The xattr file open/lookup code is needlessly complex. We can use vfs-level
operations to perform the same work, and also simplify the locking
constraints. The locking advantages will be exploited in future patches.
Signed-off-by: Jeff Mahoney <jeffm@xxxxxxxx>
---
fs/reiserfs/xattr.c | 200 +++++++++++++++++-----------------------------------
1 file changed, 66 insertions(+), 134 deletions(-)
--- a/fs/reiserfs/xattr.c 2007-05-30 15:43:39.000000000 -0400
+++ b/fs/reiserfs/xattr.c 2007-05-30 17:55:09.000000000 -0400
@@ -46,173 +46,104 @@
#include <linux/stat.h>
#include <asm/semaphore.h>
-#define FL_READONLY 128
-#define FL_DIR_SEM_HELD 256
#define PRIVROOT_NAME ".reiserfs_priv"
#define XAROOT_NAME "xattrs"
static struct reiserfs_xattr_handler *find_xattr_handler_prefix(const char
*prefix);
-/* Returns the dentry referring to the root of the extended attribute
- * directory tree. If it has already been retrieved, it is used. If it
- * hasn't been created and the flags indicate creation is allowed, we
- * attempt to create it. On error, we return a pointer-encoded error.
- */
-static struct dentry *get_xa_root(struct super_block *sb, int flags)
-{
- struct dentry *privroot = dget(REISERFS_SB(sb)->priv_root);
- struct dentry *xaroot;
+#define xattr_may_create(flags) (!flags || flags & XATTR_CREATE)
- /* This needs to be created at mount-time */
- if (!privroot)
- return ERR_PTR(-ENODATA);
+static struct dentry *lookup_or_create_dir(struct dentry *parent,
+ const char *name, int flags)
+{
+ struct dentry *dentry;
+ BUG_ON(!parent);
- mutex_lock_nested(&privroot->d_inode->i_mutex, I_MUTEX_XATTR);
- if (REISERFS_SB(sb)->xattr_root) {
- xaroot = dget(REISERFS_SB(sb)->xattr_root);
- goto out;
- }
+ mutex_lock_nested(&parent->d_inode->i_mutex, I_MUTEX_XATTR);
- xaroot = lookup_one_len(XAROOT_NAME, privroot, strlen(XAROOT_NAME));
- if (IS_ERR(xaroot)) {
- goto out;
- } else if (!xaroot->d_inode) {
+ dentry = lookup_one_len(name, parent, strlen(name));
+ if (IS_ERR(dentry)) {
+ mutex_unlock(&parent->d_inode->i_mutex);
+ return dentry;
+ } else if (!dentry->d_inode) {
int err = -ENODATA;
- if (flags == 0 || flags & XATTR_CREATE)
- err = privroot->d_inode->i_op->mkdir(privroot->d_inode,
- xaroot, 0700);
+
+ if (xattr_may_create(flags))
+ err = vfs_mkdir(parent->d_inode, dentry, NULL, 0700);
+
if (err) {
- dput(xaroot);
- xaroot = ERR_PTR(err);
- goto out;
+ dput(dentry);
+ dentry = ERR_PTR(err);
}
}
- REISERFS_SB(sb)->xattr_root = dget(xaroot);
- out:
- mutex_unlock(&privroot->d_inode->i_mutex);
- dput(privroot);
- return xaroot;
+ mutex_unlock(&parent->d_inode->i_mutex);
+ return dentry;
+}
+
+static struct dentry *open_xa_root(struct super_block *sb, int flags)
+{
+ struct dentry *privroot = REISERFS_SB(sb)->priv_root;
+ if (!privroot)
+ return ERR_PTR(-ENODATA);
+ return lookup_or_create_dir(privroot, XAROOT_NAME, flags);
}
-/* Opens the directory corresponding to the inode's extended attribute store.
- * If flags allow, the tree to the directory may be created. If creation is
- * prohibited, -ENODATA is returned. */
static struct dentry *open_xa_dir(const struct inode *inode, int flags)
{
struct dentry *xaroot, *xadir;
char namebuf[17];
- xaroot = get_xa_root(inode->i_sb, flags);
+ xaroot = open_xa_root(inode->i_sb, flags);
if (IS_ERR(xaroot))
return xaroot;
- /* ok, we have xaroot open */
snprintf(namebuf, sizeof(namebuf), "%X.%X",
le32_to_cpu(INODE_PKEY(inode)->k_objectid),
inode->i_generation);
- xadir = lookup_one_len(namebuf, xaroot, strlen(namebuf));
- if (IS_ERR(xadir)) {
- dput(xaroot);
- return xadir;
- }
-
- if (!xadir->d_inode) {
- int err;
- if (flags == 0 || flags & XATTR_CREATE) {
- /* Although there is nothing else trying to create this directory,
- * another directory with the same hash may be created, so we need
- * to protect against that */
- err =
- xaroot->d_inode->i_op->mkdir(xaroot->d_inode, xadir,
- 0700);
- if (err) {
- dput(xaroot);
- dput(xadir);
- return ERR_PTR(err);
- }
- }
- if (!xadir->d_inode) {
- dput(xaroot);
- dput(xadir);
- return ERR_PTR(-ENODATA);
- }
- }
+ xadir = lookup_or_create_dir(xaroot, namebuf, flags);
dput(xaroot);
return xadir;
+
}
-/* Returns a dentry corresponding to a specific extended attribute file
- * for the inode. If flags allow, the file is created. Otherwise, a
- * valid or negative dentry, or an error is returned. */
-static struct dentry *get_xa_file_dentry(const struct inode *inode,
- const char *name, int flags)
+static struct file *open_xattr_file(const struct inode *inode,
+ const char *name, int flags)
{
struct dentry *xadir, *xafile;
int err = 0;
xadir = open_xa_dir(inode, flags);
- if (IS_ERR(xadir)) {
+ if (IS_ERR(xadir))
return ERR_PTR(PTR_ERR(xadir));
- } else if (xadir && !xadir->d_inode) {
- dput(xadir);
- return ERR_PTR(-ENODATA);
- }
+ mutex_lock_nested(&xadir->d_inode->i_mutex, I_MUTEX_XATTR);
xafile = lookup_one_len(name, xadir, strlen(name));
if (IS_ERR(xafile)) {
- dput(xadir);
- return ERR_PTR(PTR_ERR(xafile));
+ err = PTR_ERR(xafile);
+ goto out;
}
- if (xafile->d_inode) { /* file exists */
- if (flags & XATTR_CREATE) {
- err = -EEXIST;
- dput(xafile);
- goto out;
- }
- } else if (flags & XATTR_REPLACE || flags & FL_READONLY) {
- goto out;
- } else {
- /* inode->i_mutex is down, so nothing else can try to create
- * the same xattr */
- err = xadir->d_inode->i_op->create(xadir->d_inode, xafile,
- 0700 | S_IFREG, NULL);
+ if (xafile->d_inode && (flags & XATTR_CREATE))
+ err = -EEXIST;
- if (err) {
- dput(xafile);
- goto out;
- }
+ if (!xafile->d_inode) {
+ err = -ENODATA;
+ if (xattr_may_create(flags))
+ err = vfs_create(xadir->d_inode, xafile,
+ 0700|S_IFREG, NULL);
}
- out:
- dput(xadir);
if (err)
- xafile = ERR_PTR(err);
- return xafile;
-}
-
-/* Opens a file pointer to the attribute associated with inode */
-static struct file *open_xa_file(const struct inode *inode, const char *name,
- int flags)
-{
- struct dentry *xafile;
- struct file *fp;
-
- xafile = get_xa_file_dentry(inode, name, flags);
- if (IS_ERR(xafile))
- return ERR_PTR(PTR_ERR(xafile));
- else if (!xafile->d_inode) {
dput(xafile);
- return ERR_PTR(-ENODATA);
- }
-
- fp = dentry_open(xafile, NULL, O_RDWR);
- /* dentry_open dputs the dentry if it fails */
-
- return fp;
+out:
+ mutex_unlock(&xadir->d_inode->i_mutex);
+ dput(xadir);
+ if (err)
+ return ERR_PTR(err);
+ return dentry_open(xafile, NULL, O_RDWR);
}
/*
@@ -455,7 +386,7 @@ reiserfs_xattr_set(struct inode *inode,
xahash = xattr_hash(buffer, buffer_size);
open_file:
- fp = open_xa_file(inode, name, flags);
+ fp = open_xattr_file(inode, name, flags);
if (IS_ERR(fp)) {
err = PTR_ERR(fp);
goto out;
@@ -573,7 +504,7 @@ reiserfs_xattr_get(const struct inode *i
if (get_inode_sd_version(inode) == STAT_DATA_V1)
return -EOPNOTSUPP;
- fp = open_xa_file(inode, name, FL_READONLY);
+ fp = open_xattr_file(inode, name, XATTR_REPLACE);
if (IS_ERR(fp)) {
err = PTR_ERR(fp);
goto out;
@@ -586,12 +517,12 @@ reiserfs_xattr_get(const struct inode *i
/* Just return the size needed */
if (buffer == NULL) {
err = isize - sizeof(struct reiserfs_xattr_header);
- goto out_dput;
+ goto out_fput;
}
if (buffer_size < isize - sizeof(struct reiserfs_xattr_header)) {
err = -ERANGE;
- goto out_dput;
+ goto out_fput;
}
while (file_pos < isize) {
@@ -606,7 +537,7 @@ reiserfs_xattr_get(const struct inode *i
page = reiserfs_get_page(xinode, file_pos >> PAGE_CACHE_SHIFT);
if (IS_ERR(page)) {
err = PTR_ERR(page);
- goto out_dput;
+ goto out_fput;
}
lock_page(page);
@@ -625,7 +556,7 @@ reiserfs_xattr_get(const struct inode *i
"associated with %k", name,
INODE_PKEY(inode));
err = -EIO;
- goto out_dput;
+ goto out_fput;
}
hash = le32_to_cpu(rxh->h_hash);
}
@@ -644,9 +575,10 @@ reiserfs_xattr_get(const struct inode *i
"Invalid hash for xattr (%s) associated "
"with %k", name, INODE_PKEY(inode));
err = -EIO;
+ goto out_fput;
}
- out_dput:
+ out_fput:
fput(fp);
out:
@@ -686,9 +618,7 @@ __reiserfs_xattr_del(struct dentry *xadi
return -EIO;
}
- err = dir->i_op->unlink(dir, dentry);
- if (!err)
- d_delete(dentry);
+ err = vfs_unlink(xadir->d_inode, dentry, NULL);
out_file:
dput(dentry);
@@ -702,7 +632,7 @@ int reiserfs_xattr_del(struct inode *ino
struct dentry *dir;
int err;
- dir = open_xa_dir(inode, FL_READONLY);
+ dir = open_xa_dir(inode, XATTR_REPLACE);
if (IS_ERR(dir)) {
err = PTR_ERR(dir);
goto out;
@@ -748,7 +678,7 @@ int reiserfs_delete_xattrs(struct inode
return 0;
}
reiserfs_read_lock_xattrs(inode->i_sb);
- dir = open_xa_dir(inode, FL_READONLY);
+ dir = open_xa_dir(inode, XATTR_REPLACE);
reiserfs_read_unlock_xattrs(inode->i_sb);
if (IS_ERR(dir)) {
err = PTR_ERR(dir);
@@ -774,9 +704,11 @@ int reiserfs_delete_xattrs(struct inode
/* Leftovers besides . and .. -- that's not good. */
if (dir->d_inode->i_nlink <= 2) {
- root = get_xa_root(inode->i_sb, XATTR_REPLACE);
+ root = open_xa_root(inode->i_sb, XATTR_REPLACE);
reiserfs_write_lock_xattrs(inode->i_sb);
+ mutex_lock_nested(&root->d_inode->i_mutex, I_MUTEX_XATTR);
err = vfs_rmdir(root->d_inode, dir);
+ mutex_unlock(&root->d_inode->i_mutex);
reiserfs_write_unlock_xattrs(inode->i_sb);
dput(root);
} else {
@@ -841,7 +773,7 @@ int reiserfs_chown_xattrs(struct inode *
return 0;
}
reiserfs_read_lock_xattrs(inode->i_sb);
- dir = open_xa_dir(inode, FL_READONLY);
+ dir = open_xa_dir(inode, XATTR_REPLACE);
reiserfs_read_unlock_xattrs(inode->i_sb);
if (IS_ERR(dir)) {
if (PTR_ERR(dir) != -ENODATA)
@@ -1038,7 +970,7 @@ ssize_t reiserfs_listxattr(struct dentry
reiserfs_read_lock_xattr_i(dentry->d_inode);
reiserfs_read_lock_xattrs(dentry->d_sb);
- dir = open_xa_dir(dentry->d_inode, FL_READONLY);
+ dir = open_xa_dir(dentry->d_inode, XATTR_REPLACE);
reiserfs_read_unlock_xattrs(dentry->d_sb);
if (IS_ERR(dir)) {
err = PTR_ERR(dir);
--
-
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