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author | Nicolai Stange <nicstange@gmail.com> | 2017-10-31 00:15:52 +0100 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-11-07 20:25:02 +0100 |
commit | c9afbec27089cd6b4e621b639f41c7fc726c3bf1 (patch) | |
tree | bb66d582f6668101cdbca5e6a3592f2398271443 /fs/debugfs | |
parent | IB/hfi1: convert to debugfs_file_get() and -put() (diff) | |
download | linux-c9afbec27089cd6b4e621b639f41c7fc726c3bf1.tar.xz linux-c9afbec27089cd6b4e621b639f41c7fc726c3bf1.zip |
debugfs: purge obsolete SRCU based removal protection
Purge the SRCU based file removal race protection in favour of the new,
refcount based debugfs_file_get()/debugfs_file_put() API.
Fixes: 49d200deaa68 ("debugfs: prevent access to removed files' private data")
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/debugfs')
-rw-r--r-- | fs/debugfs/file.c | 48 | ||||
-rw-r--r-- | fs/debugfs/inode.c | 7 |
2 files changed, 0 insertions, 55 deletions
diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c index d3a972b45ff0..53f5c9a2af88 100644 --- a/fs/debugfs/file.c +++ b/fs/debugfs/file.c @@ -22,7 +22,6 @@ #include <linux/slab.h> #include <linux/atomic.h> #include <linux/device.h> -#include <linux/srcu.h> #include <asm/poll.h> #include "internal.h" @@ -48,53 +47,6 @@ const struct file_operations debugfs_noop_file_operations = { .llseek = noop_llseek, }; -/** - * debugfs_use_file_start - mark the beginning of file data access - * @dentry: the dentry object whose data is being accessed. - * @srcu_idx: a pointer to some memory to store a SRCU index in. - * - * Up to a matching call to debugfs_use_file_finish(), any - * successive call into the file removing functions debugfs_remove() - * and debugfs_remove_recursive() will block. Since associated private - * file data may only get freed after a successful return of any of - * the removal functions, you may safely access it after a successful - * call to debugfs_use_file_start() without worrying about - * lifetime issues. - * - * If -%EIO is returned, the file has already been removed and thus, - * it is not safe to access any of its data. If, on the other hand, - * it is allowed to access the file data, zero is returned. - * - * Regardless of the return code, any call to - * debugfs_use_file_start() must be followed by a matching call - * to debugfs_use_file_finish(). - */ -int debugfs_use_file_start(const struct dentry *dentry, int *srcu_idx) - __acquires(&debugfs_srcu) -{ - *srcu_idx = srcu_read_lock(&debugfs_srcu); - barrier(); - if (d_unlinked(dentry)) - return -EIO; - return 0; -} -EXPORT_SYMBOL_GPL(debugfs_use_file_start); - -/** - * debugfs_use_file_finish - mark the end of file data access - * @srcu_idx: the SRCU index "created" by a former call to - * debugfs_use_file_start(). - * - * Allow any ongoing concurrent call into debugfs_remove() or - * debugfs_remove_recursive() blocked by a former call to - * debugfs_use_file_start() to proceed and return to its caller. - */ -void debugfs_use_file_finish(int srcu_idx) __releases(&debugfs_srcu) -{ - srcu_read_unlock(&debugfs_srcu, srcu_idx); -} -EXPORT_SYMBOL_GPL(debugfs_use_file_finish); - #define F_DENTRY(filp) ((filp)->f_path.dentry) const struct file_operations *debugfs_real_fops(const struct file *filp) diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c index 6449eb935540..f587aded46b5 100644 --- a/fs/debugfs/inode.c +++ b/fs/debugfs/inode.c @@ -27,14 +27,11 @@ #include <linux/parser.h> #include <linux/magic.h> #include <linux/slab.h> -#include <linux/srcu.h> #include "internal.h" #define DEBUGFS_DEFAULT_MODE 0700 -DEFINE_SRCU(debugfs_srcu); - static struct vfsmount *debugfs_mount; static int debugfs_mount_count; static bool debugfs_registered; @@ -693,8 +690,6 @@ void debugfs_remove(struct dentry *dentry) inode_unlock(d_inode(parent)); if (!ret) simple_release_fs(&debugfs_mount, &debugfs_mount_count); - - synchronize_srcu(&debugfs_srcu); } EXPORT_SYMBOL_GPL(debugfs_remove); @@ -768,8 +763,6 @@ void debugfs_remove_recursive(struct dentry *dentry) if (!__debugfs_remove(child, parent)) simple_release_fs(&debugfs_mount, &debugfs_mount_count); inode_unlock(d_inode(parent)); - - synchronize_srcu(&debugfs_srcu); } EXPORT_SYMBOL_GPL(debugfs_remove_recursive); |