[Patch] tmpfs/ramfs accounting

Christoph Rohland (cr@sap.com)
02 Jul 2001 13:46:41 +0200


Hi Alan,

here is the patch you backed out for -ac22.

I slightly changed the approach: I do not rely on removepage to
calculate the fs size any more since the special-casing was ugly and
PG_marker was dropped. But I use removepage for the shmem_nrpages
calculation.

Please apply
Christoph

diff -uNr 5-ac22/fs/ramfs/inode.c 5-ac22-fix/fs/ramfs/inode.c
--- 5-ac22/fs/ramfs/inode.c Mon Jul 2 09:13:18 2001
+++ 5-ac22-fix/fs/ramfs/inode.c Mon Jul 2 09:55:52 2001
@@ -289,7 +289,7 @@
return 0;
}

-static void ramfs_truncatepage(struct page *page)
+static void ramfs_removepage(struct page *page)
{
struct inode *inode = (struct inode *)page->mapping->host;

@@ -659,7 +659,7 @@
writepage: ramfs_writepage,
prepare_write: ramfs_prepare_write,
commit_write: ramfs_commit_write,
- truncatepage: ramfs_truncatepage,
+ removepage: ramfs_removepage,
};

static struct file_operations ramfs_file_operations = {
diff -uNr 5-ac22/include/linux/fs.h 5-ac22-fix/include/linux/fs.h
--- 5-ac22/include/linux/fs.h Mon Jul 2 09:35:39 2001
+++ 5-ac22-fix/include/linux/fs.h Mon Jul 2 10:32:04 2001
@@ -375,7 +375,7 @@
int (*sync_page)(struct page *);
int (*prepare_write)(struct file *, struct page *, unsigned, unsigned);
int (*commit_write)(struct file *, struct page *, unsigned, unsigned);
- void (*truncatepage)(struct page *); /* called from truncate_complete_page */
+ void (*removepage)(struct page *); /* called when page gets removed from the inode */
/* Unfortunately this kludge is needed for FIBMAP. Don't use it */
int (*bmap)(struct address_space *, long);
};
diff -uNr 5-ac22/mm/filemap.c 5-ac22-fix/mm/filemap.c
--- 5-ac22/mm/filemap.c Mon Jul 2 09:13:29 2001
+++ 5-ac22-fix/mm/filemap.c Mon Jul 2 10:22:52 2001
@@ -87,6 +87,9 @@
{
struct address_space * mapping = page->mapping;

+ if (mapping->a_ops->removepage)
+ mapping->a_ops->removepage(page);
+
mapping->nrpages--;
list_del(&page->list);
page->mapping = NULL;
@@ -211,9 +214,6 @@
if (!page->buffers || block_flushpage(page, 0))
lru_cache_del(page);

- if (page->mapping->a_ops->truncatepage)
- page->mapping->a_ops->truncatepage(page);
-
/*
* We remove the page from the page cache _after_ we have
* destroyed all buffer-cache references to it. Otherwise some
diff -uNr 5-ac22/mm/shmem.c 5-ac22-fix/mm/shmem.c
--- 5-ac22/mm/shmem.c Mon Jul 2 09:13:29 2001
+++ 5-ac22-fix/mm/shmem.c Mon Jul 2 10:54:55 2001
@@ -34,6 +34,7 @@
#define TMPFS_MAGIC 0x01021994

#define ENTRIES_PER_PAGE (PAGE_SIZE/sizeof(unsigned long))
+#define SHMEM_MAX_BLOCKS (SHMEM_NR_DIRECT + ENTRIES_PER_PAGE*ENTRIES_PER_PAGE)

#define SHMEM_SB(sb) (&sb->u.shmem_sb)

@@ -51,6 +52,11 @@

#define BLOCKS_PER_PAGE (PAGE_SIZE/512)

+static void shmem_removepage(struct page *page)
+{
+ atomic_dec(&shmem_nrpages);
+}
+
/*
* shmem_recalc_inode - recalculate the size of an inode
*
@@ -69,11 +75,9 @@
* (inode->i_mapping->nrpages + info->swapped)
*
* It has to be called with the spinlock held.
- *
- * The swap parameter is a performance hack for truncate.
*/

-static void shmem_recalc_inode(struct inode * inode, unsigned long swap)
+static void shmem_recalc_inode(struct inode * inode)
{
unsigned long freed;

@@ -85,7 +89,6 @@
spin_lock (&sbinfo->stat_lock);
sbinfo->free_blocks += freed;
spin_unlock (&sbinfo->stat_lock);
- atomic_sub(freed-swap, &shmem_nrpages);
}
}

@@ -202,7 +205,7 @@
out:
info->max_index = index;
info->swapped -= freed;
- shmem_recalc_inode(inode, freed);
+ shmem_recalc_inode(inode);
spin_unlock (&info->lock);
up(&info->sem);
}
@@ -257,7 +260,7 @@
entry = shmem_swp_entry(info, page->index);
if (IS_ERR(entry)) /* this had been allocted on page allocation */
BUG();
- shmem_recalc_inode(page->mapping->host, 0);
+ shmem_recalc_inode(page->mapping->host);
error = -EAGAIN;
if (entry->val)
BUG();
@@ -265,7 +268,6 @@
*entry = swap;
error = 0;
/* Remove the page from the page cache */
- atomic_dec(&shmem_nrpages);
lru_cache_del(page);
remove_inode_page(page);

@@ -1086,6 +1088,8 @@
unsigned long max_inodes, inodes;
struct shmem_sb_info *sbinfo = SHMEM_SB(sb);

+ max_blocks = sbinfo->max_blocks;
+ max_inodes = sbinfo->max_inodes;
if (shmem_parse_options (data, NULL, &max_blocks, &max_inodes))
return -EINVAL;

@@ -1134,7 +1138,7 @@
sbinfo->free_blocks = blocks;
sbinfo->max_inodes = inodes;
sbinfo->free_inodes = inodes;
- sb->s_maxbytes = (unsigned long long)(SHMEM_NR_DIRECT + (ENTRIES_PER_PAGE*ENTRIES_PER_PAGE)) << PAGE_CACHE_SHIFT;
+ sb->s_maxbytes = (unsigned long long) SHMEM_MAX_BLOCKS << PAGE_CACHE_SHIFT;
sb->s_blocksize = PAGE_CACHE_SIZE;
sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
sb->s_magic = TMPFS_MAGIC;
@@ -1155,7 +1159,8 @@


static struct address_space_operations shmem_aops = {
- writepage: shmem_writepage
+ removepage: shmem_removepage,
+ writepage: shmem_writepage,
};

static struct file_operations shmem_file_operations = {
@@ -1334,9 +1339,11 @@
struct qstr this;
int vm_enough_memory(long pages);

- error = -ENOMEM;
+ if (size > (unsigned long long) SHMEM_MAX_BLOCKS << PAGE_CACHE_SHIFT)
+ return ERR_PTR(-EINVAL);
+
if (!vm_enough_memory((size) >> PAGE_SHIFT))
- goto out;
+ return ERR_PTR(-ENOMEM);

this.name = name;
this.len = strlen(name);
@@ -1344,7 +1351,7 @@
root = tmpfs_fs_type.kern_mnt->mnt_root;
dentry = d_alloc(root, &this);
if (!dentry)
- goto out;
+ return ERR_PTR(-ENOMEM);

error = -ENFILE;
file = get_empty_filp();
@@ -1370,7 +1377,6 @@
put_filp(file);
put_dentry:
dput (dentry);
-out:
return ERR_PTR(error);
}
/*

-
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