diff options
| -rw-r--r-- | Documentation/admin-guide/blockdev/zram.rst | 2 | ||||
| -rw-r--r-- | drivers/block/zram/zram_drv.c | 16 | ||||
| -rw-r--r-- | drivers/block/zram/zram_drv.h | 1 |
3 files changed, 19 insertions, 0 deletions
diff --git a/Documentation/admin-guide/blockdev/zram.rst b/Documentation/admin-guide/blockdev/zram.rst index 678d70d6e1c3..714a5171bfc0 100644 --- a/Documentation/admin-guide/blockdev/zram.rst +++ b/Documentation/admin-guide/blockdev/zram.rst @@ -47,6 +47,8 @@ The list of possible return codes: -ENOMEM zram was not able to allocate enough memory to fulfil your needs. -EINVAL invalid input has been provided. +-EAGAIN re-try operation later (e.g. when attempting to run recompress + and writeback simultaneously). ======== ============================================================= If you use 'echo', the returned value is set by the 'echo' utility, diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index d61750c1c5b5..37a284f709ba 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -627,6 +627,12 @@ static ssize_t writeback_store(struct device *dev, goto release_init_lock; } + /* Do not permit concurrent post-processing actions. */ + if (atomic_xchg(&zram->pp_in_progress, 1)) { + up_read(&zram->init_lock); + return -EAGAIN; + } + if (!zram->backing_dev) { ret = -ENODEV; goto release_init_lock; @@ -753,6 +759,7 @@ next: free_block_bdev(zram, blk_idx); __free_page(page); release_init_lock: + atomic_set(&zram->pp_in_progress, 0); up_read(&zram->init_lock); return ret; @@ -1883,6 +1890,12 @@ static ssize_t recompress_store(struct device *dev, goto release_init_lock; } + /* Do not permit concurrent post-processing actions. */ + if (atomic_xchg(&zram->pp_in_progress, 1)) { + up_read(&zram->init_lock); + return -EAGAIN; + } + if (algo) { bool found = false; @@ -1950,6 +1963,7 @@ next: __free_page(page); release_init_lock: + atomic_set(&zram->pp_in_progress, 0); up_read(&zram->init_lock); return ret; } @@ -2146,6 +2160,7 @@ static void zram_reset_device(struct zram *zram) zram->disksize = 0; zram_destroy_comps(zram); memset(&zram->stats, 0, sizeof(zram->stats)); + atomic_set(&zram->pp_in_progress, 0); reset_bdev(zram); comp_algorithm_set(zram, ZRAM_PRIMARY_COMP, default_compressor); @@ -2383,6 +2398,7 @@ static int zram_add(void) zram->disk->fops = &zram_devops; zram->disk->private_data = zram; snprintf(zram->disk->disk_name, 16, "zram%d", device_id); + atomic_set(&zram->pp_in_progress, 0); /* Actual capacity set using sysfs (/sys/block/zram<id>/disksize */ set_capacity(zram->disk, 0); diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h index 914cb6629969..73a9d47d76ba 100644 --- a/drivers/block/zram/zram_drv.h +++ b/drivers/block/zram/zram_drv.h @@ -140,5 +140,6 @@ struct zram { #ifdef CONFIG_ZRAM_MEMORY_TRACKING struct dentry *debugfs_dir; #endif + atomic_t pp_in_progress; }; #endif |