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author | Al Viro <viro@zeniv.linux.org.uk> | 2022-08-16 17:57:56 +0200 |
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committer | Al Viro <viro@zeniv.linux.org.uk> | 2022-08-17 23:25:04 +0200 |
commit | 25885a35a72007cf28ec5f9ba7169c5c798f7167 (patch) | |
tree | 948589bcdf9420b67123d83eab2cf7f7d8bdbcf8 /fs/readdir.c | |
parent | locks: fix TOCTOU race when granting write lease (diff) | |
download | linux-25885a35a72007cf28ec5f9ba7169c5c798f7167.tar.xz linux-25885a35a72007cf28ec5f9ba7169c5c798f7167.zip |
Change calling conventions for filldir_t
filldir_t instances (directory iterators callbacks) used to return 0 for
"OK, keep going" or -E... for "stop". Note that it's *NOT* how the
error values are reported - the rules for those are callback-dependent
and ->iterate{,_shared}() instances only care about zero vs. non-zero
(look at emit_dir() and friends).
So let's just return bool ("should we keep going?") - it's less confusing
that way. The choice between "true means keep going" and "true means
stop" is bikesheddable; we have two groups of callbacks -
do something for everything in directory, until we run into problem
and
find an entry in directory and do something to it.
The former tended to use 0/-E... conventions - -E<something> on failure.
The latter tended to use 0/1, 1 being "stop, we are done".
The callers treated anything non-zero as "stop", ignoring which
non-zero value did they get.
"true means stop" would be more natural for the second group; "true
means keep going" - for the first one. I tried both variants and
the things like
if allocation failed
something = -ENOMEM;
return true;
just looked unnatural and asking for trouble.
[folded suggestion from Matthew Wilcox <willy@infradead.org>]
Acked-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/readdir.c')
-rw-r--r-- | fs/readdir.c | 68 |
1 files changed, 34 insertions, 34 deletions
diff --git a/fs/readdir.c b/fs/readdir.c index 09e8ed7d4161..9c53edb60c03 100644 --- a/fs/readdir.c +++ b/fs/readdir.c @@ -140,7 +140,7 @@ struct readdir_callback { int result; }; -static int fillonedir(struct dir_context *ctx, const char *name, int namlen, +static bool fillonedir(struct dir_context *ctx, const char *name, int namlen, loff_t offset, u64 ino, unsigned int d_type) { struct readdir_callback *buf = @@ -149,14 +149,14 @@ static int fillonedir(struct dir_context *ctx, const char *name, int namlen, unsigned long d_ino; if (buf->result) - return -EINVAL; + return false; buf->result = verify_dirent_name(name, namlen); - if (buf->result < 0) - return buf->result; + if (buf->result) + return false; d_ino = ino; if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) { buf->result = -EOVERFLOW; - return -EOVERFLOW; + return false; } buf->result++; dirent = buf->dirent; @@ -169,12 +169,12 @@ static int fillonedir(struct dir_context *ctx, const char *name, int namlen, unsafe_put_user(namlen, &dirent->d_namlen, efault_end); unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end); user_write_access_end(); - return 0; + return true; efault_end: user_write_access_end(); efault: buf->result = -EFAULT; - return -EFAULT; + return false; } SYSCALL_DEFINE3(old_readdir, unsigned int, fd, @@ -219,7 +219,7 @@ struct getdents_callback { int error; }; -static int filldir(struct dir_context *ctx, const char *name, int namlen, +static bool filldir(struct dir_context *ctx, const char *name, int namlen, loff_t offset, u64 ino, unsigned int d_type) { struct linux_dirent __user *dirent, *prev; @@ -232,18 +232,18 @@ static int filldir(struct dir_context *ctx, const char *name, int namlen, buf->error = verify_dirent_name(name, namlen); if (unlikely(buf->error)) - return buf->error; + return false; buf->error = -EINVAL; /* only used if we fail.. */ if (reclen > buf->count) - return -EINVAL; + return false; d_ino = ino; if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) { buf->error = -EOVERFLOW; - return -EOVERFLOW; + return false; } prev_reclen = buf->prev_reclen; if (prev_reclen && signal_pending(current)) - return -EINTR; + return false; dirent = buf->current_dir; prev = (void __user *) dirent - prev_reclen; if (!user_write_access_begin(prev, reclen + prev_reclen)) @@ -260,12 +260,12 @@ static int filldir(struct dir_context *ctx, const char *name, int namlen, buf->current_dir = (void __user *)dirent + reclen; buf->prev_reclen = reclen; buf->count -= reclen; - return 0; + return true; efault_end: user_write_access_end(); efault: buf->error = -EFAULT; - return -EFAULT; + return false; } SYSCALL_DEFINE3(getdents, unsigned int, fd, @@ -307,7 +307,7 @@ struct getdents_callback64 { int error; }; -static int filldir64(struct dir_context *ctx, const char *name, int namlen, +static bool filldir64(struct dir_context *ctx, const char *name, int namlen, loff_t offset, u64 ino, unsigned int d_type) { struct linux_dirent64 __user *dirent, *prev; @@ -319,13 +319,13 @@ static int filldir64(struct dir_context *ctx, const char *name, int namlen, buf->error = verify_dirent_name(name, namlen); if (unlikely(buf->error)) - return buf->error; + return false; buf->error = -EINVAL; /* only used if we fail.. */ if (reclen > buf->count) - return -EINVAL; + return false; prev_reclen = buf->prev_reclen; if (prev_reclen && signal_pending(current)) - return -EINTR; + return false; dirent = buf->current_dir; prev = (void __user *)dirent - prev_reclen; if (!user_write_access_begin(prev, reclen + prev_reclen)) @@ -342,13 +342,13 @@ static int filldir64(struct dir_context *ctx, const char *name, int namlen, buf->prev_reclen = reclen; buf->current_dir = (void __user *)dirent + reclen; buf->count -= reclen; - return 0; + return true; efault_end: user_write_access_end(); efault: buf->error = -EFAULT; - return -EFAULT; + return false; } SYSCALL_DEFINE3(getdents64, unsigned int, fd, @@ -397,7 +397,7 @@ struct compat_readdir_callback { int result; }; -static int compat_fillonedir(struct dir_context *ctx, const char *name, +static bool compat_fillonedir(struct dir_context *ctx, const char *name, int namlen, loff_t offset, u64 ino, unsigned int d_type) { @@ -407,14 +407,14 @@ static int compat_fillonedir(struct dir_context *ctx, const char *name, compat_ulong_t d_ino; if (buf->result) - return -EINVAL; + return false; buf->result = verify_dirent_name(name, namlen); - if (buf->result < 0) - return buf->result; + if (buf->result) + return false; d_ino = ino; if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) { buf->result = -EOVERFLOW; - return -EOVERFLOW; + return false; } buf->result++; dirent = buf->dirent; @@ -427,12 +427,12 @@ static int compat_fillonedir(struct dir_context *ctx, const char *name, unsafe_put_user(namlen, &dirent->d_namlen, efault_end); unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end); user_write_access_end(); - return 0; + return true; efault_end: user_write_access_end(); efault: buf->result = -EFAULT; - return -EFAULT; + return false; } COMPAT_SYSCALL_DEFINE3(old_readdir, unsigned int, fd, @@ -471,7 +471,7 @@ struct compat_getdents_callback { int error; }; -static int compat_filldir(struct dir_context *ctx, const char *name, int namlen, +static bool compat_filldir(struct dir_context *ctx, const char *name, int namlen, loff_t offset, u64 ino, unsigned int d_type) { struct compat_linux_dirent __user *dirent, *prev; @@ -484,18 +484,18 @@ static int compat_filldir(struct dir_context *ctx, const char *name, int namlen, buf->error = verify_dirent_name(name, namlen); if (unlikely(buf->error)) - return buf->error; + return false; buf->error = -EINVAL; /* only used if we fail.. */ if (reclen > buf->count) - return -EINVAL; + return false; d_ino = ino; if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) { buf->error = -EOVERFLOW; - return -EOVERFLOW; + return false; } prev_reclen = buf->prev_reclen; if (prev_reclen && signal_pending(current)) - return -EINTR; + return false; dirent = buf->current_dir; prev = (void __user *) dirent - prev_reclen; if (!user_write_access_begin(prev, reclen + prev_reclen)) @@ -511,12 +511,12 @@ static int compat_filldir(struct dir_context *ctx, const char *name, int namlen, buf->prev_reclen = reclen; buf->current_dir = (void __user *)dirent + reclen; buf->count -= reclen; - return 0; + return true; efault_end: user_write_access_end(); efault: buf->error = -EFAULT; - return -EFAULT; + return false; } COMPAT_SYSCALL_DEFINE3(getdents, unsigned int, fd, |