On Thu, 2005-10-20 at 12:24 -0400, Charles P. Wright wrote:
> I'll take a bite of the apple. I've committed your diff to the latest
> snapshot.
Here's another patch on top of what you already applied.
it attempts to wrap ever function that calls branchget/put within a
read_lock/read_unlock pair.
look it over, I'm not so sure that I got the lock ordering right (vis a
vis w/ dentry locking).
Is there any other functions that depend on the sb branch structure not
changing that would have to be wrapped?
diff -rNu unionfs-20051020-1229/commonfops.c unionfs-20051020-1229.new/commonfops.c
--- unionfs-20051020-1229/commonfops.c 2005-10-20 12:29:42.000000000 -0400
+++ unionfs-20051020-1229.new/commonfops.c 2005-10-20 14:30:44.000000000 -0400
@@ -28,11 +28,9 @@
{
struct putmap *putmap;
- unionfs_read_lock(sb);
-
if (generation == atomic_read(&stopd(sb)->usi_generation)) {
branchput(sb, index);
- goto out;
+ return;
}
ASSERT(stopd(sb)->usi_firstputmap <= generation);
@@ -51,9 +49,6 @@
fist_dprint(8, "Freeing putmap %d.\n", generation);
KFREE(putmap);
}
-
- out:
- unionfs_read_unlock(sb);
}
char *get_random_name(int size, unsigned char *name)
@@ -182,14 +177,16 @@
dentry = file->f_dentry;
lock_dentry(dentry);
PASSERT(dentry);
+ sb = dentry->d_sb;
+ PASSERT(sb);
+ unionfs_read_lock(sb);
+
if (!unionfs_d_revalidate(dentry, 0) && !d_deleted(dentry)) {
err = -ESTALE;
goto out;
}
fist_print_dentry("file revalidate in", dentry);
- sb = dentry->d_sb;
- PASSERT(sb);
sbgen = atomic_read(&stopd(sb)->usi_generation);
dgen = atomic_read(&dtopd(dentry)->udi_generation);
fgen = atomic_read(&ftopd(file)->ufi_generation);
@@ -349,9 +346,7 @@
bend = fbend(file);
for (bindex = bstart; bindex <= bend; bindex++) {
if (ftohf_index(file, bindex)) {
- unionfs_read_lock(dentry->d_sb);
branchput(dentry->d_sb, bindex);
- unionfs_read_unlock(dentry->d_sb);
fput(ftohf_index(file, bindex));
set_ftohf_index(file, bindex, NULL);
}
@@ -363,6 +358,7 @@
out:
fist_print_dentry("file revalidate out", dentry);
unlock_dentry(dentry);
+ unionfs_read_unlock(dentry->d_sb);
print_exit_status(err);
return err;
}
@@ -411,6 +407,9 @@
lock_dentry(dentry);
locked = 1;
+ //need this to ensure branchget/put are in same generation
+ unionfs_read_lock(inode->i_sb);
+
bstart = fbstart(file) = dbstart(dentry);
bend = fbend(file) = dbend(dentry);
@@ -512,6 +511,9 @@
if (locked)
unlock_dentry(dentry);
+
+ unionfs_read_unlock(inode->i_sb);
+
print_exit_status(err);
return err;
}
@@ -537,7 +539,9 @@
if (hidden_file) {
fput(hidden_file);
+ unionfs_read_lock(inode->i_sb);
branchput_gen(fgen, inode->i_sb, bindex);
+ unionfs_read_unlock(inode->i_sb);
}
}
KFREE(ftohf_ptr(file));
diff -rNu unionfs-20051020-1229/copyup.c unionfs-20051020-1229.new/copyup.c
--- unionfs-20051020-1229/copyup.c 2005-10-20 12:29:42.000000000 -0400
+++ unionfs-20051020-1229.new/copyup.c 2005-10-20 14:32:18.000000000 -0400
@@ -226,6 +226,8 @@
sb = dir->i_sb;
+ unionfs_read_lock(sb);
+
if ((err = is_robranch_super(sb, new_bindex)))
goto out;
@@ -422,6 +424,8 @@
}
}
+ unionfs_read_unlock(sb);
+
fist_print_dentry("OUT: copyup_dentry", dentry);
fist_print_inode("OUT: copyup_dentry", dentry->d_inode);
diff -rNu unionfs-20051020-1229/dirhelper.c unionfs-20051020-1229.new/dirhelper.c
--- unionfs-20051020-1229/dirhelper.c 2005-10-20 12:29:42.000000000 -0400
+++ unionfs-20051020-1229.new/dirhelper.c 2005-10-20 14:32:44.000000000 -0400
@@ -175,6 +175,8 @@
sb = dentry->d_sb;
+ unionfs_read_lock(sb);
+
ASSERT(S_ISDIR(dentry->d_inode->i_mode));
if ((err = unionfs_partial_lookup(dentry)))
@@ -245,6 +247,8 @@
KFREE(buf);
}
+ unionfs_read_unlock(sb);
+
print_exit_status(err);
return err;
}
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