diff options
author | Nick Piggin <npiggin@suse.de> | 2009-01-04 21:00:53 +0100 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-01-04 22:33:20 +0100 |
commit | 54566b2c1594c2326a645a3551f9d989f7ba3c5e (patch) | |
tree | b373f3283fe5e197d0df29cd6b645c35adf1076c /fs | |
parent | viafb: fix crashes due to 4k stack overflow (diff) | |
download | linux-54566b2c1594c2326a645a3551f9d989f7ba3c5e.tar.xz linux-54566b2c1594c2326a645a3551f9d989f7ba3c5e.zip |
fs: symlink write_begin allocation context fix
With the write_begin/write_end aops, page_symlink was broken because it
could no longer pass a GFP_NOFS type mask into the point where the
allocations happened. They are done in write_begin, which would always
assume that the filesystem can be entered from reclaim. This bug could
cause filesystem deadlocks.
The funny thing with having a gfp_t mask there is that it doesn't really
allow the caller to arbitrarily tinker with the context in which it can be
called. It couldn't ever be GFP_ATOMIC, for example, because it needs to
take the page lock. The only thing any callers care about is __GFP_FS
anyway, so turn that into a single flag.
Add a new flag for write_begin, AOP_FLAG_NOFS. Filesystems can now act on
this flag in their write_begin function. Change __grab_cache_page to
accept a nofs argument as well, to honour that flag (while we're there,
change the name to grab_cache_page_write_begin which is more instructive
and does away with random leading underscores).
This is really a more flexible way to go in the end anyway -- if a
filesystem happens to want any extra allocations aside from the pagecache
ones in ints write_begin function, it may now use GFP_KERNEL (rather than
GFP_NOFS) for common case allocations (eg. ocfs2_alloc_write_ctxt, for a
random example).
[kosaki.motohiro@jp.fujitsu.com: fix ubifs]
[kosaki.motohiro@jp.fujitsu.com: fix fuse]
Signed-off-by: Nick Piggin <npiggin@suse.de>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: <stable@kernel.org> [2.6.28.x]
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[ Cleaned up the calling convention: just pass in the AOP flags
untouched to the grab_cache_page_write_begin() function. That
just simplifies everybody, and may even allow future expansion of the
logic. - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs')
-rw-r--r-- | fs/affs/file.c | 2 | ||||
-rw-r--r-- | fs/afs/write.c | 2 | ||||
-rw-r--r-- | fs/buffer.c | 4 | ||||
-rw-r--r-- | fs/cifs/file.c | 2 | ||||
-rw-r--r-- | fs/ecryptfs/mmap.c | 2 | ||||
-rw-r--r-- | fs/ext3/inode.c | 2 | ||||
-rw-r--r-- | fs/ext3/namei.c | 3 | ||||
-rw-r--r-- | fs/ext4/inode.c | 4 | ||||
-rw-r--r-- | fs/ext4/namei.c | 3 | ||||
-rw-r--r-- | fs/fuse/file.c | 4 | ||||
-rw-r--r-- | fs/gfs2/ops_address.c | 2 | ||||
-rw-r--r-- | fs/hostfs/hostfs_kern.c | 2 | ||||
-rw-r--r-- | fs/jffs2/file.c | 2 | ||||
-rw-r--r-- | fs/libfs.c | 2 | ||||
-rw-r--r-- | fs/namei.c | 13 | ||||
-rw-r--r-- | fs/nfs/file.c | 2 | ||||
-rw-r--r-- | fs/reiserfs/inode.c | 2 | ||||
-rw-r--r-- | fs/smbfs/file.c | 2 | ||||
-rw-r--r-- | fs/ubifs/file.c | 9 |
19 files changed, 34 insertions, 30 deletions
diff --git a/fs/affs/file.c b/fs/affs/file.c index 1377b1240b6e..9246cb4aa018 100644 --- a/fs/affs/file.c +++ b/fs/affs/file.c @@ -628,7 +628,7 @@ static int affs_write_begin_ofs(struct file *file, struct address_space *mapping } index = pos >> PAGE_CACHE_SHIFT; - page = __grab_cache_page(mapping, index); + page = grab_cache_page_write_begin(mapping, index, flags); if (!page) return -ENOMEM; *pagep = page; diff --git a/fs/afs/write.c b/fs/afs/write.c index d6b85dab35fc..3fb36d433621 100644 --- a/fs/afs/write.c +++ b/fs/afs/write.c @@ -144,7 +144,7 @@ int afs_write_begin(struct file *file, struct address_space *mapping, candidate->state = AFS_WBACK_PENDING; init_waitqueue_head(&candidate->waitq); - page = __grab_cache_page(mapping, index); + page = grab_cache_page_write_begin(mapping, index, flags); if (!page) { kfree(candidate); return -ENOMEM; diff --git a/fs/buffer.c b/fs/buffer.c index 776ae091d3b0..a13f09b696f7 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -1996,7 +1996,7 @@ int block_write_begin(struct file *file, struct address_space *mapping, page = *pagep; if (page == NULL) { ownpage = 1; - page = __grab_cache_page(mapping, index); + page = grab_cache_page_write_begin(mapping, index, flags); if (!page) { status = -ENOMEM; goto out; @@ -2502,7 +2502,7 @@ int nobh_write_begin(struct file *file, struct address_space *mapping, from = pos & (PAGE_CACHE_SIZE - 1); to = from + len; - page = __grab_cache_page(mapping, index); + page = grab_cache_page_write_begin(mapping, index, flags); if (!page) return -ENOMEM; *pagep = page; diff --git a/fs/cifs/file.c b/fs/cifs/file.c index b1e1fc6a6e6a..12bb656fbe75 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -2074,7 +2074,7 @@ static int cifs_write_begin(struct file *file, struct address_space *mapping, cFYI(1, ("write_begin from %lld len %d", (long long)pos, len)); - page = __grab_cache_page(mapping, index); + page = grab_cache_page_write_begin(mapping, index, flags); if (!page) { rc = -ENOMEM; goto out; diff --git a/fs/ecryptfs/mmap.c b/fs/ecryptfs/mmap.c index 04d7b3fa1ac6..46cec2b69796 100644 --- a/fs/ecryptfs/mmap.c +++ b/fs/ecryptfs/mmap.c @@ -288,7 +288,7 @@ static int ecryptfs_write_begin(struct file *file, loff_t prev_page_end_size; int rc = 0; - page = __grab_cache_page(mapping, index); + page = grab_cache_page_write_begin(mapping, index, flags); if (!page) return -ENOMEM; *pagep = page; diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c index c4bdccf976b5..5fa453b49a64 100644 --- a/fs/ext3/inode.c +++ b/fs/ext3/inode.c @@ -1161,7 +1161,7 @@ static int ext3_write_begin(struct file *file, struct address_space *mapping, to = from + len; retry: - page = __grab_cache_page(mapping, index); + page = grab_cache_page_write_begin(mapping, index, flags); if (!page) return -ENOMEM; *pagep = page; diff --git a/fs/ext3/namei.c b/fs/ext3/namei.c index 297ea8dfac7c..1dd2abe6313e 100644 --- a/fs/ext3/namei.c +++ b/fs/ext3/namei.c @@ -2175,8 +2175,7 @@ retry: * We have a transaction open. All is sweetness. It also sets * i_size in generic_commit_write(). */ - err = __page_symlink(inode, symname, l, - mapping_gfp_mask(inode->i_mapping) & ~__GFP_FS); + err = __page_symlink(inode, symname, l, 1); if (err) { drop_nlink(inode); unlock_new_inode(inode); diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 7c3325e0b005..6702a49992a6 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -1346,7 +1346,7 @@ retry: goto out; } - page = __grab_cache_page(mapping, index); + page = grab_cache_page_write_begin(mapping, index, flags); if (!page) { ext4_journal_stop(handle); ret = -ENOMEM; @@ -2550,7 +2550,7 @@ retry: goto out; } - page = __grab_cache_page(mapping, index); + page = grab_cache_page_write_begin(mapping, index, flags); if (!page) { ext4_journal_stop(handle); ret = -ENOMEM; diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index da98a9012fa5..9fd2a5e1be4d 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -2212,8 +2212,7 @@ retry: * We have a transaction open. All is sweetness. It also sets * i_size in generic_commit_write(). */ - err = __page_symlink(inode, symname, l, - mapping_gfp_mask(inode->i_mapping) & ~__GFP_FS); + err = __page_symlink(inode, symname, l, 1); if (err) { clear_nlink(inode); unlock_new_inode(inode); diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 34930a964b82..4c9ee7011265 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -646,7 +646,7 @@ static int fuse_write_begin(struct file *file, struct address_space *mapping, { pgoff_t index = pos >> PAGE_CACHE_SHIFT; - *pagep = __grab_cache_page(mapping, index); + *pagep = grab_cache_page_write_begin(mapping, index, flags); if (!*pagep) return -ENOMEM; return 0; @@ -779,7 +779,7 @@ static ssize_t fuse_fill_write_pages(struct fuse_req *req, break; err = -ENOMEM; - page = __grab_cache_page(mapping, index); + page = grab_cache_page_write_begin(mapping, index, 0); if (!page) break; diff --git a/fs/gfs2/ops_address.c b/fs/gfs2/ops_address.c index 27563816e1c5..15f710f2d4da 100644 --- a/fs/gfs2/ops_address.c +++ b/fs/gfs2/ops_address.c @@ -675,7 +675,7 @@ static int gfs2_write_begin(struct file *file, struct address_space *mapping, goto out_trans_fail; error = -ENOMEM; - page = __grab_cache_page(mapping, index); + page = grab_cache_page_write_begin(mapping, index, flags); *pagep = page; if (unlikely(!page)) goto out_endtrans; diff --git a/fs/hostfs/hostfs_kern.c b/fs/hostfs/hostfs_kern.c index 3a31451ac170..5c538e0ec14b 100644 --- a/fs/hostfs/hostfs_kern.c +++ b/fs/hostfs/hostfs_kern.c @@ -501,7 +501,7 @@ int hostfs_write_begin(struct file *file, struct address_space *mapping, { pgoff_t index = pos >> PAGE_CACHE_SHIFT; - *pagep = __grab_cache_page(mapping, index); + *pagep = grab_cache_page_write_begin(mapping, index, flags); if (!*pagep) return -ENOMEM; return 0; diff --git a/fs/jffs2/file.c b/fs/jffs2/file.c index 5a98aa87c853..5edc2bf20581 100644 --- a/fs/jffs2/file.c +++ b/fs/jffs2/file.c @@ -132,7 +132,7 @@ static int jffs2_write_begin(struct file *filp, struct address_space *mapping, uint32_t pageofs = index << PAGE_CACHE_SHIFT; int ret = 0; - pg = __grab_cache_page(mapping, index); + pg = grab_cache_page_write_begin(mapping, index, flags); if (!pg) return -ENOMEM; *pagep = pg; diff --git a/fs/libfs.c b/fs/libfs.c index e960a8321902..bdaec17fa388 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -360,7 +360,7 @@ int simple_write_begin(struct file *file, struct address_space *mapping, index = pos >> PAGE_CACHE_SHIFT; from = pos & (PAGE_CACHE_SIZE - 1); - page = __grab_cache_page(mapping, index); + page = grab_cache_page_write_begin(mapping, index, flags); if (!page) return -ENOMEM; diff --git a/fs/namei.c b/fs/namei.c index dd5c9f0bf829..df2d3df4f049 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -2817,18 +2817,23 @@ void page_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie) } } -int __page_symlink(struct inode *inode, const char *symname, int len, - gfp_t gfp_mask) +/* + * The nofs argument instructs pagecache_write_begin to pass AOP_FLAG_NOFS + */ +int __page_symlink(struct inode *inode, const char *symname, int len, int nofs) { struct address_space *mapping = inode->i_mapping; struct page *page; void *fsdata; int err; char *kaddr; + unsigned int flags = AOP_FLAG_UNINTERRUPTIBLE; + if (nofs) + flags |= AOP_FLAG_NOFS; retry: err = pagecache_write_begin(NULL, mapping, 0, len-1, - AOP_FLAG_UNINTERRUPTIBLE, &page, &fsdata); + flags, &page, &fsdata); if (err) goto fail; @@ -2852,7 +2857,7 @@ fail: int page_symlink(struct inode *inode, const char *symname, int len) { return __page_symlink(inode, symname, len, - mapping_gfp_mask(inode->i_mapping)); + !(mapping_gfp_mask(inode->i_mapping) & __GFP_FS)); } const struct inode_operations page_symlink_inode_operations = { diff --git a/fs/nfs/file.c b/fs/nfs/file.c index d319b49f8f06..90f292b520d2 100644 --- a/fs/nfs/file.c +++ b/fs/nfs/file.c @@ -354,7 +354,7 @@ static int nfs_write_begin(struct file *file, struct address_space *mapping, file->f_path.dentry->d_name.name, mapping->host->i_ino, len, (long long) pos); - page = __grab_cache_page(mapping, index); + page = grab_cache_page_write_begin(mapping, index, flags); if (!page) return -ENOMEM; *pagep = page; diff --git a/fs/reiserfs/inode.c b/fs/reiserfs/inode.c index 145c2d3e5e01..ed04f47007f8 100644 --- a/fs/reiserfs/inode.c +++ b/fs/reiserfs/inode.c @@ -2561,7 +2561,7 @@ static int reiserfs_write_begin(struct file *file, } index = pos >> PAGE_CACHE_SHIFT; - page = __grab_cache_page(mapping, index); + page = grab_cache_page_write_begin(mapping, index, flags); if (!page) return -ENOMEM; *pagep = page; diff --git a/fs/smbfs/file.c b/fs/smbfs/file.c index e4f8d51a5553..92d5e8ffb639 100644 --- a/fs/smbfs/file.c +++ b/fs/smbfs/file.c @@ -297,7 +297,7 @@ static int smb_write_begin(struct file *file, struct address_space *mapping, struct page **pagep, void **fsdata) { pgoff_t index = pos >> PAGE_CACHE_SHIFT; - *pagep = __grab_cache_page(mapping, index); + *pagep = grab_cache_page_write_begin(mapping, index, flags); if (!*pagep) return -ENOMEM; return 0; diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c index fe82d2464d46..bf37374567fa 100644 --- a/fs/ubifs/file.c +++ b/fs/ubifs/file.c @@ -219,7 +219,8 @@ static void release_existing_page_budget(struct ubifs_info *c) } static int write_begin_slow(struct address_space *mapping, - loff_t pos, unsigned len, struct page **pagep) + loff_t pos, unsigned len, struct page **pagep, + unsigned flags) { struct inode *inode = mapping->host; struct ubifs_info *c = inode->i_sb->s_fs_info; @@ -247,7 +248,7 @@ static int write_begin_slow(struct address_space *mapping, if (unlikely(err)) return err; - page = __grab_cache_page(mapping, index); + page = grab_cache_page_write_begin(mapping, index, flags); if (unlikely(!page)) { ubifs_release_budget(c, &req); return -ENOMEM; @@ -438,7 +439,7 @@ static int ubifs_write_begin(struct file *file, struct address_space *mapping, return -EROFS; /* Try out the fast-path part first */ - page = __grab_cache_page(mapping, index); + page = grab_cache_page_write_begin(mapping, index, flags); if (unlikely(!page)) return -ENOMEM; @@ -483,7 +484,7 @@ static int ubifs_write_begin(struct file *file, struct address_space *mapping, unlock_page(page); page_cache_release(page); - return write_begin_slow(mapping, pos, len, pagep); + return write_begin_slow(mapping, pos, len, pagep, flags); } /* |