fs: Preserve error code in get_empty_filp(), part 2

Allocating a file structure in function get_empty_filp() might fail because
of several reasons:
 - not enough memory for file structures
 - operation is not allowed
 - user is over its limit

Currently the function returns NULL in all cases and we loose the exact
reason of the error. All callers of get_empty_filp() assume that the function
can fail with ENFILE only.

Return error through pointer. Change all callers to preserve this error code.

[AV: cleaned up a bit, carved the get_empty_filp() part out into a separate commit
(things remaining here deal with alloc_file()), removed pipe(2) behaviour change]

Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com>
Reviewed-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/arch/ia64/kernel/perfmon.c b/arch/ia64/kernel/perfmon.c
index ea39eba61ef5abcdf087b027879196b49d75bb03..433f5e8a2cd147cd7ae696d3e42b0123f6b4f306 100644 (file)
--- a/arch/ia64/kernel/perfmon.c
+++ b/arch/ia64/kernel/perfmon.c
@@ -2221,9 +2221,9 @@ pfm_alloc_file(pfm_context_t *ctx)
        d_add(path.dentry, inode);
 
        file = alloc_file(&path, FMODE_READ, &pfm_file_ops);
-       if (!file) {
+       if (IS_ERR(file)) {
                path_put(&path);
-               return ERR_PTR(-ENFILE);
+               return file;
        }
 
        file->f_flags = O_RDONLY;

diff --git a/fs/anon_inodes.c b/fs/anon_inodes.c
index 28d39fb84ae38bcce08c5d6e54c0655453f83413..a14eb0c1cd8cf5c98b9c4894e1cfd20c675e04b8 100644 (file)
--- a/fs/anon_inodes.c
+++ b/fs/anon_inodes.c
@@ -131,7 +131,6 @@ struct file *anon_inode_getfile(const char *name,
        struct qstr this;
        struct path path;
        struct file *file;
-       int error;
 
        if (IS_ERR(anon_inode_inode))
                return ERR_PTR(-ENODEV);
@@ -143,7 +142,7 @@ struct file *anon_inode_getfile(const char *name,
         * Link the inode to a directory entry by creating a unique name
         * using the inode sequence number.
         */
-       error = -ENOMEM;
+       file = ERR_PTR(-ENOMEM);
        this.name = name;
        this.len = strlen(name);
        this.hash = 0;
@@ -160,9 +159,8 @@ struct file *anon_inode_getfile(const char *name,
 
        d_instantiate(path.dentry, anon_inode_inode);
 
-       error = -ENFILE;
        file = alloc_file(&path, OPEN_FMODE(flags), fops);
-       if (!file)
+       if (IS_ERR(file))
                goto err_dput;
        file->f_mapping = anon_inode_inode->i_mapping;
 
@@ -177,7 +175,7 @@ err_dput:
        path_put(&path);
 err_module:
        module_put(fops->owner);
-       return ERR_PTR(error);
+       return file;
 }
 EXPORT_SYMBOL_GPL(anon_inode_getfile);
 

diff --git a/fs/file_table.c b/fs/file_table.c
index cd76d4fdf4a497c5653267affd1e79bff250c791..aa07d3684a2e8e13bdf4ae36eb5dc0ba98641223 100644 (file)
--- a/fs/file_table.c
+++ b/fs/file_table.c
@@ -173,7 +173,7 @@ struct file *alloc_file(struct path *path, fmode_t mode,
 
        file = get_empty_filp();
        if (IS_ERR(file))
-               return NULL;
+               return file;
 
        file->f_path = *path;
        file->f_mapping = path->dentry->d_inode->i_mapping;

diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index edb42ea60c761afff0cf8876c6d7bccb724eb4dd..99fe7ef2f09b7e967800dae8892807fca2d7a0cd 100644 (file)
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -923,8 +923,7 @@ struct file *hugetlb_file_setup(const char *name, unsigned long addr,
                                struct user_struct **user,
                                int creat_flags, int page_size_log)
 {
-       int error = -ENOMEM;
-       struct file *file;
+       struct file *file = ERR_PTR(-ENOMEM);
        struct inode *inode;
        struct path path;
        struct dentry *root;
@@ -964,7 +963,7 @@ struct file *hugetlb_file_setup(const char *name, unsigned long addr,
                goto out_shm_unlock;
 
        path.mnt = mntget(hugetlbfs_vfsmount[hstate_idx]);
-       error = -ENOSPC;
+       file = ERR_PTR(-ENOSPC);
        inode = hugetlbfs_get_inode(root->d_sb, NULL, S_IFREG | S_IRWXUGO, 0);
        if (!inode)
                goto out_dentry;
@@ -973,7 +972,7 @@ struct file *hugetlb_file_setup(const char *name, unsigned long addr,
        size += addr & ~huge_page_mask(hstate);
        num_pages = ALIGN(size, huge_page_size(hstate)) >>
                        huge_page_shift(hstate);
-       error = -ENOMEM;
+       file = ERR_PTR(-ENOMEM);
        if (hugetlb_reserve_pages(inode, 0, num_pages, NULL, acctflag))
                goto out_inode;
 
@@ -981,10 +980,9 @@ struct file *hugetlb_file_setup(const char *name, unsigned long addr,
        inode->i_size = size;
        clear_nlink(inode);
 
-       error = -ENFILE;
        file = alloc_file(&path, FMODE_WRITE | FMODE_READ,
                        &hugetlbfs_file_operations);
-       if (!file)
+       if (IS_ERR(file))
                goto out_dentry; /* inode is already attached */
 
        return file;
@@ -998,7 +996,7 @@ out_shm_unlock:
                user_shm_unlock(size, *user);
                *user = NULL;
        }
-       return ERR_PTR(error);
+       return file;
 }
 
 static int __init init_hugetlbfs_fs(void)

diff --git a/fs/pipe.c b/fs/pipe.c
index 39baf6c3ebb0f3046ef8bc5939f391b062091925..64a494cef0a00be57d0800637b71caf2537c2694 100644 (file)
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -1037,13 +1037,13 @@ int create_pipe_files(struct file **res, int flags)
 
        err = -ENFILE;
        f = alloc_file(&path, FMODE_WRITE, &write_pipefifo_fops);
-       if (!f)
+       if (IS_ERR(f))
                goto err_dentry;
 
        f->f_flags = O_WRONLY | (flags & (O_NONBLOCK | O_DIRECT));
 
        res[0] = alloc_file(&path, FMODE_READ, &read_pipefifo_fops);
-       if (!res[0])
+       if (IS_ERR(res[0]))
                goto err_file;
 
        path_get(&path);

diff --git a/ipc/shm.c b/ipc/shm.c
index 8c9402d298a0fb6a1ce3f9840670dfa4d9fda5b6..de389e639e7e58c36e72543c2b7b250768340080 100644 (file)
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -1042,7 +1042,8 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr,
                          is_file_hugepages(shp->shm_file) ?
                                &shm_file_operations_huge :
                                &shm_file_operations);
-       if (!file)
+       err = PTR_ERR(file);
+       if (IS_ERR(file))
                goto out_free;
 
        file->private_data = sfd;

diff --git a/mm/shmem.c b/mm/shmem.c
index 814d5546cb35c80cf33cdcf2467edaa53134965e..abf07f754277c787534603f115f4e5f39b23e92a 100644 (file)
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2913,10 +2913,10 @@ struct file *shmem_file_setup(const char *name, loff_t size, unsigned long flags
                goto put_dentry;
 #endif
 
-       error = -ENFILE;
        file = alloc_file(&path, FMODE_WRITE | FMODE_READ,
                  &shmem_file_operations);
-       if (!file)
+       error = PTR_ERR(file);
+       if (IS_ERR(file))
                goto put_dentry;
 
        return file;

diff --git a/net/socket.c b/net/socket.c
index 2ca51c719ef984cdadef749008456cf7bd5e1ae4..f4a8c5a0b8d759296ebdc57b2f01b3bae8ebe388 100644 (file)
--- a/net/socket.c
+++ b/net/socket.c
@@ -370,11 +370,11 @@ struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname)
 
        file = alloc_file(&path, FMODE_READ | FMODE_WRITE,
                  &socket_file_ops);
-       if (unlikely(!file)) {
+       if (unlikely(IS_ERR(file))) {
                /* drop dentry, keep inode */
                ihold(path.dentry->d_inode);
                path_put(&path);
-               return ERR_PTR(-ENFILE);
+               return file;
        }
 
        sock->file = file;