From 1601ea068b886da1f8f8d4e18b9403e9e24adef6 Mon Sep 17 00:00:00 2001 From: Damien Le Moal Date: Mon, 15 Mar 2021 12:43:55 +0900 Subject: [PATCH 1/3] zonefs: prevent use of seq files as swap file The sequential write constraint of sequential zone file prevent their use as swap files. Only allow conventional zone files to be used as swap files. Fixes: 8dcc1a9d90c1 ("fs: New zonefs file system") Cc: Reviewed-by: Johannes Thumshirn Signed-off-by: Damien Le Moal --- fs/zonefs/super.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/fs/zonefs/super.c b/fs/zonefs/super.c index 0fe76f376dee2..a3d074f986604 100644 --- a/fs/zonefs/super.c +++ b/fs/zonefs/super.c @@ -165,6 +165,21 @@ static int zonefs_writepages(struct address_space *mapping, return iomap_writepages(mapping, wbc, &wpc, &zonefs_writeback_ops); } +static int zonefs_swap_activate(struct swap_info_struct *sis, + struct file *swap_file, sector_t *span) +{ + struct inode *inode = file_inode(swap_file); + struct zonefs_inode_info *zi = ZONEFS_I(inode); + + if (zi->i_ztype != ZONEFS_ZTYPE_CNV) { + zonefs_err(inode->i_sb, + "swap file: not a conventional zone file\n"); + return -EINVAL; + } + + return iomap_swapfile_activate(sis, swap_file, span, &zonefs_iomap_ops); +} + static const struct address_space_operations zonefs_file_aops = { .readpage = zonefs_readpage, .readahead = zonefs_readahead, @@ -177,6 +192,7 @@ static const struct address_space_operations zonefs_file_aops = { .is_partially_uptodate = iomap_is_partially_uptodate, .error_remove_page = generic_error_remove_page, .direct_IO = noop_direct_IO, + .swap_activate = zonefs_swap_activate, }; static void zonefs_update_stats(struct inode *inode, loff_t new_isize) From ebfd68cd0c1e81267c757332385cb96df30dacce Mon Sep 17 00:00:00 2001 From: Damien Le Moal Date: Wed, 10 Mar 2021 15:20:28 +0900 Subject: [PATCH 2/3] zonefs: Fix O_APPEND async write handling zonefs updates the size of a sequential zone file inode only on completion of direct writes. When executing asynchronous append writes (with a file open with O_APPEND or using RWF_APPEND), the use of the current inode size in generic_write_checks() to set an iocb offset thus leads to unaligned write if an application issues an append write operation with another write already being executed. Fix this problem by introducing zonefs_write_checks() as a modified version of generic_write_checks() using the file inode wp_offset for an append write iocb offset. Also introduce zonefs_write_check_limits() to replace generic_write_check_limits() call. This zonefs special helper makes sure that the maximum file limit used is the maximum size of the file being accessed. Since zonefs_write_checks() already truncates the iov_iter, the calls to iov_iter_truncate() in zonefs_file_dio_write() and zonefs_file_buffered_write() are removed. Fixes: 8dcc1a9d90c1 ("fs: New zonefs file system") Cc: Reviewed-by: Johannes Thumshirn Signed-off-by: Damien Le Moal --- fs/zonefs/super.c | 78 +++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 68 insertions(+), 10 deletions(-) diff --git a/fs/zonefs/super.c b/fs/zonefs/super.c index a3d074f986604..3427c99abb4d5 100644 --- a/fs/zonefs/super.c +++ b/fs/zonefs/super.c @@ -743,6 +743,68 @@ static ssize_t zonefs_file_dio_append(struct kiocb *iocb, struct iov_iter *from) return ret; } +/* + * Do not exceed the LFS limits nor the file zone size. If pos is under the + * limit it becomes a short access. If it exceeds the limit, return -EFBIG. + */ +static loff_t zonefs_write_check_limits(struct file *file, loff_t pos, + loff_t count) +{ + struct inode *inode = file_inode(file); + struct zonefs_inode_info *zi = ZONEFS_I(inode); + loff_t limit = rlimit(RLIMIT_FSIZE); + loff_t max_size = zi->i_max_size; + + if (limit != RLIM_INFINITY) { + if (pos >= limit) { + send_sig(SIGXFSZ, current, 0); + return -EFBIG; + } + count = min(count, limit - pos); + } + + if (!(file->f_flags & O_LARGEFILE)) + max_size = min_t(loff_t, MAX_NON_LFS, max_size); + + if (unlikely(pos >= max_size)) + return -EFBIG; + + return min(count, max_size - pos); +} + +static ssize_t zonefs_write_checks(struct kiocb *iocb, struct iov_iter *from) +{ + struct file *file = iocb->ki_filp; + struct inode *inode = file_inode(file); + struct zonefs_inode_info *zi = ZONEFS_I(inode); + loff_t count; + + if (IS_SWAPFILE(inode)) + return -ETXTBSY; + + if (!iov_iter_count(from)) + return 0; + + if ((iocb->ki_flags & IOCB_NOWAIT) && !(iocb->ki_flags & IOCB_DIRECT)) + return -EINVAL; + + if (iocb->ki_flags & IOCB_APPEND) { + if (zi->i_ztype != ZONEFS_ZTYPE_SEQ) + return -EINVAL; + mutex_lock(&zi->i_truncate_mutex); + iocb->ki_pos = zi->i_wpoffset; + mutex_unlock(&zi->i_truncate_mutex); + } + + count = zonefs_write_check_limits(file, iocb->ki_pos, + iov_iter_count(from)); + if (count < 0) + return count; + + iov_iter_truncate(from, count); + return iov_iter_count(from); +} + /* * Handle direct writes. For sequential zone files, this is the only possible * write path. For these files, check that the user is issuing writes @@ -760,8 +822,7 @@ static ssize_t zonefs_file_dio_write(struct kiocb *iocb, struct iov_iter *from) struct super_block *sb = inode->i_sb; bool sync = is_sync_kiocb(iocb); bool append = false; - size_t count; - ssize_t ret; + ssize_t ret, count; /* * For async direct IOs to sequential zone files, refuse IOCB_NOWAIT @@ -779,12 +840,11 @@ static ssize_t zonefs_file_dio_write(struct kiocb *iocb, struct iov_iter *from) inode_lock(inode); } - ret = generic_write_checks(iocb, from); - if (ret <= 0) + count = zonefs_write_checks(iocb, from); + if (count <= 0) { + ret = count; goto inode_unlock; - - iov_iter_truncate(from, zi->i_max_size - iocb->ki_pos); - count = iov_iter_count(from); + } if ((iocb->ki_pos | count) & (sb->s_blocksize - 1)) { ret = -EINVAL; @@ -844,12 +904,10 @@ static ssize_t zonefs_file_buffered_write(struct kiocb *iocb, inode_lock(inode); } - ret = generic_write_checks(iocb, from); + ret = zonefs_write_checks(iocb, from); if (ret <= 0) goto inode_unlock; - iov_iter_truncate(from, zi->i_max_size - iocb->ki_pos); - ret = iomap_file_buffered_write(iocb, from, &zonefs_iomap_ops); if (ret > 0) iocb->ki_pos += ret; From 6980d29ce4da223ad7f0751c7f1d61d3c6b54ab3 Mon Sep 17 00:00:00 2001 From: Chao Yu Date: Tue, 16 Mar 2021 20:30:26 +0800 Subject: [PATCH 3/3] zonefs: fix to update .i_wr_refcnt correctly in zonefs_open_zone() 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 --- fs/zonefs/super.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/fs/zonefs/super.c b/fs/zonefs/super.c index 3427c99abb4d5..049e36c69ed70 100644 --- a/fs/zonefs/super.c +++ b/fs/zonefs/super.c @@ -1040,9 +1040,7 @@ static int zonefs_open_zone(struct inode *inode) mutex_lock(&zi->i_truncate_mutex); - zi->i_wr_refcnt++; - if (zi->i_wr_refcnt == 1) { - + if (!zi->i_wr_refcnt) { if (atomic_inc_return(&sbi->s_open_zones) > sbi->s_max_open_zones) { atomic_dec(&sbi->s_open_zones); ret = -EBUSY; @@ -1052,7 +1050,6 @@ static int zonefs_open_zone(struct inode *inode) if (i_size_read(inode) < zi->i_max_size) { ret = zonefs_zone_mgmt(inode, REQ_OP_ZONE_OPEN); if (ret) { - zi->i_wr_refcnt--; atomic_dec(&sbi->s_open_zones); goto unlock; } @@ -1060,6 +1057,8 @@ static int zonefs_open_zone(struct inode *inode) } } + zi->i_wr_refcnt++; + unlock: mutex_unlock(&zi->i_truncate_mutex);