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authorLinus Torvalds <torvalds@linux-foundation.org>2016-01-11 13:13:23 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2016-01-11 13:13:23 -0800
commit32fb378437a1d716e72a442237d7ead1f435ecf0 (patch)
tree411b25023d4df908fb8ca4517185d49c37c51e10 /mm/shmem.c
parent19ccb28e296d5afa299db1003d37e5d37994d46e (diff)
parentfceef393a538134f03b778c5d2519e670269342f (diff)
downloadop-kernel-dev-32fb378437a1d716e72a442237d7ead1f435ecf0.zip
op-kernel-dev-32fb378437a1d716e72a442237d7ead1f435ecf0.tar.gz
Merge branch 'work.symlinks' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs RCU symlink updates from Al Viro: "Replacement of ->follow_link/->put_link, allowing to stay in RCU mode even if the symlink is not an embedded one. No changes since the mailbomb on Jan 1" * 'work.symlinks' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: switch ->get_link() to delayed_call, kill ->put_link() kill free_page_put_link() teach nfs_get_link() to work in RCU mode teach proc_self_get_link()/proc_thread_self_get_link() to work in RCU mode teach shmem_get_link() to work in RCU mode teach page_get_link() to work in RCU mode replace ->follow_link() with new method that could stay in RCU mode don't put symlink bodies in pagecache into highmem namei: page_getlink() and page_follow_link_light() are the same thing ufs: get rid of ->setattr() for symlinks udf: don't duplicate page_symlink_inode_operations logfs: don't duplicate page_symlink_inode_operations switch befs long symlinks to page_symlink_operations
Diffstat (limited to 'mm/shmem.c')
-rw-r--r--mm/shmem.c48
1 files changed, 28 insertions, 20 deletions
diff --git a/mm/shmem.c b/mm/shmem.c
index 2afcdbb..d00c92f 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2438,7 +2438,6 @@ static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *s
int len;
struct inode *inode;
struct page *page;
- char *kaddr;
struct shmem_inode_info *info;
len = strlen(symname) + 1;
@@ -2477,9 +2476,8 @@ static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *s
}
inode->i_mapping->a_ops = &shmem_aops;
inode->i_op = &shmem_symlink_inode_operations;
- kaddr = kmap_atomic(page);
- memcpy(kaddr, symname, len);
- kunmap_atomic(kaddr);
+ inode_nohighmem(inode);
+ memcpy(page_address(page), symname, len);
SetPageUptodate(page);
set_page_dirty(page);
unlock_page(page);
@@ -2492,23 +2490,34 @@ static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *s
return 0;
}
-static const char *shmem_follow_link(struct dentry *dentry, void **cookie)
+static void shmem_put_link(void *arg)
{
- struct page *page = NULL;
- int error = shmem_getpage(d_inode(dentry), 0, &page, SGP_READ, NULL);
- if (error)
- return ERR_PTR(error);
- unlock_page(page);
- *cookie = page;
- return kmap(page);
+ mark_page_accessed(arg);
+ put_page(arg);
}
-static void shmem_put_link(struct inode *unused, void *cookie)
+static const char *shmem_get_link(struct dentry *dentry,
+ struct inode *inode,
+ struct delayed_call *done)
{
- struct page *page = cookie;
- kunmap(page);
- mark_page_accessed(page);
- page_cache_release(page);
+ struct page *page = NULL;
+ int error;
+ if (!dentry) {
+ page = find_get_page(inode->i_mapping, 0);
+ if (!page)
+ return ERR_PTR(-ECHILD);
+ if (!PageUptodate(page)) {
+ put_page(page);
+ return ERR_PTR(-ECHILD);
+ }
+ } else {
+ error = shmem_getpage(inode, 0, &page, SGP_READ, NULL);
+ if (error)
+ return ERR_PTR(error);
+ unlock_page(page);
+ }
+ set_delayed_call(done, shmem_put_link, page);
+ return page_address(page);
}
#ifdef CONFIG_TMPFS_XATTR
@@ -2653,7 +2662,7 @@ static ssize_t shmem_listxattr(struct dentry *dentry, char *buffer, size_t size)
static const struct inode_operations shmem_short_symlink_operations = {
.readlink = generic_readlink,
- .follow_link = simple_follow_link,
+ .get_link = simple_get_link,
#ifdef CONFIG_TMPFS_XATTR
.setxattr = shmem_setxattr,
.getxattr = shmem_getxattr,
@@ -2664,8 +2673,7 @@ static const struct inode_operations shmem_short_symlink_operations = {
static const struct inode_operations shmem_symlink_inode_operations = {
.readlink = generic_readlink,
- .follow_link = shmem_follow_link,
- .put_link = shmem_put_link,
+ .get_link = shmem_get_link,
#ifdef CONFIG_TMPFS_XATTR
.setxattr = shmem_setxattr,
.getxattr = shmem_getxattr,
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