From 4f01fdec5bed5abd43cdb9823baca30d55cf01f6 Mon Sep 17 00:00:00 2001 From: Salvatore Bonaccorso Date: Mon, 4 Dec 2017 11:16:30 +0100 Subject: [PATCH 2/2] locks: __break_lease cleanup in preparation of allowing direct removal of leases Closes: #883217 --- ...ak_lease-cleanup-in-preparation-of-allowi.patch | 130 +++++++++++++++++++++ debian/patches/series | 1 + 2 files changed, 131 insertions(+) create mode 100644 debian/patches/bugfix/all/locks-__break_lease-cleanup-in-preparation-of-allowi.patch diff --git a/debian/patches/bugfix/all/locks-__break_lease-cleanup-in-preparation-of-allowi.patch b/debian/patches/bugfix/all/locks-__break_lease-cleanup-in-preparation-of-allowi.patch new file mode 100644 index 000000000..b52e876fa --- /dev/null +++ b/debian/patches/bugfix/all/locks-__break_lease-cleanup-in-preparation-of-allowi.patch @@ -0,0 +1,130 @@ +From: Jeff Layton +Date: Mon, 1 Sep 2014 14:53:41 -0400 +Subject: locks: __break_lease cleanup in preparation of allowing direct + removal of leases +Origin: https://git.kernel.org/linus/03d12ddf845a4eb874ffa558d65a548aee9b715b +Bug-Debian: https://bugs.debian.org/883217 + +Eliminate an unneeded "flock" variable. We can use "fl" as a loop cursor +everywhere. Add a any_leases_conflict helper function as well to +consolidate a bit of code. + +Signed-off-by: Jeff Layton +Reviewed-by: Christoph Hellwig +[carnil: backport for 3.16: + - adjust context +] +--- + fs/locks.c | 49 +++++++++++++++++++++++++------------------------ + 1 file changed, 25 insertions(+), 24 deletions(-) + +--- a/fs/locks.c ++++ b/fs/locks.c +@@ -1307,6 +1307,20 @@ static bool leases_conflict(struct file_ + return locks_conflict(breaker, lease); + } + ++static bool ++any_leases_conflict(struct inode *inode, struct file_lock *breaker) ++{ ++ struct file_lock *fl; ++ ++ lockdep_assert_held(&inode->i_lock); ++ ++ for (fl = inode->i_flock ; fl && IS_LEASE(fl); fl = fl->fl_next) { ++ if (leases_conflict(fl, breaker)) ++ return true; ++ } ++ return false; ++} ++ + /** + * __break_lease - revoke all outstanding leases on file + * @inode: the inode of the file to return +@@ -1323,10 +1337,9 @@ static bool leases_conflict(struct file_ + int __break_lease(struct inode *inode, unsigned int mode, unsigned int type) + { + int error = 0; +- struct file_lock *new_fl, *flock; ++ struct file_lock *new_fl; + struct file_lock *fl; + unsigned long break_time; +- bool lease_conflict = false; + int want_write = (mode & O_ACCMODE) != O_RDONLY; + + new_fl = lease_alloc(NULL, want_write ? F_WRLCK : F_RDLCK); +@@ -1338,17 +1351,7 @@ int __break_lease(struct inode *inode, u + + time_out_leases(inode); + +- flock = inode->i_flock; +- if ((flock == NULL) || !IS_LEASE(flock)) +- goto out; +- +- for (fl = flock; fl && IS_LEASE(fl); fl = fl->fl_next) { +- if (leases_conflict(fl, new_fl)) { +- lease_conflict = true; +- break; +- } +- } +- if (!lease_conflict) ++ if (!any_leases_conflict(inode, new_fl)) + goto out; + + break_time = 0; +@@ -1358,7 +1361,7 @@ int __break_lease(struct inode *inode, u + break_time++; /* so that 0 means no break time */ + } + +- for (fl = flock; fl && IS_LEASE(fl); fl = fl->fl_next) { ++ for (fl = inode->i_flock; fl && IS_LEASE(fl); fl = fl->fl_next) { + if (!leases_conflict(fl, new_fl)) + continue; + if (want_write) { +@@ -1367,7 +1370,7 @@ int __break_lease(struct inode *inode, u + fl->fl_flags |= FL_UNLOCK_PENDING; + fl->fl_break_time = break_time; + } else { +- if (lease_breaking(flock)) ++ if (lease_breaking(inode->i_flock)) + continue; + fl->fl_flags |= FL_DOWNGRADE_PENDING; + fl->fl_downgrade_time = break_time; +@@ -1382,12 +1385,12 @@ int __break_lease(struct inode *inode, u + } + + restart: +- break_time = flock->fl_break_time; ++ break_time = inode->i_flock->fl_break_time; + if (break_time != 0) + break_time -= jiffies; + if (break_time == 0) + break_time++; +- locks_insert_block(flock, new_fl); ++ locks_insert_block(inode->i_flock, new_fl); + trace_break_lease_block(inode, new_fl); + spin_unlock(&inode->i_lock); + error = wait_event_interruptible_timeout(new_fl->fl_wait, +@@ -1396,17 +1399,15 @@ restart: + trace_break_lease_unblock(inode, new_fl); + locks_delete_block(new_fl); + if (error >= 0) { +- if (error == 0) +- time_out_leases(inode); + /* + * Wait for the next conflicting lease that has not been + * broken yet + */ +- for (flock = inode->i_flock; flock && IS_LEASE(flock); +- flock = flock->fl_next) { +- if (leases_conflict(new_fl, flock)) +- goto restart; +- } ++ if (error == 0) ++ time_out_leases(inode); ++ if (any_leases_conflict(inode, new_fl)) ++ goto restart; ++ + error = 0; + } + diff --git a/debian/patches/series b/debian/patches/series index 4ab96adb2..50a0f5f7a 100644 --- a/debian/patches/series +++ b/debian/patches/series @@ -252,6 +252,7 @@ bugfix/all/mm-mmap.c-expand_downwards-don-t-require-the-gap-if-.patch bugfix/x86/mmap-remember-the-map_fixed-flag-as-vm_fixed.patch bugfix/x86/mmap-add-an-exception-to-the-stack-gap-for-hotspot-jvm.patch bugfix/all/locks-remove-i_have_this_lease-check-from-__break_le.patch +bugfix/all/locks-__break_lease-cleanup-in-preparation-of-allowi.patch # memfd_create() & kdbus backport features/all/kdbus/mm-allow-drivers-to-prevent-new-writable-mappings.patch -- 2.15.1