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author | Miklos Szeredi <mszeredi@suse.cz> | 2015-01-06 12:45:35 +0300 |
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committer | Miklos Szeredi <mszeredi@suse.cz> | 2015-01-06 12:45:35 +0300 |
commit | 21f621741a770c119e7529a3f5c0e6b7c91383a3 (patch) | |
tree | 4393194807e351d0c2922673d44409a656a87259 /fs/fuse/dev.c | |
parent | b1940cd21c0f4abdce101253e860feff547291b0 (diff) | |
download | linux-21f621741a770c119e7529a3f5c0e6b7c91383a3.tar.xz |
fuse: fix LOOKUP vs INIT compat handling
Analysis from Marc:
"Commit 7078187a795f ("fuse: introduce fuse_simple_request() helper")
from the above pull request triggers some EIO errors for me in some tests
that rely on fuse
Looking at the code changes and a bit of debugging info I think there's a
general problem here that fuse_get_req checks and possibly waits for
fc->initialized, and this was always called first. But this commit
changes the ordering and in many places fc->minor is now possibly used
before fuse_get_req, and we can't be sure that fc has been initialized.
In my case fuse_lookup_init sets req->out.args[0].size to the wrong size
because fc->minor at that point is still 0, leading to the EIO error."
Fix by moving the compat adjustments into fuse_simple_request() to after
fuse_get_req().
This is also more readable than the original, since now compatibility is
handled in a single function instead of cluttering each operation.
Reported-by: Marc Dionne <marc.c.dionne@gmail.com>
Tested-by: Marc Dionne <marc.c.dionne@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Fixes: 7078187a795f ("fuse: introduce fuse_simple_request() helper")
Diffstat (limited to 'fs/fuse/dev.c')
-rw-r--r-- | fs/fuse/dev.c | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index ba1107977f2e..c847d6b225e2 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -511,6 +511,39 @@ void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req) } EXPORT_SYMBOL_GPL(fuse_request_send); +static void fuse_adjust_compat(struct fuse_conn *fc, struct fuse_args *args) +{ + if (fc->minor < 4 && args->in.h.opcode == FUSE_STATFS) + args->out.args[0].size = FUSE_COMPAT_STATFS_SIZE; + + if (fc->minor < 9) { + switch (args->in.h.opcode) { + case FUSE_LOOKUP: + case FUSE_CREATE: + case FUSE_MKNOD: + case FUSE_MKDIR: + case FUSE_SYMLINK: + case FUSE_LINK: + args->out.args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE; + break; + case FUSE_GETATTR: + case FUSE_SETATTR: + args->out.args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE; + break; + } + } + if (fc->minor < 12) { + switch (args->in.h.opcode) { + case FUSE_CREATE: + args->in.args[0].size = sizeof(struct fuse_open_in); + break; + case FUSE_MKNOD: + args->in.args[0].size = FUSE_COMPAT_MKNOD_IN_SIZE; + break; + } + } +} + ssize_t fuse_simple_request(struct fuse_conn *fc, struct fuse_args *args) { struct fuse_req *req; @@ -520,6 +553,9 @@ ssize_t fuse_simple_request(struct fuse_conn *fc, struct fuse_args *args) if (IS_ERR(req)) return PTR_ERR(req); + /* Needs to be done after fuse_get_req() so that fc->minor is valid */ + fuse_adjust_compat(fc, args); + req->in.h.opcode = args->in.h.opcode; req->in.h.nodeid = args->in.h.nodeid; req->in.numargs = args->in.numargs; |