diff options
| -rw-r--r-- | Documentation/filesystems/locking.rst | 1 | ||||
| -rw-r--r-- | fs/locks.c | 90 | ||||
| -rw-r--r-- | fs/nfsd/nfs4layouts.c | 23 | ||||
| -rw-r--r-- | fs/nfsd/nfs4state.c | 19 | ||||
| -rw-r--r-- | include/linux/filelock.h | 1 |
5 files changed, 84 insertions, 50 deletions
diff --git a/Documentation/filesystems/locking.rst b/Documentation/filesystems/locking.rst index 77704fde9845..04c7691e50e0 100644 --- a/Documentation/filesystems/locking.rst +++ b/Documentation/filesystems/locking.rst @@ -416,6 +416,7 @@ lm_change yes no no lm_breaker_owns_lease: yes no no lm_lock_expirable yes no no lm_expire_lock no no yes +lm_open_conflict yes no no ====================== ============= ================= ========= buffer_head diff --git a/fs/locks.c b/fs/locks.c index be0b79286da8..e75c8084d937 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -585,10 +585,50 @@ lease_setup(struct file_lease *fl, void **priv) __f_setown(filp, task_pid(current), PIDTYPE_TGID, 0); } +/** + * lease_open_conflict - see if the given file points to an inode that has + * an existing open that would conflict with the + * desired lease. + * @filp: file to check + * @arg: type of lease that we're trying to acquire + * + * Check to see if there's an existing open fd on this file that would + * conflict with the lease we're trying to set. + */ +static int +lease_open_conflict(struct file *filp, const int arg) +{ + struct inode *inode = file_inode(filp); + int self_wcount = 0, self_rcount = 0; + + if (arg == F_RDLCK) + return inode_is_open_for_write(inode) ? -EAGAIN : 0; + else if (arg != F_WRLCK) + return 0; + + /* + * Make sure that only read/write count is from lease requestor. + * Note that this will result in denying write leases when i_writecount + * is negative, which is what we want. (We shouldn't grant write leases + * on files open for execution.) + */ + if (filp->f_mode & FMODE_WRITE) + self_wcount = 1; + else if (filp->f_mode & FMODE_READ) + self_rcount = 1; + + if (atomic_read(&inode->i_writecount) != self_wcount || + atomic_read(&inode->i_readcount) != self_rcount) + return -EAGAIN; + + return 0; +} + static const struct lease_manager_operations lease_manager_ops = { .lm_break = lease_break_callback, .lm_change = lease_modify, .lm_setup = lease_setup, + .lm_open_conflict = lease_open_conflict, }; /* @@ -1754,52 +1794,6 @@ int fcntl_getdeleg(struct file *filp, struct delegation *deleg) return 0; } -/** - * check_conflicting_open - see if the given file points to an inode that has - * an existing open that would conflict with the - * desired lease. - * @filp: file to check - * @arg: type of lease that we're trying to acquire - * @flags: current lock flags - * - * Check to see if there's an existing open fd on this file that would - * conflict with the lease we're trying to set. - */ -static int -check_conflicting_open(struct file *filp, const int arg, int flags) -{ - struct inode *inode = file_inode(filp); - int self_wcount = 0, self_rcount = 0; - - if (flags & FL_LAYOUT) - return 0; - if (flags & FL_DELEG) - /* We leave these checks to the caller */ - return 0; - - if (arg == F_RDLCK) - return inode_is_open_for_write(inode) ? -EAGAIN : 0; - else if (arg != F_WRLCK) - return 0; - - /* - * Make sure that only read/write count is from lease requestor. - * Note that this will result in denying write leases when i_writecount - * is negative, which is what we want. (We shouldn't grant write leases - * on files open for execution.) - */ - if (filp->f_mode & FMODE_WRITE) - self_wcount = 1; - else if (filp->f_mode & FMODE_READ) - self_rcount = 1; - - if (atomic_read(&inode->i_writecount) != self_wcount || - atomic_read(&inode->i_readcount) != self_rcount) - return -EAGAIN; - - return 0; -} - static int generic_add_lease(struct file *filp, int arg, struct file_lease **flp, void **priv) { @@ -1836,7 +1830,7 @@ generic_add_lease(struct file *filp, int arg, struct file_lease **flp, void **pr percpu_down_read(&file_rwsem); spin_lock(&ctx->flc_lock); time_out_leases(inode, &dispose); - error = check_conflicting_open(filp, arg, lease->c.flc_flags); + error = lease->fl_lmops->lm_open_conflict(filp, arg); if (error) goto out; @@ -1893,7 +1887,7 @@ generic_add_lease(struct file *filp, int arg, struct file_lease **flp, void **pr * precedes these checks. */ smp_mb(); - error = check_conflicting_open(filp, arg, lease->c.flc_flags); + error = lease->fl_lmops->lm_open_conflict(filp, arg); if (error) { locks_unlink_lock_ctx(&lease->c); goto out; diff --git a/fs/nfsd/nfs4layouts.c b/fs/nfsd/nfs4layouts.c index 683bd1130afe..ad7af8cfcf1f 100644 --- a/fs/nfsd/nfs4layouts.c +++ b/fs/nfsd/nfs4layouts.c @@ -764,9 +764,28 @@ nfsd4_layout_lm_change(struct file_lease *onlist, int arg, return lease_modify(onlist, arg, dispose); } +/** + * nfsd4_layout_lm_open_conflict - see if the given file points to an inode that has + * an existing open that would conflict with the + * desired lease. + * @filp: file to check + * @arg: type of lease that we're trying to acquire + * + * The kernel will call into this operation to determine whether there + * are conflicting opens that may prevent the layout from being granted. + * For nfsd, that check is done at a higher level, so this trivially + * returns 0. + */ +static int +nfsd4_layout_lm_open_conflict(struct file *filp, int arg) +{ + return 0; +} + static const struct lease_manager_operations nfsd4_layouts_lm_ops = { - .lm_break = nfsd4_layout_lm_break, - .lm_change = nfsd4_layout_lm_change, + .lm_break = nfsd4_layout_lm_break, + .lm_change = nfsd4_layout_lm_change, + .lm_open_conflict = nfsd4_layout_lm_open_conflict, }; int diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 808c24fb5c9a..19d6d6db107f 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -5552,10 +5552,29 @@ nfsd_change_deleg_cb(struct file_lease *onlist, int arg, return -EAGAIN; } +/** + * nfsd4_deleg_lm_open_conflict - see if the given file points to an inode that has + * an existing open that would conflict with the + * desired lease. + * @filp: file to check + * @arg: type of lease that we're trying to acquire + * + * The kernel will call into this operation to determine whether there + * are conflicting opens that may prevent the deleg from being granted. + * For nfsd, that check is done at a higher level, so this trivially + * returns 0. + */ +static int +nfsd4_deleg_lm_open_conflict(struct file *filp, int arg) +{ + return 0; +} + static const struct lease_manager_operations nfsd_lease_mng_ops = { .lm_breaker_owns_lease = nfsd_breaker_owns_lease, .lm_break = nfsd_break_deleg_cb, .lm_change = nfsd_change_deleg_cb, + .lm_open_conflict = nfsd4_deleg_lm_open_conflict, }; static __be32 nfsd4_check_seqid(struct nfsd4_compound_state *cstate, struct nfs4_stateowner *so, u32 seqid) diff --git a/include/linux/filelock.h b/include/linux/filelock.h index 54b824c05299..2f5e5588ee07 100644 --- a/include/linux/filelock.h +++ b/include/linux/filelock.h @@ -49,6 +49,7 @@ struct lease_manager_operations { int (*lm_change)(struct file_lease *, int, struct list_head *); void (*lm_setup)(struct file_lease *, void **); bool (*lm_breaker_owns_lease)(struct file_lease *); + int (*lm_open_conflict)(struct file *, int); }; struct lock_manager { |