The patch titled
reiser4: update comments, fix write and truncate cryptcompress
has been added to the -mm tree. Its filename is
reiser4-update-comments-fix-write-and-truncate-cryptcompress.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: reiser4: update comments, fix write and truncate cryptcompress
From: Edward Shishkin <edward@xxxxxxxxxxx>
. Addressing the following todo items:
1) akpm wrote: <wonders what formatted and unformatted nodes
are> A brief glossary might help.
2) akpm wrote: reiser4_invalidate_pages() is a mix of reiser4
things and of things-which-the-vfs-is-supposed-to-do. It is
uncommented and I am unable to work out why it was necessary
to do this, and hence what we can do about it.
. Update comments in page_cache.c
. Fix missed modifications performed by generic_write_checks()
. Fix missed unmap_mapping_range() when truncating a cryptcompress
file
Signed-off-by: Edward Shishkin <edward@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
fs/reiser4/page_cache.c | 99 ++++++++++++++---------
fs/reiser4/plugin/cluster.h | 3
fs/reiser4/plugin/file/cryptcompress.c | 69 ++++------------
fs/reiser4/plugin/item/ctail.c | 3
4 files changed, 89 insertions(+), 85 deletions(-)
diff -puN fs/reiser4/page_cache.c~reiser4-update-comments-fix-write-and-truncate-cryptcompress fs/reiser4/page_cache.c
--- a/fs/reiser4/page_cache.c~reiser4-update-comments-fix-write-and-truncate-cryptcompress
+++ a/fs/reiser4/page_cache.c
@@ -2,6 +2,26 @@
* reiser4/README */
/* Memory pressure hooks. Fake inodes handling. */
+
+/* GLOSSARY
+
+ . Formatted and unformatted nodes.
+ Elements of reiser4 balanced tree to store data and metadata.
+ Unformatted nodes are pointed to by extent pointers. Such nodes
+ are used to store data of large objects. Unlike unformatted nodes,
+ formatted ones have associated format described by node4X plugin.
+
+ . Jnode (or journal node)
+ The in-memory header which is used to track formatted and unformatted
+ nodes, bitmap nodes, etc. In particular, jnodes are used to track
+ transactional information associated with each block(see reiser4/jnode.c
+ for details).
+
+ . Znode
+ The in-memory header which is used to track formatted nodes. Contains
+ embedded jnode (see reiser4/znode.c for details).
+*/
+
/* We store all file system meta data (and data, of course) in the page cache.
What does this mean? In stead of using bread/brelse we create special
@@ -32,8 +52,8 @@
1. when jnode-to-page mapping is established (by jnode_attach_page()), page
reference counter is increased.
- 2. when jnode-to-page mapping is destroyed (by jnode_detach_page() and
- page_detach_jnode()), page reference counter is decreased.
+ 2. when jnode-to-page mapping is destroyed (by page_clear_jnode(), page
+ reference counter is decreased.
3. on jload() reference counter on jnode page is increased, page is
kmapped and `referenced'.
@@ -592,37 +612,9 @@ void reiser4_drop_page(struct page *page
unlock_page(page);
}
-/* this is called by truncate_jnodes_range which in its turn is always called
- after truncate_mapping_pages_range. Therefore, here jnode can not have
- page. New pages can not be created because truncate_jnodes_range goes under
- exclusive access on file obtained, where as new page creation requires
- non-exclusive access obtained */
-static void invalidate_unformatted(jnode * node)
-{
- struct page *page;
-
- spin_lock_jnode(node);
- page = node->pg;
- if (page) {
- loff_t from, to;
-
- page_cache_get(page);
- spin_unlock_jnode(node);
- /* FIXME: use truncate_complete_page instead */
- from = page_offset(page);
- to = from + PAGE_CACHE_SIZE - 1;
- truncate_inode_pages_range(page->mapping, from, to);
- page_cache_release(page);
- } else {
- JF_SET(node, JNODE_HEARD_BANSHEE);
- reiser4_uncapture_jnode(node);
- unhash_unformatted_jnode(node);
- }
-}
-
#define JNODE_GANG_SIZE (16)
-/* find all eflushed jnodes from range specified and invalidate them */
+/* find all jnodes from range specified and invalidate them */
static int
truncate_jnodes_range(struct inode *inode, pgoff_t from, pgoff_t count)
{
@@ -632,6 +624,14 @@ truncate_jnodes_range(struct inode *inod
unsigned long index;
unsigned long end;
+ if (inode_file_plugin(inode) ==
+ file_plugin_by_id(CRYPTCOMPRESS_FILE_PLUGIN_ID))
+ /* No need to get rid of jnodes here: if the single jnode of
+ page cluster did not have page, then it was found and killed
+ before in
+ truncate_page_cluster_cryptcompress()->jput()->jput_final(),
+ otherwise it will be dropped by reiser4_invalidatepage() */
+ return 0;
truncated_jnodes = 0;
info = reiser4_inode_data(inode);
@@ -666,7 +666,18 @@ truncate_jnodes_range(struct inode *inod
node = gang[i];
if (node != NULL) {
index = max(index, index_jnode(node));
- invalidate_unformatted(node);
+ spin_lock_jnode(node);
+ assert("edward-1457", node->pg == NULL);
+ /* this is always called after
+ truncate_inode_pages_range(). Therefore, here
+ jnode can not have page. New pages can not be
+ created because truncate_jnodes_range goes
+ under exclusive access on file obtained,
+ where as new page creation requires
+ non-exclusive access obtained */
+ JF_SET(node, JNODE_HEARD_BANSHEE);
+ reiser4_uncapture_jnode(node);
+ unhash_unformatted_jnode(node);
truncated_jnodes++;
jput(node);
} else
@@ -678,9 +689,27 @@ truncate_jnodes_range(struct inode *inod
return truncated_jnodes;
}
-void
-reiser4_invalidate_pages(struct address_space *mapping, pgoff_t from,
- unsigned long count, int even_cows)
+/* Truncating files in reiser4: problems and solutions.
+
+ VFS calls fs's truncate after it has called truncate_inode_pages()
+ to get rid of pages corresponding to part of file being truncated.
+ In reiser4 it may cause existence of unallocated extents which do
+ not have jnodes. Flush code does not expect that. Solution of this
+ problem is straightforward. As vfs's truncate is implemented using
+ setattr operation, it seems reasonable to have ->setattr() that
+ will cut file body. However, flush code also does not expect dirty
+ pages without parent items, so it is impossible to cut all items,
+ then truncate all pages in two steps. We resolve this problem by
+ cutting items one-by-one. Each such fine-grained step performed
+ under longterm znode lock calls at the end ->kill_hook() method of
+ a killed item to remove its binded pages and jnodes.
+
+ The following function is a common part of mentioned kill hooks.
+ Also, this is called before tail-to-extent conversion (to not manage
+ few copies of the data).
+*/
+void reiser4_invalidate_pages(struct address_space *mapping, pgoff_t from,
+ unsigned long count, int even_cows)
{
loff_t from_bytes, count_bytes;
diff -puN fs/reiser4/plugin/cluster.h~reiser4-update-comments-fix-write-and-truncate-cryptcompress fs/reiser4/plugin/cluster.h
--- a/fs/reiser4/plugin/cluster.h~reiser4-update-comments-fix-write-and-truncate-cryptcompress
+++ a/fs/reiser4/plugin/cluster.h
@@ -261,7 +261,8 @@ int find_disk_cluster(reiser4_cluster_t
znode_lock_mode mode);
int flush_cluster_pages(reiser4_cluster_t *, jnode *, struct inode *);
int reiser4_deflate_cluster(reiser4_cluster_t *, struct inode *);
-void truncate_page_cluster(struct inode *inode, cloff_t start);
+void truncate_page_cluster_cryptcompress(struct inode *inode, cloff_t start,
+ int even_cows);
void invalidate_hint_cluster(reiser4_cluster_t * clust);
void put_hint_cluster(reiser4_cluster_t * clust, struct inode *inode,
znode_lock_mode mode);
diff -puN fs/reiser4/plugin/file/cryptcompress.c~reiser4-update-comments-fix-write-and-truncate-cryptcompress fs/reiser4/plugin/file/cryptcompress.c
--- a/fs/reiser4/plugin/file/cryptcompress.c~reiser4-update-comments-fix-write-and-truncate-cryptcompress
+++ a/fs/reiser4/plugin/file/cryptcompress.c
@@ -2365,25 +2365,10 @@ prepare_page_cluster(struct inode *inode
grab_cluster_pages(inode, clust));
}
-static void __truncate_page_cluster(struct inode * inode, cloff_t index)
-{
- if (reiser4_inode_get_flag(inode, REISER4_FILE_CONV_IN_PROGRESS) &&
- index == 0)
- return;
- truncate_inode_pages_range(inode->i_mapping,
- clust_to_off(index, inode),
- clust_to_off(index,
- inode) +
- inode_cluster_size(inode) - 1);
- assert("edward-1201",
- ergo(!reiser4_inode_get_flag(inode,
- REISER4_FILE_CONV_IN_PROGRESS),
- jnode_truncate_ok(inode, index)));
-}
-
/* Truncate all pages of the cluster of index @index.
This is called by ->kill_hook() method of item plugin */
-void truncate_page_cluster(struct inode *inode, cloff_t index)
+void truncate_page_cluster_cryptcompress(struct inode *inode, cloff_t index,
+ int even_cows)
{
int i;
int found = 0;
@@ -2443,7 +2428,17 @@ void truncate_page_cluster(struct inode
/* put pages found here */
forget_cluster_pages(pages, found);
truncate:
- __truncate_page_cluster(inode, index);
+ if (reiser4_inode_get_flag(inode, REISER4_FILE_CONV_IN_PROGRESS) &&
+ index == 0)
+ return;
+ reiser4_invalidate_pages(inode->i_mapping,
+ clust_to_pg(index, inode),
+ cluster_nrpages(inode),
+ even_cows);
+ assert("edward-1201",
+ ergo(!reiser4_inode_get_flag(inode,
+ REISER4_FILE_CONV_IN_PROGRESS),
+ jnode_truncate_ok(inode, index)));
return;
}
@@ -2774,7 +2769,7 @@ write_cryptcompress_flow(struct file *fi
ssize_t write_cryptcompress(struct file *file, const char __user *buf,
size_t count, loff_t *off, int *conv)
{
- ssize_t result = 0;
+ ssize_t result;
struct inode *inode;
reiser4_context *ctx;
loff_t pos = *off;
@@ -2793,23 +2788,22 @@ ssize_t write_cryptcompress(struct file
down(&reiser4_inode_data(inode)->mutex_write);
- result = generic_write_checks(file, off, &count, 0);
+ result = generic_write_checks(file, &pos, &count, 0);
if (unlikely(result != 0))
- goto unlock;
+ goto out;
if (unlikely(count == 0))
- goto unlock;
-
+ goto out;
down_write(&info->lock);
result = write_cryptcompress_flow(file, inode, buf, count, pos, conv);
if (*conv == 0)
up_write(&info->lock);
- unlock:
- up(&reiser4_inode_data(inode)->mutex_write);
+
if (result < 0)
goto out;
/* update position in a file */
*off = pos + result;
out:
+ up(&reiser4_inode_data(inode)->mutex_write);
context_set_commit_async(ctx);
reiser4_exit_context(ctx);
return result;
@@ -3677,9 +3671,8 @@ int delete_object_cryptcompress(struct i
}
/* plugin->u.file.setattr method
- see plugin.h for description */
-int setattr_cryptcompress(struct dentry *dentry, /* Object to change attributes */
- struct iattr *attr /* change description */ )
+ This implements actual truncate (see comments in reiser4/page_cache.c) */
+int setattr_cryptcompress(struct dentry *dentry, struct iattr *attr)
{
int result;
struct inode *inode;
@@ -3689,26 +3682,6 @@ int setattr_cryptcompress(struct dentry
if (result)
return result;
if (attr->ia_valid & ATTR_SIZE) {
- /* EDWARD-FIXME-HANS: VS-FIXME-HANS:
- Q: this case occurs when? truncate?
- A: yes
-
- Q: If so, why isn't this code in truncate itself instead of here?
-
- A: because vfs calls fs's truncate after it has called truncate_inode_pages to get rid of pages
- corresponding to part of file being truncated. In reiser4 it may cause existence of unallocated
- extents which do not have jnodes. Flush code does not expect that. Solution of this problem is
- straightforward. As vfs's truncate is implemented using setattr operation (common implementaion of
- which calls truncate_inode_pages and fs's truncate in case when size of file changes) - it seems
- reasonable to have reiser4_setattr which will take care of removing pages, jnodes and extents
- simultaneously in case of truncate.
- Q: do you think implementing truncate using setattr is ugly,
- and vfs needs improving, or is there some sense in which this is a good design?
-
- A: VS-FIXME-HANS:
- */
-
- /* truncate does reservation itself and requires exclusive access obtained */
if (inode->i_size != attr->ia_size) {
reiser4_context *ctx;
loff_t old_size;
diff -puN fs/reiser4/plugin/item/ctail.c~reiser4-update-comments-fix-write-and-truncate-cryptcompress fs/reiser4/plugin/item/ctail.c
--- a/fs/reiser4/plugin/item/ctail.c~reiser4-update-comments-fix-write-and-truncate-cryptcompress
+++ a/fs/reiser4/plugin/item/ctail.c
@@ -372,7 +372,8 @@ kill_hook_ctail(const coord_t * coord, p
/* disk cluster is killed */
cloff_t start =
off_to_clust(get_key_offset(&key), inode);
- truncate_page_cluster(inode, start);
+ truncate_page_cluster_cryptcompress(inode, start,
+ kdata->params.truncate);
inode_sub_bytes(inode, inode_cluster_size(inode));
}
}
_
Patches currently in -mm which might be from edward@xxxxxxxxxxx are
reiser4-vs-streamline-generic_file_-interfaces-and-filemap-fix.patch
reiser4-rename-generic_sounding_globalspatch.patch
reiser4-format-subversion-numbers-heir-set-and-file-conversion.patch
reiser4-cleanups-in-lzo-compression-library.patch
reiser4-get-rid-of-deprecated-crypto-api.patch
reiser4-get-rid-of-deprecated-crypto-api-build-fix.patch
reiser4-fix-missed-unlock-and-exit_context.patch
reiser4-use-list_head-instead-of-struct-blocknr.patch
reiser4-use-list_empty-instead-of-list_empty_careful-for.patch
reiser4-update-comments-fix-write-and-truncate-cryptcompress.patch
-
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