| Message ID | 20231221132400.1601991-34-dhowells@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | netfs, afs, 9p: Delegate high-level I/O to netfslib | expand |
Hi David, On 2023/12/21 21:23, David Howells wrote: > Make netfslib pass the maximum length to the ->prepare_write() op to tell > the cache how much it can expand the length of a write to. This allows a > write to the server at the end of a file to be limited to a few bytes > whilst writing an entire block to the cache (something required by direct > I/O). > > Signed-off-by: David Howells <dhowells@redhat.com> > Reviewed-by: Jeff Layton <jlayton@kernel.org> > cc: linux-cachefs@redhat.com > cc: linux-fsdevel@vger.kernel.org > cc: linux-mm@kvack.org > --- > fs/cachefiles/internal.h | 2 +- > fs/cachefiles/io.c | 10 ++++++---- > fs/cachefiles/ondemand.c | 2 +- > fs/netfs/fscache_io.c | 2 +- > fs/netfs/io.c | 2 +- > fs/netfs/objects.c | 1 + > fs/netfs/output.c | 25 ++++++++++--------------- > fs/smb/client/fscache.c | 2 +- > include/linux/netfs.h | 5 +++-- > 9 files changed, 25 insertions(+), 26 deletions(-) > > diff --git a/fs/cachefiles/internal.h b/fs/cachefiles/internal.h > index 2ad58c465208..1af48d576a34 100644 > --- a/fs/cachefiles/internal.h > +++ b/fs/cachefiles/internal.h > @@ -233,7 +233,7 @@ extern bool cachefiles_begin_operation(struct netfs_cache_resources *cres, > enum fscache_want_state want_state); > extern int __cachefiles_prepare_write(struct cachefiles_object *object, > struct file *file, > - loff_t *_start, size_t *_len, > + loff_t *_start, size_t *_len, size_t upper_len, > bool no_space_allocated_yet); > extern int __cachefiles_write(struct cachefiles_object *object, > struct file *file, > diff --git a/fs/cachefiles/io.c b/fs/cachefiles/io.c > index 009d23cd435b..bffffedce4a9 100644 > --- a/fs/cachefiles/io.c > +++ b/fs/cachefiles/io.c > @@ -518,7 +518,7 @@ cachefiles_prepare_ondemand_read(struct netfs_cache_resources *cres, > */ > int __cachefiles_prepare_write(struct cachefiles_object *object, > struct file *file, > - loff_t *_start, size_t *_len, > + loff_t *_start, size_t *_len, size_t upper_len, > bool no_space_allocated_yet) > { > struct cachefiles_cache *cache = object->volume->cache; > @@ -530,6 +530,8 @@ int __cachefiles_prepare_write(struct cachefiles_object *object, > down = start - round_down(start, PAGE_SIZE); > *_start = start - down; > *_len = round_up(down + len, PAGE_SIZE); > + if (down < start || *_len > upper_len) > + return -ENOBUFS; Sorry for bothering. We just found some strange when testing today-next EROFS over fscache. I'm not sure the meaning of if (down < start For example, if start is page-aligned, down == 0. so as long as start > 0 and page-aligned, it will return -ENOBUFS. Does it an intended behavior? Thanks, Gao Xiang
Gao Xiang <hsiangkao@linux.alibaba.com> wrote: > > down = start - round_down(start, PAGE_SIZE); > > *_start = start - down; > > *_len = round_up(down + len, PAGE_SIZE); > > + if (down < start || *_len > upper_len) > > + return -ENOBUFS; > > Sorry for bothering. We just found some strange when testing > today-next EROFS over fscache. > > I'm not sure the meaning of > if (down < start > > For example, if start is page-aligned, down == 0. > > so as long as start > 0 and page-aligned, it will return > -ENOBUFS. Does it an intended behavior? Yeah, I think that's wrong. Does the attached help? David --- diff --git a/fs/cachefiles/io.c b/fs/cachefiles/io.c index bffffedce4a9..7529b40bc95a 100644 --- a/fs/cachefiles/io.c +++ b/fs/cachefiles/io.c @@ -522,16 +522,22 @@ int __cachefiles_prepare_write(struct cachefiles_object *object, bool no_space_allocated_yet) { struct cachefiles_cache *cache = object->volume->cache; - loff_t start = *_start, pos; - size_t len = *_len, down; + unsigned long long start = *_start, pos; + size_t len = *_len; int ret; /* Round to DIO size */ - down = start - round_down(start, PAGE_SIZE); - *_start = start - down; - *_len = round_up(down + len, PAGE_SIZE); - if (down < start || *_len > upper_len) + start = round_down(*_start, PAGE_SIZE); + if (start != *_start) { + kleave(" = -ENOBUFS [down]"); + return -ENOBUFS; + } + if (*_len > upper_len) { + kleave(" = -ENOBUFS [up]"); return -ENOBUFS; + } + + *_len = round_up(len, PAGE_SIZE); /* We need to work out whether there's sufficient disk space to perform * the write - but we can skip that check if we have space already @@ -542,7 +548,7 @@ int __cachefiles_prepare_write(struct cachefiles_object *object, pos = cachefiles_inject_read_error(); if (pos == 0) - pos = vfs_llseek(file, *_start, SEEK_DATA); + pos = vfs_llseek(file, start, SEEK_DATA); if (pos < 0 && pos >= (loff_t)-MAX_ERRNO) { if (pos == -ENXIO) goto check_space; /* Unallocated tail */ @@ -550,7 +556,7 @@ int __cachefiles_prepare_write(struct cachefiles_object *object, cachefiles_trace_seek_error); return pos; } - if ((u64)pos >= (u64)*_start + *_len) + if (pos >= start + *_len) goto check_space; /* Unallocated region */ /* We have a block that's at least partially filled - if we're low on @@ -563,13 +569,13 @@ int __cachefiles_prepare_write(struct cachefiles_object *object, pos = cachefiles_inject_read_error(); if (pos == 0) - pos = vfs_llseek(file, *_start, SEEK_HOLE); + pos = vfs_llseek(file, start, SEEK_HOLE); if (pos < 0 && pos >= (loff_t)-MAX_ERRNO) { trace_cachefiles_io_error(object, file_inode(file), pos, cachefiles_trace_seek_error); return pos; } - if ((u64)pos >= (u64)*_start + *_len) + if (pos >= start + *_len) return 0; /* Fully allocated */ /* Partially allocated, but insufficient space: cull. */ @@ -577,7 +583,7 @@ int __cachefiles_prepare_write(struct cachefiles_object *object, ret = cachefiles_inject_remove_error(); if (ret == 0) ret = vfs_fallocate(file, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, - *_start, *_len); + start, *_len); if (ret < 0) { trace_cachefiles_io_error(object, file_inode(file), ret, cachefiles_trace_fallocate_error);
On 2024/1/3 01:11, David Howells wrote: > Gao Xiang <hsiangkao@linux.alibaba.com> wrote: > >>> down = start - round_down(start, PAGE_SIZE); >>> *_start = start - down; >>> *_len = round_up(down + len, PAGE_SIZE); >>> + if (down < start || *_len > upper_len) >>> + return -ENOBUFS; >> >> Sorry for bothering. We just found some strange when testing >> today-next EROFS over fscache. >> >> I'm not sure the meaning of >> if (down < start >> >> For example, if start is page-aligned, down == 0. >> >> so as long as start > 0 and page-aligned, it will return >> -ENOBUFS. Does it an intended behavior? > > Yeah, I think that's wrong. > > Does the attached help? (+cc more people for testing) Will test and feedback later. Thanks, Gao Xiang > > David > --- > > diff --git a/fs/cachefiles/io.c b/fs/cachefiles/io.c > index bffffedce4a9..7529b40bc95a 100644 > --- a/fs/cachefiles/io.c > +++ b/fs/cachefiles/io.c > @@ -522,16 +522,22 @@ int __cachefiles_prepare_write(struct cachefiles_object *object, > bool no_space_allocated_yet) > { > struct cachefiles_cache *cache = object->volume->cache; > - loff_t start = *_start, pos; > - size_t len = *_len, down; > + unsigned long long start = *_start, pos; > + size_t len = *_len; > int ret; > > /* Round to DIO size */ > - down = start - round_down(start, PAGE_SIZE); > - *_start = start - down; > - *_len = round_up(down + len, PAGE_SIZE); > - if (down < start || *_len > upper_len) > + start = round_down(*_start, PAGE_SIZE); > + if (start != *_start) { > + kleave(" = -ENOBUFS [down]"); > + return -ENOBUFS; > + } > + if (*_len > upper_len) { > + kleave(" = -ENOBUFS [up]"); > return -ENOBUFS; > + } > + > + *_len = round_up(len, PAGE_SIZE); > > /* We need to work out whether there's sufficient disk space to perform > * the write - but we can skip that check if we have space already > @@ -542,7 +548,7 @@ int __cachefiles_prepare_write(struct cachefiles_object *object, > > pos = cachefiles_inject_read_error(); > if (pos == 0) > - pos = vfs_llseek(file, *_start, SEEK_DATA); > + pos = vfs_llseek(file, start, SEEK_DATA); > if (pos < 0 && pos >= (loff_t)-MAX_ERRNO) { > if (pos == -ENXIO) > goto check_space; /* Unallocated tail */ > @@ -550,7 +556,7 @@ int __cachefiles_prepare_write(struct cachefiles_object *object, > cachefiles_trace_seek_error); > return pos; > } > - if ((u64)pos >= (u64)*_start + *_len) > + if (pos >= start + *_len) > goto check_space; /* Unallocated region */ > > /* We have a block that's at least partially filled - if we're low on > @@ -563,13 +569,13 @@ int __cachefiles_prepare_write(struct cachefiles_object *object, > > pos = cachefiles_inject_read_error(); > if (pos == 0) > - pos = vfs_llseek(file, *_start, SEEK_HOLE); > + pos = vfs_llseek(file, start, SEEK_HOLE); > if (pos < 0 && pos >= (loff_t)-MAX_ERRNO) { > trace_cachefiles_io_error(object, file_inode(file), pos, > cachefiles_trace_seek_error); > return pos; > } > - if ((u64)pos >= (u64)*_start + *_len) > + if (pos >= start + *_len) > return 0; /* Fully allocated */ > > /* Partially allocated, but insufficient space: cull. */ > @@ -577,7 +583,7 @@ int __cachefiles_prepare_write(struct cachefiles_object *object, > ret = cachefiles_inject_remove_error(); > if (ret == 0) > ret = vfs_fallocate(file, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, > - *_start, *_len); > + start, *_len); > if (ret < 0) { > trace_cachefiles_io_error(object, file_inode(file), ret, > cachefiles_trace_fallocate_error); >
在 2024/1/3 01:11, David Howells 写道: > Gao Xiang <hsiangkao@linux.alibaba.com> wrote: > >>> down = start - round_down(start, PAGE_SIZE); >>> *_start = start - down; >>> *_len = round_up(down + len, PAGE_SIZE); >>> + if (down < start || *_len > upper_len) >>> + return -ENOBUFS; >> >> Sorry for bothering. We just found some strange when testing >> today-next EROFS over fscache. >> >> I'm not sure the meaning of >> if (down < start >> >> For example, if start is page-aligned, down == 0. >> >> so as long as start > 0 and page-aligned, it will return >> -ENOBUFS. Does it an intended behavior? > > Yeah, I think that's wrong. > > Does the attached help? > > David > --- Tested-by: Jia Zhu <zhujia.zj@bytedance.com> > > diff --git a/fs/cachefiles/io.c b/fs/cachefiles/io.c > index bffffedce4a9..7529b40bc95a 100644 > --- a/fs/cachefiles/io.c > +++ b/fs/cachefiles/io.c > @@ -522,16 +522,22 @@ int __cachefiles_prepare_write(struct cachefiles_object *object, > bool no_space_allocated_yet) > { > struct cachefiles_cache *cache = object->volume->cache; > - loff_t start = *_start, pos; > - size_t len = *_len, down; > + unsigned long long start = *_start, pos; > + size_t len = *_len; > int ret; > > /* Round to DIO size */ > - down = start - round_down(start, PAGE_SIZE); > - *_start = start - down; > - *_len = round_up(down + len, PAGE_SIZE); > - if (down < start || *_len > upper_len) > + start = round_down(*_start, PAGE_SIZE); > + if (start != *_start) { > + kleave(" = -ENOBUFS [down]"); > + return -ENOBUFS; > + } > + if (*_len > upper_len) { > + kleave(" = -ENOBUFS [up]"); > return -ENOBUFS; > + } > + > + *_len = round_up(len, PAGE_SIZE); > > /* We need to work out whether there's sufficient disk space to perform > * the write - but we can skip that check if we have space already > @@ -542,7 +548,7 @@ int __cachefiles_prepare_write(struct cachefiles_object *object, > > pos = cachefiles_inject_read_error(); > if (pos == 0) > - pos = vfs_llseek(file, *_start, SEEK_DATA); > + pos = vfs_llseek(file, start, SEEK_DATA); > if (pos < 0 && pos >= (loff_t)-MAX_ERRNO) { > if (pos == -ENXIO) > goto check_space; /* Unallocated tail */ > @@ -550,7 +556,7 @@ int __cachefiles_prepare_write(struct cachefiles_object *object, > cachefiles_trace_seek_error); > return pos; > } > - if ((u64)pos >= (u64)*_start + *_len) > + if (pos >= start + *_len) > goto check_space; /* Unallocated region */ > > /* We have a block that's at least partially filled - if we're low on > @@ -563,13 +569,13 @@ int __cachefiles_prepare_write(struct cachefiles_object *object, > > pos = cachefiles_inject_read_error(); > if (pos == 0) > - pos = vfs_llseek(file, *_start, SEEK_HOLE); > + pos = vfs_llseek(file, start, SEEK_HOLE); > if (pos < 0 && pos >= (loff_t)-MAX_ERRNO) { > trace_cachefiles_io_error(object, file_inode(file), pos, > cachefiles_trace_seek_error); > return pos; > } > - if ((u64)pos >= (u64)*_start + *_len) > + if (pos >= start + *_len) > return 0; /* Fully allocated */ > > /* Partially allocated, but insufficient space: cull. */ > @@ -577,7 +583,7 @@ int __cachefiles_prepare_write(struct cachefiles_object *object, > ret = cachefiles_inject_remove_error(); > if (ret == 0) > ret = vfs_fallocate(file, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, > - *_start, *_len); > + start, *_len); > if (ret < 0) { > trace_cachefiles_io_error(object, file_inode(file), ret, > cachefiles_trace_fallocate_error); >
diff --git a/fs/cachefiles/internal.h b/fs/cachefiles/internal.h index 2ad58c465208..1af48d576a34 100644 --- a/fs/cachefiles/internal.h +++ b/fs/cachefiles/internal.h @@ -233,7 +233,7 @@ extern bool cachefiles_begin_operation(struct netfs_cache_resources *cres, enum fscache_want_state want_state); extern int __cachefiles_prepare_write(struct cachefiles_object *object, struct file *file, - loff_t *_start, size_t *_len, + loff_t *_start, size_t *_len, size_t upper_len, bool no_space_allocated_yet); extern int __cachefiles_write(struct cachefiles_object *object, struct file *file, diff --git a/fs/cachefiles/io.c b/fs/cachefiles/io.c index 009d23cd435b..bffffedce4a9 100644 --- a/fs/cachefiles/io.c +++ b/fs/cachefiles/io.c @@ -518,7 +518,7 @@ cachefiles_prepare_ondemand_read(struct netfs_cache_resources *cres, */ int __cachefiles_prepare_write(struct cachefiles_object *object, struct file *file, - loff_t *_start, size_t *_len, + loff_t *_start, size_t *_len, size_t upper_len, bool no_space_allocated_yet) { struct cachefiles_cache *cache = object->volume->cache; @@ -530,6 +530,8 @@ int __cachefiles_prepare_write(struct cachefiles_object *object, down = start - round_down(start, PAGE_SIZE); *_start = start - down; *_len = round_up(down + len, PAGE_SIZE); + if (down < start || *_len > upper_len) + return -ENOBUFS; /* We need to work out whether there's sufficient disk space to perform * the write - but we can skip that check if we have space already @@ -592,8 +594,8 @@ int __cachefiles_prepare_write(struct cachefiles_object *object, } static int cachefiles_prepare_write(struct netfs_cache_resources *cres, - loff_t *_start, size_t *_len, loff_t i_size, - bool no_space_allocated_yet) + loff_t *_start, size_t *_len, size_t upper_len, + loff_t i_size, bool no_space_allocated_yet) { struct cachefiles_object *object = cachefiles_cres_object(cres); struct cachefiles_cache *cache = object->volume->cache; @@ -609,7 +611,7 @@ static int cachefiles_prepare_write(struct netfs_cache_resources *cres, cachefiles_begin_secure(cache, &saved_cred); ret = __cachefiles_prepare_write(object, cachefiles_cres_file(cres), - _start, _len, + _start, _len, upper_len, no_space_allocated_yet); cachefiles_end_secure(cache, saved_cred); return ret; diff --git a/fs/cachefiles/ondemand.c b/fs/cachefiles/ondemand.c index 0254ed39f68c..9301d1eb0504 100644 --- a/fs/cachefiles/ondemand.c +++ b/fs/cachefiles/ondemand.c @@ -52,7 +52,7 @@ static ssize_t cachefiles_ondemand_fd_write_iter(struct kiocb *kiocb, return -ENOBUFS; cachefiles_begin_secure(cache, &saved_cred); - ret = __cachefiles_prepare_write(object, file, &pos, &len, true); + ret = __cachefiles_prepare_write(object, file, &pos, &len, len, true); cachefiles_end_secure(cache, saved_cred); if (ret < 0) return ret; diff --git a/fs/netfs/fscache_io.c b/fs/netfs/fscache_io.c index 79171a687930..ad572f7ee897 100644 --- a/fs/netfs/fscache_io.c +++ b/fs/netfs/fscache_io.c @@ -237,7 +237,7 @@ void __fscache_write_to_cache(struct fscache_cookie *cookie, fscache_access_io_write) < 0) goto abandon_free; - ret = cres->ops->prepare_write(cres, &start, &len, i_size, false); + ret = cres->ops->prepare_write(cres, &start, &len, len, i_size, false); if (ret < 0) goto abandon_end; diff --git a/fs/netfs/io.c b/fs/netfs/io.c index 01c7ff27228e..14c18be5aca0 100644 --- a/fs/netfs/io.c +++ b/fs/netfs/io.c @@ -199,7 +199,7 @@ static void netfs_rreq_do_write_to_cache(struct netfs_io_request *rreq) } ret = cres->ops->prepare_write(cres, &subreq->start, &subreq->len, - rreq->i_size, true); + subreq->len, rreq->i_size, true); if (ret < 0) { trace_netfs_failure(rreq, subreq, ret, netfs_fail_prepare_write); trace_netfs_sreq(subreq, netfs_sreq_trace_write_skip); diff --git a/fs/netfs/objects.c b/fs/netfs/objects.c index 93f1d7431199..b4e3bd836e5d 100644 --- a/fs/netfs/objects.c +++ b/fs/netfs/objects.c @@ -33,6 +33,7 @@ struct netfs_io_request *netfs_alloc_request(struct address_space *mapping, rreq->start = start; rreq->len = len; + rreq->upper_len = len; rreq->origin = origin; rreq->netfs_ops = ctx->ops; rreq->mapping = mapping; diff --git a/fs/netfs/output.c b/fs/netfs/output.c index 560cbcea0c0a..cc9065733b42 100644 --- a/fs/netfs/output.c +++ b/fs/netfs/output.c @@ -280,7 +280,7 @@ EXPORT_SYMBOL(netfs_queue_write_request); */ static void netfs_set_up_write_to_cache(struct netfs_io_request *wreq) { - struct netfs_cache_resources *cres; + struct netfs_cache_resources *cres = &wreq->cache_resources; struct netfs_io_subrequest *subreq; struct netfs_inode *ctx = netfs_inode(wreq->inode); struct fscache_cookie *cookie = netfs_i_cookie(ctx); @@ -294,26 +294,21 @@ static void netfs_set_up_write_to_cache(struct netfs_io_request *wreq) } _debug("write to cache"); - subreq = netfs_create_write_request(wreq, NETFS_WRITE_TO_CACHE, start, len, - netfs_write_to_cache_op_worker); - if (!subreq) + ret = fscache_begin_write_operation(cres, cookie); + if (ret < 0) return; - cres = &wreq->cache_resources; - ret = fscache_begin_read_operation(cres, cookie); - if (ret < 0) { - netfs_write_subrequest_terminated(subreq, ret, false); + ret = cres->ops->prepare_write(cres, &start, &len, wreq->upper_len, + i_size_read(wreq->inode), true); + if (ret < 0) return; - } - ret = cres->ops->prepare_write(cres, &start, &len, i_size_read(wreq->inode), - true); - if (ret < 0) { - netfs_write_subrequest_terminated(subreq, ret, false); + subreq = netfs_create_write_request(wreq, NETFS_WRITE_TO_CACHE, start, len, + netfs_write_to_cache_op_worker); + if (!subreq) return; - } - netfs_queue_write_request(subreq); + netfs_write_to_cache_op(subreq); } /* diff --git a/fs/smb/client/fscache.c b/fs/smb/client/fscache.c index e5cad149f5a2..c4a3cb736881 100644 --- a/fs/smb/client/fscache.c +++ b/fs/smb/client/fscache.c @@ -180,7 +180,7 @@ static int fscache_fallback_write_pages(struct inode *inode, loff_t start, size_ if (ret < 0) return ret; - ret = cres.ops->prepare_write(&cres, &start, &len, i_size_read(inode), + ret = cres.ops->prepare_write(&cres, &start, &len, len, i_size_read(inode), no_space_allocated_yet); if (ret == 0) ret = fscache_write(&cres, start, &iter, NULL, NULL); diff --git a/include/linux/netfs.h b/include/linux/netfs.h index a2e53ab06a1b..506c543f6888 100644 --- a/include/linux/netfs.h +++ b/include/linux/netfs.h @@ -262,6 +262,7 @@ struct netfs_io_request { atomic_t nr_copy_ops; /* Number of copy-to-cache ops in progress */ size_t submitted; /* Amount submitted for I/O so far */ size_t len; /* Length of the request */ + size_t upper_len; /* Length can be extended to here */ size_t transferred; /* Amount to be indicated as transferred */ short error; /* 0 or error that occurred */ enum netfs_io_origin origin; /* Origin of the request */ @@ -358,8 +359,8 @@ struct netfs_cache_ops { * actually do. */ int (*prepare_write)(struct netfs_cache_resources *cres, - loff_t *_start, size_t *_len, loff_t i_size, - bool no_space_allocated_yet); + loff_t *_start, size_t *_len, size_t upper_len, + loff_t i_size, bool no_space_allocated_yet); /* Prepare an on-demand read operation, shortening it to a cached/uncached * boundary as appropriate.