Commit faab35a0 authored by Luis Henriques (SUSE)'s avatar Luis Henriques (SUSE) Committed by Theodore Ts'o
Browse files

ext4: use handle to mark fc as ineligible in __track_dentry_update() 



Calling ext4_fc_mark_ineligible() with a NULL handle is racy and may result
in a fast-commit being done before the filesystem is effectively marked as
ineligible.  This patch fixes the calls to this function in
__track_dentry_update() by adding an extra parameter to the callback used in
ext4_fc_track_template().

Suggested-by: default avatarJan Kara <jack@suse.cz>
Signed-off-by: default avatarLuis Henriques (SUSE) <luis.henriques@linux.dev>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20240923104909.18342-2-luis.henriques@linux.dev


Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
parent 9852d85e

fs/ext4/fast_commit.c

+11 −8
Original line number Diff line number Diff line
@@ -379,7 +379,7 @@ void ext4_fc_mark_ineligible(struct super_block *sb, int reason, handle_t *handl 
 */

static int ext4_fc_track_template(

	handle_t *handle, struct inode *inode,

	int (*__fc_track_fn)(struct inode *, void *, bool),

	int (*__fc_track_fn)(handle_t *handle, struct inode *, void *, bool),

	void *args, int enqueue)

{

	bool update = false;
@@ -396,7 +396,7 @@ static int ext4_fc_track_template( 
		ext4_fc_reset_inode(inode);

		ei->i_sync_tid = tid;

	}

	ret = __fc_track_fn(inode, args, update);

	ret = __fc_track_fn(handle, inode, args, update);

	mutex_unlock(&ei->i_fc_lock);



	if (!enqueue)
@@ -420,7 +420,8 @@ struct __track_dentry_update_args { 
};



/* __track_fn for directory entry updates. Called with ei->i_fc_lock. */

static int __track_dentry_update(struct inode *inode, void *arg, bool update)

static int __track_dentry_update(handle_t *handle, struct inode *inode,

				 void *arg, bool update)

{

	struct ext4_fc_dentry_update *node;

	struct ext4_inode_info *ei = EXT4_I(inode);
@@ -435,14 +436,14 @@ static int __track_dentry_update(struct inode *inode, void *arg, bool update) 


	if (IS_ENCRYPTED(dir)) {

		ext4_fc_mark_ineligible(sb, EXT4_FC_REASON_ENCRYPTED_FILENAME,

					NULL);

					handle);

		mutex_lock(&ei->i_fc_lock);

		return -EOPNOTSUPP;

	}



	node = kmem_cache_alloc(ext4_fc_dentry_cachep, GFP_NOFS);

	if (!node) {

		ext4_fc_mark_ineligible(sb, EXT4_FC_REASON_NOMEM, NULL);

		ext4_fc_mark_ineligible(sb, EXT4_FC_REASON_NOMEM, handle);

		mutex_lock(&ei->i_fc_lock);

		return -ENOMEM;

	}
@@ -454,7 +455,7 @@ static int __track_dentry_update(struct inode *inode, void *arg, bool update) 
		node->fcd_name.name = kmalloc(dentry->d_name.len, GFP_NOFS);

		if (!node->fcd_name.name) {

			kmem_cache_free(ext4_fc_dentry_cachep, node);

			ext4_fc_mark_ineligible(sb, EXT4_FC_REASON_NOMEM, NULL);

			ext4_fc_mark_ineligible(sb, EXT4_FC_REASON_NOMEM, handle);

			mutex_lock(&ei->i_fc_lock);

			return -ENOMEM;

		}
@@ -576,7 +577,8 @@ void ext4_fc_track_create(handle_t *handle, struct dentry *dentry) 
}



/* __track_fn for inode tracking */

static int __track_inode(struct inode *inode, void *arg, bool update)

static int __track_inode(handle_t *handle, struct inode *inode, void *arg,

			 bool update)

{

	if (update)

		return -EEXIST;
@@ -614,7 +616,8 @@ struct __track_range_args { 
};



/* __track_fn for tracking data updates */

static int __track_range(struct inode *inode, void *arg, bool update)

static int __track_range(handle_t *handle, struct inode *inode, void *arg,

			 bool update)

{

	struct ext4_inode_info *ei = EXT4_I(inode);

	ext4_lblk_t oldstart;