The patch titled
reiser4: fix dummy ioctl_cryptcompress
has been removed from the -mm tree. Its filename was
reiser4-fix-dummy-ioctl_cryptcompress.patch
This patch was dropped because it was folded into reiser4.patch
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: reiser4: fix dummy ioctl_cryptcompress
From: Edward Shishkin <edward.shishkin@xxxxxxxxx>
. Problem: unexpected resolving to prompt when merging/updating
stuff with python-based Gentoo manager (reported by
rvalles <rvalles@xxxxxxxxxx> and
Dushan Tcholich <dusanc@xxxxxxxxx>).
Bug: User application made wrong decision about file's nature
based on returned value of ->ioctl() method for cryptcompress
file plugin.
Fix: make dummy ->ioctl() method for cryptcompress file plugin
to return -EINVAL instead of zero.
. Drop some redundant ifs.
. Update comments. Add precise definition of FCS (file conversion set)
that should be protected during file plugin conversion.
Signed-off-by: Edward Shishkin <edward.shishkin@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/reiser4/plugin/file/cryptcompress.c | 2
fs/reiser4/plugin/file/file.c | 7 -
fs/reiser4/plugin/file/file_conversion.c | 118 +++++++++++++--------
3 files changed, 78 insertions(+), 49 deletions(-)
diff -puN fs/reiser4/plugin/file/cryptcompress.c~reiser4-fix-dummy-ioctl_cryptcompress fs/reiser4/plugin/file/cryptcompress.c
--- a/fs/reiser4/plugin/file/cryptcompress.c~reiser4-fix-dummy-ioctl_cryptcompress
+++ a/fs/reiser4/plugin/file/cryptcompress.c
@@ -3627,7 +3627,7 @@ int writepages_cryptcompress(struct addr
int ioctl_cryptcompress(struct inode *inode, struct file *filp,
unsigned int cmd, unsigned long arg)
{
- return 0;
+ return RETERR(-ENOSYS);
}
/* plugin->mmap */
diff -puN fs/reiser4/plugin/file/file.c~reiser4-fix-dummy-ioctl_cryptcompress fs/reiser4/plugin/file/file.c
--- a/fs/reiser4/plugin/file/file.c~reiser4-fix-dummy-ioctl_cryptcompress
+++ a/fs/reiser4/plugin/file/file.c
@@ -1006,12 +1006,9 @@ capture_anonymous_pages(struct address_s
/* clear MOVED tag for all found pages */
for (i = 0; i < pagevec_count(&pvec); i++) {
- void *p;
-
page_cache_get(pvec.pages[i]);
- p = radix_tree_tag_clear(&mapping->page_tree, pvec.pages[i]->index,
- PAGECACHE_TAG_REISER4_MOVED);
- assert("vs-49", p == pvec.pages[i]);
+ radix_tree_tag_clear(&mapping->page_tree, pvec.pages[i]->index,
+ PAGECACHE_TAG_REISER4_MOVED);
}
write_unlock_irq(&mapping->tree_lock);
diff -puN fs/reiser4/plugin/file/file_conversion.c~reiser4-fix-dummy-ioctl_cryptcompress fs/reiser4/plugin/file/file_conversion.c
--- a/fs/reiser4/plugin/file/file_conversion.c~reiser4-fix-dummy-ioctl_cryptcompress
+++ a/fs/reiser4/plugin/file/file_conversion.c
@@ -4,8 +4,8 @@
/* *
* This file contains a converter cryptcompress->unix_file, and O(1)-heuristic,
* which allows to assign for a regular file the most reasonable plugin to be
- * managed by. Note, that we don't use back conversion because of compatibility
- * reasons (see http://dev.namesys.com/Version4.X.Y for details).
+ * managed by. Note, that we don't perform back conversion because of
+ * compatibility reasons (see http://dev.namesys.com/Version4.X.Y for details).
*
* Currently used heuristic is very simple: if first complete logical cluster
* (64K by default) of a file is incompressible, then we make a decision, that
@@ -17,12 +17,37 @@
* The conversion is accompanied by rebuilding disk structures of a file, so it
* is important to protect them from being interacted with other plugins which
* don't expect them to be in such inconsistent state. For this to be protected
- * we serialize readers and writers of pset. Writers are the processes which can
- * change it with conversion purposes; other ones are readers. Serialization is
- * performed via acquiring per-inode rw-semaphore (conv_sem).
+ * we serialize readers and writers of a file's conversion set (FCS).
*
- * (*) This heuristic can be easily changed as soon as we have a new,
- * better one.
+ * We define FCS as a file plugin id installed in inode's pset all structures
+ * specific for this id (like stat-data, etc. items). Note, that FCS is defined
+ * per file.
+ * FCS reader is defined as a set of instruction of the following type:
+ * inode_file_plugin(inode)->method();
+ * FCS writer is a set of instructions that perform file plugin conversion
+ * (convert items, update pset, etc).
+ * Example:
+ * reiser4_write_careful() supplied to VFS as a ->write() file operation is
+ * composed of the following (optional) instructions:
+ * 1 2 3
+ * *********************** ####### -------------------------------------------->
+ *
+ * 1) "****" are instructions performed on behalf of cryptcompress file plugin;
+ * 2) "####" is a FCS writer (performing a conversion cryptcompress->unix_file);
+ * 3) "----" are instructions performed on behalf of unix_file plugin;
+ * Here (1) and (3) are FCS readers.
+ *
+ * In this example FCS readers and writers are already serialized (by design),
+ * however there can be readers and writers executing at the same time in
+ * different contexts, so we need a common mechanism of serialization.
+ *
+ * Currently serialization of FCS readers and writers is performed via acquiring
+ * a special per-inode rw-semaphore (conv_sem). And yes, {down, up}_read is for
+ * FCS readers, and {down, up}_write is for FCS writers, see the macros below
+ * for passive/active protection.
+ *
+ * ---
+ * (*) This heuristic can be changed to a better one (benchmarking is needed).
* (**) Such solution allows to keep enable/disable state on disk.
*/
@@ -50,8 +75,15 @@
* protection for writers. All methods with active or passive protection
* has suffix "careful".
*/
-/* Macro for passive protection.
- method_foo contains only readers */
+/**
+ * Macros for passive protection.
+ *
+ * Construct invariant operation to be supplied to VFS.
+ * The macro accepts the following lexemes:
+ * @type - type of the value represented by the compound statement;
+ * @method - name of an operation to be supplied to VFS (reiser4 file
+ * plugin also should contain a method with such name).
+ */
#define PROT_PASSIVE(type, method, args) \
({ \
type _result; \
@@ -63,11 +95,7 @@
if (!should_protect(inode)) \
up_read(guard); \
} \
- if (inode_file_plugin(inode) == \
- file_plugin_by_id(UNIX_FILE_PLUGIN_ID)) \
- _result = method ## _unix_file args; \
- else \
- _result = method ## _cryptcompress args; \
+ _result = inode_file_plugin(inode)->method args; \
if (should_protect(inode)) \
up_read(guard); \
_result; \
@@ -83,28 +111,29 @@
if (!should_protect(inode)) \
up_read(guard); \
} \
- if (inode_file_plugin(inode) == \
- file_plugin_by_id(UNIX_FILE_PLUGIN_ID)) \
- method ## _unix_file args; \
- else \
- method ## _cryptcompress args; \
+ inode_file_plugin(inode)->method args; \
+ \
if (should_protect(inode)) \
up_read(guard); \
})
/**
- * Macro for active protection.
- * active_expr contains writers of pset;
- * NOTE: after evaluating active_expr conversion should be disabled.
+ * This macro is for invariant methods which can be decomposed
+ * into "active expression" that goes first and contains pset
+ * writers (and, hence, needs serialization), and generic plugin
+ * method which doesn't need serialization.
+ *
+ * The macro accepts the following lexemes:
+ * @type - type of the value represented by the compound statement;
+ * @method - name of invariant operation supplied to VFS;
+ * @active_expr - name of "active expression", usually some O(1) -
+ * heuristic for disabling a conversion.
*/
#define PROT_ACTIVE(type, method, args, active_expr) \
({ \
type _result = 0; \
struct rw_semaphore * guard = \
&reiser4_inode_data(inode)->conv_sem; \
- reiser4_context * ctx = reiser4_init_context(inode->i_sb); \
- if (IS_ERR(ctx)) \
- return PTR_ERR(ctx); \
\
if (should_protect(inode)) { \
down_write(guard); \
@@ -112,15 +141,7 @@
_result = active_expr; \
up_write(guard); \
} \
- if (_result == 0) { \
- if (inode_file_plugin(inode) == \
- file_plugin_by_id(UNIX_FILE_PLUGIN_ID)) \
- _result = method ## _unix_file args; \
- else \
- _result = method ## _cryptcompress args; \
- } \
- reiser4_exit_context(ctx); \
- _result; \
+ _result = inode_file_plugin(inode)->method args; \
})
/* Pass management to the unix-file plugin with "notail" policy */
@@ -547,7 +568,8 @@ static int setattr_conversion_hook(struc
*/
/*
- * Reiser4 write "careful" method. Write a file in 2 steps:
+ * Reiser4 invariant ->write() method supplied to VFS.
+ * Write a file in 2 steps:
* . start write with initial file plugin,
* switch to a new (more resonable) file plugin (if any);
* . finish write with the new plugin.
@@ -564,8 +586,9 @@ ssize_t reiser4_write_careful(struct fil
/**
* First step.
- * Sanity check: if conversion is possible,
- * then protect pset.
+ * Check, if conversion is possible.
+ * If yes, then ->write() method contains pset
+ * writers, so active protection is required.
*/
if (should_protect(inode)) {
prot = 1;
@@ -574,15 +597,16 @@ ssize_t reiser4_write_careful(struct fil
written_old = inode_file_plugin(inode)->write(file,
buf,
count,
- off, &conv);
+ off,
+ &conv);
if (prot)
up_write(guard);
if (written_old < 0 || conv == 0)
return written_old;
/**
* Conversion occurred.
- * Back conversion is impossible,
- * so don't protect at this step.
+ * Back conversion is impossible, so at
+ * this step protection is not required.
*/
assert("edward-1532",
inode_file_plugin(inode) ==
@@ -591,15 +615,23 @@ ssize_t reiser4_write_careful(struct fil
written_new = inode_file_plugin(inode)->write(file,
buf + written_old,
count - written_old,
- off, NULL);
+ off,
+ NULL);
return written_old + (written_new < 0 ? 0 : written_new);
}
int reiser4_setattr_careful(struct dentry *dentry, struct iattr *attr)
{
+ int result;
struct inode * inode = dentry->d_inode;
- return PROT_ACTIVE(int, setattr, (dentry, attr),
- setattr_conversion_hook(inode, attr));
+ reiser4_context * ctx = reiser4_init_context(inode->i_sb);
+ if (IS_ERR(ctx))
+ return PTR_ERR(ctx);
+
+ result = PROT_ACTIVE(int, setattr, (dentry, attr),
+ setattr_conversion_hook(inode, attr));
+ reiser4_exit_context(ctx);
+ return result;
}
/* Wrappers with passive protection for:
_
Patches currently in -mm which might be from edward.shishkin@xxxxxxxxx are
origin.patch
reiser4.patch
reiser4-fix-dummy-ioctl_cryptcompress.patch
reiser4-granulate-rw-serialization-when-accessing-file-conversion-set.patch
reiser4-fix-disk-cluster-synchronization.patch
reiser4-use-balance_dirty_pages_ratelimited_nr.patch
reiser4-correct-references-to-filemap_nopage.patch
reiser4-fix-null-pointer-dereference-in-reiser4_write_extent.patch
reiser4-code-cleanups.patch
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