[PATCH 05/19] Unionfs: create and consolidate helpers to path-put lower objects

From: Erez Zadok
Date: Tue Jul 29 2008 - 22:48:38 EST


Signed-off-by: Erez Zadok <ezk@xxxxxxxxxxxxx>
---
fs/unionfs/commonfops.c | 9 +------
fs/unionfs/copyup.c | 23 ++++++------------
fs/unionfs/dentry.c | 31 ++------------------------
fs/unionfs/fanout.h | 55 +++++++++++++++++++++++++++++++++++++++++++++++
fs/unionfs/lookup.c | 14 +++--------
5 files changed, 71 insertions(+), 61 deletions(-)

diff --git a/fs/unionfs/commonfops.c b/fs/unionfs/commonfops.c
index 585c5c9..5816d41 100644
--- a/fs/unionfs/commonfops.c
+++ b/fs/unionfs/commonfops.c
@@ -275,15 +275,8 @@ static int do_delayed_copyup(struct file *file)
fput(unionfs_lower_file_idx(file, bindex));
unionfs_set_lower_file_idx(file, bindex, NULL);
}
- if (unionfs_lower_mnt_idx(dentry, bindex)) {
- unionfs_mntput(dentry, bindex);
- unionfs_set_lower_mnt_idx(dentry, bindex, NULL);
- }
- if (unionfs_lower_dentry_idx(dentry, bindex)) {
- dput(unionfs_lower_dentry_idx(dentry, bindex));
- unionfs_set_lower_dentry_idx(dentry, bindex, NULL);
- }
}
+ path_put_lowers(dentry, bstart, bend, false);
iput_lowers(dentry->d_inode, bstart, bend, false);
/* for reg file, we only open it "once" */
fbend(file) = fbstart(file);
diff --git a/fs/unionfs/copyup.c b/fs/unionfs/copyup.c
index f20b984..55d48aa 100644
--- a/fs/unionfs/copyup.c
+++ b/fs/unionfs/copyup.c
@@ -866,22 +866,15 @@ void unionfs_postcopyup_setmnt(struct dentry *dentry)
*/
void unionfs_postcopyup_release(struct dentry *dentry)
{
- int bindex;
+ int bstart, bend;

BUG_ON(S_ISDIR(dentry->d_inode->i_mode));
- for (bindex = dbstart(dentry)+1; bindex <= dbend(dentry); bindex++) {
- if (unionfs_lower_mnt_idx(dentry, bindex)) {
- unionfs_mntput(dentry, bindex);
- unionfs_set_lower_mnt_idx(dentry, bindex, NULL);
- }
- if (unionfs_lower_dentry_idx(dentry, bindex)) {
- dput(unionfs_lower_dentry_idx(dentry, bindex));
- unionfs_set_lower_dentry_idx(dentry, bindex, NULL);
- }
- }
- iput_lowers(dentry->d_inode, dbstart(dentry)+1, dbend(dentry), false);
+ bstart = dbstart(dentry);
+ bend = dbend(dentry);
+
+ path_put_lowers(dentry, bstart + 1, bend, false);
+ iput_lowers(dentry->d_inode, bstart + 1, bend, false);

- bindex = dbstart(dentry);
- dbend(dentry) = bindex;
- ibend(dentry->d_inode) = ibstart(dentry->d_inode) = bindex;
+ dbend(dentry) = bstart;
+ ibend(dentry->d_inode) = ibstart(dentry->d_inode) = bstart;
}
diff --git a/fs/unionfs/dentry.c b/fs/unionfs/dentry.c
index a7960ac..51c0baf 100644
--- a/fs/unionfs/dentry.c
+++ b/fs/unionfs/dentry.c
@@ -455,8 +455,6 @@ static int unionfs_d_revalidate(struct dentry *dentry, struct nameidata *nd)

static void unionfs_d_release(struct dentry *dentry)
{
- int bindex, bstart, bend;
-
unionfs_read_lock(dentry->d_sb, UNIONFS_SMUTEX_CHILD);
if (unlikely(!UNIONFS_D(dentry)))
goto out; /* skip if no lower branches */
@@ -471,20 +469,7 @@ static void unionfs_d_release(struct dentry *dentry)
}

/* Release all the lower dentries */
- bstart = dbstart(dentry);
- bend = dbend(dentry);
- for (bindex = bstart; bindex <= bend; bindex++) {
- dput(unionfs_lower_dentry_idx(dentry, bindex));
- unionfs_set_lower_dentry_idx(dentry, bindex, NULL);
- /* NULL lower mnt is ok if this is a negative dentry */
- if (!dentry->d_inode && !unionfs_lower_mnt_idx(dentry, bindex))
- continue;
- unionfs_mntput(dentry, bindex);
- unionfs_set_lower_mnt_idx(dentry, bindex, NULL);
- }
- /* free private data (unionfs_dentry_info) here */
- kfree(UNIONFS_D(dentry)->lower_paths);
- UNIONFS_D(dentry)->lower_paths = NULL;
+ path_put_lowers_all(dentry, true);

unionfs_unlock_dentry(dentry);

@@ -500,7 +485,7 @@ out:
*/
static void unionfs_d_iput(struct dentry *dentry, struct inode *inode)
{
- int bindex, rc;
+ int rc;

BUG_ON(!dentry);
unionfs_read_lock(dentry->d_sb, UNIONFS_SMUTEX_CHILD);
@@ -508,17 +493,7 @@ static void unionfs_d_iput(struct dentry *dentry, struct inode *inode)

if (!UNIONFS_D(dentry) || dbstart(dentry) < 0)
goto drop_lower_inodes;
- for (bindex = dbstart(dentry); bindex <= dbend(dentry); bindex++) {
- if (unionfs_lower_mnt_idx(dentry, bindex)) {
- unionfs_mntput(dentry, bindex);
- unionfs_set_lower_mnt_idx(dentry, bindex, NULL);
- }
- if (unionfs_lower_dentry_idx(dentry, bindex)) {
- dput(unionfs_lower_dentry_idx(dentry, bindex));
- unionfs_set_lower_dentry_idx(dentry, bindex, NULL);
- }
- }
- dbstart(dentry) = dbend(dentry) = -1;
+ path_put_lowers_all(dentry, false);

drop_lower_inodes:
rc = atomic_read(&inode->i_count);
diff --git a/fs/unionfs/fanout.h b/fs/unionfs/fanout.h
index 94421f8..d8977bd 100644
--- a/fs/unionfs/fanout.h
+++ b/fs/unionfs/fanout.h
@@ -326,4 +326,59 @@ static inline void iput_lowers_all(struct inode *inode, bool free_lower)
ibstart(inode) = ibend(inode) = -1;
}

+/*
+ * dput/mntput all lower dentries and vfsmounts of an unionfs dentry, from
+ * bstart to bend. If @free_lower is true, then also kfree the memory used
+ * to hold the lower object pointers.
+ *
+ * XXX: implement using path_put VFS macros
+ */
+static inline void path_put_lowers(struct dentry *dentry,
+ int bstart, int bend, bool free_lower)
+{
+ struct dentry *lower_dentry;
+ struct vfsmount *lower_mnt;
+ int bindex;
+
+ BUG_ON(!dentry);
+ BUG_ON(!UNIONFS_D(dentry));
+ BUG_ON(bstart < 0);
+
+ for (bindex = bstart; bindex <= bend; bindex++) {
+ lower_dentry = unionfs_lower_dentry_idx(dentry, bindex);
+ if (lower_dentry) {
+ unionfs_set_lower_dentry_idx(dentry, bindex, NULL);
+ dput(lower_dentry);
+ }
+ lower_mnt = unionfs_lower_mnt_idx(dentry, bindex);
+ if (lower_mnt) {
+ unionfs_set_lower_mnt_idx(dentry, bindex, NULL);
+ mntput(lower_mnt);
+ }
+ }
+
+ if (free_lower) {
+ kfree(UNIONFS_D(dentry)->lower_paths);
+ UNIONFS_D(dentry)->lower_paths = NULL;
+ }
+}
+
+/*
+ * dput/mntput all lower dentries and vfsmounts, and reset start/end branch
+ * indices to -1.
+ */
+static inline void path_put_lowers_all(struct dentry *dentry, bool free_lower)
+{
+ int bstart, bend;
+
+ BUG_ON(!dentry);
+ BUG_ON(!UNIONFS_D(dentry));
+ bstart = dbstart(dentry);
+ bend = dbend(dentry);
+ BUG_ON(bstart < 0);
+
+ path_put_lowers(dentry, bstart, bend, free_lower);
+ dbstart(dentry) = dbend(dentry) = -1;
+}
+
#endif /* not _FANOUT_H */
diff --git a/fs/unionfs/lookup.c b/fs/unionfs/lookup.c
index 33be53c..f6bb748 100644
--- a/fs/unionfs/lookup.c
+++ b/fs/unionfs/lookup.c
@@ -407,18 +407,12 @@ out_drop:
d_drop(dentry);

out_free:
- /* should dput all the underlying dentries on error condition */
- bstart = dbstart(dentry);
- if (bstart >= 0) {
- bend = dbend(dentry);
- for (bindex = bstart; bindex <= bend; bindex++) {
- dput(unionfs_lower_dentry_idx(dentry, bindex));
- unionfs_mntput(dentry, bindex);
- }
- }
+ /* should dput/mntput all the underlying dentries on error condition */
+ if (dbstart(dentry) >= 0)
+ path_put_lowers_all(dentry, false);
+ /* free lower_paths unconditionally */
kfree(UNIONFS_D(dentry)->lower_paths);
UNIONFS_D(dentry)->lower_paths = NULL;
- dbstart(dentry) = dbend(dentry) = -1;

out:
if (!err && UNIONFS_D(dentry)) {
--
1.5.2.2

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/