The patch titled
reiser4: fix for drop-unused-semaphores.patch
has been added to the -mm tree. Its filename is
reiser4-fix-for-drop-unused-semaphorespatch.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: reiser4: fix for drop-unused-semaphores.patch
From: Edward Shishkin <edward@xxxxxxxxxxx>
Wait for tail conversion completion when acquiring exclusive access by
. mmap_unix_file()
. setattr_unix_file()
. release_unix_file()
Update comments.
Signed-off-by: Edward Shishkin <edward@xxxxxxxxxxx>
Cc Jonathan Briggs <jbriggs@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/reiser4/plugin/file/file.c | 37 +++++++++++----------
fs/reiser4/plugin/file/tail_conversion.c | 21 ++++++-----
2 files changed, 32 insertions(+), 26 deletions(-)
diff -puN fs/reiser4/plugin/file/file.c~reiser4-fix-for-drop-unused-semaphorespatch fs/reiser4/plugin/file/file.c
--- a/fs/reiser4/plugin/file/file.c~reiser4-fix-for-drop-unused-semaphorespatch
+++ a/fs/reiser4/plugin/file/file.c
@@ -28,6 +28,22 @@ static void drop_access(unix_file_info_t
static int hint_validate(hint_t * hint, const reiser4_key * key, int check_key,
znode_lock_mode lock_mode);
+/* Get exclusive access and make sure that file is not partially
+ * converted (It may happen that another process is doing tail
+ * conversion. If so, wait until it completes)
+ */
+static inline void get_exclusive_access_careful(unix_file_info_t * uf_info,
+ struct inode *inode)
+{
+ do {
+ get_exclusive_access(uf_info);
+ if (!reiser4_inode_get_flag(inode, REISER4_PART_IN_CONV))
+ break;
+ drop_exclusive_access(uf_info);
+ schedule();
+ } while (1);
+}
+
/* get unix file plugin specific portion of inode */
unix_file_info_t *unix_file_inode_data(const struct inode *inode)
{
@@ -1933,7 +1949,7 @@ int mmap_unix_file(struct file *file, st
uf_info = unix_file_inode_data(inode);
- get_exclusive_access(uf_info);
+ get_exclusive_access_careful(uf_info, inode);
if (!IS_RDONLY(inode) && (vma->vm_flags & (VM_MAYWRITE | VM_SHARED))) {
/*
@@ -2048,21 +2064,8 @@ int open_unix_file(struct inode *inode,
return PTR_ERR(ctx);
uf_info = unix_file_inode_data(inode);
- get_exclusive_access(uf_info);
- /*
- * it may happen that another process is doing tail conversion. Wait
- * until it completes
- */
- while (1) {
- if (reiser4_inode_get_flag(inode, REISER4_PART_IN_CONV)) {
- drop_exclusive_access(uf_info);
- schedule();
- get_exclusive_access(uf_info);
- continue;
- }
- break;
- }
+ get_exclusive_access_careful(uf_info, inode);
if (!reiser4_inode_get_flag(inode, REISER4_PART_MIXED)) {
/*
@@ -2365,7 +2368,7 @@ int release_unix_file(struct inode *inod
if (in_reiser4 == 0) {
uf_info = unix_file_inode_data(inode);
- get_exclusive_access(uf_info);
+ get_exclusive_access_careful(uf_info, inode);
if (atomic_read(&file->f_dentry->d_count) == 1 &&
uf_info->container == UF_CONTAINER_EXTENTS &&
!should_have_notail(uf_info, inode->i_size) &&
@@ -2674,7 +2677,7 @@ int setattr_unix_file(struct dentry *den
return PTR_ERR(ctx);
uf_info = unix_file_inode_data(dentry->d_inode);
- get_exclusive_access(uf_info);
+ get_exclusive_access_careful(uf_info, dentry->d_inode);
result = setattr_truncate(dentry->d_inode, attr);
drop_exclusive_access(uf_info);
context_set_commit_async(ctx);
diff -puN fs/reiser4/plugin/file/tail_conversion.c~reiser4-fix-for-drop-unused-semaphorespatch fs/reiser4/plugin/file/tail_conversion.c
--- a/fs/reiser4/plugin/file/tail_conversion.c~reiser4-fix-for-drop-unused-semaphorespatch
+++ a/fs/reiser4/plugin/file/tail_conversion.c
@@ -468,15 +468,18 @@ int tail2extent(unix_file_info_t *uf_inf
if (result)
goto error;
/*
- * we have to drop exclusive access to avoid deadlock
- * which may happen because called by
- * reiser4_writepages capture_unix_file requires to get
- * non-exclusive access to a file. It is safe to drop
- * EA in the middle of tail2extent conversion because
- * write_unix_file/unix_setattr(truncate)/release_unix_file(extent2tail)
- * are serialized by reiser4_inode->mutex_write semaphore and
- * because read_unix_file works (should at least) on
- * partially converted files
+ * We have to drop exclusive access to avoid deadlock
+ * which may happen because called by reiser4_writepages
+ * capture_unix_file requires to get non-exclusive
+ * access to a file. It is safe to drop EA in the middle
+ * of tail2extent conversion because write_unix_file,
+ * setattr_unix_file(truncate), mmap_unix_file,
+ * release_unix_file(extent2tail) checks if conversion
+ * is not in progress (see comments before
+ * get_exclusive_access_careful().
+ * Other processes that acquire non-exclusive access
+ * (read_unix_file, reiser4_writepages, etc) should work
+ * on partially converted files.
*/
drop_exclusive_access(uf_info);
/* throttle the conversion */
_
Patches currently in -mm which might be from edward@xxxxxxxxxxx are
reiser4.patch
reiser4-fix-for-drop-unused-semaphorespatch.patch
reiser4-use-simple_prepare_write-to-zero-page-data.patch
mm-clean-up-and-kernelify-shrinker-registration-reiser4.patch
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