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>

1 files changed, 65 insertions, 65 deletions

diff --git a/mm/shmem.c b/mm/shmem.c
index 9428c51ab2d6..719bd6b88d98 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -75,8 +75,8 @@ static struct vfsmount *shm_mnt;
 
 #include "internal.h"
 
-#define BLOCKS_PER_PAGE  (PAGE_CACHE_SIZE/512)
-#define VM_ACCT(size)    (PAGE_CACHE_ALIGN(size) >> PAGE_SHIFT)
+#define BLOCKS_PER_PAGE  (PAGE_SIZE/512)
+#define VM_ACCT(size)    (PAGE_ALIGN(size) >> PAGE_SHIFT)
 
 /* Pretend that each entry is of this size in directory's i_size */
 #define BOGO_DIRENT_SIZE 20
@@ -176,13 +176,13 @@ static inline int shmem_reacct_size(unsigned long flags,
 static inline int shmem_acct_block(unsigned long flags)
 {
 	return (flags & VM_NORESERVE) ?
-		security_vm_enough_memory_mm(current->mm, VM_ACCT(PAGE_CACHE_SIZE)) : 0;
+		security_vm_enough_memory_mm(current->mm, VM_ACCT(PAGE_SIZE)) : 0;
 }
 
 static inline void shmem_unacct_blocks(unsigned long flags, long pages)
 {
 	if (flags & VM_NORESERVE)
-		vm_unacct_memory(pages * VM_ACCT(PAGE_CACHE_SIZE));
+		vm_unacct_memory(pages * VM_ACCT(PAGE_SIZE));
 }
 
 static const struct super_operations shmem_ops;
@@ -300,7 +300,7 @@ static int shmem_add_to_page_cache(struct page *page,
 	VM_BUG_ON_PAGE(!PageLocked(page), page);
 	VM_BUG_ON_PAGE(!PageSwapBacked(page), page);
 
-	page_cache_get(page);
+	get_page(page);
 	page->mapping = mapping;
 	page->index = index;
 
@@ -318,7 +318,7 @@ static int shmem_add_to_page_cache(struct page *page,
 	} else {
 		page->mapping = NULL;
 		spin_unlock_irq(&mapping->tree_lock);
-		page_cache_release(page);
+		put_page(page);
 	}
 	return error;
 }
@@ -338,7 +338,7 @@ static void shmem_delete_from_page_cache(struct page *page, void *radswap)
 	__dec_zone_page_state(page, NR_FILE_PAGES);
 	__dec_zone_page_state(page, NR_SHMEM);
 	spin_unlock_irq(&mapping->tree_lock);
-	page_cache_release(page);
+	put_page(page);
 	BUG_ON(error);
 }
 
@@ -474,10 +474,10 @@ static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend,
 {
 	struct address_space *mapping = inode->i_mapping;
 	struct shmem_inode_info *info = SHMEM_I(inode);
-	pgoff_t start = (lstart + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
-	pgoff_t end = (lend + 1) >> PAGE_CACHE_SHIFT;
-	unsigned int partial_start = lstart & (PAGE_CACHE_SIZE - 1);
-	unsigned int partial_end = (lend + 1) & (PAGE_CACHE_SIZE - 1);
+	pgoff_t start = (lstart + PAGE_SIZE - 1) >> PAGE_SHIFT;
+	pgoff_t end = (lend + 1) >> PAGE_SHIFT;
+	unsigned int partial_start = lstart & (PAGE_SIZE - 1);
+	unsigned int partial_end = (lend + 1) & (PAGE_SIZE - 1);
 	struct pagevec pvec;
 	pgoff_t indices[PAGEVEC_SIZE];
 	long nr_swaps_freed = 0;
@@ -530,7 +530,7 @@ static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend,
 		struct page *page = NULL;
 		shmem_getpage(inode, start - 1, &page, SGP_READ, NULL);
 		if (page) {
-			unsigned int top = PAGE_CACHE_SIZE;
+			unsigned int top = PAGE_SIZE;
 			if (start > end) {
 				top = partial_end;
 				partial_end = 0;
@@ -538,7 +538,7 @@ static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend,
 			zero_user_segment(page, partial_start, top);
 			set_page_dirty(page);
 			unlock_page(page);
-			page_cache_release(page);
+			put_page(page);
 		}
 	}
 	if (partial_end) {
@@ -548,7 +548,7 @@ static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend,
 			zero_user_segment(page, 0, partial_end);
 			set_page_dirty(page);
 			unlock_page(page);
-			page_cache_release(page);
+			put_page(page);
 		}
 	}
 	if (start >= end)
@@ -833,7 +833,7 @@ int shmem_unuse(swp_entry_t swap, struct page *page)
 		mem_cgroup_commit_charge(page, memcg, true, false);
 out:
 	unlock_page(page);
-	page_cache_release(page);
+	put_page(page);
 	return error;
 }
 
@@ -1080,7 +1080,7 @@ static int shmem_replace_page(struct page **pagep, gfp_t gfp,
 	if (!newpage)
 		return -ENOMEM;
 
-	page_cache_get(newpage);
+	get_page(newpage);
 	copy_highpage(newpage, oldpage);
 	flush_dcache_page(newpage);
 
@@ -1120,8 +1120,8 @@ static int shmem_replace_page(struct page **pagep, gfp_t gfp,
 	set_page_private(oldpage, 0);
 
 	unlock_page(oldpage);
-	page_cache_release(oldpage);
-	page_cache_release(oldpage);
+	put_page(oldpage);
+	put_page(oldpage);
 	return error;
 }
 
@@ -1145,7 +1145,7 @@ static int shmem_getpage_gfp(struct inode *inode, pgoff_t index,
 	int once = 0;
 	int alloced = 0;
 
-	if (index > (MAX_LFS_FILESIZE >> PAGE_CACHE_SHIFT))
+	if (index > (MAX_LFS_FILESIZE >> PAGE_SHIFT))
 		return -EFBIG;
 repeat:
 	swap.val = 0;
@@ -1156,7 +1156,7 @@ repeat:
 	}
 
 	if (sgp != SGP_WRITE && sgp != SGP_FALLOC &&
-	    ((loff_t)index << PAGE_CACHE_SHIFT) >= i_size_read(inode)) {
+	    ((loff_t)index << PAGE_SHIFT) >= i_size_read(inode)) {
 		error = -EINVAL;
 		goto unlock;
 	}
@@ -1169,7 +1169,7 @@ repeat:
 		if (sgp != SGP_READ)
 			goto clear;
 		unlock_page(page);
-		page_cache_release(page);
+		put_page(page);
 		page = NULL;
 	}
 	if (page || (sgp == SGP_READ && !swap.val)) {
@@ -1327,7 +1327,7 @@ clear:
 
 	/* Perhaps the file has been truncated since we checked */
 	if (sgp != SGP_WRITE && sgp != SGP_FALLOC &&
-	    ((loff_t)index << PAGE_CACHE_SHIFT) >= i_size_read(inode)) {
+	    ((loff_t)index << PAGE_SHIFT) >= i_size_read(inode)) {
 		if (alloced) {
 			ClearPageDirty(page);
 			delete_from_page_cache(page);
@@ -1355,7 +1355,7 @@ failed:
 unlock:
 	if (page) {
 		unlock_page(page);
-		page_cache_release(page);
+		put_page(page);
 	}
 	if (error == -ENOSPC && !once++) {
 		info = SHMEM_I(inode);
@@ -1577,7 +1577,7 @@ shmem_write_begin(struct file *file, struct address_space *mapping,
 {
 	struct inode *inode = mapping->host;
 	struct shmem_inode_info *info = SHMEM_I(inode);
-	pgoff_t index = pos >> PAGE_CACHE_SHIFT;
+	pgoff_t index = pos >> PAGE_SHIFT;
 
 	/* i_mutex is held by caller */
 	if (unlikely(info->seals)) {
@@ -1601,16 +1601,16 @@ shmem_write_end(struct file *file, struct address_space *mapping,
 		i_size_write(inode, pos + copied);
 
 	if (!PageUptodate(page)) {
-		if (copied < PAGE_CACHE_SIZE) {
-			unsigned from = pos & (PAGE_CACHE_SIZE - 1);
+		if (copied < PAGE_SIZE) {
+			unsigned from = pos & (PAGE_SIZE - 1);
 			zero_user_segments(page, 0, from,
-					from + copied, PAGE_CACHE_SIZE);
+					from + copied, PAGE_SIZE);
 		}
 		SetPageUptodate(page);
 	}
 	set_page_dirty(page);
 	unlock_page(page);
-	page_cache_release(page);
+	put_page(page);
 
 	return copied;
 }
@@ -1635,8 +1635,8 @@ static ssize_t shmem_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
 	if (!iter_is_iovec(to))
 		sgp = SGP_DIRTY;
 
-	index = *ppos >> PAGE_CACHE_SHIFT;
-	offset = *ppos & ~PAGE_CACHE_MASK;
+	index = *ppos >> PAGE_SHIFT;
+	offset = *ppos & ~PAGE_MASK;
 
 	for (;;) {
 		struct page *page = NULL;
@@ -1644,11 +1644,11 @@ static ssize_t shmem_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
 		unsigned long nr, ret;
 		loff_t i_size = i_size_read(inode);
 
-		end_index = i_size >> PAGE_CACHE_SHIFT;
+		end_index = i_size >> PAGE_SHIFT;
 		if (index > end_index)
 			break;
 		if (index == end_index) {
-			nr = i_size & ~PAGE_CACHE_MASK;
+			nr = i_size & ~PAGE_MASK;
 			if (nr <= offset)
 				break;
 		}
@@ -1666,14 +1666,14 @@ static ssize_t shmem_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
 		 * We must evaluate after, since reads (unlike writes)
 		 * are called without i_mutex protection against truncate
 		 */
-		nr = PAGE_CACHE_SIZE;
+		nr = PAGE_SIZE;
 		i_size = i_size_read(inode);
-		end_index = i_size >> PAGE_CACHE_SHIFT;
+		end_index = i_size >> PAGE_SHIFT;
 		if (index == end_index) {
-			nr = i_size & ~PAGE_CACHE_MASK;
+			nr = i_size & ~PAGE_MASK;
 			if (nr <= offset) {
 				if (page)
-					page_cache_release(page);
+					put_page(page);
 				break;
 			}
 		}
@@ -1694,7 +1694,7 @@ static ssize_t shmem_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
 				mark_page_accessed(page);
 		} else {
 			page = ZERO_PAGE(0);
-			page_cache_get(page);
+			get_page(page);
 		}
 
 		/*
@@ -1704,10 +1704,10 @@ static ssize_t shmem_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
 		ret = copy_page_to_iter(page, offset, nr, to);
 		retval += ret;
 		offset += ret;
-		index += offset >> PAGE_CACHE_SHIFT;
-		offset &= ~PAGE_CACHE_MASK;
+		index += offset >> PAGE_SHIFT;
+		offset &= ~PAGE_MASK;
 
-		page_cache_release(page);
+		put_page(page);
 		if (!iov_iter_count(to))
 			break;
 		if (ret < nr) {
@@ -1717,7 +1717,7 @@ static ssize_t shmem_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
 		cond_resched();
 	}
 
-	*ppos = ((loff_t) index << PAGE_CACHE_SHIFT) + offset;
+	*ppos = ((loff_t) index << PAGE_SHIFT) + offset;
 	file_accessed(file);
 	return retval ? retval : error;
 }
@@ -1755,9 +1755,9 @@ static ssize_t shmem_file_splice_read(struct file *in, loff_t *ppos,
 	if (splice_grow_spd(pipe, &spd))
 		return -ENOMEM;
 
-	index = *ppos >> PAGE_CACHE_SHIFT;
-	loff = *ppos & ~PAGE_CACHE_MASK;
-	req_pages = (len + loff + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+	index = *ppos >> PAGE_SHIFT;
+	loff = *ppos & ~PAGE_MASK;
+	req_pages = (len + loff + PAGE_SIZE - 1) >> PAGE_SHIFT;
 	nr_pages = min(req_pages, spd.nr_pages_max);
 
 	spd.nr_pages = find_get_pages_contig(mapping, index,
@@ -1774,7 +1774,7 @@ static ssize_t shmem_file_splice_read(struct file *in, loff_t *ppos,
 		index++;
 	}
 
-	index = *ppos >> PAGE_CACHE_SHIFT;
+	index = *ppos >> PAGE_SHIFT;
 	nr_pages = spd.nr_pages;
 	spd.nr_pages = 0;
 
@@ -1784,7 +1784,7 @@ static ssize_t shmem_file_splice_read(struct file *in, loff_t *ppos,
 		if (!len)
 			break;
 
-		this_len = min_t(unsigned long, len, PAGE_CACHE_SIZE - loff);
+		this_len = min_t(unsigned long, len, PAGE_SIZE - loff);
 		page = spd.pages[page_nr];
 
 		if (!PageUptodate(page) || page->mapping != mapping) {
@@ -1793,19 +1793,19 @@ static ssize_t shmem_file_splice_read(struct file *in, loff_t *ppos,
 			if (error)
 				break;
 			unlock_page(page);
-			page_cache_release(spd.pages[page_nr]);
+			put_page(spd.pages[page_nr]);
 			spd.pages[page_nr] = page;
 		}
 
 		isize = i_size_read(inode);
-		end_index = (isize - 1) >> PAGE_CACHE_SHIFT;
+		end_index = (isize - 1) >> PAGE_SHIFT;
 		if (unlikely(!isize || index > end_index))
 			break;
 
 		if (end_index == index) {
 			unsigned int plen;
 
-			plen = ((isize - 1) & ~PAGE_CACHE_MASK) + 1;
+			plen = ((isize - 1) & ~PAGE_MASK) + 1;
 			if (plen <= loff)
 				break;
 
@@ -1822,7 +1822,7 @@ static ssize_t shmem_file_splice_read(struct file *in, loff_t *ppos,
 	}
 
 	while (page_nr < nr_pages)
-		page_cache_release(spd.pages[page_nr++]);
+		put_page(spd.pages[page_nr++]);
 
 	if (spd.nr_pages)
 		error = splice_to_pipe(pipe, &spd);
@@ -1904,10 +1904,10 @@ static loff_t shmem_file_llseek(struct file *file, loff_t offset, int whence)
 	else if (offset >= inode->i_size)
 		offset = -ENXIO;
 	else {
-		start = offset >> PAGE_CACHE_SHIFT;
-		end = (inode->i_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+		start = offset >> PAGE_SHIFT;
+		end = (inode->i_size + PAGE_SIZE - 1) >> PAGE_SHIFT;
 		new_offset = shmem_seek_hole_data(mapping, start, end, whence);
-		new_offset <<= PAGE_CACHE_SHIFT;
+		new_offset <<= PAGE_SHIFT;
 		if (new_offset > offset) {
 			if (new_offset < inode->i_size)
 				offset = new_offset;
@@ -2203,8 +2203,8 @@ static long shmem_fallocate(struct file *file, int mode, loff_t offset,
 		goto out;
 	}
 
-	start = offset >> PAGE_CACHE_SHIFT;
-	end = (offset + len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+	start = offset >> PAGE_SHIFT;
+	end = (offset + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
 	/* Try to avoid a swapstorm if len is impossible to satisfy */
 	if (sbinfo->max_blocks && end - start > sbinfo->max_blocks) {
 		error = -ENOSPC;
@@ -2237,8 +2237,8 @@ static long shmem_fallocate(struct file *file, int mode, loff_t offset,
 		if (error) {
 			/* Remove the !PageUptodate pages we added */
 			shmem_undo_range(inode,
-				(loff_t)start << PAGE_CACHE_SHIFT,
-				(loff_t)index << PAGE_CACHE_SHIFT, true);
+				(loff_t)start << PAGE_SHIFT,
+				(loff_t)index << PAGE_SHIFT, true);
 			goto undone;
 		}
 
@@ -2259,7 +2259,7 @@ static long shmem_fallocate(struct file *file, int mode, loff_t offset,
 		 */
 		set_page_dirty(page);
 		unlock_page(page);
-		page_cache_release(page);
+		put_page(page);
 		cond_resched();
 	}
 
@@ -2280,7 +2280,7 @@ static int shmem_statfs(struct dentry *dentry, struct kstatfs *buf)
 	struct shmem_sb_info *sbinfo = SHMEM_SB(dentry->d_sb);
 
 	buf->f_type = TMPFS_MAGIC;
-	buf->f_bsize = PAGE_CACHE_SIZE;
+	buf->f_bsize = PAGE_SIZE;
 	buf->f_namelen = NAME_MAX;
 	if (sbinfo->max_blocks) {
 		buf->f_blocks = sbinfo->max_blocks;
@@ -2523,7 +2523,7 @@ static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *s
 	struct shmem_inode_info *info;
 
 	len = strlen(symname) + 1;
-	if (len > PAGE_CACHE_SIZE)
+	if (len > PAGE_SIZE)
 		return -ENAMETOOLONG;
 
 	inode = shmem_get_inode(dir->i_sb, dir, S_IFLNK|S_IRWXUGO, 0, VM_NORESERVE);
@@ -2562,7 +2562,7 @@ static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *s
 		SetPageUptodate(page);
 		set_page_dirty(page);
 		unlock_page(page);
-		page_cache_release(page);
+		put_page(page);
 	}
 	dir->i_size += BOGO_DIRENT_SIZE;
 	dir->i_ctime = dir->i_mtime = CURRENT_TIME;
@@ -2835,7 +2835,7 @@ static int shmem_parse_options(char *options, struct shmem_sb_info *sbinfo,
 			if (*rest)
 				goto bad_val;
 			sbinfo->max_blocks =
-				DIV_ROUND_UP(size, PAGE_CACHE_SIZE);
+				DIV_ROUND_UP(size, PAGE_SIZE);
 		} else if (!strcmp(this_char,"nr_blocks")) {
 			sbinfo->max_blocks = memparse(value, &rest);
 			if (*rest)
@@ -2940,7 +2940,7 @@ static int shmem_show_options(struct seq_file *seq, struct dentry *root)
 
 	if (sbinfo->max_blocks != shmem_default_max_blocks())
 		seq_printf(seq, ",size=%luk",
-			sbinfo->max_blocks << (PAGE_CACHE_SHIFT - 10));
+			sbinfo->max_blocks << (PAGE_SHIFT - 10));
 	if (sbinfo->max_inodes != shmem_default_max_inodes())
 		seq_printf(seq, ",nr_inodes=%lu", sbinfo->max_inodes);
 	if (sbinfo->mode != (S_IRWXUGO | S_ISVTX))
@@ -3082,8 +3082,8 @@ int shmem_fill_super(struct super_block *sb, void *data, int silent)
 	sbinfo->free_inodes = sbinfo->max_inodes;
 
 	sb->s_maxbytes = MAX_LFS_FILESIZE;
-	sb->s_blocksize = PAGE_CACHE_SIZE;
-	sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
+	sb->s_blocksize = PAGE_SIZE;
+	sb->s_blocksize_bits = PAGE_SHIFT;
 	sb->s_magic = TMPFS_MAGIC;
 	sb->s_op = &shmem_ops;
 	sb->s_time_gran = 1;