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linux/fs/ext2/namei.c
Kirill A. Shutemov 09cbfeaf1a mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros 
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.

This promise never materialized.  And unlikely will.

We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE.  And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.

Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.

Let's stop pretending that pages in page cache are special.  They are
not.

The changes are pretty straight-forward:

 - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};

 - page_cache_get() -> get_page();

 - page_cache_release() -> put_page();

This patch contains automated changes generated with coccinelle using
script below.  For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.

The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.

There are few places in the code where coccinelle didn't reach.  I'll
fix them manually in a separate patch.  Comments and documentation also
will be addressed with the separate patch.

virtual patch

@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT

@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE

@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK

@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)

@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)

@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-04 10:41:08 -07:00

453 lines
10 KiB
C
Raw Blame History

/*
* linux/fs/ext2/namei.c
*
* Rewrite to pagecache. Almost all code had been changed, so blame me
* if the things go wrong. Please, send bug reports to
* viro@parcelfarce.linux.theplanet.co.uk
*
* Stuff here is basically a glue between the VFS and generic UNIXish
* filesystem that keeps everything in pagecache. All knowledge of the
* directory layout is in fs/ext2/dir.c - it turned out to be easily separatable
* and it's easier to debug that way. In principle we might want to
* generalize that a bit and turn it into a library. Or not.
*
* The only non-static object here is ext2_dir_inode_operations.
*
* TODO: get rid of kmap() use, add readahead.
*
* Copyright (C) 1992, 1993, 1994, 1995
* Remy Card (card@masi.ibp.fr)
* Laboratoire MASI - Institut Blaise Pascal
* Universite Pierre et Marie Curie (Paris VI)
*
* from
*
* linux/fs/minix/namei.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
*
* Big-endian to little-endian byte-swapping/bitmaps by
* David S. Miller (davem@caip.rutgers.edu), 1995
*/
#include <linux/pagemap.h>
#include <linux/quotaops.h>
#include "ext2.h"
#include "xattr.h"
#include "acl.h"
static inline int ext2_add_nondir(struct dentry *dentry, struct inode *inode)
{
int err = ext2_add_link(dentry, inode);
if (!err) {
unlock_new_inode(inode);
d_instantiate(dentry, inode);
return 0;
}
inode_dec_link_count(inode);
unlock_new_inode(inode);
iput(inode);
return err;
}
/*
* Methods themselves.
*/
static struct dentry *ext2_lookup(struct inode * dir, struct dentry *dentry, unsigned int flags)
{
struct inode * inode;
ino_t ino;
if (dentry->d_name.len > EXT2_NAME_LEN)
return ERR_PTR(-ENAMETOOLONG);
ino = ext2_inode_by_name(dir, &dentry->d_name);
inode = NULL;
if (ino) {
inode = ext2_iget(dir->i_sb, ino);
if (inode == ERR_PTR(-ESTALE)) {
ext2_error(dir->i_sb, __func__,
"deleted inode referenced: %lu",
(unsigned long) ino);
return ERR_PTR(-EIO);
}
}
return d_splice_alias(inode, dentry);
}
struct dentry *ext2_get_parent(struct dentry *child)
{
struct qstr dotdot = QSTR_INIT("..", 2);
unsigned long ino = ext2_inode_by_name(d_inode(child), &dotdot);
if (!ino)
return ERR_PTR(-ENOENT);
return d_obtain_alias(ext2_iget(d_inode(child)->i_sb, ino));
}
/*
* By the time this is called, we already have created
* the directory cache entry for the new file, but it
* is so far negative - it has no inode.
*
* If the create succeeds, we fill in the inode information
* with d_instantiate().
*/
static int ext2_create (struct inode * dir, struct dentry * dentry, umode_t mode, bool excl)
{
struct inode *inode;
int err;
err = dquot_initialize(dir);
if (err)
return err;
inode = ext2_new_inode(dir, mode, &dentry->d_name);
if (IS_ERR(inode))
return PTR_ERR(inode);
inode->i_op = &ext2_file_inode_operations;
if (test_opt(inode->i_sb, NOBH)) {
inode->i_mapping->a_ops = &ext2_nobh_aops;
inode->i_fop = &ext2_file_operations;
} else {
inode->i_mapping->a_ops = &ext2_aops;
inode->i_fop = &ext2_file_operations;
}
mark_inode_dirty(inode);
return ext2_add_nondir(dentry, inode);
}
static int ext2_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
{
struct inode *inode = ext2_new_inode(dir, mode, NULL);
if (IS_ERR(inode))
return PTR_ERR(inode);
inode->i_op = &ext2_file_inode_operations;
if (test_opt(inode->i_sb, NOBH)) {
inode->i_mapping->a_ops = &ext2_nobh_aops;
inode->i_fop = &ext2_file_operations;
} else {
inode->i_mapping->a_ops = &ext2_aops;
inode->i_fop = &ext2_file_operations;
}
mark_inode_dirty(inode);
d_tmpfile(dentry, inode);
unlock_new_inode(inode);
return 0;
}
static int ext2_mknod (struct inode * dir, struct dentry *dentry, umode_t mode, dev_t rdev)
{
struct inode * inode;
int err;
err = dquot_initialize(dir);
if (err)
return err;
inode = ext2_new_inode (dir, mode, &dentry->d_name);
err = PTR_ERR(inode);
if (!IS_ERR(inode)) {
init_special_inode(inode, inode->i_mode, rdev);
#ifdef CONFIG_EXT2_FS_XATTR
inode->i_op = &ext2_special_inode_operations;
#endif
mark_inode_dirty(inode);
err = ext2_add_nondir(dentry, inode);
}
return err;
}
static int ext2_symlink (struct inode * dir, struct dentry * dentry,
const char * symname)
{
struct super_block * sb = dir->i_sb;
int err = -ENAMETOOLONG;
unsigned l = strlen(symname)+1;
struct inode * inode;
if (l > sb->s_blocksize)
goto out;
err = dquot_initialize(dir);
if (err)
goto out;
inode = ext2_new_inode (dir, S_IFLNK | S_IRWXUGO, &dentry->d_name);
err = PTR_ERR(inode);
if (IS_ERR(inode))
goto out;
if (l > sizeof (EXT2_I(inode)->i_data)) {
/* slow symlink */
inode->i_op = &ext2_symlink_inode_operations;
inode_nohighmem(inode);
if (test_opt(inode->i_sb, NOBH))
inode->i_mapping->a_ops = &ext2_nobh_aops;
else
inode->i_mapping->a_ops = &ext2_aops;
err = page_symlink(inode, symname, l);
if (err)
goto out_fail;
} else {
/* fast symlink */
inode->i_op = &ext2_fast_symlink_inode_operations;
inode->i_link = (char*)EXT2_I(inode)->i_data;
memcpy(inode->i_link, symname, l);
inode->i_size = l-1;
}
mark_inode_dirty(inode);
err = ext2_add_nondir(dentry, inode);
out:
return err;
out_fail:
inode_dec_link_count(inode);
unlock_new_inode(inode);
iput (inode);
goto out;
}
static int ext2_link (struct dentry * old_dentry, struct inode * dir,
struct dentry *dentry)
{
struct inode *inode = d_inode(old_dentry);
int err;
err = dquot_initialize(dir);
if (err)
return err;
inode->i_ctime = CURRENT_TIME_SEC;
inode_inc_link_count(inode);
ihold(inode);
err = ext2_add_link(dentry, inode);
if (!err) {
d_instantiate(dentry, inode);
return 0;
}
inode_dec_link_count(inode);
iput(inode);
return err;
}
static int ext2_mkdir(struct inode * dir, struct dentry * dentry, umode_t mode)
{
struct inode * inode;
int err;
err = dquot_initialize(dir);
if (err)
return err;
inode_inc_link_count(dir);
inode = ext2_new_inode(dir, S_IFDIR | mode, &dentry->d_name);
err = PTR_ERR(inode);
if (IS_ERR(inode))
goto out_dir;
inode->i_op = &ext2_dir_inode_operations;
inode->i_fop = &ext2_dir_operations;
if (test_opt(inode->i_sb, NOBH))
inode->i_mapping->a_ops = &ext2_nobh_aops;
else
inode->i_mapping->a_ops = &ext2_aops;
inode_inc_link_count(inode);
err = ext2_make_empty(inode, dir);
if (err)
goto out_fail;
err = ext2_add_link(dentry, inode);
if (err)
goto out_fail;
unlock_new_inode(inode);
d_instantiate(dentry, inode);
out:
return err;
out_fail:
inode_dec_link_count(inode);
inode_dec_link_count(inode);
unlock_new_inode(inode);
iput(inode);
out_dir:
inode_dec_link_count(dir);
goto out;
}
static int ext2_unlink(struct inode * dir, struct dentry *dentry)
{
struct inode * inode = d_inode(dentry);
struct ext2_dir_entry_2 * de;
struct page * page;
int err;
err = dquot_initialize(dir);
if (err)
goto out;
de = ext2_find_entry (dir, &dentry->d_name, &page);
if (!de) {
err = -ENOENT;
goto out;
}
err = ext2_delete_entry (de, page);
if (err)
goto out;
inode->i_ctime = dir->i_ctime;
inode_dec_link_count(inode);
err = 0;
out:
return err;
}
static int ext2_rmdir (struct inode * dir, struct dentry *dentry)
{
struct inode * inode = d_inode(dentry);
int err = -ENOTEMPTY;
if (ext2_empty_dir(inode)) {
err = ext2_unlink(dir, dentry);
if (!err) {
inode->i_size = 0;
inode_dec_link_count(inode);
inode_dec_link_count(dir);
}
}
return err;
}
static int ext2_rename (struct inode * old_dir, struct dentry * old_dentry,
struct inode * new_dir, struct dentry * new_dentry )
{
struct inode * old_inode = d_inode(old_dentry);
struct inode * new_inode = d_inode(new_dentry);
struct page * dir_page = NULL;
struct ext2_dir_entry_2 * dir_de = NULL;
struct page * old_page;
struct ext2_dir_entry_2 * old_de;
int err;
err = dquot_initialize(old_dir);
if (err)
goto out;
err = dquot_initialize(new_dir);
if (err)
goto out;
old_de = ext2_find_entry (old_dir, &old_dentry->d_name, &old_page);
if (!old_de) {
err = -ENOENT;
goto out;
}
if (S_ISDIR(old_inode->i_mode)) {
err = -EIO;
dir_de = ext2_dotdot(old_inode, &dir_page);
if (!dir_de)
goto out_old;
}
if (new_inode) {
struct page *new_page;
struct ext2_dir_entry_2 *new_de;
err = -ENOTEMPTY;
if (dir_de && !ext2_empty_dir (new_inode))
goto out_dir;
err = -ENOENT;
new_de = ext2_find_entry (new_dir, &new_dentry->d_name, &new_page);
if (!new_de)
goto out_dir;
ext2_set_link(new_dir, new_de, new_page, old_inode, 1);
new_inode->i_ctime = CURRENT_TIME_SEC;
if (dir_de)
drop_nlink(new_inode);
inode_dec_link_count(new_inode);
} else {
err = ext2_add_link(new_dentry, old_inode);
if (err)
goto out_dir;
if (dir_de)
inode_inc_link_count(new_dir);
}
/*
* Like most other Unix systems, set the ctime for inodes on a
* rename.
*/
old_inode->i_ctime = CURRENT_TIME_SEC;
mark_inode_dirty(old_inode);
ext2_delete_entry (old_de, old_page);
if (dir_de) {
if (old_dir != new_dir)
ext2_set_link(old_inode, dir_de, dir_page, new_dir, 0);
else {
kunmap(dir_page);
put_page(dir_page);
}
inode_dec_link_count(old_dir);
}
return 0;
out_dir:
if (dir_de) {
kunmap(dir_page);
put_page(dir_page);
}
out_old:
kunmap(old_page);
put_page(old_page);
out:
return err;
}
const struct inode_operations ext2_dir_inode_operations = {
.create = ext2_create,
.lookup = ext2_lookup,
.link = ext2_link,
.unlink = ext2_unlink,
.symlink = ext2_symlink,
.mkdir = ext2_mkdir,
.rmdir = ext2_rmdir,
.mknod = ext2_mknod,
.rename = ext2_rename,
#ifdef CONFIG_EXT2_FS_XATTR
.setxattr = generic_setxattr,
.getxattr = generic_getxattr,
.listxattr = ext2_listxattr,
.removexattr = generic_removexattr,
#endif
.setattr = ext2_setattr,
.get_acl = ext2_get_acl,
.set_acl = ext2_set_acl,
.tmpfile = ext2_tmpfile,
};
const struct inode_operations ext2_special_inode_operations = {
#ifdef CONFIG_EXT2_FS_XATTR
.setxattr = generic_setxattr,
.getxattr = generic_getxattr,
.listxattr = ext2_listxattr,
.removexattr = generic_removexattr,
#endif
.setattr = ext2_setattr,
.get_acl = ext2_get_acl,
.set_acl = ext2_set_acl,
};
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