summaryrefslogtreecommitdiffstats
path: root/fs
diff options
context:
space:
mode:
Diffstat (limited to 'fs')
-rw-r--r--fs/ceph/mds_client.c6
-rw-r--r--fs/crypto/crypto.c51
-rw-r--r--fs/debugfs/inode.c2
-rw-r--r--fs/devpts/inode.c100
-rw-r--r--fs/ext4/crypto.c4
-rw-r--r--fs/f2fs/data.c16
-rw-r--r--fs/f2fs/file.c10
-rw-r--r--fs/ocfs2/dlm/dlmmaster.c2
-rw-r--r--fs/proc/task_mmu.c33
-rw-r--r--fs/seq_file.c7
10 files changed, 130 insertions, 101 deletions
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index 541ead4d8965..85b8517f17a0 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -386,9 +386,7 @@ void ceph_put_mds_session(struct ceph_mds_session *s)
atomic_read(&s->s_ref), atomic_read(&s->s_ref)-1);
if (atomic_dec_and_test(&s->s_ref)) {
if (s->s_auth.authorizer)
- ceph_auth_destroy_authorizer(
- s->s_mdsc->fsc->client->monc.auth,
- s->s_auth.authorizer);
+ ceph_auth_destroy_authorizer(s->s_auth.authorizer);
kfree(s);
}
}
@@ -3900,7 +3898,7 @@ static struct ceph_auth_handshake *get_authorizer(struct ceph_connection *con,
struct ceph_auth_handshake *auth = &s->s_auth;
if (force_new && auth->authorizer) {
- ceph_auth_destroy_authorizer(ac, auth->authorizer);
+ ceph_auth_destroy_authorizer(auth->authorizer);
auth->authorizer = NULL;
}
if (!auth->authorizer) {
diff --git a/fs/crypto/crypto.c b/fs/crypto/crypto.c
index 7f5804537d30..2fc8c43ce531 100644
--- a/fs/crypto/crypto.c
+++ b/fs/crypto/crypto.c
@@ -26,6 +26,7 @@
#include <linux/ratelimit.h>
#include <linux/bio.h>
#include <linux/dcache.h>
+#include <linux/namei.h>
#include <linux/fscrypto.h>
#include <linux/ecryptfs.h>
@@ -81,13 +82,14 @@ EXPORT_SYMBOL(fscrypt_release_ctx);
/**
* fscrypt_get_ctx() - Gets an encryption context
* @inode: The inode for which we are doing the crypto
+ * @gfp_flags: The gfp flag for memory allocation
*
* Allocates and initializes an encryption context.
*
* Return: An allocated and initialized encryption context on success; error
* value or NULL otherwise.
*/
-struct fscrypt_ctx *fscrypt_get_ctx(struct inode *inode)
+struct fscrypt_ctx *fscrypt_get_ctx(struct inode *inode, gfp_t gfp_flags)
{
struct fscrypt_ctx *ctx = NULL;
struct fscrypt_info *ci = inode->i_crypt_info;
@@ -113,7 +115,7 @@ struct fscrypt_ctx *fscrypt_get_ctx(struct inode *inode)
list_del(&ctx->free_list);
spin_unlock_irqrestore(&fscrypt_ctx_lock, flags);
if (!ctx) {
- ctx = kmem_cache_zalloc(fscrypt_ctx_cachep, GFP_NOFS);
+ ctx = kmem_cache_zalloc(fscrypt_ctx_cachep, gfp_flags);
if (!ctx)
return ERR_PTR(-ENOMEM);
ctx->flags |= FS_CTX_REQUIRES_FREE_ENCRYPT_FL;
@@ -147,7 +149,8 @@ typedef enum {
static int do_page_crypto(struct inode *inode,
fscrypt_direction_t rw, pgoff_t index,
- struct page *src_page, struct page *dest_page)
+ struct page *src_page, struct page *dest_page,
+ gfp_t gfp_flags)
{
u8 xts_tweak[FS_XTS_TWEAK_SIZE];
struct skcipher_request *req = NULL;
@@ -157,7 +160,7 @@ static int do_page_crypto(struct inode *inode,
struct crypto_skcipher *tfm = ci->ci_ctfm;
int res = 0;
- req = skcipher_request_alloc(tfm, GFP_NOFS);
+ req = skcipher_request_alloc(tfm, gfp_flags);
if (!req) {
printk_ratelimited(KERN_ERR
"%s: crypto_request_alloc() failed\n",
@@ -199,10 +202,9 @@ static int do_page_crypto(struct inode *inode,
return 0;
}
-static struct page *alloc_bounce_page(struct fscrypt_ctx *ctx)
+static struct page *alloc_bounce_page(struct fscrypt_ctx *ctx, gfp_t gfp_flags)
{
- ctx->w.bounce_page = mempool_alloc(fscrypt_bounce_page_pool,
- GFP_NOWAIT);
+ ctx->w.bounce_page = mempool_alloc(fscrypt_bounce_page_pool, gfp_flags);
if (ctx->w.bounce_page == NULL)
return ERR_PTR(-ENOMEM);
ctx->flags |= FS_WRITE_PATH_FL;
@@ -213,6 +215,7 @@ static struct page *alloc_bounce_page(struct fscrypt_ctx *ctx)
* fscypt_encrypt_page() - Encrypts a page
* @inode: The inode for which the encryption should take place
* @plaintext_page: The page to encrypt. Must be locked.
+ * @gfp_flags: The gfp flag for memory allocation
*
* Allocates a ciphertext page and encrypts plaintext_page into it using the ctx
* encryption context.
@@ -225,7 +228,7 @@ static struct page *alloc_bounce_page(struct fscrypt_ctx *ctx)
* error value or NULL.
*/
struct page *fscrypt_encrypt_page(struct inode *inode,
- struct page *plaintext_page)
+ struct page *plaintext_page, gfp_t gfp_flags)
{
struct fscrypt_ctx *ctx;
struct page *ciphertext_page = NULL;
@@ -233,18 +236,19 @@ struct page *fscrypt_encrypt_page(struct inode *inode,
BUG_ON(!PageLocked(plaintext_page));
- ctx = fscrypt_get_ctx(inode);
+ ctx = fscrypt_get_ctx(inode, gfp_flags);
if (IS_ERR(ctx))
return (struct page *)ctx;
/* The encryption operation will require a bounce page. */
- ciphertext_page = alloc_bounce_page(ctx);
+ ciphertext_page = alloc_bounce_page(ctx, gfp_flags);
if (IS_ERR(ciphertext_page))
goto errout;
ctx->w.control_page = plaintext_page;
err = do_page_crypto(inode, FS_ENCRYPT, plaintext_page->index,
- plaintext_page, ciphertext_page);
+ plaintext_page, ciphertext_page,
+ gfp_flags);
if (err) {
ciphertext_page = ERR_PTR(err);
goto errout;
@@ -275,7 +279,7 @@ int fscrypt_decrypt_page(struct page *page)
BUG_ON(!PageLocked(page));
return do_page_crypto(page->mapping->host,
- FS_DECRYPT, page->index, page, page);
+ FS_DECRYPT, page->index, page, page, GFP_NOFS);
}
EXPORT_SYMBOL(fscrypt_decrypt_page);
@@ -289,11 +293,11 @@ int fscrypt_zeroout_range(struct inode *inode, pgoff_t lblk,
BUG_ON(inode->i_sb->s_blocksize != PAGE_SIZE);
- ctx = fscrypt_get_ctx(inode);
+ ctx = fscrypt_get_ctx(inode, GFP_NOFS);
if (IS_ERR(ctx))
return PTR_ERR(ctx);
- ciphertext_page = alloc_bounce_page(ctx);
+ ciphertext_page = alloc_bounce_page(ctx, GFP_NOWAIT);
if (IS_ERR(ciphertext_page)) {
err = PTR_ERR(ciphertext_page);
goto errout;
@@ -301,11 +305,12 @@ int fscrypt_zeroout_range(struct inode *inode, pgoff_t lblk,
while (len--) {
err = do_page_crypto(inode, FS_ENCRYPT, lblk,
- ZERO_PAGE(0), ciphertext_page);
+ ZERO_PAGE(0), ciphertext_page,
+ GFP_NOFS);
if (err)
goto errout;
- bio = bio_alloc(GFP_KERNEL, 1);
+ bio = bio_alloc(GFP_NOWAIT, 1);
if (!bio) {
err = -ENOMEM;
goto errout;
@@ -345,13 +350,20 @@ EXPORT_SYMBOL(fscrypt_zeroout_range);
*/
static int fscrypt_d_revalidate(struct dentry *dentry, unsigned int flags)
{
- struct inode *dir = d_inode(dentry->d_parent);
- struct fscrypt_info *ci = dir->i_crypt_info;
+ struct dentry *dir;
+ struct fscrypt_info *ci;
int dir_has_key, cached_with_key;
- if (!dir->i_sb->s_cop->is_encrypted(dir))
+ if (flags & LOOKUP_RCU)
+ return -ECHILD;
+
+ dir = dget_parent(dentry);
+ if (!d_inode(dir)->i_sb->s_cop->is_encrypted(d_inode(dir))) {
+ dput(dir);
return 0;
+ }
+ ci = d_inode(dir)->i_crypt_info;
if (ci && ci->ci_keyring_key &&
(ci->ci_keyring_key->flags & ((1 << KEY_FLAG_INVALIDATED) |
(1 << KEY_FLAG_REVOKED) |
@@ -363,6 +375,7 @@ static int fscrypt_d_revalidate(struct dentry *dentry, unsigned int flags)
cached_with_key = dentry->d_flags & DCACHE_ENCRYPTED_WITH_KEY;
spin_unlock(&dentry->d_lock);
dir_has_key = (ci != NULL);
+ dput(dir);
/*
* If the dentry was cached without the key, and it is a
diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
index bece948b363d..8580831ed237 100644
--- a/fs/debugfs/inode.c
+++ b/fs/debugfs/inode.c
@@ -457,7 +457,7 @@ struct dentry *debugfs_create_automount(const char *name,
if (unlikely(!inode))
return failed_creating(dentry);
- inode->i_mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO;
+ make_empty_dir_inode(inode);
inode->i_flags |= S_AUTOMOUNT;
inode->i_private = data;
dentry->d_fsdata = (void *)f;
diff --git a/fs/devpts/inode.c b/fs/devpts/inode.c
index 655f21f99160..0b2954d7172d 100644
--- a/fs/devpts/inode.c
+++ b/fs/devpts/inode.c
@@ -128,6 +128,7 @@ static const match_table_t tokens = {
struct pts_fs_info {
struct ida allocated_ptys;
struct pts_mount_opts mount_opts;
+ struct super_block *sb;
struct dentry *ptmx_dentry;
};
@@ -358,7 +359,7 @@ static const struct super_operations devpts_sops = {
.show_options = devpts_show_options,
};
-static void *new_pts_fs_info(void)
+static void *new_pts_fs_info(struct super_block *sb)
{
struct pts_fs_info *fsi;
@@ -369,6 +370,7 @@ static void *new_pts_fs_info(void)
ida_init(&fsi->allocated_ptys);
fsi->mount_opts.mode = DEVPTS_DEFAULT_MODE;
fsi->mount_opts.ptmxmode = DEVPTS_DEFAULT_PTMX_MODE;
+ fsi->sb = sb;
return fsi;
}
@@ -384,7 +386,7 @@ devpts_fill_super(struct super_block *s, void *data, int silent)
s->s_op = &devpts_sops;
s->s_time_gran = 1;
- s->s_fs_info = new_pts_fs_info();
+ s->s_fs_info = new_pts_fs_info(s);
if (!s->s_fs_info)
goto fail;
@@ -524,17 +526,14 @@ static struct file_system_type devpts_fs_type = {
* to the System V naming convention
*/
-int devpts_new_index(struct inode *ptmx_inode)
+int devpts_new_index(struct pts_fs_info *fsi)
{
- struct super_block *sb = pts_sb_from_inode(ptmx_inode);
- struct pts_fs_info *fsi;
int index;
int ida_ret;
- if (!sb)
+ if (!fsi)
return -ENODEV;
- fsi = DEVPTS_SB(sb);
retry:
if (!ida_pre_get(&fsi->allocated_ptys, GFP_KERNEL))
return -ENOMEM;
@@ -564,11 +563,8 @@ retry:
return index;
}
-void devpts_kill_index(struct inode *ptmx_inode, int idx)
+void devpts_kill_index(struct pts_fs_info *fsi, int idx)
{
- struct super_block *sb = pts_sb_from_inode(ptmx_inode);
- struct pts_fs_info *fsi = DEVPTS_SB(sb);
-
mutex_lock(&allocated_ptys_lock);
ida_remove(&fsi->allocated_ptys, idx);
pty_count--;
@@ -578,21 +574,25 @@ void devpts_kill_index(struct inode *ptmx_inode, int idx)
/*
* pty code needs to hold extra references in case of last /dev/tty close
*/
-
-void devpts_add_ref(struct inode *ptmx_inode)
+struct pts_fs_info *devpts_get_ref(struct inode *ptmx_inode, struct file *file)
{
- struct super_block *sb = pts_sb_from_inode(ptmx_inode);
+ struct super_block *sb;
+ struct pts_fs_info *fsi;
+
+ sb = pts_sb_from_inode(ptmx_inode);
+ if (!sb)
+ return NULL;
+ fsi = DEVPTS_SB(sb);
+ if (!fsi)
+ return NULL;
atomic_inc(&sb->s_active);
- ihold(ptmx_inode);
+ return fsi;
}
-void devpts_del_ref(struct inode *ptmx_inode)
+void devpts_put_ref(struct pts_fs_info *fsi)
{
- struct super_block *sb = pts_sb_from_inode(ptmx_inode);
-
- iput(ptmx_inode);
- deactivate_super(sb);
+ deactivate_super(fsi->sb);
}
/**
@@ -604,22 +604,20 @@ void devpts_del_ref(struct inode *ptmx_inode)
*
* The created inode is returned. Remove it from /dev/pts/ by devpts_pty_kill.
*/
-struct inode *devpts_pty_new(struct inode *ptmx_inode, dev_t device, int index,
- void *priv)
+struct dentry *devpts_pty_new(struct pts_fs_info *fsi, int index, void *priv)
{
struct dentry *dentry;
- struct super_block *sb = pts_sb_from_inode(ptmx_inode);
+ struct super_block *sb;
struct inode *inode;
struct dentry *root;
- struct pts_fs_info *fsi;
struct pts_mount_opts *opts;
char s[12];
- if (!sb)
+ if (!fsi)
return ERR_PTR(-ENODEV);
+ sb = fsi->sb;
root = sb->s_root;
- fsi = DEVPTS_SB(sb);
opts = &fsi->mount_opts;
inode = new_inode(sb);
@@ -630,25 +628,21 @@ struct inode *devpts_pty_new(struct inode *ptmx_inode, dev_t device, int index,
inode->i_uid = opts->setuid ? opts->uid : current_fsuid();
inode->i_gid = opts->setgid ? opts->gid : current_fsgid();
inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
- init_special_inode(inode, S_IFCHR|opts->mode, device);
- inode->i_private = priv;
+ init_special_inode(inode, S_IFCHR|opts->mode, MKDEV(UNIX98_PTY_SLAVE_MAJOR, index));
sprintf(s, "%d", index);
- inode_lock(d_inode(root));
-
dentry = d_alloc_name(root, s);
if (dentry) {
+ dentry->d_fsdata = priv;
d_add(dentry, inode);
fsnotify_create(d_inode(root), dentry);
} else {
iput(inode);
- inode = ERR_PTR(-ENOMEM);
+ dentry = ERR_PTR(-ENOMEM);
}
- inode_unlock(d_inode(root));
-
- return inode;
+ return dentry;
}
/**
@@ -657,24 +651,10 @@ struct inode *devpts_pty_new(struct inode *ptmx_inode, dev_t device, int index,
*
* Returns whatever was passed as priv in devpts_pty_new for a given inode.
*/
-void *devpts_get_priv(struct inode *pts_inode)
+void *devpts_get_priv(struct dentry *dentry)
{
- struct dentry *dentry;
- void *priv = NULL;
-
- BUG_ON(pts_inode->i_rdev == MKDEV(TTYAUX_MAJOR, PTMX_MINOR));
-
- /* Ensure dentry has not been deleted by devpts_pty_kill() */
- dentry = d_find_alias(pts_inode);
- if (!dentry)
- return NULL;
-
- if (pts_inode->i_sb->s_magic == DEVPTS_SUPER_MAGIC)
- priv = pts_inode->i_private;
-
- dput(dentry);
-
- return priv;
+ WARN_ON_ONCE(dentry->d_sb->s_magic != DEVPTS_SUPER_MAGIC);
+ return dentry->d_fsdata;
}
/**
@@ -683,24 +663,14 @@ void *devpts_get_priv(struct inode *pts_inode)
*
* This is an inverse operation of devpts_pty_new.
*/
-void devpts_pty_kill(struct inode *inode)
+void devpts_pty_kill(struct dentry *dentry)
{
- struct super_block *sb = pts_sb_from_inode(inode);
- struct dentry *root = sb->s_root;
- struct dentry *dentry;
+ WARN_ON_ONCE(dentry->d_sb->s_magic != DEVPTS_SUPER_MAGIC);
- BUG_ON(inode->i_rdev == MKDEV(TTYAUX_MAJOR, PTMX_MINOR));
-
- inode_lock(d_inode(root));
-
- dentry = d_find_alias(inode);
-
- drop_nlink(inode);
+ dentry->d_fsdata = NULL;
+ drop_nlink(dentry->d_inode);
d_delete(dentry);
dput(dentry); /* d_alloc_name() in devpts_pty_new() */
- dput(dentry); /* d_find_alias above */
-
- inode_unlock(d_inode(root));
}
static int __init init_devpts_fs(void)
diff --git a/fs/ext4/crypto.c b/fs/ext4/crypto.c
index db9ae6e18154..6a6c27373b54 100644
--- a/fs/ext4/crypto.c
+++ b/fs/ext4/crypto.c
@@ -32,6 +32,7 @@
#include <linux/random.h>
#include <linux/scatterlist.h>
#include <linux/spinlock_types.h>
+#include <linux/namei.h>
#include "ext4_extents.h"
#include "xattr.h"
@@ -482,6 +483,9 @@ static int ext4_d_revalidate(struct dentry *dentry, unsigned int flags)
struct ext4_crypt_info *ci;
int dir_has_key, cached_with_key;
+ if (flags & LOOKUP_RCU)
+ return -ECHILD;
+
dir = dget_parent(dentry);
if (!ext4_encrypted_inode(d_inode(dir))) {
dput(dir);
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 53fec0872e60..5dafb9cef12e 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -992,7 +992,7 @@ submit_and_realloc:
if (f2fs_encrypted_inode(inode) &&
S_ISREG(inode->i_mode)) {
- ctx = fscrypt_get_ctx(inode);
+ ctx = fscrypt_get_ctx(inode, GFP_NOFS);
if (IS_ERR(ctx))
goto set_error_page;
@@ -1092,14 +1092,24 @@ int do_write_data_page(struct f2fs_io_info *fio)
}
if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode)) {
+ gfp_t gfp_flags = GFP_NOFS;
/* wait for GCed encrypted page writeback */
f2fs_wait_on_encrypted_page_writeback(F2FS_I_SB(inode),
fio->old_blkaddr);
-
- fio->encrypted_page = fscrypt_encrypt_page(inode, fio->page);
+retry_encrypt:
+ fio->encrypted_page = fscrypt_encrypt_page(inode, fio->page,
+ gfp_flags);
if (IS_ERR(fio->encrypted_page)) {
err = PTR_ERR(fio->encrypted_page);
+ if (err == -ENOMEM) {
+ /* flush pending ios and wait for a while */
+ f2fs_flush_merged_bios(F2FS_I_SB(inode));
+ congestion_wait(BLK_RW_ASYNC, HZ/50);
+ gfp_flags |= __GFP_NOFAIL;
+ err = 0;
+ goto retry_encrypt;
+ }
goto out_writepage;
}
}
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 443e07705c2a..90d1157a09f9 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -441,7 +441,7 @@ static int f2fs_file_mmap(struct file *file, struct vm_area_struct *vma)
static int f2fs_file_open(struct inode *inode, struct file *filp)
{
int ret = generic_file_open(inode, filp);
- struct inode *dir = filp->f_path.dentry->d_parent->d_inode;
+ struct dentry *dir;
if (!ret && f2fs_encrypted_inode(inode)) {
ret = fscrypt_get_encryption_info(inode);
@@ -450,9 +450,13 @@ static int f2fs_file_open(struct inode *inode, struct file *filp)
if (!fscrypt_has_encryption_key(inode))
return -ENOKEY;
}
- if (f2fs_encrypted_inode(dir) &&
- !fscrypt_has_permitted_context(dir, inode))
+ dir = dget_parent(file_dentry(filp));
+ if (f2fs_encrypted_inode(d_inode(dir)) &&
+ !fscrypt_has_permitted_context(d_inode(dir), inode)) {
+ dput(dir);
return -EPERM;
+ }
+ dput(dir);
return ret;
}
diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c
index 9aed6e202201..13719d3f35f8 100644
--- a/fs/ocfs2/dlm/dlmmaster.c
+++ b/fs/ocfs2/dlm/dlmmaster.c
@@ -2455,6 +2455,8 @@ int dlm_deref_lockres_done_handler(struct o2net_msg *msg, u32 len, void *data,
spin_unlock(&dlm->spinlock);
+ ret = 0;
+
done:
dlm_put(dlm);
return ret;
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 229cb546bee0..541583510cfb 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -1518,6 +1518,32 @@ static struct page *can_gather_numa_stats(pte_t pte, struct vm_area_struct *vma,
return page;
}
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+static struct page *can_gather_numa_stats_pmd(pmd_t pmd,
+ struct vm_area_struct *vma,
+ unsigned long addr)
+{
+ struct page *page;
+ int nid;
+
+ if (!pmd_present(pmd))
+ return NULL;
+
+ page = vm_normal_page_pmd(vma, addr, pmd);
+ if (!page)
+ return NULL;
+
+ if (PageReserved(page))
+ return NULL;
+
+ nid = page_to_nid(page);
+ if (!node_isset(nid, node_states[N_MEMORY]))
+ return NULL;
+
+ return page;
+}
+#endif
+
static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
unsigned long end, struct mm_walk *walk)
{
@@ -1527,14 +1553,14 @@ static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
pte_t *orig_pte;
pte_t *pte;
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
ptl = pmd_trans_huge_lock(pmd, vma);
if (ptl) {
- pte_t huge_pte = *(pte_t *)pmd;
struct page *page;
- page = can_gather_numa_stats(huge_pte, vma, addr);
+ page = can_gather_numa_stats_pmd(*pmd, vma, addr);
if (page)
- gather_stats(page, md, pte_dirty(huge_pte),
+ gather_stats(page, md, pmd_dirty(*pmd),
HPAGE_PMD_SIZE/PAGE_SIZE);
spin_unlock(ptl);
return 0;
@@ -1542,6 +1568,7 @@ static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
if (pmd_trans_unstable(pmd))
return 0;
+#endif
orig_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
do {
struct page *page = can_gather_numa_stats(*pte, vma, addr);
diff --git a/fs/seq_file.c b/fs/seq_file.c
index e85664b7c7d9..19f532e7d35e 100644
--- a/fs/seq_file.c
+++ b/fs/seq_file.c
@@ -72,9 +72,10 @@ int seq_open(struct file *file, const struct seq_operations *op)
mutex_init(&p->lock);
p->op = op;
-#ifdef CONFIG_USER_NS
- p->user_ns = file->f_cred->user_ns;
-#endif
+
+ // No refcounting: the lifetime of 'p' is constrained
+ // to the lifetime of the file.
+ p->file = file;
/*
* Wrappers around seq_open(e.g. swaps_open) need to be
OpenPOWER on IntegriCloud