return error;
-}
-
-static int gfs2_sharewrite_fault(struct vm_area_struct *vma,
-                                               struct vm_fault *vmf)
-{
-       struct file *file = vma->vm_file;
-       struct gfs2_file *gf = file->private_data;
-       struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
-       struct gfs2_holder i_gh;
-       int alloc_required;
-       int error;
-       int ret = 0;
-
-       error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
-       if (error)
-               goto out;
-
-       set_bit(GIF_PAGED, &ip->i_flags);
-       set_bit(GIF_SW_PAGED, &ip->i_flags);
-
-       error = gfs2_write_alloc_required(ip,
-                                       (u64)vmf->pgoff << PAGE_CACHE_SHIFT,
-                                       PAGE_CACHE_SIZE, &alloc_required);
-       if (error) {
-               ret = VM_FAULT_OOM; /* XXX: are these right? */
-               goto out_unlock;
-       }
-
-       set_bit(GFF_EXLOCK, &gf->f_flags);
-       ret = filemap_fault(vma, vmf);
-       clear_bit(GFF_EXLOCK, &gf->f_flags);
-       if (ret & VM_FAULT_ERROR)
-               goto out_unlock;
-
-       if (alloc_required) {
-               /* XXX: do we need to drop page lock around 
alloc_page_backing?*/
-               error = alloc_page_backing(ip, vmf->page);
-               if (error) {
-                       /*
-                        * VM_FAULT_LOCKED should always be the case for
-                        * filemap_fault, but it may not be in a future
-                        * implementation.
-                        */
-                       if (ret & VM_FAULT_LOCKED)
-                               unlock_page(vmf->page);
-                       page_cache_release(vmf->page);
-                       ret = VM_FAULT_OOM;
-                       goto out_unlock;
-               }
-               set_page_dirty(vmf->page);
-       }
-
-out_unlock:
-       gfs2_glock_dq_uninit(&i_gh);
-out:
-       return ret;
-}
-
-struct vm_operations_struct gfs2_vm_ops_private = {
-       .fault = gfs2_private_fault,
-};
-
-struct vm_operations_struct gfs2_vm_ops_sharewrite = {
-       .fault = gfs2_sharewrite_fault,
-};
-
diff --git a/fs/gfs2/ops_vm.h b/fs/gfs2/ops_vm.h
deleted file mode 100644
index 4ae8f43..0000000
--- a/fs/gfs2/ops_vm.h
+++ /dev/null
@@ -1,18 +0,0 @@
-/*
- * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
- * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
- *
- * This copyrighted material is made available to anyone wishing to use,
- * modify, copy, or redistribute it subject to the terms and conditions
- * of the GNU General Public License version 2.
- */
-
-#ifndef __OPS_VM_DOT_H__
-#define __OPS_VM_DOT_H__
-
-#include <linux/mm.h>
-
-extern struct vm_operations_struct gfs2_vm_ops_private;
-extern struct vm_operations_struct gfs2_vm_ops_sharewrite;
-
-#endif /* __OPS_VM_DOT_H__ */
-
To unsubscribe from this list: send the line "unsubscribe git-commits-head" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to