Searched hist:fc1b1e135c3f72382f792e6c319fc088d5523ad5 (Results 1 – 4 of 4) sorted by relevance
/openbmc/linux/fs/notify/ |
H A D | fsnotify.h | diff fc1b1e135c3f72382f792e6c319fc088d5523ad5 Sun May 12 06:30:07 CDT 2024 Amir Goldstein <amir73il@gmail.com> fsnotify: clear PARENT_WATCHED flags lazily
[ Upstream commit 172e422ffea20a89bfdc672741c1aad6fbb5044e ]
In some setups directories can have many (usually negative) dentries. Hence __fsnotify_update_child_dentry_flags() function can take a significant amount of time. Since the bulk of this function happens under inode->i_lock this causes a significant contention on the lock when we remove the watch from the directory as the __fsnotify_update_child_dentry_flags() call from fsnotify_recalc_mask() races with __fsnotify_update_child_dentry_flags() calls from __fsnotify_parent() happening on children. This can lead upto softlockup reports reported by users.
Fix the problem by calling fsnotify_update_children_dentry_flags() to set PARENT_WATCHED flags only when parent starts watching children.
When parent stops watching children, clear false positive PARENT_WATCHED flags lazily in __fsnotify_parent() for each accessed child.
Suggested-by: Jan Kara <jack@suse.cz> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Stephen Brennan <stephen.s.brennan@oracle.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Sasha Levin <sashal@kernel.org>
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H A D | mark.c | diff fc1b1e135c3f72382f792e6c319fc088d5523ad5 Sun May 12 06:30:07 CDT 2024 Amir Goldstein <amir73il@gmail.com> fsnotify: clear PARENT_WATCHED flags lazily
[ Upstream commit 172e422ffea20a89bfdc672741c1aad6fbb5044e ]
In some setups directories can have many (usually negative) dentries. Hence __fsnotify_update_child_dentry_flags() function can take a significant amount of time. Since the bulk of this function happens under inode->i_lock this causes a significant contention on the lock when we remove the watch from the directory as the __fsnotify_update_child_dentry_flags() call from fsnotify_recalc_mask() races with __fsnotify_update_child_dentry_flags() calls from __fsnotify_parent() happening on children. This can lead upto softlockup reports reported by users.
Fix the problem by calling fsnotify_update_children_dentry_flags() to set PARENT_WATCHED flags only when parent starts watching children.
When parent stops watching children, clear false positive PARENT_WATCHED flags lazily in __fsnotify_parent() for each accessed child.
Suggested-by: Jan Kara <jack@suse.cz> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Stephen Brennan <stephen.s.brennan@oracle.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Sasha Levin <sashal@kernel.org>
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H A D | fsnotify.c | diff fc1b1e135c3f72382f792e6c319fc088d5523ad5 Sun May 12 06:30:07 CDT 2024 Amir Goldstein <amir73il@gmail.com> fsnotify: clear PARENT_WATCHED flags lazily
[ Upstream commit 172e422ffea20a89bfdc672741c1aad6fbb5044e ]
In some setups directories can have many (usually negative) dentries. Hence __fsnotify_update_child_dentry_flags() function can take a significant amount of time. Since the bulk of this function happens under inode->i_lock this causes a significant contention on the lock when we remove the watch from the directory as the __fsnotify_update_child_dentry_flags() call from fsnotify_recalc_mask() races with __fsnotify_update_child_dentry_flags() calls from __fsnotify_parent() happening on children. This can lead upto softlockup reports reported by users.
Fix the problem by calling fsnotify_update_children_dentry_flags() to set PARENT_WATCHED flags only when parent starts watching children.
When parent stops watching children, clear false positive PARENT_WATCHED flags lazily in __fsnotify_parent() for each accessed child.
Suggested-by: Jan Kara <jack@suse.cz> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Stephen Brennan <stephen.s.brennan@oracle.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Sasha Levin <sashal@kernel.org>
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/openbmc/linux/include/linux/ |
H A D | fsnotify_backend.h | diff fc1b1e135c3f72382f792e6c319fc088d5523ad5 Sun May 12 06:30:07 CDT 2024 Amir Goldstein <amir73il@gmail.com> fsnotify: clear PARENT_WATCHED flags lazily
[ Upstream commit 172e422ffea20a89bfdc672741c1aad6fbb5044e ]
In some setups directories can have many (usually negative) dentries. Hence __fsnotify_update_child_dentry_flags() function can take a significant amount of time. Since the bulk of this function happens under inode->i_lock this causes a significant contention on the lock when we remove the watch from the directory as the __fsnotify_update_child_dentry_flags() call from fsnotify_recalc_mask() races with __fsnotify_update_child_dentry_flags() calls from __fsnotify_parent() happening on children. This can lead upto softlockup reports reported by users.
Fix the problem by calling fsnotify_update_children_dentry_flags() to set PARENT_WATCHED flags only when parent starts watching children.
When parent stops watching children, clear false positive PARENT_WATCHED flags lazily in __fsnotify_parent() for each accessed child.
Suggested-by: Jan Kara <jack@suse.cz> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Stephen Brennan <stephen.s.brennan@oracle.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Sasha Levin <sashal@kernel.org>
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