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| author | Al Viro <viro@zeniv.linux.org.uk> | 2015-11-17 01:07:57 -0500 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2015-12-08 22:41:36 -0500 |
| commit | 21fc61c73c3903c4c312d0802da01ec2b323d174 (patch) | |
| tree | a26c29e3fbb766f00b023724e9e5b8b9bba9b879 /fs/namei.c | |
| parent | aa80deab33a8fb180e718f5e45514db19aade165 (diff) | |
| download | linux-21fc61c73c3903c4c312d0802da01ec2b323d174.tar.bz2 | |
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 <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/namei.c')
| -rw-r--r-- | fs/namei.c | 9 |
1 files changed, 3 insertions, 6 deletions
diff --git a/fs/namei.c b/fs/namei.c index 4bae5cbfaa85..2808958e6c67 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -4527,7 +4527,8 @@ static const char *page_getlink(struct dentry * dentry, void **cookie) if (IS_ERR(page)) return (char*)page; *cookie = page; - kaddr = kmap(page); + BUG_ON(mapping_gfp_mask(mapping) & __GFP_HIGHMEM); + kaddr = page_address(page); nd_terminate_link(kaddr, dentry->d_inode->i_size, PAGE_SIZE - 1); return kaddr; } @@ -4541,7 +4542,6 @@ EXPORT_SYMBOL(page_follow_link_light); void page_put_link(struct inode *unused, void *cookie) { struct page *page = cookie; - kunmap(page); page_cache_release(page); } EXPORT_SYMBOL(page_put_link); @@ -4565,7 +4565,6 @@ int __page_symlink(struct inode *inode, const char *symname, int len, int nofs) struct page *page; void *fsdata; int err; - char *kaddr; unsigned int flags = AOP_FLAG_UNINTERRUPTIBLE; if (nofs) flags |= AOP_FLAG_NOFS; @@ -4576,9 +4575,7 @@ retry: if (err) goto fail; - kaddr = kmap_atomic(page); - memcpy(kaddr, symname, len-1); - kunmap_atomic(kaddr); + memcpy(page_address(page), symname, len-1); err = pagecache_write_end(NULL, mapping, 0, len-1, len-1, page, fsdata); |