kernel/linux.git/fs/zonefs, branch v5.10.257

zonefs: Improve error handling

2024-03-01T12:16:43+00:00

commit 14db5f64a971fce3d8ea35de4dfc7f443a3efb92 upstream. Write error handling is racy and can sometime lead to the error recovery path wrongly changing the inode size of a sequential zone file to an incorrect value which results in garbage data being readable at the end of a file. There are 2 problems: 1) zonefs_file_dio_write() updates a zone file write pointer offset after issuing a direct IO with iomap_dio_rw(). This update is done only if the IO succeed for synchronous direct writes. However, for asynchronous direct writes, the update is done without waiting for the IO completion so that the next asynchronous IO can be immediately issued. However, if an asynchronous IO completes with a failure right before the i_truncate_mutex lock protecting the update, the update may change the value of the inode write pointer offset that was corrected by the error path (zonefs_io_error() function). 2) zonefs_io_error() is called when a read or write error occurs. This function executes a report zone operation using the callback function zonefs_io_error_cb(), which does all the error recovery handling based on the current zone condition, write pointer position and according to the mount options being used. However, depending on the zoned device being used, a report zone callback may be executed in a context that is different from the context of __zonefs_io_error(). As a result, zonefs_io_error_cb() may be executed without the inode truncate mutex lock held, which can lead to invalid error processing. Fix both problems as follows: - Problem 1: Perform the inode write pointer offset update before a direct write is issued with iomap_dio_rw(). This is safe to do as partial direct writes are not supported (IOMAP_DIO_PARTIAL is not set) and any failed IO will trigger the execution of zonefs_io_error() which will correct the inode write pointer offset to reflect the current state of the one on the device. - Problem 2: Change zonefs_io_error_cb() into zonefs_handle_io_error() and call this function directly from __zonefs_io_error() after obtaining the zone information using blkdev_report_zones() with a simple callback function that copies to a local stack variable the struct blk_zone obtained from the device. This ensures that error handling is performed holding the inode truncate mutex. This change also simplifies error handling for conventional zone files by bypassing the execution of report zones entirely. This is safe to do because the condition of conventional zones cannot be read-only or offline and conventional zone files are always fully mapped with a constant file size. Reported-by: Shin'ichiro Kawasaki Fixes: 8dcc1a9d90c1 ("fs: New zonefs file system") Cc: stable@vger.kernel.org Signed-off-by: Damien Le Moal Tested-by: Shin'ichiro Kawasaki Reviewed-by: Johannes Thumshirn Reviewed-by: Himanshu Madhani Signed-off-by: Greg Kroah-Hartman

zonefs: Fix error message in zonefs_file_dio_append()

2023-04-05T09:23:51+00:00

commit 88b170088ad2c3e27086fe35769aa49f8a512564 upstream. Since the expected write location in a sequential file is always at the end of the file (append write), when an invalid write append location is detected in zonefs_file_dio_append(), print the invalid written location instead of the expected write location. Fixes: a608da3bd730 ("zonefs: Detect append writes at invalid locations") Cc: stable@vger.kernel.org Signed-off-by: Damien Le Moal Reviewed-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Reviewed-by: Himanshu Madhani Signed-off-by: Greg Kroah-Hartman

zonefs: Detect append writes at invalid locations

2023-01-24T06:19:56+00:00

commit a608da3bd730d718f2d3ebec1c26f9865f8f17ce upstream. Using REQ_OP_ZONE_APPEND operations for synchronous writes to sequential files succeeds regardless of the zone write pointer position, as long as the target zone is not full. This means that if an external (buggy) application writes to the zone of a sequential file underneath the file system, subsequent file write() operation will succeed but the file size will not be correct and the file will contain invalid data written by another application. Modify zonefs_file_dio_append() to check the written sector of an append write (returned in bio->bi_iter.bi_sector) and return -EIO if there is a mismatch with the file zone wp offset field. This change triggers a call to zonefs_io_error() and a zone check. Modify zonefs_io_error_cb() to not expose the unexpected data after the current inode size when the errors=remount-ro mode is used. Other error modes are correctly handled already. Fixes: 02ef12a663c7 ("zonefs: use REQ_OP_ZONE_APPEND for sync DIO") Cc: stable@vger.kernel.org Signed-off-by: Damien Le Moal Reviewed-by: Johannes Thumshirn Signed-off-by: Greg Kroah-Hartman

zonefs: fix zone report size in __zonefs_io_error()

2022-12-02T16:40:05+00:00

[ Upstream commit 7dd12d65ac646046a3fe0bbf9a4e86f4514207b3 ] When an IO error occurs, the function __zonefs_io_error() is used to issue a zone report to obtain the latest zone information from the device. This function gets a zone report for all zones used as storage for a file, which is always 1 zone except for files representing aggregated conventional zones. The number of zones of a zone report for a file is calculated in __zonefs_io_error() by doing a bit-shift of the inode i_zone_size field, which is equal to or larger than the device zone size. However, this calculation does not take into account that the last zone of a zoned device may be smaller than the zone size reported by bdev_zone_sectors() (which is used to set the bit shift size). As a result, if an error occurs for an IO targetting such last smaller zone, the zone report will ask for 0 zones, leading to an invalid zone report. Fix this by using the fact that all files require a 1 zone report, except if the inode i_zone_size field indicates a zone size larger than the device zone size. This exception case corresponds to a mount with aggregated conventional zones. A check for this exception is added to the file inode initialization during mount. If an invalid setup is detected, emit an error and fail the mount (check contributed by Johannes Thumshirn). Signed-off-by: Johannes Thumshirn Signed-off-by: Damien Le Moal Signed-off-by: Sasha Levin

zonefs: fix zonefs_iomap_begin() for reads

2022-06-25T13:16:08+00:00

commit c1c1204c0d0c1dccc1310b9277fb2bd8b663d8fe upstream. If a readahead is issued to a sequential zone file with an offset exactly equal to the current file size, the iomap type is set to IOMAP_UNWRITTEN, which will prevent an IO, but the iomap length is calculated as 0. This causes a WARN_ON() in iomap_iter(): [17309.548939] WARNING: CPU: 3 PID: 2137 at fs/iomap/iter.c:34 iomap_iter+0x9cf/0xe80 [...] [17309.650907] RIP: 0010:iomap_iter+0x9cf/0xe80 [...] [17309.754560] Call Trace: [17309.757078] [17309.759240] ? lock_is_held_type+0xd8/0x130 [17309.763531] iomap_readahead+0x1a8/0x870 [17309.767550] ? iomap_read_folio+0x4c0/0x4c0 [17309.771817] ? lockdep_hardirqs_on_prepare+0x400/0x400 [17309.778848] ? lock_release+0x370/0x750 [17309.784462] ? folio_add_lru+0x217/0x3f0 [17309.790220] ? reacquire_held_locks+0x4e0/0x4e0 [17309.796543] read_pages+0x17d/0xb60 [17309.801854] ? folio_add_lru+0x238/0x3f0 [17309.807573] ? readahead_expand+0x5f0/0x5f0 [17309.813554] ? policy_node+0xb5/0x140 [17309.819018] page_cache_ra_unbounded+0x27d/0x450 [17309.825439] filemap_get_pages+0x500/0x1450 [17309.831444] ? filemap_add_folio+0x140/0x140 [17309.837519] ? lock_is_held_type+0xd8/0x130 [17309.843509] filemap_read+0x28c/0x9f0 [17309.848953] ? zonefs_file_read_iter+0x1ea/0x4d0 [zonefs] [17309.856162] ? trace_contention_end+0xd6/0x130 [17309.862416] ? __mutex_lock+0x221/0x1480 [17309.868151] ? zonefs_file_read_iter+0x166/0x4d0 [zonefs] [17309.875364] ? filemap_get_pages+0x1450/0x1450 [17309.881647] ? __mutex_unlock_slowpath+0x15e/0x620 [17309.888248] ? wait_for_completion_io_timeout+0x20/0x20 [17309.895231] ? lock_is_held_type+0xd8/0x130 [17309.901115] ? lock_is_held_type+0xd8/0x130 [17309.906934] zonefs_file_read_iter+0x356/0x4d0 [zonefs] [17309.913750] new_sync_read+0x2d8/0x520 [17309.919035] ? __x64_sys_lseek+0x1d0/0x1d0 Furthermore, this causes iomap_readahead() to loop forever as iomap_readahead_iter() always returns 0, making no progress. Fix this by treating reads after the file size as access to holes, setting the iomap type to IOMAP_HOLE, the iomap addr to IOMAP_NULL_ADDR and using the length argument as is for the iomap length. To simplify the code with this change, zonefs_iomap_begin() is split into the read variant, zonefs_read_iomap_begin() and zonefs_read_iomap_ops, and the write variant, zonefs_write_iomap_begin() and zonefs_write_iomap_ops. Reported-by: Jorgen Hansen Fixes: 8dcc1a9d90c1 ("fs: New zonefs file system") Signed-off-by: Damien Le Moal Reviewed-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Reviewed-by: Jorgen Hansen Signed-off-by: Greg Kroah-Hartman

zonefs: fix handling of explicit_open option on mount

2022-06-14T16:32:47+00:00

commit a2a513be7139b279f1b5b2cee59c6c4950c34346 upstream. Ignoring the explicit_open mount option on mount for devices that do not have a limit on the number of open zones must be done after the mount options are parsed and set in s_mount_opts. Move the check to ignore the explicit_open option after the call to zonefs_parse_options() in zonefs_fill_super(). Fixes: b5c00e975779 ("zonefs: open/close zone on file open/close") Cc: Signed-off-by: Damien Le Moal Reviewed-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Signed-off-by: Greg Kroah-Hartman

zonefs: Clear inode information flags on inode creation

2022-05-09T07:05:06+00:00

commit 694852ead287a3433126e7ebda397b242dc99624 upstream. Ensure that the i_flags field of struct zonefs_inode_info is cleared to 0 when initializing a zone file inode, avoiding seeing the flag ZONEFS_ZONE_OPEN being incorrectly set. Fixes: b5c00e975779 ("zonefs: open/close zone on file open/close") Cc: Signed-off-by: Damien Le Moal Reviewed-by: Johannes Thumshirn Reviewed-by: Chaitanya Kulkarni Reviewed-by: Hans Holmberg Signed-off-by: Greg Kroah-Hartman

zonefs: Fix management of open zones

2022-05-09T07:05:06+00:00

commit 1da18a296f5ba4f99429e62a7cf4fdbefa598902 upstream. The mount option "explicit_open" manages the device open zone resources to ensure that if an application opens a sequential file for writing, the file zone can always be written by explicitly opening the zone and accounting for that state with the s_open_zones counter. However, if some zones are already open when mounting, the device open zone resource usage status will be larger than the initial s_open_zones value of 0. Ensure that this inconsistency does not happen by closing any sequential zone that is open when mounting. Furthermore, with ZNS drives, closing an explicitly open zone that has not been written will change the zone state to "closed", that is, the zone will remain in an active state. Since this can then cause failures of explicit open operations on other zones if the drive active zone resources are exceeded, we need to make sure that the zone is not active anymore by resetting it instead of closing it. To address this, zonefs_zone_mgmt() is modified to change a REQ_OP_ZONE_CLOSE request into a REQ_OP_ZONE_RESET for sequential zones that have not been written. Fixes: b5c00e975779 ("zonefs: open/close zone on file open/close") Cc: Signed-off-by: Damien Le Moal Reviewed-by: Johannes Thumshirn Reviewed-by: Hans Holmberg Signed-off-by: Greg Kroah-Hartman

zonefs: add MODULE_ALIAS_FS

2021-12-22T08:30:57+00:00

commit 8ffea2599f63fdbee968b894eab78170abf3ec2c upstream. Add MODULE_ALIAS_FS() to load the module automatically when you do "mount -t zonefs". Fixes: 8dcc1a9d90c1 ("fs: New zonefs file system") Cc: stable # 5.6+ Signed-off-by: Naohiro Aota Reviewed-by: Johannes Thumshirn Signed-off-by: Damien Le Moal Signed-off-by: Greg Kroah-Hartman

zonefs: fix to update .i_wr_refcnt correctly in zonefs_open_zone()

2021-03-25T08:04:05+00:00

commit 6980d29ce4da223ad7f0751c7f1d61d3c6b54ab3 upstream. In zonefs_open_zone(), if opened zone count is larger than .s_max_open_zones threshold, we missed to recover .i_wr_refcnt, fix this. Fixes: b5c00e975779 ("zonefs: open/close zone on file open/close") Cc: Signed-off-by: Chao Yu Signed-off-by: Damien Le Moal Signed-off-by: Greg Kroah-Hartman