From 71480663b751de1bdfafaa2f668ceabaea78b68b Mon Sep 17 00:00:00 2001 From: Carlos Maiolino Date: Tue, 25 Jul 2023 16:45:05 +0200 Subject: [PATCH] shmem: make shmem_get_inode() return ERR_PTR instead of NULL 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 Signed-off-by: Carlos Maiolino Reviewed-by: Jan Kara Message-Id: <20230725144510.253763-3-cem@kernel.org> Signed-off-by: Christian Brauner --- mm/shmem.c | 211 ++++++++++++++++++++++++++++++----------------------- 1 file changed, 119 insertions(+), 92 deletions(-) diff --git a/mm/shmem.c b/mm/shmem.c index be71cdcaeb14..e89c35c65586 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2365,67 +2365,74 @@ 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); - if (sbinfo->noswap) - mapping_set_unevictable(inode->i_mapping); - 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); + INIT_LIST_HEAD(&info->swaplist); + if (sbinfo->noswap) + mapping_set_unevictable(inode->i_mapping); + 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; } @@ -3074,27 +3081,30 @@ 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; @@ -3105,20 +3115,26 @@ 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)) { + error = PTR_ERR(inode); + goto err_out; } + + 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); + +err_out: return finish_open_simple(file, error); out_iput: iput(inode); @@ -3293,8 +3309,9 @@ 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); @@ -3932,12 +3949,13 @@ 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; @@ -4000,8 +4018,10 @@ 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); @@ -4011,7 +4031,7 @@ 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) @@ -4380,10 +4400,16 @@ 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 mnt_idmap *idmap, 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 */ @@ -4408,9 +4434,10 @@ 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; -- 2.34.1