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shmem: make shmem_get_inode() return ERR_PTR instead of NULL
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Make shmem_get_inode() return ERR_PTR instead of NULL on error. This will be
useful later when we introduce quota support.

There should be no functional change.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
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@intel-lab-lkp
Lukas Czerner authored and intel-lab-lkp committed Apr 3, 2023
1 parent 955b96d commit 98aa926
Showing 1 changed file with 114 additions and 91 deletions.
205 changes: 114 additions & 91 deletions mm/shmem.c
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Expand Up @@ -2354,65 +2354,71 @@ static struct inode *shmem_get_inode(struct mnt_idmap *idmap, struct super_block
struct shmem_inode_info *info;
struct shmem_sb_info *sbinfo = SHMEM_SB(sb);
ino_t ino;
int err;

err = shmem_reserve_inode(sb, &ino);
if (err)
return ERR_PTR(err);

if (shmem_reserve_inode(sb, &ino))
return NULL;

inode = new_inode(sb);
if (inode) {
inode->i_ino = ino;
inode_init_owner(idmap, inode, dir, mode);
inode->i_blocks = 0;
inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
inode->i_generation = get_random_u32();
info = SHMEM_I(inode);
memset(info, 0, (char *)inode - (char *)info);
spin_lock_init(&info->lock);
atomic_set(&info->stop_eviction, 0);
info->seals = F_SEAL_SEAL;
info->flags = flags & VM_NORESERVE;
info->i_crtime = inode->i_mtime;
info->fsflags = (dir == NULL) ? 0 :
SHMEM_I(dir)->fsflags & SHMEM_FL_INHERITED;
if (info->fsflags)
shmem_set_inode_flags(inode, info->fsflags);
INIT_LIST_HEAD(&info->shrinklist);
INIT_LIST_HEAD(&info->swaplist);
simple_xattrs_init(&info->xattrs);
cache_no_acl(inode);
mapping_set_large_folios(inode->i_mapping);

switch (mode & S_IFMT) {
default:
inode->i_op = &shmem_special_inode_operations;
init_special_inode(inode, mode, dev);
break;
case S_IFREG:
inode->i_mapping->a_ops = &shmem_aops;
inode->i_op = &shmem_inode_operations;
inode->i_fop = &shmem_file_operations;
mpol_shared_policy_init(&info->policy,
shmem_get_sbmpol(sbinfo));
break;
case S_IFDIR:
inc_nlink(inode);
/* Some things misbehave if size == 0 on a directory */
inode->i_size = 2 * BOGO_DIRENT_SIZE;
inode->i_op = &shmem_dir_inode_operations;
inode->i_fop = &simple_dir_operations;
break;
case S_IFLNK:
/*
* Must not load anything in the rbtree,
* mpol_free_shared_policy will not be called.
*/
mpol_shared_policy_init(&info->policy, NULL);
break;
}

lockdep_annotate_inode_mutex_key(inode);
} else
if (!inode) {
shmem_free_inode(sb);
return ERR_PTR(-ENOSPC);
}

inode->i_ino = ino;
inode_init_owner(idmap, inode, dir, mode);
inode->i_blocks = 0;
inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
inode->i_generation = get_random_u32();
info = SHMEM_I(inode);
memset(info, 0, (char *)inode - (char *)info);
spin_lock_init(&info->lock);
atomic_set(&info->stop_eviction, 0);
info->seals = F_SEAL_SEAL;
info->flags = flags & VM_NORESERVE;
info->i_crtime = inode->i_mtime;
info->fsflags = (dir == NULL) ? 0 :
SHMEM_I(dir)->fsflags & SHMEM_FL_INHERITED;
if (info->fsflags)
shmem_set_inode_flags(inode, info->fsflags);
INIT_LIST_HEAD(&info->shrinklist);
INIT_LIST_HEAD(&info->swaplist);
simple_xattrs_init(&info->xattrs);
cache_no_acl(inode);
mapping_set_large_folios(inode->i_mapping);

switch (mode & S_IFMT) {
default:
inode->i_op = &shmem_special_inode_operations;
init_special_inode(inode, mode, dev);
break;
case S_IFREG:
inode->i_mapping->a_ops = &shmem_aops;
inode->i_op = &shmem_inode_operations;
inode->i_fop = &shmem_file_operations;
mpol_shared_policy_init(&info->policy,
shmem_get_sbmpol(sbinfo));
break;
case S_IFDIR:
inc_nlink(inode);
/* Some things misbehave if size == 0 on a directory */
inode->i_size = 2 * BOGO_DIRENT_SIZE;
inode->i_op = &shmem_dir_inode_operations;
inode->i_fop = &simple_dir_operations;
break;
case S_IFLNK:
/*
* Must not load anything in the rbtree,
* mpol_free_shared_policy will not be called.
*/
mpol_shared_policy_init(&info->policy, NULL);
break;
}

lockdep_annotate_inode_mutex_key(inode);
return inode;
}

Expand Down Expand Up @@ -2927,27 +2933,30 @@ shmem_mknod(struct mnt_idmap *idmap, struct inode *dir,
struct dentry *dentry, umode_t mode, dev_t dev)
{
struct inode *inode;
int error = -ENOSPC;
int error;

inode = shmem_get_inode(idmap, dir->i_sb, dir, mode, dev, VM_NORESERVE);
if (inode) {
error = simple_acl_create(dir, inode);
if (error)
goto out_iput;
error = security_inode_init_security(inode, dir,
&dentry->d_name,
shmem_initxattrs, NULL);
if (error && error != -EOPNOTSUPP)
goto out_iput;

error = 0;
dir->i_size += BOGO_DIRENT_SIZE;
dir->i_ctime = dir->i_mtime = current_time(dir);
inode_inc_iversion(dir);
d_instantiate(dentry, inode);
dget(dentry); /* Extra count - pin the dentry in core */
}
if (IS_ERR(inode))
return PTR_ERR(inode);

error = simple_acl_create(dir, inode);
if (error)
goto out_iput;
error = security_inode_init_security(inode, dir,
&dentry->d_name,
shmem_initxattrs, NULL);
if (error && error != -EOPNOTSUPP)
goto out_iput;

error = 0;
dir->i_size += BOGO_DIRENT_SIZE;
dir->i_ctime = dir->i_mtime = current_time(dir);
inode_inc_iversion(dir);
d_instantiate(dentry, inode);
dget(dentry); /* Extra count - pin the dentry in core */
return error;

out_iput:
iput(inode);
return error;
Expand All @@ -2958,21 +2967,24 @@ shmem_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
struct file *file, umode_t mode)
{
struct inode *inode;
int error = -ENOSPC;
int error;

inode = shmem_get_inode(idmap, dir->i_sb, dir, mode, 0, VM_NORESERVE);
if (inode) {
error = security_inode_init_security(inode, dir,
NULL,
shmem_initxattrs, NULL);
if (error && error != -EOPNOTSUPP)
goto out_iput;
error = simple_acl_create(dir, inode);
if (error)
goto out_iput;
d_tmpfile(file, inode);
}

if (IS_ERR(inode))
return PTR_ERR(inode);

error = security_inode_init_security(inode, dir,
NULL,
shmem_initxattrs, NULL);
if (error && error != -EOPNOTSUPP)
goto out_iput;
error = simple_acl_create(dir, inode);
if (error)
goto out_iput;
d_tmpfile(file, inode);
return finish_open_simple(file, error);

out_iput:
iput(inode);
return error;
Expand Down Expand Up @@ -3146,8 +3158,9 @@ static int shmem_symlink(struct mnt_idmap *idmap, struct inode *dir,

inode = shmem_get_inode(idmap, dir->i_sb, dir, S_IFLNK | 0777, 0,
VM_NORESERVE);
if (!inode)
return -ENOSPC;

if (IS_ERR(inode))
return PTR_ERR(inode);

error = security_inode_init_security(inode, dir, &dentry->d_name,
shmem_initxattrs, NULL);
Expand Down Expand Up @@ -3762,12 +3775,13 @@ static int shmem_fill_super(struct super_block *sb, struct fs_context *fc)
struct shmem_options *ctx = fc->fs_private;
struct inode *inode;
struct shmem_sb_info *sbinfo;
int error = -ENOMEM;

/* Round up to L1_CACHE_BYTES to resist false sharing */
sbinfo = kzalloc(max((int)sizeof(struct shmem_sb_info),
L1_CACHE_BYTES), GFP_KERNEL);
if (!sbinfo)
return -ENOMEM;
return error;

sb->s_fs_info = sbinfo;

Expand Down Expand Up @@ -3829,8 +3843,10 @@ static int shmem_fill_super(struct super_block *sb, struct fs_context *fc)

inode = shmem_get_inode(&nop_mnt_idmap, sb, NULL, S_IFDIR | sbinfo->mode, 0,
VM_NORESERVE);
if (!inode)
if (IS_ERR(inode)) {
error = PTR_ERR(inode);
goto failed;
}
inode->i_uid = sbinfo->uid;
inode->i_gid = sbinfo->gid;
sb->s_root = d_make_root(inode);
Expand All @@ -3840,7 +3856,7 @@ static int shmem_fill_super(struct super_block *sb, struct fs_context *fc)

failed:
shmem_put_super(sb);
return -ENOMEM;
return error;
}

static int shmem_get_tree(struct fs_context *fc)
Expand Down Expand Up @@ -4209,10 +4225,16 @@ EXPORT_SYMBOL_GPL(shmem_truncate_range);
#define shmem_vm_ops generic_file_vm_ops
#define shmem_anon_vm_ops generic_file_vm_ops
#define shmem_file_operations ramfs_file_operations
#define shmem_get_inode(idmap, sb, dir, mode, dev, flags) ramfs_get_inode(sb, dir, mode, dev)
#define shmem_acct_size(flags, size) 0
#define shmem_unacct_size(flags, size) do {} while (0)

static inline struct inode *shmem_get_inode(struct super_block *sb, struct inode *dir,
umode_t mode, dev_t dev, unsigned long flags)
{
struct inode *inode = ramfs_get_inode(sb, dir, mode, dev);
return inode ? inode : ERR_PTR(-ENOSPC);
}

#endif /* CONFIG_SHMEM */

/* common code */
Expand All @@ -4237,9 +4259,10 @@ static struct file *__shmem_file_setup(struct vfsmount *mnt, const char *name, l

inode = shmem_get_inode(&nop_mnt_idmap, mnt->mnt_sb, NULL,
S_IFREG | S_IRWXUGO, 0, flags);
if (unlikely(!inode)) {

if (IS_ERR(inode)) {
shmem_unacct_size(flags, size);
return ERR_PTR(-ENOSPC);
return ERR_CAST(inode);
}
inode->i_flags |= i_flags;
inode->i_size = size;
Expand Down

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