reiserfs: make per-inode xattr locking more fine grained
The per-inode locking can be made more fine-grained to surround just the interaction with the filesystem itself. This really only applies to protecting reads during a write, since concurrent writes are barred with inode->i_mutex at the vfs level. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Jeff Mahoney
Linus Torvalds
parent
d984561b32
commit
8b6dd72a44
|
|
@ -29,10 +29,8 @@
|
|||
* to the inode so that unnecessary lookups are avoided.
|
||||
*
|
||||
* Locking works like so:
|
||||
* The xattr root (/.reiserfs_priv/xattrs) is protected by its i_mutex.
|
||||
* The xattr dir (/.reiserfs_priv/xattrs/<oid>.<gen>) is protected by
|
||||
* inode->xattr_sem.
|
||||
* The xattrs themselves are likewise protected by the xattr_sem.
|
||||
* Directory components (xattr root, xattr dir) are protectd by their i_mutex.
|
||||
* The xattrs themselves are protected by the xattr_sem.
|
||||
*/
|
||||
|
||||
#include <linux/reiserfs_fs.h>
|
||||
|
|
@ -55,6 +53,8 @@
|
|||
#define PRIVROOT_NAME ".reiserfs_priv"
|
||||
#define XAROOT_NAME "xattrs"
|
||||
|
||||
static struct reiserfs_xattr_handler *find_xattr_handler_prefix(const char *);
|
||||
|
||||
/* Helpers for inode ops. We do this so that we don't have all the VFS
|
||||
* overhead and also for proper i_mutex annotation.
|
||||
* dir->i_mutex must be held for all of them. */
|
||||
|
|
@ -339,12 +339,14 @@ int xattr_readdir(struct inode *inode, filldir_t filler, void *buf)
|
|||
return res;
|
||||
}
|
||||
|
||||
/* expects xadir->d_inode->i_mutex to be locked */
|
||||
static int
|
||||
__reiserfs_xattr_del(struct dentry *xadir, const char *name, int namelen)
|
||||
{
|
||||
struct dentry *dentry;
|
||||
struct inode *dir = xadir->d_inode;
|
||||
int err = 0;
|
||||
struct reiserfs_xattr_handler *xah;
|
||||
|
||||
dentry = lookup_one_len(name, xadir, namelen);
|
||||
if (IS_ERR(dentry)) {
|
||||
|
|
@ -372,6 +374,14 @@ __reiserfs_xattr_del(struct dentry *xadir, const char *name, int namelen)
|
|||
return -EIO;
|
||||
}
|
||||
|
||||
/* Deletion pre-operation */
|
||||
xah = find_xattr_handler_prefix(name);
|
||||
if (xah && xah->del) {
|
||||
err = xah->del(dentry->d_inode, name);
|
||||
if (err)
|
||||
goto out;
|
||||
}
|
||||
|
||||
err = xattr_unlink(dir, dentry);
|
||||
|
||||
out_file:
|
||||
|
|
@ -398,7 +408,7 @@ reiserfs_delete_xattrs_filler(void *buf, const char *name, int namelen,
|
|||
/* This is called w/ inode->i_mutex downed */
|
||||
int reiserfs_delete_xattrs(struct inode *inode)
|
||||
{
|
||||
int err = 0;
|
||||
int err = -ENODATA;
|
||||
struct dentry *dir, *root;
|
||||
struct reiserfs_transaction_handle th;
|
||||
int blocks = JOURNAL_PER_BALANCE_CNT * 2 + 2 +
|
||||
|
|
@ -414,14 +424,19 @@ int reiserfs_delete_xattrs(struct inode *inode)
|
|||
goto out;
|
||||
} else if (!dir->d_inode) {
|
||||
dput(dir);
|
||||
return 0;
|
||||
goto out;
|
||||
}
|
||||
|
||||
mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_XATTR);
|
||||
err = xattr_readdir(dir->d_inode, reiserfs_delete_xattrs_filler, dir);
|
||||
mutex_unlock(&dir->d_inode->i_mutex);
|
||||
if (err)
|
||||
goto out_dir;
|
||||
if (err) {
|
||||
dput(dir);
|
||||
goto out;
|
||||
}
|
||||
|
||||
root = dget(dir->d_parent);
|
||||
dput(dir);
|
||||
|
||||
/* We start a transaction here to avoid a ABBA situation
|
||||
* between the xattr root's i_mutex and the journal lock.
|
||||
|
|
@ -435,19 +450,14 @@ int reiserfs_delete_xattrs(struct inode *inode)
|
|||
err = journal_begin(&th, inode->i_sb, blocks);
|
||||
if (!err) {
|
||||
int jerror;
|
||||
root = dget(dir->d_parent);
|
||||
mutex_lock_nested(&root->d_inode->i_mutex, I_MUTEX_XATTR);
|
||||
err = xattr_rmdir(root->d_inode, dir);
|
||||
jerror = journal_end(&th, inode->i_sb, blocks);
|
||||
mutex_unlock(&root->d_inode->i_mutex);
|
||||
dput(root);
|
||||
|
||||
err = jerror ?: err;
|
||||
}
|
||||
|
||||
out_dir:
|
||||
dput(dir);
|
||||
|
||||
dput(root);
|
||||
out:
|
||||
if (!err)
|
||||
REISERFS_I(inode)->i_flags =
|
||||
|
|
@ -484,7 +494,7 @@ reiserfs_chown_xattrs_filler(void *buf, const char *name, int namelen,
|
|||
|
||||
if (!S_ISDIR(xafile->d_inode->i_mode)) {
|
||||
mutex_lock_nested(&xafile->d_inode->i_mutex, I_MUTEX_CHILD);
|
||||
err = notify_change(xafile, attrs);
|
||||
err = reiserfs_setattr(xafile, attrs);
|
||||
mutex_unlock(&xafile->d_inode->i_mutex);
|
||||
}
|
||||
dput(xafile);
|
||||
|
|
@ -520,13 +530,16 @@ int reiserfs_chown_xattrs(struct inode *inode, struct iattr *attrs)
|
|||
err = xattr_readdir(dir->d_inode, reiserfs_chown_xattrs_filler, &buf);
|
||||
|
||||
if (!err)
|
||||
err = notify_change(dir, attrs);
|
||||
err = reiserfs_setattr(dir, attrs);
|
||||
mutex_unlock(&dir->d_inode->i_mutex);
|
||||
|
||||
attrs->ia_valid = ia_valid;
|
||||
out_dir:
|
||||
dput(dir);
|
||||
out:
|
||||
if (err)
|
||||
reiserfs_warning(inode->i_sb, "jdm-20007",
|
||||
"Couldn't chown all xattrs (%d)\n", err);
|
||||
return err;
|
||||
}
|
||||
|
||||
|
|
@ -635,9 +648,8 @@ reiserfs_xattr_set(struct inode *inode, const char *name, const void *buffer,
|
|||
if (get_inode_sd_version(inode) == STAT_DATA_V1)
|
||||
return -EOPNOTSUPP;
|
||||
|
||||
/* Empty xattrs are ok, they're just empty files, no hash */
|
||||
if (buffer && buffer_size)
|
||||
xahash = xattr_hash(buffer, buffer_size);
|
||||
if (!buffer)
|
||||
return reiserfs_xattr_del(inode, name);
|
||||
|
||||
dentry = get_xa_file_dentry(inode, name, flags);
|
||||
if (IS_ERR(dentry)) {
|
||||
|
|
@ -645,13 +657,19 @@ reiserfs_xattr_set(struct inode *inode, const char *name, const void *buffer,
|
|||
goto out;
|
||||
}
|
||||
|
||||
down_write(&REISERFS_I(inode)->i_xattr_sem);
|
||||
|
||||
xahash = xattr_hash(buffer, buffer_size);
|
||||
REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
|
||||
|
||||
/* Resize it so we're ok to write there */
|
||||
newattrs.ia_size = buffer_size;
|
||||
newattrs.ia_ctime = current_fs_time(inode->i_sb);
|
||||
newattrs.ia_valid = ATTR_SIZE | ATTR_CTIME;
|
||||
mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_XATTR);
|
||||
err = notify_change(dentry, &newattrs);
|
||||
down_write(&dentry->d_inode->i_alloc_sem);
|
||||
err = reiserfs_setattr(dentry, &newattrs);
|
||||
up_write(&dentry->d_inode->i_alloc_sem);
|
||||
mutex_unlock(&dentry->d_inode->i_mutex);
|
||||
if (err)
|
||||
goto out_filp;
|
||||
|
|
@ -712,6 +730,7 @@ reiserfs_xattr_set(struct inode *inode, const char *name, const void *buffer,
|
|||
}
|
||||
|
||||
out_filp:
|
||||
up_write(&REISERFS_I(inode)->i_xattr_sem);
|
||||
dput(dentry);
|
||||
|
||||
out:
|
||||
|
|
@ -747,10 +766,7 @@ reiserfs_xattr_get(const struct inode *inode, const char *name, void *buffer,
|
|||
goto out;
|
||||
}
|
||||
|
||||
/* protect against concurrent access. xattrs are backed by
|
||||
* regular files, but they're not regular files. The updates
|
||||
* must be atomic from the perspective of the user. */
|
||||
mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_XATTR);
|
||||
down_read(&REISERFS_I(inode)->i_xattr_sem);
|
||||
|
||||
isize = i_size_read(dentry->d_inode);
|
||||
REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
|
||||
|
|
@ -758,12 +774,12 @@ reiserfs_xattr_get(const struct inode *inode, const char *name, void *buffer,
|
|||
/* Just return the size needed */
|
||||
if (buffer == NULL) {
|
||||
err = isize - sizeof(struct reiserfs_xattr_header);
|
||||
goto out_dput;
|
||||
goto out_unlock;
|
||||
}
|
||||
|
||||
if (buffer_size < isize - sizeof(struct reiserfs_xattr_header)) {
|
||||
err = -ERANGE;
|
||||
goto out_dput;
|
||||
goto out_unlock;
|
||||
}
|
||||
|
||||
while (file_pos < isize) {
|
||||
|
|
@ -778,7 +794,7 @@ reiserfs_xattr_get(const struct inode *inode, const char *name, void *buffer,
|
|||
page = reiserfs_get_page(dentry->d_inode, file_pos);
|
||||
if (IS_ERR(page)) {
|
||||
err = PTR_ERR(page);
|
||||
goto out_dput;
|
||||
goto out_unlock;
|
||||
}
|
||||
|
||||
lock_page(page);
|
||||
|
|
@ -797,7 +813,7 @@ reiserfs_xattr_get(const struct inode *inode, const char *name, void *buffer,
|
|||
"associated with %k", name,
|
||||
INODE_PKEY(inode));
|
||||
err = -EIO;
|
||||
goto out_dput;
|
||||
goto out_unlock;
|
||||
}
|
||||
hash = le32_to_cpu(rxh->h_hash);
|
||||
}
|
||||
|
|
@ -818,8 +834,8 @@ reiserfs_xattr_get(const struct inode *inode, const char *name, void *buffer,
|
|||
err = -EIO;
|
||||
}
|
||||
|
||||
out_dput:
|
||||
mutex_unlock(&dentry->d_inode->i_mutex);
|
||||
out_unlock:
|
||||
up_read(&REISERFS_I(inode)->i_xattr_sem);
|
||||
dput(dentry);
|
||||
|
||||
out:
|
||||
|
|
@ -852,8 +868,6 @@ int reiserfs_xattr_del(struct inode *inode, const char *name)
|
|||
}
|
||||
|
||||
/* Actual operations that are exported to VFS-land */
|
||||
|
||||
static struct reiserfs_xattr_handler *find_xattr_handler_prefix(const char *);
|
||||
/*
|
||||
* Inode operation getxattr()
|
||||
*/
|
||||
|
|
@ -868,9 +882,7 @@ reiserfs_getxattr(struct dentry * dentry, const char *name, void *buffer,
|
|||
get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
|
||||
return -EOPNOTSUPP;
|
||||
|
||||
reiserfs_read_lock_xattr_i(dentry->d_inode);
|
||||
err = xah->get(dentry->d_inode, name, buffer, size);
|
||||
reiserfs_read_unlock_xattr_i(dentry->d_inode);
|
||||
return err;
|
||||
}
|
||||
|
||||
|
|
@ -890,9 +902,7 @@ reiserfs_setxattr(struct dentry *dentry, const char *name, const void *value,
|
|||
get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
|
||||
return -EOPNOTSUPP;
|
||||
|
||||
reiserfs_write_lock_xattr_i(dentry->d_inode);
|
||||
err = xah->set(dentry->d_inode, name, value, size, flags);
|
||||
reiserfs_write_unlock_xattr_i(dentry->d_inode);
|
||||
return err;
|
||||
}
|
||||
|
||||
|
|
@ -910,21 +920,11 @@ int reiserfs_removexattr(struct dentry *dentry, const char *name)
|
|||
get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
|
||||
return -EOPNOTSUPP;
|
||||
|
||||
reiserfs_write_lock_xattr_i(dentry->d_inode);
|
||||
/* Deletion pre-operation */
|
||||
if (xah->del) {
|
||||
err = xah->del(dentry->d_inode, name);
|
||||
if (err)
|
||||
goto out;
|
||||
}
|
||||
|
||||
err = reiserfs_xattr_del(dentry->d_inode, name);
|
||||
|
||||
dentry->d_inode->i_ctime = CURRENT_TIME_SEC;
|
||||
mark_inode_dirty(dentry->d_inode);
|
||||
|
||||
out:
|
||||
reiserfs_write_unlock_xattr_i(dentry->d_inode);
|
||||
return err;
|
||||
}
|
||||
|
||||
|
|
@ -986,7 +986,6 @@ ssize_t reiserfs_listxattr(struct dentry * dentry, char *buffer, size_t size)
|
|||
get_inode_sd_version(dentry->d_inode) == STAT_DATA_V1)
|
||||
return -EOPNOTSUPP;
|
||||
|
||||
reiserfs_read_lock_xattr_i(dentry->d_inode);
|
||||
dir = open_xa_dir(dentry->d_inode, XATTR_REPLACE);
|
||||
if (IS_ERR(dir)) {
|
||||
err = PTR_ERR(dir);
|
||||
|
|
@ -1005,19 +1004,16 @@ ssize_t reiserfs_listxattr(struct dentry * dentry, char *buffer, size_t size)
|
|||
mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_XATTR);
|
||||
err = xattr_readdir(dir->d_inode, reiserfs_listxattr_filler, &buf);
|
||||
mutex_unlock(&dir->d_inode->i_mutex);
|
||||
if (err)
|
||||
goto out_dir;
|
||||
|
||||
if (buf.r_pos > buf.r_size && buffer != NULL)
|
||||
err = -ERANGE;
|
||||
else
|
||||
err = buf.r_pos;
|
||||
if (!err) {
|
||||
if (buf.r_pos > buf.r_size && buffer != NULL)
|
||||
err = -ERANGE;
|
||||
else
|
||||
err = buf.r_pos;
|
||||
}
|
||||
|
||||
out_dir:
|
||||
dput(dir);
|
||||
|
||||
out:
|
||||
reiserfs_read_unlock_xattr_i(dentry->d_inode);
|
||||
out:
|
||||
return err;
|
||||
}
|
||||
|
||||
|
|
@ -1115,12 +1111,8 @@ static int reiserfs_check_acl(struct inode *inode, int mask)
|
|||
struct posix_acl *acl;
|
||||
int error = -EAGAIN; /* do regular unix permission checks by default */
|
||||
|
||||
reiserfs_read_lock_xattr_i(inode);
|
||||
|
||||
acl = reiserfs_get_acl(inode, ACL_TYPE_ACCESS);
|
||||
|
||||
reiserfs_read_unlock_xattr_i(inode);
|
||||
|
||||
if (acl) {
|
||||
if (!IS_ERR(acl)) {
|
||||
error = posix_acl_permission(inode, acl, mask);
|
||||
|
|
|
|||
|
|
@ -418,9 +418,7 @@ int reiserfs_cache_default_acl(struct inode *inode)
|
|||
int ret = 0;
|
||||
if (reiserfs_posixacl(inode->i_sb) && !IS_PRIVATE(inode)) {
|
||||
struct posix_acl *acl;
|
||||
reiserfs_read_lock_xattr_i(inode);
|
||||
acl = reiserfs_get_acl(inode, ACL_TYPE_DEFAULT);
|
||||
reiserfs_read_unlock_xattr_i(inode);
|
||||
ret = (acl && !IS_ERR(acl));
|
||||
if (ret)
|
||||
posix_acl_release(acl);
|
||||
|
|
@ -452,11 +450,8 @@ int reiserfs_acl_chmod(struct inode *inode)
|
|||
if (!clone)
|
||||
return -ENOMEM;
|
||||
error = posix_acl_chmod_masq(clone, inode->i_mode);
|
||||
if (!error) {
|
||||
reiserfs_write_lock_xattr_i(inode);
|
||||
if (!error)
|
||||
error = reiserfs_set_acl(inode, ACL_TYPE_ACCESS, clone);
|
||||
reiserfs_write_unlock_xattr_i(inode);
|
||||
}
|
||||
posix_acl_release(clone);
|
||||
return error;
|
||||
}
|
||||
|
|
|
|||
|
|
@ -59,7 +59,7 @@ struct reiserfs_inode_info {
|
|||
struct posix_acl *i_acl_default;
|
||||
#endif
|
||||
#ifdef CONFIG_REISERFS_FS_XATTR
|
||||
struct rw_semaphore xattr_sem;
|
||||
struct rw_semaphore i_xattr_sem;
|
||||
#endif
|
||||
struct inode vfs_inode;
|
||||
};
|
||||
|
|
|
|||
|
|
@ -67,24 +67,6 @@ extern struct reiserfs_xattr_handler user_handler;
|
|||
extern struct reiserfs_xattr_handler trusted_handler;
|
||||
extern struct reiserfs_xattr_handler security_handler;
|
||||
|
||||
static inline void reiserfs_write_lock_xattr_i(struct inode *inode)
|
||||
{
|
||||
down_write(&REISERFS_I(inode)->i_xattr_sem);
|
||||
}
|
||||
static inline void reiserfs_write_unlock_xattr_i(struct inode *inode)
|
||||
{
|
||||
up_write(&REISERFS_I(inode)->i_xattr_sem);
|
||||
}
|
||||
static inline void reiserfs_read_lock_xattr_i(struct inode *inode)
|
||||
{
|
||||
down_read(&REISERFS_I(inode)->i_xattr_sem);
|
||||
}
|
||||
|
||||
static inline void reiserfs_read_unlock_xattr_i(struct inode *inode)
|
||||
{
|
||||
up_read(&REISERFS_I(inode)->i_xattr_sem);
|
||||
}
|
||||
|
||||
static inline void reiserfs_init_xattr_rwsem(struct inode *inode)
|
||||
{
|
||||
init_rwsem(&REISERFS_I(inode)->i_xattr_sem);
|
||||
|
|
@ -96,10 +78,6 @@ static inline void reiserfs_init_xattr_rwsem(struct inode *inode)
|
|||
#define reiserfs_setxattr NULL
|
||||
#define reiserfs_listxattr NULL
|
||||
#define reiserfs_removexattr NULL
|
||||
#define reiserfs_write_lock_xattrs(sb) do {;} while(0)
|
||||
#define reiserfs_write_unlock_xattrs(sb) do {;} while(0)
|
||||
#define reiserfs_read_lock_xattrs(sb)
|
||||
#define reiserfs_read_unlock_xattrs(sb)
|
||||
|
||||
#define reiserfs_permission NULL
|
||||
|
||||
|
|
|
|||
Reference in New Issue