From 21fc61c73c3903c4c312d0802da01ec2b323d174 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 17 Nov 2015 01:07:57 -0500 Subject: don't put symlink bodies in pagecache into highmem kmap() in page_follow_link_light() needed to go - allowing to hold an arbitrary number of kmaps for long is a great way to deadlocking the system. new helper (inode_nohighmem(inode)) needs to be used for pagecache symlinks inodes; done for all in-tree cases. page_follow_link_light() instrumented to yell about anything missed. Signed-off-by: Al Viro --- fs/nilfs2/namei.c | 1 + 1 file changed, 1 insertion(+) (limited to 'fs/nilfs2/namei.c') diff --git a/fs/nilfs2/namei.c b/fs/nilfs2/namei.c index c9a1a491aa91..90b3ba960b9b 100644 --- a/fs/nilfs2/namei.c +++ b/fs/nilfs2/namei.c @@ -161,6 +161,7 @@ static int nilfs_symlink(struct inode *dir, struct dentry *dentry, /* slow symlink */ inode->i_op = &nilfs_symlink_inode_operations; + inode_nohighmem(inode); inode->i_mapping->a_ops = &nilfs_aops; err = page_symlink(inode, symname, l); if (err) -- cgit v1.2.1 From 6b2553918d8b4e6de9853fd6315bec7271a2e592 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 17 Nov 2015 10:20:54 -0500 Subject: replace ->follow_link() with new method that could stay in RCU mode new method: ->get_link(); replacement of ->follow_link(). The differences are: * inode and dentry are passed separately * might be called both in RCU and non-RCU mode; the former is indicated by passing it a NULL dentry. * when called that way it isn't allowed to block and should return ERR_PTR(-ECHILD) if it needs to be called in non-RCU mode. It's a flagday change - the old method is gone, all in-tree instances converted. Conversion isn't hard; said that, so far very few instances do not immediately bail out when called in RCU mode. That'll change in the next commits. Signed-off-by: Al Viro --- fs/nilfs2/namei.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/nilfs2/namei.c') diff --git a/fs/nilfs2/namei.c b/fs/nilfs2/namei.c index 90b3ba960b9b..63dddb7d4b18 100644 --- a/fs/nilfs2/namei.c +++ b/fs/nilfs2/namei.c @@ -569,7 +569,7 @@ const struct inode_operations nilfs_special_inode_operations = { const struct inode_operations nilfs_symlink_inode_operations = { .readlink = generic_readlink, - .follow_link = page_follow_link_light, + .get_link = page_get_link, .put_link = page_put_link, .permission = nilfs_permission, }; -- cgit v1.2.1 From fceef393a538134f03b778c5d2519e670269342f Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 29 Dec 2015 15:58:39 -0500 Subject: switch ->get_link() to delayed_call, kill ->put_link() Signed-off-by: Al Viro --- fs/nilfs2/namei.c | 1 - 1 file changed, 1 deletion(-) (limited to 'fs/nilfs2/namei.c') diff --git a/fs/nilfs2/namei.c b/fs/nilfs2/namei.c index 63dddb7d4b18..7ccdb961eea9 100644 --- a/fs/nilfs2/namei.c +++ b/fs/nilfs2/namei.c @@ -570,7 +570,6 @@ const struct inode_operations nilfs_special_inode_operations = { const struct inode_operations nilfs_symlink_inode_operations = { .readlink = generic_readlink, .get_link = page_get_link, - .put_link = page_put_link, .permission = nilfs_permission, }; -- cgit v1.2.1