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author | David Howells <dhowells@redhat.com> | 2023-05-22 14:50:12 +0100 |
---|---|---|
committer | Jens Axboe <axboe@kernel.dk> | 2023-05-24 08:42:16 -0600 |
commit | 6ef48ec391c8733c89fce33b5a6a2747aa1b8178 (patch) | |
tree | 5b7f783fe79165d8f05284856d78057fdae56052 /fs | |
parent | 54919f94ec52549b7efcd074567ccb68c49830df (diff) | |
download | lwn-6ef48ec391c8733c89fce33b5a6a2747aa1b8178.tar.gz lwn-6ef48ec391c8733c89fce33b5a6a2747aa1b8178.zip |
zonefs: Provide a splice-read wrapper
Provide a splice_read wrapper for zonefs. This does some checks before
proceeding and locks the inode across the call to filemap_splice_read() and
a size check in case of truncation. Splicing from direct I/O is handled by
the caller.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Christoph Hellwig <hch@lst.de>
cc: Al Viro <viro@zeniv.linux.org.uk>
cc: Jens Axboe <axboe@kernel.dk>
cc: Darrick J. Wong <djwong@kernel.org>
cc: linux-xfs@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
cc: linux-block@vger.kernel.org
cc: linux-mm@kvack.org
Acked-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20230522135018.2742245-26-dhowells@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'fs')
-rw-r--r-- | fs/zonefs/file.c | 40 |
1 files changed, 39 insertions, 1 deletions
diff --git a/fs/zonefs/file.c b/fs/zonefs/file.c index 132f01d3461f..65d4c4fe6364 100644 --- a/fs/zonefs/file.c +++ b/fs/zonefs/file.c @@ -752,6 +752,44 @@ inode_unlock: return ret; } +static ssize_t zonefs_file_splice_read(struct file *in, loff_t *ppos, + struct pipe_inode_info *pipe, + size_t len, unsigned int flags) +{ + struct inode *inode = file_inode(in); + struct zonefs_inode_info *zi = ZONEFS_I(inode); + struct zonefs_zone *z = zonefs_inode_zone(inode); + loff_t isize; + ssize_t ret = 0; + + /* Offline zones cannot be read */ + if (unlikely(IS_IMMUTABLE(inode) && !(inode->i_mode & 0777))) + return -EPERM; + + if (*ppos >= z->z_capacity) + return 0; + + inode_lock_shared(inode); + + /* Limit read operations to written data */ + mutex_lock(&zi->i_truncate_mutex); + isize = i_size_read(inode); + if (*ppos >= isize) + len = 0; + else + len = min_t(loff_t, len, isize - *ppos); + mutex_unlock(&zi->i_truncate_mutex); + + if (len > 0) { + ret = filemap_splice_read(in, ppos, pipe, len, flags); + if (ret == -EIO) + zonefs_io_error(inode, false); + } + + inode_unlock_shared(inode); + return ret; +} + /* * Write open accounting is done only for sequential files. */ @@ -896,7 +934,7 @@ const struct file_operations zonefs_file_operations = { .llseek = zonefs_file_llseek, .read_iter = zonefs_file_read_iter, .write_iter = zonefs_file_write_iter, - .splice_read = generic_file_splice_read, + .splice_read = zonefs_file_splice_read, .splice_write = iter_file_splice_write, .iopoll = iocb_bio_iopoll, }; |